Examination of the nervous system Flashcards
Exam methods
HISTORY Observe (inspection?) Touch (palpation) Pain (palpation) Additional
History
More important than in any other problem
Exact problem/duration/constant vs periodic/changes before
Additionally: environment and housing Feeding Other animals Vaccinations Breed-predisposition and age
Observe (general impression?)
Inspection without movement:
- body posture
- head position
- eye position and movement
- consciousness
- reaction to stimuli
Inspection with movement:
- walking
- turning
- sitting and standing
Touch- physical exam without causing pain
Palpation Postural reactions Spinal reflexes Cranial nerves Sensitivity of skin and mucus membranes
Must differentiate from orthopoedic problems
Pain- exam of pain perception
supf vs deep
Instruments: reflex hammer, artificial clamp/needle, penlight
Goal of physical exam
Locate the problem! if not neurologic is likely to be metabolic, orthopoedic or toxic
If is neurologic: need to check if its central: brain/SC or peripheral
Additional exams
X-ray Myelography CT MRI Lab exams
Myelography
contrast injected into subarachnoid space
Diagnose compression of the SC
CT
Contrast IV or orally
Enhances density differences btw lesions and the surrounding parenchyma
Good for demonstrating vessels
Better images of bone, soft tissues, and air-filled lungs
Sedation is required
MRI
Good anatomical detail of soft tissues (higher water content) but anaesthesia is needed
EEG
Electroencephalography
Surface activity of the electrical activity of the cerebrum
EMG
Electromyography
Electrical activity of the muscles
Lab exams
CSF- obtain through occipital puncture
Blood- haematology and biochem
Urine- pathogens, toxins, metabolic alterations
Exam of the head
Inspection
Palpation
Inspection of the head
Posture:
-Abnormal head position: lateral turn, tilted, opisthotonus, weakness of neck muscles
-Turning/tilt of the head and neck
Palpation of head
Shape Mobility Ears Signs of pain Facial expression Detailed exam of the eyes
Palpation- shape
if symmetrical or asymmetrical changes
e.g hydrocephalus bulging of skull
Palpation- facial expression
eyelids
nostrils
ears
Palpation- detailed exam of the eyes
Position and mobility of eyeballs and pupils
Anisocoria when pupil size is not the same
Exam of spine
Inspection
Palpation
Inspection of spine
Curved spine not primary neuro disorder- could be due to malnutrition during growth
Kyphosis- dorsal elevation
Lordosis- concave
Scoliosis- lateral curvature
Palpation of spine
Shape
Position- luxation
Sensitivity- induce pain!
Mental status is an examination of..
Thalamocortex
- thalamus: relay centre
- cortex: goal directed behaviour
Brainstem
- coordinates vital functions
- ARAS
Mental status
Consciousness
Behaviour
Mental status- consciousness
Reduced mental function:
- depressed/obtuned
- somnolentia=drowsiness
- delirium
- dementia
Increased
- excitation
- aggression
Episodic alteration of consciousness
Narcolepsy- fall into deep sleep suddenly
Syncope- loss of consciousness sever heart problems cause cerebral hypoxia
Seizure- clonic-tonic
Behaviour
Alterations in behaviour Decreased/ increased reactivity Cognitive dysfunction Involuntary postures Involuntary compulsive movements Special behaviour abnormalities Seizures/convulsions Other forms of convulsions
Alterations in behaviour
Aggression Vocalisation Abnormal sexual activity Excitation Mania e.g tail-biting
Decreased reactivity
Standing in the manger?- lead poisoning
Head press- hydrocephalus
Dementia
Deep coma
Cognitive dysfunctions
Usually related to age
Somnolence
Changes in sleep-wake cycles
Abnormal urination/defecation
Involuntary postures
Head tilt
Opisthotonus
Involuntary/ compulsive movements
Walking in circles
Compulsive walking in circles- pacing
Special behaviour abnormalities
Hallucination- partial epilepsy
Paraesthesia- psychogenic dermatitis- Aujeszky’s disease
May lead to automutilation
Seizures
Usually associated with
Regarding muscle function
Classification
Other forms
Seizures are usually associated with
Loss of consciousness (involvement of reticular formation)
Increased or decreased voluntary muscle tone- urination/defecation
Visceral muscle activity
Altered behaviour
Seizures: regarding muscle function
Tonic
Clonic
Toncio-clonic
Classification of seizures
Partial- localized but may become generalized
Complex partial- partial seizure with loss of consciousness
Generalized- diffuse in brain, generalized tonic-clonic
Structural- intracranial disease e.g hydrocephalus
Extra-cerebral- metabolic reasons e.g hypoglycaemia
Secondary epilepsy due to e.g distemper
Other forms of convulsions
Do NOT necessarily have to be associated with the CNS Tetanus Tetany Tremor Tic Myoclonus Fibrillation
Tetanus
inflamm Tail-lifting Opisthotonus Spastic tetraparesis- extensor muscles are activated Risus sardonicus Salivation
Exam of proprioception i.e the postural reactions
Wheelbarrowing test Hopping tests Knucking over Placing reactions Extensor postural thrust reaction
What is ataxia
Lack of coordination during muscle function (movement)
Usually caused by CNS damage
Ataxia- classification by signs
Static- signs even in standing position- the most severe
Locomotive
Intentional: head tremor when fine movement is required
Ataxia- classification by anatomical origin
Cortical
Cerebellar
Vestibular
Spinal
Cortical ataxia
Circling
Lateral head turn
Behavioural and mental state alterations
Cerebellar ataxia
Wide based stance Dysmetria or hypermetria Nystagmus Balance issues Conscious centre still normal
Vestibular ataxia
Ipsilateral head tilt
Leans/falls/rolls to the affected side but no circling
ALWAYS nystagmus
Bilateral lesions- extreme swaying of head
Spinal (proprioceptive)
Paresis/ paralysis
Hindlimbs ALWAYS
Knuckle over
Lethargic and weak
What is paresis, paralysis/plegia
Abnormal posture or movement due to reduced or increased muscular tone
paresis, paralysis/plegia - extraneural forms
Rhabdomyopathy
NM junction
Vascular
paresis, paralysis/plegia - diagnostic methods
Inspection
Palpation
Evaluation of muscle tone
Need to determine if its atony, hypo or hypertony
paresis, paralysis/plegia- classification
By severity
By affected limbs
By muscle tone
By origin- related to motor neuron nucleus
Classification based on severity
paresis- partial loss of strength
paralysis/plegia- complete loss of strength
Classification based on the affected limbs
mono: one limb e.g N radialis or fibularis
tetra: all limbs
para: hind limbs
hemi: ipsilateral (same side)
Classification based on muscle tone
spastic, rigid
atonic, flaccid
Classification based on origin- motor neuron nucleus
UMN: above the nucleus
LMN: in/below the nucleus
paresis, paralysis/plegia: non-neuro
Botulism
Ionophore ABx in chickens
Olfactory nerve
Use food to examine but block vision- otherwise II would be examined
Hyposomia- partial lack of smell
Anosomia- complete lack of smell
Optic nerve
Vision! (amaurosis=complete blindness)
Falling cotton test
Leading into objects
Pupillary light (+III)
Menace (+VII)
Oculomotor nerve
Examination of pupils
Anisocaria= both pupils not the same size
Mydriasis
Miosis
Horner’s syndrome- symp
*therefore pupillary light reflex?
Oculomotor, trochlear and abducent nerves
Position and movement of eyeballs
Normal- eyeballs move simultaneously and their axis are parallel
Physio nystagmus- movement of head
Patho nystagmus- horizontal, vertical, rotary
Strabism- abnormal position of eyeballs, the axis are not parallel (like cross-eyed?)
Trigeminal nerve
Sensory: feeling of face, palpebral and conreal reflex
Motor: temporal and masseter muscles
-paralysis- sagging lower jaw
-tic- repeated contractions of chewing muscles, can be seen with distemper
-trismus- tonic spasm of chewing muscles, can be seen with tetanus and myositis
Tests: corneal (lateral canthus) and palpebral (medial canthus) reflexes
Facial nerve
Facial: taste to rostral 1/3 of tongue
Motor: muscles of facial expression
menace (+II) palpebral (+5) and corneal (+5) reflexes
Paralysis: nasal plane drawn towards healthy side i.e asymmetry
Ptosis: sagging of upper eyelid
Lip sagging
Ear sagging (central)
Vestibulocochlear nerve
Hearing
Deafness= anacusis
Congenital- white dog argentino
Vestibular
Dysfunction is vestibular syndrome
Ipsilateral head tilt, leaning, and falling
Nysatgmus- horizontal
Glossopharyngeal and vagus nerves
Pharynx and larynx Caud 2/3 of tongue: glossopharyngeal sensory and vagus is motor Paralysis: -dysphagia -laryngeal paralysis
Test: swallowing/gag reflex- after swallowing dogs always lick their nose
Accessory nerve
Motor: to traps, sternocephalicus, brachiocephalicus
Paralysis:
Bilateral sagging of head
Atrophy of above muscle groups
Hypoglossal
Motor to tongue!!
Paralysis: abnormal protruding and retracting
What is a spinal reflex?
Involuntary and immediate response to an appropriate stimulus 0= areflexia 1= hyporeflexia 2= normoreflexia 3= hyperreflexia 4= hyperreflexia with clonus
Abnormal reflexes
Reflex irraditation- reaches a wider muscle group
Contralateral/crossed reflex- other side of the body
Classification of spinal reflexes
Proprioceptive/myotatic/stretch
=normal body position against gravity
Nociceptive (painful) reflexes
What are the proprioceptive reflexes
Thoracic limb
- extensor carpi radialis
- triceps
- biceps
Pelvic limb reflexes
- patellar
- achilles
Extensor carpi radialis reflex
Afferent and Efferent nerve: N. radialis
Center: C7-T1
Hit muscle belly
Triceps reflex
Afferent and effernt nerve: N. Radialis (same as ext carpi radialis)
Center C7-T1 (same an ext carpi)
Hammer just prox to olecranon
Biceps reflex
Afferent and efferent nerve: N. musculocutaneous
Center: C6-C8
Foreginger on tendon of biceps and is struck with the other finger
Patellar reflex
Afferent and efferent nerve: N. Femoralis
Center: L4-L6
Hammer on tendon
Achilles reflex
Afferent and efferent nerve: N. Sciaticus tibialis
Center: L6-S2
Directly over the hock caudally
What are the nociceptive reflexes
Flexor (withdrawal) reflex
Perineal reflex
Panniculus
Flexor (withdrawal) reflex
Thoracic limb:
Center: C6-T1
All flexor muscles no pain involved because the animal moves limbs before there’s time to cause pain
Pelvic limb
Center: L4-S1…. same as above for the rest
Perineal reflex (is it supposed to say perianal?)
Afferent nerve: N. pudendalis Efferent nerve: -anal sphincter: N. pudendalis -tail flexion: N. rectalis caudalis Center: S1-S3 Tone and then contraction of tail is checked
Panniculus reflex
Afferent nerves: spinal segments
Efferent nerve: N. thoracicus lateralis
Aids in location spinal injury- shaking of skin
Start in lumbar, then work cranially
Examination of pain perception: types of pain
Superficial pain
Deep pain
Spinal pain
Superficial pain
Skin/ mucus membranes: hemostat/needle
Pain provoking percussion
Normal: twitch/withdrawal and behavioural e.g crying
Pathway: receptor - spinal ggl.- thalamus- cortex
Evaluation of superficial pain
Normaesthesia
Hyperaesthesia
Anaesthesia
Paraesthesia
Deep pain
Only if supf is absent
Squeeze digit/ claw with hemostat
Spinal pain
Not all spinal diseases can cause it
Not always neural clinical signs, but always pain at lesion which can cause behavioural changes
History of spinal pain
Stiff neck, not leaning down to bowl to eat
Not jumping on sofa or climbing stairs
