Neuro Flashcards

Question

Clonus elicited during tendon reflex tenting is indicative of

Answer 1

Chronic UMN disease

Answer 2

Musculoutaneous N; C6-8

Answer 3

Radial nerve, C7 - T1

Answer 4

Femoral nerve, L4-L6

Answer 5

Sciatic nerve, L6-S2

Answer 6

Lateral thoracic nerve, C8-T1

Answer 7

Sacral spinal cord S1-S3 and various branches of the pudendal nerve

Answer 8

Spinal shock refers to a transient lack of reflex activity caudal to a severe spinal cord lesion; this phenomenon of hypotonia and hyporeflexia with lesions that should cause UMN signs is uncommon and short-lived in dogs and cats compared with humans. A form of this phenomenon may frequently be observed in dogs with spinal cord infarction (fibrocartilaginous embolic myelopathy) in the T3–L3 spinal cord region. These patients typically exhibit UMN signs with the exception of poor withdrawal reflexes; the withdrawal reflex returns to normal within 72 hours

Answer 9

Spinothalamic tract

Answer 10

Normal Saline. The blood-brain barrier prevents colloidosmotic pressure from working in the brain, so osmotic pressure becomes more important (sodium).

Answer 11

Transfrontal, rostrotentorial and suboccipital

Answer 12

Dorsal sagittal sinus and transverse sinuses

Answer 13

To remove meningiomas in the olfactory bulb

Answer 14

Suboccipital craniotomy

Answer 15

Swelling, hemorrhage and cardiovascular dysfunction (brainstem surgery)

Answer 16

Meningiomas, followed by gliomas

Answer 17

Pneumonia, 20%; 50% mortality

Answer 18

Yes, the success rate is high and the same as for the initial surgery

Answer 19

Caudal cervical myelopathy. Ambulatory patients with caudal cervical myelopathy tend to have obvious pelvic limb weakness and ataxia, with less severe, sometimes even subtle, thoracic limb dysfunction. In many such cases, the thoracic limbs move with short, stilted steps, whereas the pelvic limbs display obvious ataxia

Answer 20

A phenomenon called central cord syndrome is sometimes appreciated in dogs and cats with caudal cervical spinal cord lesions that are confined to the central region of the cord. In this syndrome, the thoracic limbs display severe lower motor neuron (LMN) weakness, but the pelvic limbs are minimally affected or neurologically normal. This occurs because the centrally located lesion interferes with LMNs innervating the thoracic limbs, but it spares the more peripherally located white matter upper motor tracts that innervate the pelvic limb LMNs. Central cord syndrome is most commonly associated with intraaxial lesions like syringomyelia and neoplasia

Answer 21

Descending tracts from the medullary respiratory centers traverse the cervical spinal cord to innervate the phrenic nerve LMNs (C5–C7) and the LMNs of intercostal muscles in the thoracic spinal cord. Damage to these tracts can lead to respiratory compromise. Caudal cervical spinal cord lesions that spare innervation to the phrenic nerve LMNs (e.g., lesions caudal to the C5–C7 segments) but disrupt normal activation of intercostal LMNs can lead to the phenomenon of abdominal breathing. In this scenario, the diaphragm bears the sole burden of moving air through the lungs because of the denervated chest wall, and this motion causes the abdomen to visibly move back and forth during respiration.

Answer 22

Tonic input to the sympathetic LMNs in the thoracolumbar spinal cord that maintain normal blood pressure is provided by neurons in the medulla (rostroventrolateral medulla). Because these medullary neurons send their processes through the cervical spinal cord, cervical myelopathies may be associated with severe hypotension.

Answer 23

Ventral approach - technically less demanding, more bone available for implant placement, limited exposure of the spinal cord, higher likelihood of severe venous sinus hemorrhage. Dorsal approach - allows wide decompression / access to the dorsal and lateral aspect of the spinal cord, technically more difficult, slower patient recovery, minimal stock for implant placement (articular facets)

Answer 24

Apical ligament, Alar ligaments and transverse ligament

Answer 25

Sternocephalicus and sternohyoideus and longus colli muscles

Answer 26

rectus capitis dorsalis muscle cranially and the spinalis cervicis muscle caudally ; elevate the multifidus muscle (C4-C7)

Answer 27

HNPE cases are characteristically peracute to acute and tend to cause fairly severe neurologic dysfunction (nonambulatory tetraparesis or tetraplegia), often without obvious evidence of cervical hyperesthesia; this contrasts with typical calcified type I extrusions, which commonly lead to substantial cervical hyperesthesia that is less frequently associated with severe neurologic dysfunction

Answer 28

Normal - hyperintense (The annulus is hypointense) Degenerative – hypointense

Answer 29

Unilateral cervical pain with or without lameness (Root signature) without proprioceptive or motor deficits

Answer 30

Other diseases that can cause similar or identical signs of cervical disc extrusion/protrusion include inflammatory/infectious conditions (e.g., corticosteroid-responsive meningitis, discospondylitis, granulomatous meningoencephalomyelitis), syringomyelia, traumatic fracture/luxation, neoplasia, and congenital abnormalities (e.g., Chiari-like malformation [CLM], AA instability, atlanto-occipital overlapping [AOO]).

Answer 31

50 to 70% Strict cage restriction, NSAIDs (no steroids) and possibly adjunct analgesics such as tramadol or pregabalin; 30% recurrence

Answer 32

Yes (Limited number of reported cases). The biochemical nature of the extruded material allows for a more rapid resorption compared with calcified disk material.

Answer 33

Repeated episodes of pain, pain that is not responding to medical therapy or severe neurologic deficits (tetraparesis, tetraplegia)

Answer 34

Ventral slot

Answer 35

Transient neurologic worsening and venous sinus hemorrhage

Answer 36

99%; 1 week

Answer 37

Disc associated CSM (DA-CSM) and Osseous-associated CSM (OA-CSM)

Answer 38

Middle-age to older, large and giant breed dogs (Doberman pinchers). Typically affecting the caudal cervical vertebrae, particularly C5-C6, C6-C7

Answer 39

Combination of vertebral malformation and malarticulation typically affecting the caudal cervical vertebrae and associated soft tissue structures (disc, articular process joint capsules, dorsal longitudinal ligament and ligamentum flavum). Soft tissue structures become hypertrophied, leading to impingement of the spinal cord

Answer 40

Congenital bony stenosis of cervical vertebrae most commonly occurring in young large or giant breed dogs (usually 1–3 years, great Dane, mastiff, Bernese mountain dog, Doberman pincher, basset hound). Typically called “ wobbler syndrome” ; has several distinguishing characteristics from DA-CSM. Primarily bony proliferation associated with the articular processes and associated joint capsule, as well as the dorsal lamina and pedicles, usually without substantial disc protrusion. Cystic enlargement of the articular process joint capsule (extradural synovial cyst) may also be observed.

Answer 41

C2-C3 through T1-T2

Answer 42

Doberman pincher, Rottweiler

Answer 43

Young adult giant breeds (great Dane, mastiff) with progressive signs of cervical myelopathy

Answer 44

Signs of caudal cervical myelopathy with pelvic limbs usually more obviously affected than thoracic limbs. If ambulatory, the patient typically exhibits a stiff, choppy, shuffling thoracic limb gait and an ataxic, wide-based pelvic limb gate (two engine gait). Thoracic limb posture characterized by elbow abduction and internal rotation of the digits. Signs of proprioceptive deficits maybe exacerbated by making the patient walk with a slightly extended head/neck. Patient may be reluctant to walk in this position.

Answer 45

MRI with linear traction views

Answer 46

Ventral compression from a malaligned vertebral body, Protruded dorsal annulus, hypertrophied dorsal longitudinal ligament, dorsal compression from hypertrophied ligamentum flavum, lateral compression from hypertrophied articular facets and associated joint capsule tissue.

Answer 47

Yes, medical treatment consisting of cage confinement for 3 to 4 weeks, anti-inflammatory medication (prednisone) and potentially the use of a neck brace Is effective in approximately 53% of the cases. Median survival for medical management 3.6 years compared with 5 years for surgical management. Patient treated medically and more likely to be euthanized due to worsening neurologic condition than those surgically treated.

Answer 48

Distraction-stabilization procedures (Not ventral slot) using pin or screw placement into vertebral bodies with a PMMA bridge, and PMMA “plug” insertion into the distracted ventral slot.

Answer 49

Dorsal laminectomy

Answer 50

Chiari-like malformation (CLM) AA instability Atlanto-occipital overlapping (AOO) Dorsal compression at C1–C2

Answer 51

Hypoplasia or aplasia of the dens

Answer 52

Miniature toy breed dog, younger than two years of age. Yorkshire terrier, Pomeranian, toy poodle, Chihuahua, Pekinese. May occur in cats.

Answer 53

neck pain and varying degrees of ataxia of all four limbs. Nonambulatory tetraparesis and tetraplegia occur in severe cases.

Answer 54

Radiographs typically diagnose AA instability but require stress views which can be dangerous. MRI is much safer but does not offer a good bone detail. CT offers good detail saw MRI followed by CT is a current recommendation.

Answer 55

Respiratory and cardiac arrest due to damage to brainstem centers Upper respiratory function disorder such as gagging, coughing and laryngeal paralysis Aspiration pneumonia, likely due to pharyngeal disorder

Answer 56

Above 80% Length of clinical disease prior to surgery and severity of clinical dysfunction

Answer 57

Craniocervical (most commonly over C2 C3) and caudal thoracic regions. Typically located on the dorsal or dorsal lateral aspect of the spinal cord

Answer 58

Rottweiler, typically in the cranial cervical region. Also pugs and French bulldogs

Answer 59

Slowly Progressive ataxia and tetraparesis

Answer 60

Mild mononuclear pleocytosis with elevated protein concentration

Answer 61

Osteosarcoma, chondrosarcoma, myeloma, fibrosarcoma and hemangiosarcoma

Answer 62

Lymphosarcoma (primary or metastatic)

Answer 63

Meningiomas and MNST‘s

Answer 64

Cervical intumescence

Answer 65

Spinal hyperesthesia

Answer 66

Type II disc protrusion, Syringomyelia, CCSM, CJA’s, infectious/inflammatory disorders and neoplasia

Answer 67

Liposarcoma, myeloma, meningioma & glioma

Answer 68

Poor, with median postoperative survival of approximately 5 to 6 months. Disease-free interval of approximately one month.

Answer 69

Fibrocartilagenous embolism

Answer 70

Corticosteroids have not been shown to be beneficial and significantly increase the risk of gastrointestinal ulcers. PEG has not been shown to be a benefit either.

Answer 71

Stabilization and decompression. The most pressing goal is stabilization

Answer 72

ASIF small fragment reduction forcep

Answer 73

Hemi laminectomy is the unilateral removal of the lamina, articular processes and part of the pedicle. Dorsal laminectomy is removal of the dorsal lamina bilaterally, including removal of the dorsal spinous process

Answer 74

Thoracolumbar

Answer 75

The “elbow” of the transverse process, oriented cranially and slightly ventral lateral

Answer 76

Trapezius, rhomboideus, serratus dorsalis, spinallis and semispinalis

Answer 77

Spinal nerves

Answer 78

Intercapital ligament

Answer 79

T12-T13; T13-L1

Answer 80

L1-L2; L2-L3

Answer 81

Tape 2 IVDD

Answer 82

The Cobb angle is derived from the intersection of two lines: one of the cranial aspect of the kyphotic vertebral segment and the other on the caudal aspect of the segment. Angles above 35° are associated with a higher chance of neurologic dysfunction in dogs with vertebral Kyphoscoliosis formation

Answer 83

Modified segmental spinal fixation (spinal stapling) and vertebral body pins with PMMA

Answer 84

Thoracolumbar region, typically between 10th thoracic and third lumbar vertebrae, typically extra medullary intradural, six months to three years of age, German shepherds

Answer 85

The patellar reflex may appear hyperreflexive when the inhibitory action of the stifle flexion muscle group is removed by disruption of the nerve supply to these muscles. This is frequently the case with cauda equina syndrome, when contributing roots to the sciatic nerves are affected.

Answer 86

Class I: neurapraxia Class II: axonotmesis Class III: neurotmesis

Answer 87

Dogs with transitional lumbosacral vertebrae are eight times as likely to develop DLSS

Answer 88

German Shepherd, presumably due to the high incidence of transitional lumbosacral vertebrae and articular facet joint tropism (asymmetry between left and right processes) Chronic history of pain and unilateral or bilateral lameness with or without pelvic limb weakness. Difficulty rising, inability or unwillingness to climb stairs, scuffing of the toenails in the back limbs, muscle atrophy of the caudal thighs, urinary or fecal incontinence, abnormal tail carriage, biting/chewing at the base of the tail or paws

Answer 89

Lumbosacral pain on palpation (Most common finding), progressive loss of pelvic limb proprioception, followed by loss of motor function (weakness) typically associated with the area of the sciatic nerve. Deficient pelvic limb withdrawal reflex at the level of the hock[(Flexion of the hip and stifle remain normal)

Answer 90

MRI, followed by Discography and epidurography

Answer 91

Less than 1 year

Answer 92

Nerve root tumor (neurofibroma, meningioma)

Answer 93

No, steroids have not been shown to protect spinal tissue/nerve roots.

Answer 94

Decreased interthalamic adhesion thickness; enlarged ventricles, brain atrophy

Answer 95

Neurotoxic Beta amyloid (neurotoxic A-beta)

Answer 96

Catecholamine disfunction

Answer 97

Levetiracetam; potential mechanisms of action include improved central nervous system mitochondrial function and associated improved synaptic transmission come out inhibition of beta amyloid-induced astrocyte glutamate release.

Answer 98

Type II IVDD

Answer 99

Hypothyroidism, followed by chronic renal disease and hyperadrenocorticism

Answer 100

Cavalier King Charles spaniel Presumably due to this breeds propensity to develop heart disease, inherited platelet abnormalities, or to local aberrations in regional arterial blood flow resulting in Chiari like malformations (CLMs)

Answer 101

Set an onset of acute discomfort during exercise, followed by non-progressive paraparesis or paralysis without discomfort. Focal discomfort can typically be elicited at the site of infarct in the first 12 hours.

Answer 102

T3-L3, followed by L4-S1

Answer 103

Hyperintense Contrast enhancement varies depending on timing Since onset

Answer 104

Staffordshire terrier – FCE Border collie - HNPE

Answer 105

Perivascular infiltrates of primarily mononuclear cells (lymphocytes, macrophages and plasma cells)

Answer 106

Autoimmune, specifically delayed type hypersensitivity reaction ( T cell mediated)

Answer 107

White matter. Focal, multifocal and ocular

Answer 108

Necrotizing Meningoencephalitis (NME) and necrotizing Leukoencephalitis (NLE). Both similar and characterized by multiple cavitary necrotic nonsuppurative inflammatory brain lesions that involve both gray and white matter.

Answer 109

Pug, Maltese

Answer 110

Seizures, cerebellovestibular disfunction, Cervical hyperesthesia

Answer 111

Steroid responsive meningitis (SRMA)

Answer 112

Young (less than two years old) , medium to large breed (boxers, Bernese mountain dogs). Acute onset of cervical hyperesthesia accompanied by lethargy and a stiff gait.

Answer 113

Marked polymorphonuclear pleocytosis (predominantly or exclusively non-degenerative neutrophils), elevated protein concentration

Answer 114

Staphylococcus spp. ( S. aureus; S. pseudointermedius); Streptococcus, Brucella, Aspergillus

Answer 115

Medium to giant breed (especially great Danes), any age but more commonly after 10 years of age

Answer 116

Gradual onset of lethargy (Occasionally acute), spinal hyperesthesia, stilted pelvic limb gait if lumbosacral, fever and anorexia Lumbosacral junction

Answer 117

Urinary bladder

Answer 118

Myasthenia gravis, autoimmune polymyositis, polyradiculoneuritis, tick paralysis

Answer 119

Common peroneal nerve and cranialis tibialis nerve

Answer 120

Autoimmune disorder characterized by the production of antibodies against nicotinic acetylcholine receptors of skeletal muscle. The typical presentation includes antibody attack in skeletal muscle and weakness which tends to worsen with exercise. Megaesophagus is also common in dogs and rare and cats (large amount of striated muscle in dog’s esophagus.)

Answer 121

Mediastinal tumor (thymoma)

Answer 122

Anticholinesterase drugs (pyridostigmine or neostigmine), possible with immunosuppressive doses of prednisone

Answer 123

Systemic lupus erythematosus, the use of trimethoprim sulfa drugs in Doberman pinschers and thymomas

Answer 124

Newfoundland and boxers. Newfoundland usually develop the condition early in life. Boxers typically develop the condition as a paraneoplastic syndrome

Answer 125

Acute idiopathic polyradiculoneuritis

Answer 126

Idiopathic inflammatory disorder involving both axons and myelin of ventral nerve roots. Typical presentation includes acute development of lower motor neuron paresis/plegia, usually beginning in the pelvic limbs and eventually involving thoracic limbs. Spinal reflexes are typically absent. Proprioceptive placing reactions will be normal for as long as motor ability is still present.

Answer 127

Dermacentor (North América) and Ixodes (Australia)

Answer 128

1) sensorium and behavioral 2) posture and gait 3) postural reactions 4) spinal reflexes, muscle tone, muscle mass 5) cranial nerves 6) cutaneous sensation

Answer 129

A collection of nuclei in the brainstem which extends from the thalamus to the medulla. Its function is to arouse the cerebellum, and includes the projection pathways for a conscious sensory perception. An alteration in sensorium may be a result of lesions affecting both cerebral hemispheres or a focal lesion affecting the reticular activating system

Answer 130

Uncoordinated gait resulting from lesions in the vestibular system, cerebellum or proprioceptive system

Answer 131

Because of the close association between these nerves and the vestibular nucleus on the rostral medulla

Answer 132

Contralateral postural reaction abnormalities with normal gait, possibly accompanied by contralateral menace and sensory deficits

Answer 133

C6-T2 (most likely), but also possibly C1-C5 if segmental reflexes are exaggerated.

Answer 134

L6-S1 (Sciatic nerve)

Answer 135

Tibial nerve

Answer 136

Common peroneal nerve (Fibular)

Answer 137

“In a normal animal that is standing, if one limb is flexed off the ground, the contralateral limb develops increased muscular tone of the extensors to bear more of the patient's weight and avoid falling. This reaction occurs without volition and is part of a local reflex arc between the left and right limbs. However, in a patient in lateral recumbency, flexion of a limb should not “result in extension of the contralateral limb because the patient is not bearing weight. In lateral recumbency, this reflex extension is inhibited by descending upper motor neuron input. In patients with lesions cranial to the spinal cord segments containing the lower motor neuron units of the limbs, a crossed extensor reflex may be elicited when the withdrawal-flexor reflex is evaluated. Reflex extension may occur in the limb opposite to that being tested, implicating an upper motor neuron lesion on the side where the limb extends. Although this typically is an abnormal reflex indicative of upper motor neuron disease, normal dogs occasionally have crossed extensor reflexes. To avoid voluntary extension of the contralateral limb as a response to the noxious stimulus, the withdrawal-flexor reflex should be elicited with a very mild pinch, and the opposite limb should be observed for extension”

Answer 138

“Regional segmental spinal nerves carry sensory impulses into the spinal cord, where they are relayed cranially to spinal cord segments C8 and T1. At this level, a synapse occurs on the lower motor neurons of both lateral thoracic nerves that innervate the cutaneous trunci muscle. ” The reflex remains positive1 to 2 vertebral segments caudal to the site of lesion Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 139

“This reflex is named after the experience of closing the blade of a pocket knife. As the knife blade is folded closed, resistance to closure is appreciated until a point after which the knife blade folds easily. Analogous to closing a pocket knife, in patients with a lesion affecting the upper motor neuron tracts and consequent extensor tone, there is the presence of increased tone that prevents forced flexion of the limb by the examiner until it suddenly gives way to complete flexion without resistance. This reflex is aimed at protecting from overstretch of the muscle. It is mediated through Golgi tendon organs embedded in tendons; when stimulated, there is a reflex inhibition of the muscle.” More likely to be encountered with upper motor neuron disease Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 140

Motor to the muscles of expression, parasympathetic to the lachrymal glands, sensory to the tongue (taste)

Answer 141

Motor to the lateral rectus and retractor bulbi muscles; medial strabismus

Answer 142

Motor and sensory to the pharynx; gagging reflex; dysphasia

Answer 143

Functions: Sensory and motor to the tongue, larynx and viscera Tests: Gag reflex, oculocardiac reflex, observation of inspiratory stridor Dysfunction: diminished gag reflects, dysphasia, laryngeal paralysis, megaesophagus

Answer 144

External branch is Motor to the trapezius muscle The internal range joints with cranial nerve X to innervate the larynx

Answer 145

Motor to the tongue. Tongue atrophy, inability to retract to either side

Answer 146

“The menace response requires a functional retina, optic nerve, optic tract, lateral geniculate nucleus of the thalamus (diencephalon), and optic radiation and occipital lobe of the cerebrum, as well as the efferent pathway, which includes the facial neurons, nerves, and the muscles for facial expression—specifically the orbicularis muscle for closure of the palpebral fissure.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 147

“The indirect pupillary light reflex occurs because most of the optic nerve fibers cross at the optic chiasm, and then most fibers cross back at the level of the pre-tectal nucleus, stimulating the parasympathetic oculomotor nuclei of CN III bilaterally.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 148

Cranial nerve III (Oculomotor); Controls the Levator Palpebral superioris muscle and is parasympathetic to the pupil.

Answer 149

“For the sympathetic innervation, the preganglionic neurons are distributed in the thoracolumbar spinal cord. Axons from preganglionic neurons synapse in the ganglia of the sympathetic trunk adjacent to the vertebral column. Preganglionic sympathetic neurons destined to innervate the eye are located in the T1 through T3 spinal cord segments. After leaving the vertebral column, axons course through the cranial thoracic cavity, pass through the brachial plexus to join descending fibers “of the vagus, and form the vagosympathetic trunk, which courses in the carotid sheath. These sympathetic fibers course in the carotid sheath to the cranial cervical ganglia. Preganglionic axons synapse in the cranial cervical ganglia located ventromedial to the tympanic bullae. Postganglionic axons enter the cranial cavity; join with axons of the ophthalmic branch of the trigeminal nerve, which exits the cranial cavity via the orbital fissure; and ultimately innervate the dilator muscle of the pupil in the iris. In addition, an upper motor neuron system facilitates the function of the preganglionic sympathetics. This upper motor neuron system begins in the hypothalamus and descends in the lateral funiculus of the spinal cord” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 150

“Sensory branches (ophthalmic nerve medially, maxillary nerve laterally) of the trigeminal nerve mediate the afferent arm of the palpebral reflex, and the palpebral branch of the facial nerve mediates the efferent motor arm” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 151

“With unilateral mandibular nerve dysfunction (e.g., trigeminal nerve sheath neoplasia), no loss of jaw function will be appreciable, but profound muscle atrophy may be present. ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 152

“With bilateral mandibular nerve dysfunction (e.g., idiopathic trigeminal neuritis), the patient may have a “dropped jaw” due to an inability to close the mouth and may drool excessively. ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 153

“A patient with a severely contused sciatic nerve typically maintains sensation to the medial aspect of the paw. If the medial surface of the paw is stimulated in a patient with injury only involving the sciatic nerve, the animal will be able to flex the hip joint because of intact innervation of the iliopsoas muscle (innervated by spinal nerve L1 through L4) and the rectus femoris muscle (innervated by the femoral nerve), but the stifle, tarsus, and digits will not flex. Therefore, the medial, dorsal, and plantar surfaces of the pelvic limb paw should be tested for the withdrawal-flexor reflex and for nociception.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 154

Prosencephalon, mid to caudal brainstem (midbrain, pons and medulla oblongata), cerebellum, spinal cord and lower motor neurons

Answer 155

“ambulatory patients with C6-T2 spinal cord lesion typically have a disconnected, “two-engine,” gait, in which the thoracic limbs are “short and choppy” (lower motor neuron quality gait) and pelvic “limbs are long-strided and hypermetric (general proprioceptive ataxia and upper motor neuron paresis).2 If a spinal cord lesion is in the lumbar intumescence, lower motor neuron signs will be present in the pelvic limbs.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 156

Recurrent laryngeal nerve

Answer 157

Serum creatinine kinase Serum electrolytes Blood or plasma lactate Urine testing for myoglobinuria Thyroid hormone screening Acetylcholine receptor antibody assay

Answer 158

“ventricles, of which there are four: one lateral ventricle within each cerebral hemisphere, the third ventricle within the diencephalon, and the fourth ventricle lying ventral to the cerebellum. ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 159

To conduct CSF between the third and fourth ventricles

Answer 160

Pia matter and arachnoid

Answer 161

Arachnoid and dura matter

Answer 162

It becomes fused with the periosteum of the skull it is therefore indistinguishable

Answer 163

Oligodendrocytes

Answer 164

Astrocytes

Answer 165

Mean arterial blood pressure and intracranial pressure CPP= MABP-ICP

Answer 166

“Marked hypotension or elevation in intracranial pressure may reduce cerebral perfusion enough to cause ischemia of neurons in the medulla. This in turn causes a massive increase in systemic vasomotor tone to increase mean arterial blood pressure and therefore cerebral perfusion pressure. The resultant systemic vasoconstriction can be so intense that it is damaging to other organs such as the kidneys. The ensuing systemic hypertension activates baroreceptors, causing a reflex bradycardia (Cushing's reflex).” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 167

10% vs 65%

Answer 168

“Substances not only are excluded from entry to the central nervous system by the blood-brain barrier, but are actively extruded by energy-dependent efflux pumps such as p-glycoprotein.33 Mutations in the gene encoding this protein (the multi-drug-resistance gene—MDR1, now called ABCB1) are a well-known cause of susceptibility to adverse effects of drugs such as ivermectin in Collie breeds.1” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 169

“Circulating lymphocyte and monocyte numbers are depressed for several days after acute spinal cord injury,133 and lymphocyte function is depressed for several months after both spinal cord injury and stroke.35 This is accompanied by elevations in serum adrenocorticotropic hormone (ACTH) and catecholamines and increased urine cortisol. Conversely, circulating neutrophil numbers increase,133 and the capacity for oxidative bursting, which can be associated with injury to distant organs, is enhanced.65 The term central nervous system injury–induced immunodepression (CIDS) has been coined to refer to the syndrome of immunodeficiency associated with central nervous system injury.105 From the surgeon's perspective, these pathologic events are important because they highlight the potentially deleterious effects of indiscriminate use of corticosteroids in the treatment of patients with acute central nervous system trauma.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 170

Trauma leads to direct injury to neuronal, axonal in glial cell membranes as well as blood vessels. The decreased perfusion reduces energy supply to neurons and glia cells, causing ion pumps to fail or reverse, subsequently leading to cell membrane damage and increased permeability. Intracellular sodium, chloride and calcium ions increase, upsetting osmotic balance and causing cellular edema. The increase in intracellular calcium and sodium is perpetuated by an increase in extracellular glutamate which, in excess of concentrations, can cause neuron and oligodendrocyte death. This happens because extracellular glutamate concentrations are typically regulated by astrocytes. Mechanical damage to neurons, energetic deficit and impaired uptake by astrocytes leads to an increase in the concentration of glutamate which activates NMDA receptors, leading to an increase in Intracellular calcium. Increased intracellular calcium leads to activation of intracellular proteases such as Calpains and caspase, which destroy the cytoskeleton and initiate apoptosis. Intracellular calcium also activates phospholipase a which initiates the cyclooxygenase pathway and starts the inflammatory response. Finally, intracellular hypercalcemia binds to phosphate in further depletes the cellular energetic metabolism.

Answer 171

“Traumatic injury to the central nervous system rapidly initiates an inflammatory response within the damaged tissue (which is more pronounced in the spinal cord than in the cerebrum139) and contributes to the secondary injury that develops after the primary impact.124 Upregulation of peptidase matrix metalloproteinase 9 following injury has been identified as an important early trigger to the inflammatory response.114 Microglial cells release the cytokines interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-α), as well as potentially toxic chemicals such as hydrogen peroxide, nitric oxide, and proteinases, within minutes of injury.57 Two phases of cellular infiltration then occur: first, influx of neutrophils, which peaks within a few hours, then influx of macrophages, which reaches a peak at 5 to 7 days.43 This second phase of cellular infiltration coincides with secondary demyelination and loss of axons.16,17 If circulating macrophages are experimentally depleted, the functional outcome is improved, suggesting that they play an important role in tissue damage and functional loss.18,57,125 However, some products of activated phagocytic cells, through production of appropriate growth factors, may aid recovery of tissue integrity and revascularization after tissue damage.94,107 In addition, evidence suggests that inflammation[…]” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 172

Reduction of vasogenic edema

Answer 173

“With more chronic compression, necrosis and apoptosis of glial cells (oligodendrocytes and astrocytes), neurons, and axons may occur.27,51,69,176 In both clinical27 and experimental51 compression, demyelination is a prominent pathologic feature. Oligodendrocytes have high energy requirements to produce and maintain the myelin sheath, and compression may result in ischemia and therefore oligodendrocyte death. Oligodendrocytes are extremely sensitive to the excitotoxic effects of glutamate101 (acting through both AMPA and NMDA channels),92 the concentration of which increases when active astrocytic uptake fails and the action of white matter glutamate transporters is reversed. The concentration of glutamate in cerebrospinal fluid is elevated in dogs with chronic compressive lesions involving the thoracolumbar spinal cord, suggesting that excitotoxicity may play a pathophysiologic role in chronic compression” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 174

Surgical decompression has been linked to a rapid increase in blood flow as well as with relief of the physical deformation of myelin and axons. The improvement in blood flow will restore the much needed nutrient supply to oligodendrocytes, maintaining or repairing myelin production. It will also allow astrocytes to uptake glutamate and reverse vasogenic edema.

Answer 175

Metabolic energy deficit, leading to demyelination due to oligodendrocyte failure and vasogenic edema due to astrocyte failure (inability to uptake glutamate) Production of free oxygen radicals (as a result of the oxidation of iron and copper from hemoglobin), which damage neuronal, glial and endothelial cells

Answer 176

Lymphocytes

Answer 177

Blockage of the mesencephalic aqueduct Is one form of congenital malformation which leads to increased pressure within the third and lateral ventricles and secondary (obstructive) hydrocephalus with subsequent cell death

Answer 178

Imbalance of excitatory and inhibitory neurotransmitters, presence of neurotoxins such as ammonia, urea and phosphates

Answer 179

“the presence of neurotoxins such as ammonia, urea, and phosphates (hepatic and uremic encephalopathy), ionic imbalances (uremic encephalopathy), and changes in blood pressure (uremic encephalopathy).” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 180

Hemangiosarcomas, melanomas & carcinomas

Answer 181

“Cytotoxic edema manifests as intracellular swelling in the presence of a normal blood-brain barrier and arises as the result of failure of ion pumps at the cell membrane, allowing excessive entry of sodium “and water. It is commonly associated with ischemia and hypoxia (both of which can occur with contusion, vascular disease, and other diseases that can affect energy balance, such as repeated seizures), metabolic disorders, and intoxication and usually is most pronounced within astrocytes. ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 182

“Vasogenic edema results from increased vascular permeability and causes accumulation of extracellular fluid, particularly within white matter tracts. It is commonly associated with contusion, inflammatory disease, vascular disease, and compressive diseases such as neoplasia. ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 183

“Categorizing edema by type allows prediction of the best means of treatment. For instance, cytotoxic edema is best treated by alleviation of the underlying cause, whereas corticosteroids are effective in reducing perilesional vasogenic edema.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 184

“Hansen type I degeneration, the nucleus undergoes progressive decrease in proteoglycan content, with consequent dehydration and accumulation of mineral (also known as chondroid degeneration). This degeneration leads to loss of its ability to withstand pressure equally and causes secondary degeneration and “tearing in the annulus fibrosus. Finally, in an acute episode of mechanical stress, the nucleus is expelled through a tear in the annulus (usually termed intervertebral disc extrusion). Because the nucleus is eccentrically placed within the annulus, the expelled nucleus tends to be projected dorsally and to affect the spinal cord. The resultant injury consists of varying degrees of both contusion and compression.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 185

“Hansen type II degeneration, the nucleus is progressively dehydrated and replaced by fibrinoid tissue, with a consequent increase in stress transfer to the annulus. The annulus then undergoes a “wear-and-tear” degeneration that leads to rupture of fibers over a period of months to years. This allows the nucleus to cause protrusions of the dorsal aspect of the annulus, which compresses the spinal cord” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 186

“distress, subnormal temperatures, and gastrointestinal disturbances.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 187

“astrocytic proliferation and hypertrophy (termed astrocytosis or gliosis) commonly evolve to produce a “scar,” which is easily observed on histologic examination. Although this astrocytosis reconstitutes a central nervous system environment, it can have detrimental consequences, for instance, by forming a barrier to regrowth of axons.46 Astrocytosis found at epileptogenic foci could be considered to have proseizure or antiseizure activity, although the balance of opinion appears to suggest that astrocytosis is primarily a response to abnormal activity in the neurons.5,82” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 188

“diseases that alter cerebrospinal fluid flow (classically causing turbulence), such as arachnoiditis, Chiari-like malformations, and elevated intracranial pressure due to brain neoplasia, can all result in syringomyelia” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 189

In response to distruction of afferent input, cells tend to upregulate their number of receptors to a given neurotransmitter leading to “hypersensitivity“ to this substance. The response to the nearest transmitter may also change via changes in the types of ion channels expressed on the surface of the cell (alteration in sodium channel properties of bladder afferents after chronic spinal injury, for example)

Answer 190

Dogs: L5-L6 Cats: L6-L7

Answer 191

“Yellow or straw-tinged cerebrospinal fluid is referred to as xanthochromic, and it suggests previous subarachnoid hemorrhage (in the absence of hyperbilirubinemia). Xanthochromia is caused by an accumulation of blood pigments such as hemoglobin, and it may occur within several hours of an acute hemorrhagic insult (trauma, bleeding disorders, and occasionally severe central nervous system inflammation).” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 192

“Degenerative myelopathy (syn: degenerative radiculomyelopathy) is a neurodegenerative disorder that primarily affects the spinal cord of middle-aged to older dogs, and, rarely, older cats.4,38,91 The disorder is a diffuse axonopathy associated with necrosis primarily in the lateral and ventral funiculi of the thoracolumbar spinal cord segments (Figure 30.2).38 The axonopathy is accompanied by secondary demyelination and astrogliosis. Degenerative myelopathy is overrepresented in the German Shepherd Dog, the Pembroke Welsh Corgi, the Boxer, and the Rhodesian Ridgeback but also has been reported in the Siberian Husky, the Miniature Poodle, and the Chesapeake Bay Retriever. “Neuroanatomic localization in dogs with degenerative myelopathy commonly is consistent with a lesion involving the third thoracic through third lumbar (T3-L3 myelopathy) spinal cord segments, and the disease is typified by a progressive upper motor neuron paresis and general proprioceptive ataxia in the pelvic limbs.3” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 193

Canine distemper

Answer 194

Steroid responsive meningitis-arthritis

Answer 195

“Steroid-responsive meningitis-arteritis is a sporadic disorder characterized by episodes of profound cervical hyperesthesia, depression, and pyrexia.38 Clinical signs result from combined meningitis and arteritis of leptomeningeal vessels (Figure 30.3). Arteritis also may involve the vessels of the heart, mediastinum, and thyroid glands.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 196

Bloodwork: polymorphonuclear pleocytosis (predominantly neutrophils, occasionally degenerative), hyperglobulinemia CSF: elevated protein levels, elevated IgA levels C-Reactive protein

Answer 197

“A second, more chronic form of steroid-responsive meningitis-arteritis may occur following relapses of acute disease and/or inadequate treatment.137 In this form of disease, meningeal fibrosis secondary to the inflammatory process may obstruct cerebrospinal fluid flow or occlude the vasculature, rarely causing secondary hydrocephalus or ischemia of the central nervous system parenchyma, respectively.126 Involvement of the motor and proprioceptive systems may lead to variable degrees of paresis and ataxia; other neurologic signs, such as a menace deficit, anisocoria, or vestibular signs, may occur with severe disease.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 198

Female, toy/terrier breeds, approximately five years old Rapidly progressing multifocal CNS disease, vestibulocerebelar signs, seizures, cervical spine, visual deficits.

Answer 199

Disseminated, local and ocular

Answer 200

“Granulomatous meningoencephalomyelitis is an angiocentric, nonsuppurative, mixed lymphoid inflammatory process affecting predominantly the white matter of the cerebrum, caudal brainstem, cervical spinal cord, and meninges (Figure 30.4).17,35 The focal form of granulomatous meningoencephalomyelitis is a true mass lesion resulting from the coalescence of perivascular cellular infiltrates, involving a large number of blood vessels in one region. “The ocular form of granulomatous meningoencephalomyelitis also consists of perivascular cellular infiltrates primarily localized to the retinal or postretinal aspects of the optic nerve and optic chiasm.99,126 ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 201

Yes, females are more commonly affected

Answer 202

“granulomatous meningoencephalomyelitis is a nonspecific inflammatory response to various antigens, of which pathogens may constitute an important subset.”

Answer 203

Initial phase - typically asymptomatic non-supportive leptomeningitis and perivascular encephalitis Gray matter disease - typically one week - dogs may die within 2 to 3 weeks with seizures or progress into white matter disease White matter disease (most common form) - three weeks post infection, characterized by demyelination with axonal sparing. Dogs typically die within 4 to 5 weeks or recover with minimal central nervous system injury Necrotizing Meningoencephalitis (approximately 4 to 5 weeks post infection) nonsuppurative inflammation following the demyelination phase. Thought to occur secondary to exuberant inflammatory response to the white matter lesions. Typically combined with chorioretinitis and UTIs. Some dogs may recover while others may die.

Answer 204

Congenital anomalies (decompensating hydrocephalus, Chiari like malformations) AA subluxation trauma neurotoxins (mycotoxins) Metabolic disease

Answer 205

Meningoencephalitis (Multifocal neurologic signs; Unique cerebellar presentation caused by Neospora reported in dogs) Myositis-polyradiculoneuritis: juvenile dogs younger than six months of age, myositis, progressive radiculoneuritis, pronounced muscle atrophy

Answer 206

“Transmission of T. gondii to dogs and cats most commonly occurs secondary to carnivorous ingestion of encysted bradyzoites or tachyzoites, but sporozoites and tachyzoites also may be transmitted orofecally and transplacentally.42 The cat is the definitive host for T. gondii and excretes oocysts in its feces. Oocysts sporulate and may infect other mammals in 1 to 5 days. All mammals, including cats, may become intermediate hosts upon ingestion of sporulated oocysts. Multiple organ infection, including ocular, central nervous system, pulmonary, liver, and skeletal muscle involvement, may occur concurrently in intermediate hosts. Focal and/or diffuse infiltration of lymphocytes, plasma cells, and histiocytes may be present in the meninges and neuroparenchyma of the central nervous system.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 207

Cats, fecal oral transmission. Oocysts become infected in feces within 1 to 5 days. Cats typically become infected through consumption of infected meat. Contact with oocyts in fecal material leads to infection as an intermediate host, which can occur to cats, dogs humans and many other species

Answer 208

Dogs, presumably fecal oral. Vertical transmission is also very likely given the multiple dogs in a litter are frequently affected

Answer 209

“PESANK” Pasteurella spp., Escherichia coli, Staphylococcus spp., Actinomyces spp., Nocardia spp., Klebsiella spp.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 210

Must select antibiotics to cross the blood brain barrier Hematogenous spread (urinary tract infection) direct inoculation from traumatic wounds or needles (CSF tap) direct extension from structures of the head (eyes, ears, nasal cavity via cribriform plate) Paraspinal absences, migrating foreign bodies, tail fractures or infections in cats

Answer 211

Antibiotic choice should ideally be based on culture and sensitivity. Whether based on culture or empirically, must administer intravenous for the first three days to reach adequate blood levels more rapidly. Followed with three months of oral treatment. Options include metronidazole, fluoroquinolones, chloramphenicol and trimethoprim sulfa Third generation cephalosporins like ceftiofur (IM) and cefpodoxime (orally)

Answer 212

Large breed, male, middle-age. Breeds include great Dane, Rottweilers, labrador retriever, German Shepherd and English bulldog.

Answer 213

40% Burkett, BA et al, JAVMA 2005

Answer 214

Brucella canis

Answer 215

German Shepherd

Answer 216

“Objective measurement of the ischemic lesion included a ratio of the length of the ischemic lesion to the length of the C6 or T2 vertebral body (lesion-to-length ratio). In addition, the maximal cross-sectional area of the hyperintense lesion on T2-weighted images was evaluated as a percentage of total cross-sectional area of the spinal cord. The presence of MRI abnormalities was not significantly associated with the timing of imaging but was associated with ambulatory status on presentation. Severity of signs on presentation was associated with extent of the lesion on MRI. “Affected dogs recover voluntary motor activity, regain unassisted ambulation, and achieve maximal recovery at 6 days (range, 2.5 to 15 days), 11 days (range, 4 to 136 days), and 3.75 months (range, 1 to 12 months), respectively.39 Unsuccessful (euthanized, severe proprioceptive and motor deficits, urinary or fecal incontinence) recoveries occurred when the MRI lesion-to-vertebral length ratio was ≥ 2, and successful (clinically normal or mild general proprioceptive/motor deficits) when the ratio was ≤ 2. With lesion-to-vertebral length ratios ≥ 2 and ≤ 2, 60% had an unsuccessful outcome and 100% had a successful outcome, respectively. MRI therefore may be helpful in predicting outcome in dogs with fibrocartilaginous embolic myelopathy. ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 217

Central spinal cord syndrome, affecting the white matter deep in the spinal cord

Answer 218

Lower motor neuron affecting the brachial plexus or peripheral nerve roots of C6-T2 (non-spinal).

Answer 219

Flexor withdrawal reflexes

Answer 220

The panniculus muscle extends from the lower cervical region approximately the level of the sixth lumbar vertebra it is innervated by the lateral thoracic nerve which originates at C8-T1. Testing is based on pinching or breaking the skin starting at the level of the wings of the ileum in progress in cranially reflects will stop approximately two segments caudal to the site of lesion

Answer 221

The motor tracts innervating the pelvic limbs are located more peripherally in the spinal cord, and are thereby more prone to external trauma

Answer 222

Cystic lesions affecting the dorsal aspect of the spinal cord (more commonly caudal to T2) may cause disruption of the sensory pathways for defecation. Reflex defecation/urination remain intact

Answer 223

“A modified ventral approach to the cervical vertebral column via a paramedian dissection also has been described.31 After identification of the sternocephalicus and sternohyoideus muscles, the right sternocephalicus muscle is separated from the right sternohyoideus muscle (Figure 31.3). The sternohyoideus muscles are then retracted to the left with the trachea, esophagus, and carotid sheath. Further exposure of the vertebrae after this point is as for the standard approach. This approach helps protect the trachea, right recurrent laryngeal nerve, and the contents of the right carotid sheath (the vagosympathetic trunk, carotid artery, and internal jugular vein), while providing increased exposure of the caudal cervical vertebrae after elevation of the longus colli and longus capital muscles and decreasing the likelihood of hemorrhage from the right caudal thyroid artery.31”

Answer 224

The vagosympathetic trunk, common carotid artery and internal jugular vein

Answer 225

The cranial thyroid artery and the recurrent laryngeal nerve

Answer 226

Palpate the articular processes of C3 to C6 Perform a curvilinear incision from C2 to the cranial margin of the scapula Incise the platysma muscle to expose the brachycephalic and the trapezius muscles. In the cranial cervical region the splenius and the Serratur ventralis are exposed by blindly dividing and retracting the brachycephalicus muscle (grid technique) Superficial fibers of the Serratus ventralis I bluntly divided and retracted exposing the longissimus system

Answer 227

Perform a long curvilinear incision 3 to 4 cm cranially from the midpoint of the cranial border of the scapula to appoint located slightly distal to the greater tubercle of the humerus Incise the platysma muscle and the fascia cervicalis exposing the cleidocervicalis, omotransversarius and the trapezius muscles. Ligate the superficial cervical artery and vein as they emerge between the cleidocervicalis and the trapezius muscles. Retract the superficial cervical lymph node, which lies medial to these vessels, caudally. Incise the omotransversarius muscle near its insertion of the distal end of the spine of the scapula and retract cranially Continue dissection mediately to the deep fascia along the border of the cleidocervicalis muscle. Place a Gelpi retractor between this muscle and the trapezius. Retract the scapula caudally with a Farabeuf retractor to expose the nerves of the plexus

Answer 228

Internal carotid, external carotid and occipital arteries

Answer 229

Young small breed dogs such as Yorkshire terriers, Chihuahuas, Pomeranians and Pekingese. Less frequently reported in large breed dogs but overrepresented in the standard poodle

Answer 230

Increased distance between the dorsal lamina of the atlas and the spinous process of the axis

Answer 231

Dorsal atlantoaxial wiring Nuchal Ligament technique Dorsal cross pinning Kishigami Atlantoaxial tension band

Answer 232

“brachiocephalic, suprascapular, subscapular, axillary, musculocutaneous, radial, median, ulnar, dorsal thoracic, lateral thoracic, long thoracic, pectoral, and muscular branches.146” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 233

The dorsal root, immediately as it emerges from the spinal cord (intradural). Spinal nerves lack an epi-neuron at this site, making them more vulnerable to traction

Answer 234

Grade 1 - neurapraxia (Interruption of function and conduction without structural change). Recovery is likely Grade 2 - Axonotmesis (damage to axon is severe enough that Walerian degeneration of the distal portion of the nerve follows. Internal architecture is preserved including in the neuron and Schwann sheath). Recovery as possible but may take a few weeks Grade 3 - Neurotmesis (disruption of axons and endoneuron but for secular orientation is preserved by an intact perineurium.). Grade 4 - Neurotmesis (disruption of the Perineurium) Grade 5 - Neurotmesis (The entire nerve is severed)

Answer 235

C6-C7 Musculocutaneous, axillary, subscapular and suprascapular nerves The extensor muscles of the elbow are not affected, so the animal can bear weight on the affected limb. There is loss of shoulder movement and elbow joint flexion, and atrophy of the supraspinatus and infraspinatus muscles usually develop overtime

Answer 236

Radial nerve, median nerve and ulnar nerve C8-T2 The limb may be carried in a flexed position because the nerves that control elbow And shoulder flexion (musculocutaneous, axillary and suprascapular nerves) remain intact. The patient is unable to bear weight on the limb due to inability to extend of the elbow and the carpus since the necessary muscles are innervated by the radial nerve (Involved in 92% of cases)

Answer 237

The preganglionic fibers that innervate the eye originate at T1. Injury to these fibers will lead to sympathetic denervation, leading to myosis/ptosis/exposure of the nictitating membrane

Answer 238

The panniculus muscle is innervated by the lateral thoracic nerve which originates from spinal segments C8-T1 Injury to those segments is common with caudal brachial plexus injuries

Answer 239

The patient will most likely present with complete paralysis of the limb (dragging). The shoulder will be carried lower than the contralateral side. The limb is likely to be completely analgesic distal to the elbow but sensory routes can sometimes be spared

Answer 240

Hemosiderin deposition secondary to hemorrhage

Answer 241

The re-innervation of a denervated motor or sensory end organ

Answer 242

Patients affected by a complete avulsion of the radial nerve are expected to have a guarded to poor prognosis. all patients must be given a 4–6 weeks before a grave prognosis is pronounced. Options may include carpal arthrodesis (if able to extend the elbow, although quite rare) or more likely amputation.

Answer 243

Middle-age to older large and giant breed dogs. Most commonly observed in the lumbosacral junction, frequently in combination with degenerative lumbosacral stenosis. The cysts typically arise from the zygapophyseal joints, likely as a response to degeneration. Best diagnosed via MRI (hyperintense on T2-weighed images)

Answer 244

zygapophyseal joint.

Answer 245

“Funkquist A involves removing the spinous process, laminae, articular processes, and approximately half of the dorsal portion of the pedicles of a vertebra to gain access to the vertebral canal. It provides maximum exposure of the vertebral canal.84 Funkquist B leaves the articular processes and pedicles intact but removes the spinous process and laminae. A modified dorsal laminectomy is midway between Funkquist A and Funkquist B. For the modified dorsal laminectomy, the laminae, spinous process, and caudal articular processes are removed. The medial aspect(s) of the pedicles is undercut to enhance exposure, but the cranial articular processes remain intact ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 246

Phenoxybenzamine and prazosin

Answer 247

Griffiths Modified 5-Point scale 0: normal 1: Pain, not severe enough to result in neurologic disfunction 2: Paresis with or without pain; the degree of paresis or proprioceptive deficits become worse as disease becomes more severe 3: Plegia; total loss of voluntary movement in the affected limbs (and/or tail) 4: Plegia with loss of voluntary urinary function 5: Plegia with loss of voluntary urinary function AND loss of nociception in the affected limb (and /or tail)

Answer 248

Reported diagnostic accuracy 70 to 99%, but less accurate than CT or MRI for lateralize lesions.

Answer 249

Non-contrast CT is as diagnostic as myelography for IVDE in chondrodystrophic breeds, but the work-up must be completed with CT-myelogram or MRI if no lesions are found that explain the patient’s neurologic exam findings. More sensitive than conventional myelography for lateralized lesions.

Answer 250

- Best soft tissue contrast among available imaging techniques (lowest risk of false-negative results as compared to previous techniques). - Allows obtention of images in multiple planes without repositioning the patient. - Myelography is not necessary (in contrast with CT) since tissue contrast can be manipulated with different acquisition sequences. - Requires general anesthesia; - Study takes significantly more time that CT; - MRI devices are more expensive and require more maintenance.

Answer 251

Presence of nociception (“deep pain”) at the time of diagnosis. 80 to 95% of dogs with preserved nociception recover motor function within 2 weeks of surgery, as compared to 50% for those without preserved nociception. The previous notion that dogs who lost nociception for longer than 48 hours have a grave prognosis for return of normal function appears to be erroneous according to more recent reports. These dogs appear to have a similar prognosis top those who lost nociception within less than 48 hours. Only presence or absence of nociception has been consistently associated with better or worse prognosis.

Answer 252

“Intervertebral disc material is typically hypointense on T1-weighted (T1W) and T2-weighted (T2W) images, although in some instances animals may extrude nondegenerate nucleus pulposus (particularly common in the cervical vertebral column), which appears isointense on T1W images and hyperintense on T2W images.2” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 253

“Failure of the laminae to fuse dorsally is referred to as spina bifida and is often associated with concomitant neural tube malformation, especially meningocele (meninges herniated through the bony defect) or meningomyelocele (meninges and spinal cord herniated through the bony defect).268” Minx cats and screw tail dogs are predisposed Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 254

“Pilonidal sinus (dermoid sinus) refers to a congenital condition wherein the skin fails to completely separate from the neural tube during embryonic development.12,67 Phenotypically, the defect is a focal tubular structure (sinus) with a cutaneous opening lined by squamous epithelium and occasionally hair follicles.6 The sinus penetrates deeper tissues and in some cases reaches the level of the dura mater. The defect is found on the dorsal midline in dogs, with most cases reported in the cervicothoracic or sacrococcygeal regions.118,182 The presence of a pilonidal or dermoid sinus has been reported in cases of spina bifida as well” Rhodesian Ridgeback “Clinical features are dependent on the location of the sinus and the degree of tissue penetration. Infection of the sinus may lead to myelitis or meningitis. Pain and neurologic dysfunction may occur secondary to inflammation or as a result of the tethering effect the sinus has on the spinal cord or nerve roots” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 255

“Incomplete separation of the neuroectoderm from ectodermal tissue can entrap viable ectodermal cells within the central nervous system, leading to a condition termed epidermoid cyst (cholesteatoma). The cyst is lined by keratinizing stratified squamous epithelium.102,178,221,265 Epidermoid cysts most commonly form at or near midline during closure of the neural tube.241 Growth of the cyst occurs via accumulation of keratinocytes, keratinaceous material, and cholesterol. Affected animals are usually normal at birth but develop signs as the cyst enlarges and compresses adjacent neural tissue. Clinical signs reflect the anatomic level involved.39,241 Epidermoid cysts have been reported intracranially (within the caudal cranial fossa) and less commonly within the spinal cord.h The condition is thought to be congenital; however, an acquired cyst may develop secondary to implantation of epithelial cells after repeated cerebrospinal fluid collection in young dogs.154 Histopathologic evaluation of tissue from the cyst is the only way to confirm the diagnosis. Theoretically, complete removal of the tissue can be curative; however, few reports of successful treatment exist in the veterinary literature.37” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 256

“Subarachnoid diverticula are defined as focal accumulations of cerebrospinal fluid within the arachnoid membrane or subarachnoid space.67,94 This fluid-filled area tends to form over the dorsal or dorsolateral aspect of the spinal cord, with very few reports of ventral diverticula. The structures have no epithelial lining; therefore, technically, they are not a true cyst and instead have been referred to as a “pseudocysts.”93 Pseudonyms for this condition include arachnoid pseudocyst, meningeal or leptomeningeal cyst, and arachnoid cyst.” “Clinical features include a protracted progressive history of general proprioceptive ataxia and upper motor neuron paresis and also incontinence.11,261 Any breed or age can be affected, but younger adult (<18 months) Pugs and Rottweilers represent the most commonly reported breeds, and males tend to be predisposed” “The lesion may be approached by dorsal laminectomy or hemilaminectomy, and the laminectomy should be large enough to allow complete access to the diverticulum on the basis of preoperative imaging. The diverticulum may be fenestrated or marsupialized. Although relatively few cases of subarachnoid diverticula are reported in the literature, a trend toward better outcomes is seen if the incised dura is marsupialized by suturing it to the surrounding fascia. Surgical removal of the diverticulum may allow spinal cord decompression; however, re-formation of the lesion is a reported complication.261 Those cases that are younger in age and have had a shorter duration of clinical signs may have a better prognosis.261” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 257

“Myelodysplasia is a congenital malformation of the spinal cord most commonly reported in Weimaraner dogs.44 Incomplete or abnormal fusion of the neural tube along the sagittal plane leads to neurologic dysfunction. Clinical features that strongly suggest myelodysplasia include early onset (1 to 2 months of age) of a nonpainful T3-L3 myelopathy. One consistent feature of affected dogs is the use of both pelvic limbs simultaneously to propel themselves forward (bunny-hopping). Decreased proprioception of the pelvic limbs is also common. Results of myelography and CT are typically normal because the lesion is microscopic. Magnetic resonance imaging has not been well evaluated. In suspected cases, testing is performed to rule out other diseases that mimic this condition. No treatment is known; however, affected dogs do no not appear to be in pain, and signs are rarely progressive.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 258

40 to 70% for IVDD 12% for traumatic spinal injury

Answer 259

Basic assessment for concomitant thoracic, abdominal and cerebral injury Very brief neurological assessment to determine the presence or absence of nociception Immediate stabilization of the entire body using straps or tape against a rigid platform (a board). The head should also be stabilized if cervical trauma suspected. Light sedation/analgesia should be used as needed

Answer 260

Extrarenal nephroblastoma (dogs) Lymphoma (cats)

Answer 261

Cervical region; extradural (50%)

Answer 262

“Adverse effects of radiation are classified as early (acute) or late (chronic).61,106 Early effects occur in proliferating tissues such as epithelium and bone marrow.” Late adverse effects involve nonproliferating tissues such as nervous tissue, vascular tissue, and bone. These effects occur 6 months to years after radiation therapy63,165 and include white matter necrosis; atrophy, hemorrhage, or infarction of nervous tissues; chronic progressive myelitis due to vascular injury; and fibrosis/gliosis” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 263

“Myokymia, involuntary muscle contractions resulting in vermiform (rippling) movements of the overlying skin and muscle cramping, may occur as a late side effect to radiation.149 Regular periodic injections of botulinum toxin into the affected muscle can control the clinical signs.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 264

“Samarium-153 EDTMP (Samarium-153 lexidronam, Sm-153) is an injectable radioisotope that concentrates in areas of osteoblastic activity. This drug has been used for palliation of pain due to osteosarcoma and metastatic bone neoplasms in “dogs. Response rates for osteosarcoma were 60% to 80% for 3 months. Side effects primarily involve myelosuppression. ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 265

Cervical and lumbar intumescence. Major nerves arise from these locations (i.e. radial nerve, owner nerve, femoral nerve, etc.), and the rhizotomy (excision of a nerve route) may result in significant disability.

Answer 266

“Primary neoplasms include neoplasms arising from ependyma, glia (astrocytoma, oligodendroglioma, undifferentiated glial neoplasms), other neuroectodermal precursors, or stromal origins (primary sarcoma).82,83,130,137,153 In dogs, the two most common intramedullary primary neoplasms are ependymoma and astrocytoma.122,130,171,192,196 However, in one report, primary sarcoma of the spinal cord accounted for approximately 50% ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 267

“In normal swallowing, food is grasped by the teeth and formed into a bolus by rapid tongue movements. The bolus is pushed up and back by the base of the tongue into the oropharynx. The hypopharyngeal, pterygopharyngeal, and palatopharyngeal muscles contract and force the bolus through the relaxed upper esophageal sphincter (cricopharyngeal, thyropharyngeal muscles) into the cervical portion of the esophagus. The cricopharyngeal muscle contracts after the bolus passes. Cricopharyngeal muscle tone is linked to deglutition and the respiratory cycle. During swallowing, the airways are protected by the soft palate (which closes the nasopharynx) and the epiglottis (which flips back to close the glottis). “Cricopharyngeal achalasia is characterized by inadequate relaxation of the cricopharyngeal muscle and/or lack of coordination with pharyngeal muscle contractions during swallowing. This disrupts the cricopharyngeal phase of swallowing, causing food to remain in the pharynx and produce gagging, regurgitation, aspiration, and coughing.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 268

Rare condition, typically affecting springer or cocker spaniels as well as miniature poodles. Clinical signs are typically noticed at the beginning of eating solid food. Gagging, retching, expulsion of saliva covered food are typical. Regurgitation occurs immediately after swallowing. Most patients have a voracious appetite but eventually become anorexic and lose weight. Pharyngeal dysphasia is caused by inadequate pharyngeal contraction and typically affects older dogs. May also be associated with esophageal hypomotility and megaesophagus.

Answer 269

Medical treatment: intralesional injection of botulinum toxin. Improving therapeutic modalities Surgical treatment: cricopharyngeal myectomy. Typically curative, but potentially disastrous if misdiagnosed (affected by other pharyngeal dysphasias)

Answer 270

“Of most clinical importance in terms of conscious perception and reaction to noxious stimuli are the spinothalamic and spinocervicothalamic tract.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 271

“Local inflammatory mediators in peripheral tissue are responsible for creating the signal that will ultimately be perceived as pain. Such mediators released by tissue after injury include bradykinin, prostaglandins, leukotrienes, serotonin, arachidonic acid, histamine, nerve growth factor, tumor necrosis factor, substance P, acetylcholine, adenosine triphosphate, and protons. Many of these inflammatory mediators and cytokines are released from epithelial cells, endothelial cells, mast cells, macrophages, and platelets. Prostaglandin E2 (PGE2) is an arachidonic acid metabolite generated by cyclooxygenase (COX) released from damaged cells. Bradykinin is a potent pain-producing peptide; it directly activates Aδ and C fibers and increases the synthesis and release of prostaglandins by nearby cells.2,7–10 If unabated, stimulation of peripheral nociceptors by these mediators can lead to release of additional inflammatory mediators by the nociceptors themselves, leading to amplification of the local inflammation via a process of neurogenic inflammation” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 272

“If unabated, stimulation of peripheral nociceptors by these mediators can lead to release of additional inflammatory mediators by the nociceptors themselves, leading to amplification of the local inflammation via a process of neurogenic inflammation. In addition to cytokines already mentioned, nociceptors may release other chemicals such as substance P and calcitonin gene-related peptide. Both these peptides can cause increased tissue edema by direct actions on venules. They also activate local mast cells, leading to histamine release; histamine accentuates the pain response by decreasing the threshold for nociceptor activation. These processes can ultimately lead to peripheral sensitization, a phenomenon in which nociceptor afferent neurons become hyperexcitable to stimuli, effectively increasing the gain of the response of these peripheral neurons to potentially noxious stimuli” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 273

“histamine accentuates the pain response by decreasing the threshold for nociceptor activation.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 274

“Glutamate is the predominant excitatory neurotransmitter released by Aδ and C fibers in the spinal cord gray matter. ” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 275

“Wind-up via excessive glutamate activation of neuronal NMDA receptors.• Release of normal inhibition of NMDA receptor overstimulation via co-release of substance P and CGRP from hyperstimulated C-fibers (see earlier). This involves Mg++ channels.• Transcriptional and translational changes in postsynaptic dorsal horn neurons (pain “memory”).• Activation of central nervous system microglial cells (by substance P, glutamate, etc.), which upregulate cyclooxygenase-2, and release other neuroactive substances (which increase excitability of dorsal horn neurons).• Axonal sprouting, altered neuronal connectivity and cell death; all associated with microglial cell activation.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 276

“In addition to mechanisms within the peripheral nervous system (PNS) and CNS that serve to exacerbate painful states, there are a number of segmental (spinal cord) and suprasegmental (brain) modulatory systems within the CNS that act to ameliorate the sensation of pain. At the spinal cord level, some interneurons of the dorsal gray column are inhibitory to projection neurons that provide the majority of axons for the various pain-transmitting spinal cord pathways. These interneurons can be stimulated by fast-conducting, nonnociceptive myelinated Aβ fibers (normally convey touch, pressure, and some proprioceptive sensation) as well as by a subset of nonnociceptive Aδ fibers. When stimulated, these fibers can, via excitation of the inhibitory interneuron, prohibit firing of the slower conducting C fibers. In other words, by the time the nociceptive stimulus carried by the C fiber arrives at the dorsal horn, an inhibitory interneuron that has been excited by a faster conducting myelinated fiber has already been given the signal to prohibit C fiber stimulation of dorsal horn projection neurons. This is the basis of the gate control theory. In essence, the faster conducting nonnociceptive fibers “close the gate” to slower conducting nociceptive fibers. The inhibitory interneurons involved in[…]” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 277

Sciatic nerve ( L6-S1) Femoral nerve (L4-L6) Ventral motor branches to the psoas major muscle group for hip flexion

Answer 278

“In the thoracic limb, the dorsal thoracic, axillary, musculocutaneous, median, ulnar, and radial nerves are responsible for flexion of the shoulder, elbow, carpus, and digits. The nerves responsible for this reflex arise from spinal cord segments C6-T2.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 279

Grade 0: para- or tetraplegia with no deep nociception Grade 1: para- or tetraplegia with no superficial nociception Grade 2: para- or tetraplegia with nociception Grade 3: non ambulatory para- or tetraparesis Grade 4: ambulatory para- or tetraparesis with GP ataxia Grade 5: spinal hyperesthesia only

Answer 280

• English Staffordshire bull terriers are prone to FCE, whereas border collies are prone to HNPE. • HNPE dogs are more likely to vocalize at onset of signs, compared with FCE dogs. • HNPE dogs are more likely to have C1–C5 lesions than FCE dogs. • HNPE dogs are more likely to exhibit spinal hyperesthesia on initial examination than FCE dogs • HNPE dogs are more likely to be ambulatory at time of hospital discharge than FCE dogs. • FCE dogs are more likely to have L4–S3 lesions (and long-term fecal incontinence) than HNPE dogs. Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 281

myasthenia gravis (MG) autoimmune polymyositis polyradiculoneuritis tick paralysis.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 282

“Acquired MG is an autoimmune disorder of the neuromuscular junction in which autoantibodies are formed against nicotinic acetylcholine (ACh) receptors of skeletal muscle. ” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 283

“Megaesophagus is a frequent feature of acquired MG in dogs because of the high proportion of skeletal muscle in the canine esophagus; ” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 284

“There is a bimodal age distribution for acquired MG in both dogs and cats, with peak incidences at approximately 3 and 10 years of age. Both males and females are affected, although there may be a slight decreased tendency for sexually intact dogs to develop MG. Breeds most commonly afflicted with MG include German shepherds, golden retrievers, and Labrador retrievers. Other breeds with a relatively high risk for MG include Akitas, terriers, and German shorthaired pointers. Somali cats (related to Abyssinians) and Abyssinian cats are at risk for developing acquired MG.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 285

“Dogs and cats with MG typically do not have specific neurologic deficits but display varying levels of weakness. It is common for pelvic limb weakness to be the main (sometimes the only) clinical manifestation in dogs with MG; this feature often leads to misdiagnosis of MG as either a myelopathy or pelvic limb musculoskeletal disorder.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 286

Focal MG: Clinical Signs of Appendicular (Limb) Muscle Weakness. Can present as megaesophagus, pharyngeal weakness, laryngeal weakness, and/or facial muscle weakness: each of these may be the sole presentation or may occur in any combination Generalized MG: Clinical Signs of Appendicular Weakness. Typically see most (or all) of weakness in pelvic limbs, but thoracic limbs can be involved Acute Fulminating MG: Rapid Onset and Progression of Severe Weakness. Profound focal and appendicular weakness. Acute onset, rapid progression to nonambulatory tetraparesis and respiratory distress. Usually fatal” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 287

“Mediastinal masses (typically thymoma) are much more common in cats with acquired MG than in myasthenic dogs; in one retrospective study of 235 cats with acquired MG, 52% had evidence of a mediastinal mass (vs. 3.4% in dogs).1” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 288

“The most definitive blood test for the diagnosis of acquired MG is an immunoprecipitation radioimmunoassay that quantitates serum autoantibodies directed against the ACh receptor. Concentrations of ACh receptor antibody above 0.6 nM/L and 0.3 nM/L are diagnostic for MG in dogs and cats, respectively. The edrophonium (Tensilon) challenge test may provide a presumptive diagnosis of MG in patients while awaiting results of an radioimmunoassay if it is clearly positive (i.e., the patient displays a clear improvement in strength shortly after administration of IV edrophonium). However, some dogs with various myopathies will also display increased strength after receiving edrophonium. Although the association between MG and thyroid disease is tenuous, thyroid status should be evaluated in MG patients.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 289

Anticholinesterase Drugs Pyridostigmine (preferred anticholinesterase drug) Neostigmine (only if pyridostigmine is not available) Immunosuppressive Drugs Azathioprine (dogs) Cyclosporine Mycophenolate mofetil (dogs) Thymectomy Thymic hyperplasia (not evaluated in dogs and cats) Thymoma (not until MG signs controlled) Hormonal Therapy Thyroxine if dog is hypothyroid Nutritional Support Elevated feedings Gastrostomy tube feedings Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 290

“Medical management of acquired MG in dogs and cats is typically either oral pyridostigmine or oral pyridostigmine plus immunosuppressive therapy (see Box 30.14). Treatment options for canine and feline MG are summarized in Box 44.2. Prednisolone often causes an initial worsening of weakness in dogs with MG; this adverse effect is potentially severe enough to justify avoiding prednisolone as an immunosuppressive agent for canine MG. A similar adverse effect of prednisolone treatment has not been documented for cats with acquired MG.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 291

Alert - conscious, responsive (normal) Obtunded - depressed, listless and disoriented. Easily aroused with minor stimulus (“out of it”). Lesion: Forebrain Stuporous - unconscious but can be aroused with a strong stimulus. I lesion: usually brainstem or diffuse forebrain. Comatose - unconscious and not aroused even with strong stimulus. Lesion: brainstem or diffuse forebrain

Answer 292

V,VI and VII Trigeminal nerve (V, ophthalmic branch) - afferent pathway Abducens (VI) - efferent, motor to retractor bulbi muscle Facial (VII) - efferent, motor to palpebral muscles (blink reflex)

Answer 293

Blink reflex Corneal reflex Trigeminofacial reflex (stimulate maxillary region/medial canthus and observe blink) Stimulate inner pinna and observe behavioral response

Answer 294

Attitude - position of the eyes and head in relation to the body Posture - position of the body respect to gravity

Answer 295

Bilateral vestibular Peripheral vestibular apparatus

Answer 296

“Caudal cervical spinal cord lesions that spare innervation to the phrenic nerve LMNs (e.g., lesions caudal to the C5–C7 segments) but disrupt normal activation of intercostal LMNs can lead to the phenomenon of abdominal breathing. In this scenario, the diaphragm bears the sole burden of moving air through the lungs because of the denervated chest wall, and this motion causes the abdomen to visibly move back and forth during respiration” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 297

“Tonic input to the sympathetic LMNs in the thoracolumbar spinal cord that maintain normal blood pressure is provided by neurons in the medulla (rostroventrolateral medulla). Because these medullary neurons send their processes through the cervical spinal cord, cervical myelopathies may be associated with severe hypotension.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 298

“The first cervical vertebra (C1), the atlas, has a shortened body (the ventral arch); wide, shelf-like transverse processes (wings); and modified articular processes. The ventral tubercle of C1 feels like a distinctive “spike” when palpated during a ventral approach (Fig. 40.2), compared with the smooth “bump” of the ventral aspect of the intervertebral disc spaces. ” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 299

“No intervertebral disc is found between the first and second cervical vertebrae.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 300

“The dorsal spinous process of C2 (the axis) is a distinctive bladelike structure, the caudal aspect of which is very thick and partially overhangs the dorsal aspect of C3. The dorsal spinous process of C3 is extremely small and is sometimes nonapparent, especially in miniature and toy dog breeds. The dorsal lamina of C3 in these small breeds may be very short as well. It is important not to confuse C4 with C3 while performing a dorsal approach in the cranial cervical spine, especially in small dogs and cats.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 301

“The transverse processes of C6 are very prominent ventral structures that are easily palpated during the ventral approach. The dorsal aspect of the first rib as it articulates with T1 can also be palpated during the ventral approach; however, the surgeon must be cautious not to rupture the thin cupula pleura during palpation of this structure.” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 302

“The most common complications are transient neurologic worsening after surgery and venous sinus hemorrhage (which may require transfusion)” “In a large (546 cases) retrospective study of dogs with cervical disc extrusions treated via ventral slot surgery, acute adverse events were documented in approximately 10% of the patients. These adverse events were considered to be major in 6.4% of cases (deterioration in neurologic status, persistent pain, intraoperative hemorrhage), and roughly half of this group required reoperation. Adverse events in this study were associated with NSAID administration, less experienced surgeons, C7–T1 extrusions, and intraoperative hypotension” Excerpt From Small Animal Surgery E-Book Theresa Welch Fossum DVM, MS, PhD, Dipl ACVS https://books.apple.com/us/book/small-animal-surgery-e-book/id1367916984 This material may be protected by copyright.

Answer 303

○ Neurapraxia: transient conduction block to the nerves without anatomic interruption (avulsion) ○ Axonotmesis: partial avulsion of brachial plexus nerves (disruption of the axon; endoneurium, perineurium, epineurium remain intact) ○ Neurotmesis: complete avulsion of brachial plexus nerves (axon and surrounding connective tissue)

Answer 304

○ Loss of ipsilateral cutaneous trunci reflex ■ Lateral thoracic nerve injury (C8-T1 spinal nerve roots) ○ Ipsilateral Horner's syndrome ■ Sympathetic pathway (T1-T3 spinal nerve roots)

Answer 305

Lameness or paresis with hypotonia and hyporeflexia of the thoracic limbs, +/− ipsilateral Horner's syndrome, +/− loss of ipsilateral cutaneous trunci, and normal pelvic limbs

Answer 306

- Neoplasia: soft-tissue sarcoma, lymphoma • Intervertebral disc disease (lateralized) • Musculoskeletal injury: fracture, joint dislocation, muscle avulsion • Neuropathy: rabies encephalomyelitis, acute canine polyradiculoneuritis/coonhound paralysis

Answer 307

• Trauma (Brachial plexus injury) ○ Preservation of deep pain sensation warrants a fair to good prognosis for return to function over weeks to months. ○ Loss of deep pain sensation suggests an avulsion and warrants a grave prognosis for return to function. ○ Lack of any neurologic improvement over a 4-6 week period suggests permanent injury. • Brachial plexus neuritis carries a guarded prognosis, but recovery has been reported. • Overall prognosis is poor for malignant nerve sheath tumors that are not surgically resectable.

Answer 308

• Supportive care/monitoring/resuscitation for traumatic injuries • Prevent self-mutilation or trauma to the affected limbs: ○ Booties to protect the paw ○ Elizabethan collar to prevent licking and chewing ○ Neuropathic analgesia ■ Gabapentin (10 mg/kg PO q 8h): may prevent paresthesia and self-mutilation • Glucocorticoids: might be of benefit for brachial plexus neuritis, although sufficient scientific information to support their use has not been confirmed.

Answer 309

• Prevent self-mutilation • Physical rehabilitation: maintain joint mobility and prevent muscle contracture ○ Target all joints of the affected limbs ○ Passive-range-of-motion (PROM) exercises for 10-15 minutes 3-5 times daily • Limb amputation may be indicated in cases with ○ Permanent unilateral brachial plexus avulsion (no improvement after 6 weeks) ○ Documented or highly suspect malignant nerve sheath neoplasia • Radiation therapy can be considered for cases of brachial plexus tumors • Limb-sparing treatments (e.g., nerve root transplantation, transposition, neurotization, muscle transposition) for brachial plexus avulsions are often unrewarding with limited reports of recovery of neurologic function in the affected limb.

Answer 310

Small sensory branch to the inner concave aspect of the pinna. D. Cutaneous sensory testing 1. Autonomous zone of facial nerve (dog and cat) Fold over the pinna. Touch or gently pinch the inner surface of the pinna in the area of the fold. Observe for the ipsilateral eye to blink, ear movement and a conscious response (turning head, growling, etc). CN VII afferent, CN VII efferent, cerebral cortex

Answer 311

SRT spinothalamic tract Reticulothalamic tract Tectospinal tract

Answer 312

5 to 12 mmHg

Answer 313

Choroid plexus Pituitary gland CN-V

Answer 314

Supraspinous ligament Dorsal longitudinal ligament Ventral, longitudinal ligament

Answer 315

Interspinous ligament. Intertransverse ligament Yellow ligaments

Answer 316

Skin Subcutaneous Thoracolumbar fascia Multifidus musculature > transect tendons of attachment to the zygapophyseal joints Longissimus lumborum musculature > transect tendon of attachment to the accessory process > Spinal root and vessels located immediately ventral and cranial to these tendons

Answer 317

“Funkquist A involves removing the spinous process, laminae, articular processes, and approximately half of the dorsal portion of the pedicles of a vertebra to gain access to the vertebral canal. It provides maximum exposure of the vertebral canal” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 318

“Funkquist B leaves the articular processes and pedicles intact but removes the spinous process and laminae” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 319

“A modified dorsal laminectomy is midway between Funkquist A and Funkquist B. For the modified dorsal laminectomy, the laminae, spinous process, and caudal articular processes are removed. The medial aspect(s) of the pedicles is undercut to enhance exposure, but the cranial articular processes remain intact” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 320

Short Tau Inversion Recovery (STIR) Suppresses signal from epidural fat to enhance the contrast of extruded or protruded disc material

Answer 321

Fluid-attenuated Inversion Recovery (FLAIR) Attenuates CSF signal to highlight extruded or protruded disc material

Answer 322

1) Imaging abnormalities do not necessarily indicate clinical disease (i.e. L7-S1 disk protrusion common in asymptomatic large breed dogs) 2) Diffuse spinal cord compression can be the result of hemorrhage, neoplasia, or empyema. 3) Subarachnoid administration of iodinated contrast can worsen the clinical status of patients with parenchyma spinal cord disease

Answer 323

“Incomplete separation of the neuroectoderm from ectodermal tissue can entrap viable ectodermal cells within the central nervous system, leading to a condition termed epidermoid cyst (cholesteatoma). ” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 324

“Pilonidal sinus (dermoid sinus) refers to a congenital condition wherein the skin fails to completely separate from the neural tube during embryonic development.” Excerpt From Veterinary Surgery: Small Animal Expert Consult Spencer A. Johnston VMD, DACVS & Karen M. Tobias DVM, MS, DACVS https://books.apple.com/us/book/veterinary-surgery-small-animal-expert-consult/id1250368401 This material may be protected by copyright.

Answer 325

Coagulase positive staphylococci like staphylococcus aureus or intermedius

Answer 326

Cephalexin, six weeks

Answer 327

Pseudohyperreflexia: Loss of sciatic nerve tone, leading to exaggerated femoral nerve response (quadriceps)