Neurology (SA) Flashcards
What occurs if the basal ganglia are damged?
Movement Disorders
Which structures make up the ectomeninx?
Dura mater
Which structures make up the endomeninx?
Arachnoid mater
Pia mater
Which structures make up the endomeninx?
Arachnoid mater
Pia mater
What is the Dura Mater fused to?
Periosteum of the skull
What are the two folds of the dura mater?
Falx cerebri
Tentorium Cerebelli
What is the space between the arachnoid and the dura mater known as?
The subdural space
What is the space between the arachnoid and pia mater known as?
the subarachnoid space
The space between which two meninges is filled with circulating CSF and trabeculae?
Arachnoid and Pia Mater (subarachnoid space)
How does the pia mater differ from the other two meninges?
Highly Vascularised - merges with tunica adventitia of BVs in brain tissue
What are the main functions of the CSF in relation to the CNS?
Provides Nutrition, physical support and a volume buffer to the CNS.
How does the CNS affect neurons?
Transports neurotransmitters and maintains a stable environment for neurons
What does the CSF contain (in low levels)?
amino-acids
K+
glucose
What does the CSF not contain?
cells & protein
Where is the CSF produced?
choroid plexi
What type of substances can pass into the CSF?
lipid soluble
List the 4 arteries that supply blood to the brain
Internal Carotid
Basilar
Maxillary
Vertebral
Which are the two main blood supply arteries in the dog?
Internal Carotid/Basilar
Which are the two main blood supply arteries in the cat?
Maxillary via rete mirabile
Label the following diagram detailing venous drainage of the brain.
C1-C5
Which spinal cord segments supply the thoracic limb?
C6-T2
Which spinal cord segments supply the thorax and abdomen?
T3-L3
Which spinal cord segments supply the pelvic limb/perineum?
L4-S3
Which spinal cord segments supply the tail?
Cd1-Cd5
Which spinal cord segments supply the tail?
Cd1-Cd5
Where is a good region for sampling CSF?
lumbar cistern
What effect does an UMN usually have on a LMN?
inhibitory
where do UMNs supplying flexor muscles travel?
lateral funiculi
where do UMNs supplying extensor muscles travel?
ventral funiculi
which neurotransmitter is present at the NMJ?
Acetylcholine
What does a muscle need to contract?
An intact LMN
what do reflexes NOT require?
UMN input
what happens if there is a loss of UMN input in a reflex arc?
reflex will be exaggerated - less co-ordination, strength same
What happens to a muscle if a LMN is injured?
Loss of RAT (reflex, atrophy and tone)
Where does the pyramidal tract run?
caudally in the central medulla in triangular shape
What does the pyramidal tract control?
fine, voluntary movement
What does the extrapyramidal tract control?
posture, subconscious rhythmic movements
What can the cerebellum NOT do with regard to movement?
initiate movement
What is sensory adaptation?
constant stimulus > receptor potential decreases > impulses decrease freq > perception fades
What are 4 modalities of somatic sensation?
Tactile, Thermal, Pain, Proprioception
Give 2 examples of fast adapting touch receptor.
Meissners corpuscle (fine touch) & tactile hairs (crude touch)
Give 2 examples of slow adapting touch receptor
Merkels discs (fine) and Ruffinis end-organ (stretch)
Name a pressure receptor
Pacinian corpuscle
Describe the structure of a lamellated corpuscle.
multi-layered connective tissue capsule enclosing dendrite
What is an itch caused by?
stimulation of free-nerve endings by body chemicals
Where are cold receptors located?
epidermis
Where are warm receptors located?
dermis
Which type of fibres conduct chronic pain?
unmyelinated
What is nociceptive pain a response to?
harmful stimuli - extreme temperatures, strong mechanical/chemical stimuli
What is activated in nociceptive pain?
nociceptors on free nerve endings
What is activated in neurogenic pain?
impulses in other parts of the nervous pathway (not free nerve endings)
What is pain sensitisation?
With increased exposure to noxious stimuli, nerves become hypersensitive to weak stimuli.
What are the 3 ways in which analgesia may work to reduce pain?
Inhibit nociceptors
Block pain impulse conduction
Block signal transmission in CNS pain pathways
Name the two somatosensory pathways.
Dorsal Column
Spinothalamic Tract
What does the dorsal column detect?
Skin: pressure/touch
Joints
Muscles
What does the spinothalamic column detect?
Pain
Temperature
Describe the gate theory of pain.
gate neurons are stimulates by other branches of sensory nerves in skin and inhibit neurotransmitter release in the dorsal synapse of pain pathway.
What is proprioception?
sense of the relative position of body parts to ensure appropriate posture
What are signs of conscious proprioceptive deficits?
Stumbling, knuckling, intention tremors
What does subconscious proprioception control?
Sitting/standing, scratching, breathing, chewing, locomotion
What is the main sign of a deficit in subconscious proprioception?
Ataxia - differentiate from weakness!!
Name the Cranial Nerves
I Olfactory II Optic III Oculomotor IV Trochlear V Trigeminal VI Abducens VII Facial VIII Vestibulocochlear IX Glossopharyngeal X Vagus XI Accessory XII Hypoglossal
Which area of the brain coordinates homeostasis, motivation and emotion?
The limbic system
Which part of the limbic system determines memory?
The hippocampus
lesions in which brain region cause behavioural and emotional changes?
The frontal lobe
How does rabies affect the brain?
Produces inclusion bodies (negri bodies) in the hippocampus and cerebellar purkinje fibres.
Spontaneouss discharge of which area causes epileptic seizures?
The Hippocampus
Which part of the brainstem is responsible for vegetative function?
Ascending Reticular Activating System
What are the 4 main signs of hypothalamic lesion?
- Abnormal water consumption
- Abnormal appetite
- Abnormal temperature regulation
- heme-neglect
Label the following neuroepithelial cell.
1.
2.
3.
4.
Which part of a vestibular cell senses changes in head position?
Microvilli.
Where in the inner ear do sensory hairs in the endolymph form cupulae?
Semi-circular canals
In which sense organ do sensory hairs, endolymph and calcium carbonate crystals work in unison?
Otolith organ
Which cranial nerve works alongside otolith organs to provide information about head position?
VIII (vestibulocochlear)
How do the otolith organs provide a 3D image of head movement?
located in 3 semicircular canals which are in 3 planes at right angles to each other.
Which sense organ is responsible for static balance?
Otolith Organ (linear)
Which sense organ is responsible for dynamic balance?
Ampullae (circular)
What are the 3 main reflexes which govern posture?
- Vestibular Reflexes
- Tonic Neck Reflexes
- Righting Reflexes
which reflexes co-ordinate flexion and extension of limb muscles to shift the centre of gravity?
Vestibular Relfexes
What is the difference between vestibular and tonic neck reflexes?
V: head position alters without change in head-neck angle
TN: head-neck angle changes but head position the same relative to the vertical axis.
Which receptors are involved in the righting reflex?
Vestibular Organs Muscle Spindles (neck) Pressure Sensors (skin)
What is the vestibule-ocular reflex?
stabilises retinal image during rapid acceleration of the head
What are the signs of vestibular syndrome?
Head tilt, Circling and Nystagmus
What are the two major categories of receptor in the PNS?
Adrenergic
Cholinergic
Where are all of the sympathetic ganglia?
The spinal cord (sympathetic chain)
What are the two subtypes of cholinergic receptor?
Nicotinic (2 further divisions)
Muscarinic (3 further divisions)
What are the two major subtypes of adrenergic receptor?
Alpha and Beta
What is the aim of anticonvulsant drugs?
to stabilise membranes in the CNS
How do anticonvulsants stabilise the CNS?
increase GABA (inhibitory neurotransmitter) or decrease Na influx
Which stimulant is used to stimulate chemoreceptors in the aorta/carotid body of neonates?
Doxapram (for sluggish neonates)
How do phenothiazine derivatives work?
block dopamine receptors and inhibit serotonin
How do Benzodiazepines work?
enhance GABA action
How do alpha 2 agonists work?
bind to presynaptic adrenergic receptors - reduce noradrenaline release
How do opioids work?
activate receptors associated with pain modulation
What are the 3 major types of opioid receptor?
Kappa, Mew and Delta
What are the 4 major effects of opioids?
Analgesia, Sedationm, euphoria and antitussives
How is neuroleptanalgesia produced?
Opioid + Sedative
How do local anaesthetics work?
Elevate threshold potential and reduce Na permeability –> decreases APs in nerves
Which local anaesthetic can be used to treat ventricular tachycardia?
Lidocaine
How do injectable anaesthetics work?
Enhance GABA activity
Reduce Glutamine activity
some unknown MOAs
What areas of the brain do anxiolytics (such as benzodiazepines) work on?
Cerebral cortex, limbic system, thalamus
How do antidepressants work?
increase monoamine activity
Influx of what triggers neurotransmitter exocytosis?
Calcium Ions
How is Ach inactivated?
Broken Down by AChE before reuptake at pre-synaptic neuron
How is Noradrenaline inactivated?
uptake at the pre-synaptic neurone
Which substance inhibits monoamine re-uptake?
fluoxetine
Which neurotransmitters are monoamines?
Noradrenaline, Dopamine, Serotonin
Which substance inhibits ACh breakdown?
neostigmine
What is the primary excitatory neurotransmitter in the brain?
Glutamate
What is the primary inhibitory neurotransmitter in the brain?
GABA
What is synaptic summation?
Multiple sub threshold inputs acting simultaneously to create an AP.
What is negative summation?
multiple inhibitory neurons firing to prevent an AP.
What does the vestibulaocerebellum affect?
Balance and eye movement
What does the spinocerebellum affect?
motor execution
what does the cerebrocerebellum affect?
motor planning
What are 3 major signs of cerebellar dysfunction?
Ataxia
Dysmetria
Intention Tremors
what are the 3 anatomical lobes of the cerebellum?
Anterior, Posterior and Flocconodular
What causes cognitive dysfunction syndrome in dogs?
Beta-amyloid plaque deposition
Neurofibrillary Tangles
Which are the fastest opening nerve fibres?
Alpha adrenergic
Which are the slowest nerve fibres for pain?
C-fibres (unmyelinated)
What are the two ventrolateral ascending pain pathways?
Spinothalamic
Spinoreticular
What is the role of the hypothalamus?
Homestasis
The hypothalamus releases neurohormones which act on what?
The pituitary gland
The portal venous system in the pituitary stalk links which 2 areas together?
Anterior pituitary and Hypothalamus
What causes narcolepsy?
Abnormal orexin receptor or protein
What is the FIRST component of a neurological exam?
Observation
What blood tests should be run on a potential neurological case?
Haem/Biochem
Endocrine
Serology - ID/AutoIm
Toxicology
What is Myasthenia Gravis?
Autoimmune condition - blockade of Ach receptor at NMJ
How can we test for Myasthenia Gravis?
Administer Edrophonium Chloride - temporary increase in Ach at synapses to overcome blockade
What is Horner’s Syndrome?
Loss of sympathetic stimulation to the eye
How do we test for Horner’s?
Phenylephrine in eye - causes pupil dilation if Horner’s +
Name the 6 signals which modulate the satiety/appetite centres.
Glucose CCK GI filling Smell Vision Body Fat Reserves
Which substance, produced by fat, inhibits appetite in the hypothalamus?
Leptin
Which substance stimulates feeding by acting on the brainstem?
Ghrelin
What effect do sedatives have which tranquillisers do not?
Cause Drowsiness (tranquillised patients and calm but alert)
Give two examples of a sedative
Xylazine
Medetomodine
Give two examples of a tranquilliser
Diazepam (minor)
ACP (major
What are the two major effects of Benzodiazepines?
Sedation
Muscle Relaxation
How do Benzodiazepines work?
GABA agonism
Which drug is a benzodiazepine antagonist?
Flumazenil - used to reverse resp depression
What effects do alpha2 agonists have?
Calming Drowsiness Visceral Analgesia Muscle Relaxation Reduction in subsequent anaesthetic doses.
What is the primary side effect of an alpha 2 agonist?
CVS depression
Which alpha 2 antagonist can be used to reverse an agonist?
Atipamezole
Which receptors do phenothiazines antagonise?
Histamine H1
Adrenergic A1
Muscarinic
Give 2 uses for ACP
Strong Sedative
Anaesthetic Pre-med
What must you be careful of with ACP?
enhances effects of other narcotics - REDUCE DOSES!
What class of drugs does Azaperone belong to?
Butyrophenones
What are the effects of azaperone?
Neuroleptic
Sedative
Potent anti-emetic
What is “Ictus”?
The epileptic seizure
What are the signs of a full brain (generalised) seizure?
Bilateral convulsions
Loss of consciousness
May be”absent”
What are the signs of a focal secure?
Automatisms
Possible progression
What is epilepsy caused by?
Mass firing of APs in the brain
How can we depress the synaptic activity responsible for epilepsy?
Inc GABA release Inc GABA efficacy Dec GABA uptake Use GABA analogues Dec GLUT release Dec GLUT efficacy
How does Phenobarbitone decrease epileptic seizures?
increases GABA efficacy at receptor
How does levatiracetam work?
Blocks Ca channels to prevent Ca influx & glutamate release
How does gabapentin work?
Blocks Ca channels to prevent Ca influx & glutamate release
How does KBr work?
Blocks Na channels to prevent Na influx & glutamate release
Who must not receive KBr?
CATS
Which is the longest acting anti-epileptic drug?
Phenobarbital (36h)
Which is the shortest acting anti-epileptic drug?
Gabapentin (3h)
What are the 3 main rules for anti-epileptic drugs?
DON’T:
Change drugs suddenly
Withdraw meds suddenly
Give phenothiazines
How does lidocaine work?
Blocks Voltage-gated Na channels in the post-synaptic membrane
What are the 4 main local anaesthetics used in veterinary medicine?
Procaine
Lidocaine
Mepivicaine
Bupivicaine
Which local anaesthetics cause vasodilation?
Procaine
Lidocaine
Which local anaesthetics cause vasoconstriction?
Bupivicaine
Which local anaesthetic has high toxicity?
Bupivicaine
Place the 4 major veterinary local anaesthetics in order of DOA. (Short –> long)
Procaine (30min)
Lidocaine (30-45min)
Mepivicaine (90-120min)
Bupivicaine (4-6h)
Which local anaesthetics have a fast onset?
Lidocaine
Mepivicaine
What are the 4 major systemic effects of opioid drugs
Neuroleptanalgesia
Restraint
Anti-diarrhoea
Anti-Jussive
Which is the gold standard opioid pre-med?
Morphine
What effect does morphine have on the cortex?
Sedation
What effect does morhpine have on the medulla?
Stimulation then depression
OR
Depression
Where is morphine metabolised?
Liver
Which short-acting opiate may cause histamine release if given IV?
Pethidine
Which opioid is highly fast and potent?
Fentanyl
Which opiate is long-acting but causes less euphoria than morphine?
Methadone
Which opioid has a slow onset and offset?
Buprenorphine
What are the 4 major side-effects of opioid drugs?
Resp Depression
Vagal stimulation
Constipation
Nausea
What are the 3 major opioid receptors?
Delta
Mew
Kappa
Which opiates are ONLY full mew agonists?
Morphine
Pethidine
Methadone
Fentanyl
Which opiates are full mew AND kappa agonists?
Etorphine
Which drugs are kappa agonists and mew antagonists?
Buprenorphine
Butorphanol
Which drug is a full opioid receptor antagonist?
Naloxone
How do opiates effect the post-synaptic membrane?
Activation of inwardly rectifying K+ channels
How do opiates effect the pre-synaptic membrane?
Inhibition of Ca channels
Which two modes of pain do opiates block?
Psychological
AND
Nociception
How can we produce effective neuroleptanalgesia with two drug classes?
Opioid + Neuroleptic
i.e. ACP + butorphanol
Which opioid is rapidly fatal to humans?
Etorphine
Which analeptic can be used to reduce resp depression of other opioids?
Doxapram
How does amitriptyline work?
Monoamine oxidase inhibitor
What is the MOA of amantidine?
NMDA blocker
What can be used to control neuropathic pain?
GABApentin
What are the two main components of the forebrain?
Cerebral cortex
Diencephalon
What are the three main components of the brainstem?
Midbrain
Pons
Medulla Oblongata
Define the 4 functional divisions of the spine.
C1-C5
C6-T2
T3-L3
L4-S3
Where is grey matter located?
Brain - surface
Spinal Cord - Centre
What does Grey Matter contain?
Cell Bodies
What is the function of Grey Matter?
Processing Information
Where is the white matter located?
Brain - deep parts
Spinal Cord - superficial
What does white matter contain?
Myelinated axon tracts
What is the function of White Matter?
Connects neurons
What neuron is in the ventral horn?
Motor Neuron Cell Body
What neuron is in the dorsal horn?
Sensory Neuron Cell Body
Where is the sympathetic ANS located?
Craniosacral
Where is the parasympathetic ANS located?
Thoracolumbar
How does a UMN lesion affect the bladder?
Distended
Hard to Express
How does an LMN lesion affect the bladder?
Distended
Continually overflowing and dribbling
Testing the Flexor reflex in the thoracic limb allows you to assess which PN?
All TL PNs
Testing the Flexor reflex in the thoracic limb allows you to assess which SC segment?
C6 - T2
Testing the Biceps reflex in the thoracic limb allows you to assess which PN?
Musculocutaneous
Testing the Biceps reflex in the thoracic limb allows you to assess which SC segment?
C6-C8
Testing the Triceps reflex in the thoracic limb allows you to assess which PN?
Radial
Testing the Triceps reflex in the thoracic limb allows you to assess which SC segment?
C7 - T2
Testing the Ext Carpi Rad reflex in the thoracic limb allows you to assess which PN?
Radial
Testing the Ext Carpi Rad reflex in the thoracic limb allows you to assess which SC segment?
C7 - T2
Testing the Flexor reflex in the Pelvic limb allows you to assess which PN?
Sciatic
Testing the Flexor reflex in the Pelvic limb allows you to assess which SC segment?
L6 - S1
Testing the Patellar reflex in the Pelvic limb allows you to assess which PN?
Femoral
Testing the Patellar reflex in the Pelvic limb allows you to assess which SC segment?
L4 - L6
Testing the Gastroc reflex in the Pelvic limb allows you to assess which PN?
Tibial
Testing the Gastroc reflex in the Pelvic limb allows you to assess which SC segment?
L7 - S1
Where do pyramidal UMNs start?
Cerebral Cortex
Where do extrapyramidal UMNs start?
Brainstem
What do pyramidal UMNs control?
Skilled movement
What do Extrapyramidal UMNs control?
Tonic support against gravity.
Initiate voluntary movement.
Where is conscious proprioception information transmitted to?
Cerebral cortex (contralateral)
Where is unconscious proprioception information transmitted to?
Cerebellum (ipsilateral)
What is proprioception?
Sensory detection of position and movement of muscles and joints
How many vestibular nuclei exist in the brain?
4 in either side of the pons and medulla
Where do the vestibular nuclei project to? (3 places)
Spinal Cord (facilitate ipsilateral extensor, inhibit contralateral extensor)
Brainstem (co-ordinate head/eye movement, vomit centre and balance)
Cerebellum (inhibitory)
What are the 4 main functions of the cerebellum?
Control motor activity
Co-ordinate UMN movement
Maintain balance
Regulate muscle tone (& therefore posture)
How do we assess conscious perception of vision?
Menace
How do we assess reflex visual perception?
PLR
What component of the CNS are we assessing with the menace response?
Forebrain
What component of the CNS are we assessing with the PLR?
CN II/CN III
What are the 4 things that we should observe from a distance on neurological exam?
Mentation
Posture
Gait
Behaviour
What are 5 key things to ask during a neuro history?
Trauma Hx? Acute/Chronic? Pain? Progression? Episodic?
What is the difference between stuporous and comatose?
Stuporous - can be roused by painful stimuli
comatose - unresponsive
BOTH = unconscious
An animal is showing hemineglect syndrome - where is its brain lesion located?
Forebrain
An animal is showing reduced palpebral reflex - where is its brain lesion located?
Trigeminal (v) or Facial Nerve (VII)
An animal is showing postural deficits - where is its brain lesion located?
ANYWHERE
An animal is showing dysmetria - where is its brain lesion located?
Cerebellum
An animal is showing subtle proprioceptive deficits - where is its brain lesion located?
Spine
An animal is showing compulsive walking/circling - where is its brain lesion located?
Forebrain
An animal is showing loss of head orientation - where is its brain lesion located?
Vestibular Sytem
An animal has become aggressive - where is its brain lesion located?
Forebrain
What is Schiff-Sherrington?
Hyperextension of TL
Paralysis of PL
What causes Schiff-Sherrington?
Lesion in thoracic or lumbar spine
Decerebrate rigidity is caused by a lesion where?
Rostral Brainstem
Decerebellate rigidity is caused by a lesion where?
Rostral Cerebellum
What does Decerebrate rigidity present as?
Extension of all limbs and opisthotonus
Stupor/comatose
How does Decerebrate rigidity present?
Extension of all limbs and opisthotonus
Stupor/comatose
How does Decerebellate rigidity present?
Hyperextended TLs
Normal mentation
What does “Paresis” mean?
Weakness - reduced voluntary movement
What does “Paralysis” mean?
Complete absence of voluntary movement
Name 6 different postural tests for the dog.
Paw Position Hopping Hip Sway Wheelbarrow Extensor Postural Thrust Placing Responses
What are the thoracic spinal withdrawal reflex tests?
Digit pinch
Extensor Carpi Radialis, Biceps, Triceps
What are the pelvic spinal withdrawal reflex tests?
Digit Pinch
Patellar, Cranial tibial, Gastrocnemius, Perineal
Where does information from the cutaneous trunci reflex enter the spinal cord?
2 Vertebral Spaces cranially to test.
Name 3 behavioural responses to pain
Turning Head
Trying to bite
Vocalising
Apart from palpation, how can we assess for spinal pain?
Move neck in all directions.
Move tail
Palpate lumbosacral region.
Eye position at rest may tell us about the function of which cranial nerve(s)?
III (oculomotor), IV (trochlear) and VI (abducens)
Which cranial nerves does the PLR test for?
II (optic) and III (oculomotor)
Deficits in which CNs may cause a physiological nystagmus?
III (oculomotor), IV (trochlear) and VI (abducens)
the BAER tests which CN?
VIII (vestibulocochlear)
An inability to see objects, and reduced menace response indicates a problem with which CN?
II (optic)
At what age does the menace response become a valid test?
12 weeks old
Looking at the symmetry of mucous membranes can tell us about which cranial nerve?
V (Trigeminal)
The Corneal Reflex tells us about the function of which CN(s)?
V (trigeminal), VI (abducens and VII (facial)
A lack of gag reflex tells us about which CN(s)
IX (glossopharyngeal) and X (Vagus)
Nasal Mucosa Stim test assesses which CN?
V - ophthalmic branch
reduced physiological nystagmus indicates what?
Raised ICP
What are the 4 clinical signs of Horners?
Mitosis
Ptosis of upper eyelid
Protruded 3rd Eyelid
Enopthalmus
What causes Horners?
Compression of the sympathetic chain
Disorientation/Depression is a sign of a lesion in which part of the brain?
Forebrain
Depression/stupor/coma is a sign of a lesion in which part of the brain?
Brainstem
Vestibular Signs are a sign of a lesion in which part of the brain?
Brainstem or Cerebellum
Intention Tremors are a sign of a lesion in which part of the brain?
Cerebellum
Decerebellate rigidity is a sign of a lesion in which part of the brain?
Cerebellum
Contralateral blindness is a sign of a lesion in which part of the brain?
Forebrain
Ipsilateral abnormal menace with normal vision is a sign of a lesion in which part of the brain?
Cerebellum
Deficits in CN III-XII are a sign of a lesion in which part of the brain?
Brainstem
Ipsilateral/total paresis is a sign of a lesion in which part of the brain?
Brainstem
Ataxia with broad base and hypermetria is a sign of a lesion in which part of the brain?
Cerebellum
Circling is a sign of a lesion in which part of the brain?
Forebrain
Delayed movements with hypermetria is a sign of a lesion in which part of the brain?
Cerebellum
Respiratory/Cardiac abnormalities can be caused by a lesion in which part of the brain?
Brainstem
Decreased postural responses in all limbs is a sign of a lesion in which part of the brain?
Brainstem
Decreased postural responses in ipsilateral limbs is a sign of a lesion in which part of the brain?
Brainstem
Decreased postural responses in contralateral limbs is a sign of a lesion in which part of the brain?
Forebrain
Seizures are a sign of a lesion in which part of the brain?
Forebrain
Hemi-Neglect syndrome are a sign of a lesion in which part of the brain?
Forebrain
A ipsilateral head tilt is caused by a lesion in which part of the brain?
Vestibular System
A Paradoxical head tilt is caused by a lesion in which part of the brain?
Cerebellum
Vertical nystagmus is caused by a lesion where?
Central Nervous System
Horizontal nystagmus is caused by a lesion where?
PNS - fast phase away from lesion!
Where is the Cervical intumescence?
C6-T2
Where is the Lumbosacral intumescence?
L4-S3
What are the 3 signs of a lesion in C1-C5?
Tetra/hemi - paresis/plegia
Normal Spinal Reflexes
Normal Muscle Tone
What are the 3 signs of a lesion in C6-T2?
Tetra/hemi - paresis/plegia (POSSIBLE monoparesis)
Reduce TL reflexes +/- cutaneous trunci
Reduced muscle tone
What are the 3 signs of a lesion in T3-L3?
Paraparesis/Plegia
Normal Spinal Reflexes w/reduced cutaneous trunci
Normal muscle tone
What are the 3 signs of a lesion in L4-S3?
Paraparesis/Plegia (POSSIBLE mono paresis)
Dec reflexes in pelvic limbs
Reduced muscle tone/atrophy
What additional sign is present in a caudal lesion between L4 and S3?
Reduced anal tone/perineal reflex
What are 4 factors that may lead to a misleading reduction in spinal reflexes?
Pain
Subtle Lesion
Acute Spinal Shock
Old age
What Cx would you see in a Grade 1 Severity spinal injury?
Spinal Pain only
What Cx would you see in a Grade 2 Severity spinal injury?
Ambulatory Paresis
What Cx would you see in a Grade 3 Severity spinal injury?
Non-ambulatory Paresis
What Cx would you see in a Grade 4 Severity spinal injury?
Paralysis
What Cx would you see in a Grade 5 Severity spinal injury?
Paralysis + loss of pain sensation
How many pairs of Spinal Nerves are there in the dog?
36
How would a motor neuropathy present?
Flaccid Paresis
Reduced Tone
Muscle Atrophy
How would a sensory neuropathy present?
Decreases Sensation
Paraesthesia
How do all neuropathies present?
Reduced spinal reflexes
OR
Reduced CN reflexes
A reduced in reflexes in all 4 limbs would be indicative of what lesion?
Polyneuropathy
Give an example of a pre-synaptic junctionopathy.
Botulism
Give an example of a post-synaptic junctionopathy.
Myasthenia Gravis
How do myopathies present?
Generalised weakness/exercise intolerance WITHOUT proprioceptive deficits
Acute, Non-progressive Central Vestibular signs are likely caused by what type of disease?
Cerebrovascular
How do cerebrovascular lesions appear on MRI?
Well-defined
Sharply Demarcated
Minimal/No mass effect
What are 3 conditions associated with cerebrovascular disease.
CKD
Hypertension
Hyperadrenocorticism
An acute, progressive CNS disease with multifocal signs is often caused by what?
Meningioencephalomyelitis of unknown origin
Which type of MUO is commonly found in young (3-8y) toy breeds?
Granulomatous
What are the 3 forms of granulomatous meningioencephalomyelitis?
Disseminated (most common)
Focal
Ocular
What may focal granulomatous meningioencephalomyelitis be confused with?
Neoplasia
What are the common presenting signs of disseminated granulomatous meningioencephalomyelitis?
Multifocal - all brain regions affected
What are the common presenting signs of Ocular granulomatous meningioencephalomyelitis?
Acute onset visual impairment.
Dilated, non-responsive pupils
optic disc oedema
How does GME present on MRI?
Multiple Hyperintensities
Irregular Margins
WM > GM
What does CSF analysis of a patient with GME show?
Pleocytosis
Increased Protein
(occasionally normal)
Which breeds are commonly affected by Necrotising meningoencephalitis?
Pug
Chihuahua
Yorkie
What type of MUO often presents with seizures, blindness, altered behaviour, circling and depression?
Necrotising Meningoencephalitis
How do the signs of Necrotising meningoencephalitis occur?
Acute
Rapidly Progressive
What is the primary aim of treatment for MUOs?
IMMUNOSUPPRESSION
What is the primary drug used to treat an MUO?
Corticosteroids
What can be used as a secondary therapy for MUOs?
Cytosine arabinoside
also azathioprine, ciclosprine, lomustine, procarbazine
What is the MST for GME?
14 days
How long will a NE dog live for untreated?
3m
How long will a NE dog live for if receiving double immunosuppression?
180d
What would you expect in a CSF sample from an FIP patient?
High Protein
Pleocytosis
FCoV RNA (PCR)
How would the brain of an FIP cat appear on MRI?
Enhanced periventricular contrast
Ventricular Dilation
Hydrocephalus
How would you relieve neurological signs in a hypothyroid patient?
Levothyroxine
What neurological signs may be present in a hypothyroid patient?
Peripheral or Central Vestibular Disease
Which antibiotic has been linked with neurotoxicity leading to CVS, seizures, tremors and rigidity?
Metronidazole
How can you improve the record time for a patient with antibiotic-induced neurotoxicity?
Stop Antibiotic
Give Diazepam!
What is the role of thiamine in the brain?
Oxidation of glucose in Krebs cycle
Which patients may commonly present with thiamine deficiency?
Cats on an all-fish diet
What are the clinical signs of thiamine deficiency?
Anorexia Lethargy Vestibular Signs Seizures Mydriasis w/reduced PLR
What is the most common primary brain tumour in the small animal?
Caudal Fossa Meningioma
Which neurological structures pass the middle ear, and therefore can be affected by otitis?
CN VII (Facial) CN VIII (Vestibulocochlear) Sympathetic Supply to the eye
What are the Primary Factors for Otitis Media/Interna?
Hypersensitivity
Keratinisation Defects
What are the Predisposing Factors for Otitis Media/Interna?
Conformation (hairy, narrow, pendulous)
Iatrogenic (over cleaning)
Swimming
What are the Perpetuating Factors for Otitis Media/Interna?
Infections (Malassezia, Staphs, Pseudomonas, Proteus)
How can you identify idiopathic vestibular disease from other peripheral vestibular diseases?
No central signs (proprioceptive deficits)
No vertical nystagmus
Multiple CNs affected
How is idiopathic vestibular disease treated?
NO Tx - Spontaneous Recovery (3-4w)
How does Idiopathic Vestibular Disease present in the dog?
Acute peripheral signs - roll, fall, vomit, ataxia
Head tilt
Horizontal/Rotatory Nystagmus
How does Idiopathic Vestibular Disease present in the dog?
2 Forms:
Atypical: acute but Cx progressive
PVD: acute & non-progressive
What are the 3 causes of Facial Nerve Paralysis?
Idiopathic
Brainstem Lesions
Middle Ear Disease
What are the major signs of facial nerve paresis/paralysis?
Drooping of face, widened palpebral fissure,
absence/reduced corneal/palpebral reflex
How do we treat Facial Nerve Paralysis?
Lubricate the eye & wait for recovery
What are the 4 classifications for hearing issues?
Age of Onset
Underlying Cause
Location
Sensorineural or Conductive
What are the 3 most common types of deafness in the dog?
Congenital sensorineural deafness
Acquired sensorineural deafness
Acquired Conductive Deafness
Which type of deafness is most common in white pigmented, blue eyed dogs/cats?
Congenital sensorineural deafness
Name 5 causes of Acquired Deafness
Chronic Otitis (Int/Med) Ototoxicity Noise Trauma Old Ace Anaesthesia
What does BAER stand for?
Brainstem Auditory Evoked Response
What does OAE stand for?
OtoAcoustic Emissions
What does the BAER test?
Electrical responses of CNVIII and auditory portion of brainstem
What does OAE test?
Measures low-level sounds produced by ear as part of normal hearing
Which test is the most reliable for deafness?
BAER
Which is the cheapest, first-line test for deafness?
OAE
What is ICP related to?
The volume of:
The brain
Blood supplying the brain
The CSF
What is the formula for Cerebral Perfusion Pressure?
CPP = maBP - ICP
To where does the forebrain herniate?
Under the tentorium
To where does the cerebellum herniate?
Through the Foramen Magnum
Name 5 signs of increased ICP
Depression/Stupor Cushings Reflex Altered PLR Vestibular Eye Movement Abnormal posture
What is the Cushings Reflex?
Increased ICP –> Bradycardia and Hypertension
How does increased ICP cause hypertension?
alpha 1 adrenergic activation –> systemic vasoconstriction
How does increased ICP cause bradycardia?
Carotid artery baroreceptors sense hypertension –> vagal activation
What is the common presentation of Idiopathic Tremor Syndrome?
Small Breed Dog
Fine, rapid tremor (worsens with stress)
Head tilt & reduced menace
Ataxia
How is Idiopathic Tremor Syndrome diagnosed?
CSF - inflammatory
+/- MRI to rule out other problems
How is Idiopathic Tremor Syndrome treated?
CS for 4-6m
Diazepam initially
+/- other immunosuppressive drugs
What are the 3 main routes of infection for Bacterial Meningoencephalitis?
Haematogenous
CSF
Direct (eyes, ear, nasal sinus, trauma)
What are the Cx for Bacterial Meningoencephalitis?
Acute CNS (obtunded & deficits)
Neck Pain
Pyrexia
How do we treat Bacterial Meningoencephalitis?
Antibiotics +/- surgical drainage
What is the prognosis for Bacterial Meningoencephalitis?
Guarded!
Name 2 protozoa which may infect the brain.
Toxoplasma Gondii
Neospora Caninum
Name 3 viruses which may infect the brain
FIP (FeCoV)
FIV (retrovirus)
Canine Distemper
Name 1 bacteria that may infect the brain
Cryptococcus
What signs would an intoxicated dog show?
ACUTE seizures
+ GI/CV/Resp signs
+Muscle tremor/fasciculation
Name 5 common substances which may cause neurotoxicity in dogs.
OPs Pyrethroids Lead Avermectins Antidepressants
What would classify a primary head injury?
Physical disruption of parenchyma
What would classify a secondary head injury?
Inflammation/haemorrhage causing increased ICP
Which grade of head injury would we intervene with medically?
Secondary
What can we use for monitoring prognosis in a head trauma patient?
Modified Glasgow Coma Scale
What may indicate the need for surgery in a head trauma patient?
Fractures with compression or contamination
Haematomas
Severely Raised ICP
What is the aim of IVFT in a head trauma case?
Restore intravascular volume to ensure adequate CPP
What should be avoided in fluids for the head trauma patient?
Glucose - causes poor outcome
What are the 3 effects of giving 7.5% saline to a head trauma patient?
Reverse Shock
Decrease ICP
Increase CBF/blood delivery
How does mannitol decrease ICP?
Dec Blood Viscosity
> Inc CBF
> Inc Free Radical Scavenging
What are the two principles for mannitol administration?
0.5-1g/kg slow bolus over 20min
Follow with crystalloids (prevent dehydration)
When is mannitol contraindicated?
Hypovolaemia
When is Hypertonic Saline contraindicated?
Hyponatraemia
Cardiac/Resp Disease
Outside what BP range is cerebral blood flow affected?
90-140mmhg
How does pain affect ICP?
pain = inc BP = inc ICP
How does hypothermia affect the head trauma patient?
shivering increases O2 demands
How does hyperthermia affect the head trauma patient?
affects metabolic rate
How should a head trauma patient be positioned in their kennel?
Raise Head!
Avoid jugular compression
Turn q4-6h
What supportive treatment should be given to a head trauma patient?
Urinary Catheter Nutritional support (NG/oesoph tube)
Which drugs should NEVER be used in head trauma cases?
Steroids
How do hydrocephalus cases present?
Domed Head Persistent Fontanelle Abnormal Behaviour ?Seizures Vestibular Signs
How do corpus callous abnormalities present?
Adipsia + HyperNa Seizures Abnormal behaviour Tremor Circling
How do hydraencephaly cases present?
circling
abnormal behaviour
seizures (later)
What are the four pathogenic components of hepatic encephalopathy?
Hyperammonaemia
Neuroinflammation
Dec Neurotransmission
Cerebral Oedema
What is the most common underlying cause of hepatic encephalopathy?
PSS
What are the 2 major & 2 minor categories of presenting sign in hepatic encephalopathy?
Major: Vague/Forebrain
Minor: brainstem/cerebellar
What vague signs may be present for hepatic encephalopathy?
Failure to thrive
Weight loss
PUPD
GI signs
What forebrain signs may be present for hepatic encephalopathy?
Behaviour change
Pacing
Blindness
Seizure
How is hepatic encephalopathy diagnosed?
BAST
Fasting Ammonia
US
CT angiography
What 5 treatments should be used in combination for hepatic encephalopathy?
Lactulose Antibiotics Low protein diet Seizure control Minimise contributing factors
What are the possible underlying causes for hypoglycaemia?
Insulinoma Insulin Overdose Liver Disease Glycogen Storage Disease Juvenile Hypoglycaemia
What are the clinical signs of hypoglycaemia?
Lethargy/Hunger Depression/anxiety Weakness/temors Reduced Vision Seizures
How is hypoglycaemia diagnosed?
Blood Glucose <3mmol/L
Clinical Signs
What are the clinical signs for sodium derangement?
Altered Mentation
Blindness
Seizures
Coma/Death
What is the role of calcium in the brain?
Presynaptic Neurotransmitter - stabilise nerve/muscle membranes
What are the clinical signs of hypocalcaemia?
muscle spasm/cramp/twitch trembling stiffness tonic-clonic spasm seizures
What is the pathogenesis of hypocalcaemia?
spontaneous discharge due to inc excitability from inc permeability to Na
What are the most common primary brain tumours in the dog?
intra-axial: glioma
Extra-axial: meningioma/choroid plexus tumour
Which tumours commonly metastasise to the brain?
Haemangiosarcoma
What is the most common sign in supratentorial tumours?
Seizure
What is the most common sign in infratentorial tumours?
Vestibular Dysfunction
What is the MST for infratentorial tumours?
28d
What is the MST for supratentorial tumours?
178d
how can you treat CNS neoplasia in the dog?
AEDs (min sedative)
anti-inflm dose of preds
analgesia
Name common inflammatory spinal diseases.
SRMA MUO Discospondylitis Toxoplasma Neospora FIP/FeLV
Name some common degenerative spinal disease of the SA.
IVDD
CSM
LSDS
DM
What dogs are commonly affected by SRMA?
Young (6-18m)
What are the clinical signs of SRMA?
Lethargy/Anorexia
Stiffness & fever
cervical rigidity
neurological deficits
Which disease is often concurrent with SRMA?
IMPA
What does SRMA stand for?
Steroid Responsive Meningitis - Arteritis
How is SRMA diagnosed?
CSF:
acute - neutrophilic pleocytosis
Chronic - mononuclear pleocytosis
What is the best Tx for SRMA?
Corticosteroids 6-9m
+/-azathioprine/cyclosporine
What is the Px for SRMA?
Good - but potential relapse
What is discospondylitis?
IVD/adjacent vertebrae infection
How does discospondylitis present?
Marked Spinal Pain
1/3 have systemic illness
How would you diagnose discospondylitis from imaging?
Rx/MRI/CT
Narrowing of IVD space
Rough endplates
How would you treat Discospondylitis?
8w Antibiotics
analgesia
What does MUO stand for?
Meningiomyelitis of Unknown Origin
How does MUO present?
Subacute
Progressive
Painful
?asymmetrical/multifocal
What are the 2 methods for diagnosis of an MUO?
MRI - variable
CT - pleocytosis
Name 3 common causes for spinal fractures in the canine patient.
RTA
Bite
Falling From Height
How are spinal fractures diagnosed?
Neuro exam (CARE) Rx - Thorax/Abdo w/ orthogonal views
What is an important Ddx for an MUO?
IVDD
What is the 3 compartment rule of spinal fractures?
If fracture affects 2+ compartments –> unstable and therefore surgical
What is contained in the dorsal spinal compartment?
articular processes
laminae
pedicles
spinous processes
What is contained in the middle spinal compartment?
Dorsal longitudinal ligament
Dorsal Vertebral body
Dorsal Annulus Fibrosus
What is contained in the ventral spinal compartment?
Ventral Vertebral Body
Lat/Vental AF
Nucleus pulposus
What is contained in the ventral spinal compartment?
Ventral Vertebral Body
Lat/Vental AF
Nucleus pulposus
Ventral Longitudinal ligament
What should our PRIMARY Tx for spinal fractures be?
Stabilise and Analgesia
What is the prognosis for a spinal fracture without deep pain present?
<5%
Which dogs are commonly affected by AA instability?
young dogs
toy breeds
Describe the onset of AA instability.
Acute OR Chronic
Waxing/waning
What are 2 common causes of AA instability?
Aplasia/hypoplasia of dens
or
Trauma
What are the clinical signs of AA instability?
Neck pain
Ataxia/Tetraparesis
How is an AA instability managed conservatively?
Conservative splint for 6-12w
What is the prognosis for surgical Tx of AA instability?
Guarded: High preoperative morbidity/mortality
What is a chiari-like malformation?
mismatched caudal fossa volume/contents w/ caudal displacement of the cerebellum via foramen magnum
What are the 3 types of chair-like malformation?
Hydromyelia
Syringomyelia
Syringohydromyelia
What are the clinical signs of CLM?
Neck pain
Neck scratching
torticollis
TL weakness
How can we Tx CLM medically?
Gabapentin
NSAID
Furosemide
C/S, paracetamol/opioids
Can we Tx CLM surgically?
Yes - 50% of cases will improve BUT high recurrence
How do ischaemic myelopathies present?
Per-Acute
Non-painful
Lateralised
What is a key exacerbating factor for ischaemic myelopathy?
Exercise
What is the underlying pathogenesis for ischaemic myelopathy?
nucleus pulposus fibrocartilage embolises in SC vasculature
What may cause a traumatic disc extrusion?
RTA, Fall, Exercise
How do TDEs present?
Acute
Non-Painful
Non-progressive
What is the underlying pathogenesis of a TDE?
herniated N. pulpous is non-mineralised > cord contusion w/min compression
How can we treat TDEs?
Supportive care & physiotherapy
When does IVDD present in chondrodystrophic breeds?
1st 2y of life
When does IVDD present in non-chondrodystrophic breeds?
After middle age
What type of metamorphosis is present in IVDD of non-chondrodystrophic breeds
Fibroid
What type of metamorphosis is present in IVDD of chondrodystrophic breeds?
Chondroid
What is a type 1 disc extrusion?
Extrusion - N. pulposus herniates through annular fibres
What is a type 2 disc extrusion?
Protrusion of annular ligament & shifted N. pulp
how does T1 IVDD present?
Acute
Progressive
Painful
how does T2 IVDD present?
Slowly progressive
Chronic
What age of dog is affected by T1 IVDD?
3-6y chondrodystrophic
6-8 otherwise
What age of dog is affected by T2 IVDD?
Older dogs
What is the nucleus invaded by in IVDD of chondrodystrophic breeds?
hyaline cartilage
What is the nucleus invaded by in IVDD of non-chondrodystrophic breeds?
fibrocartilage
Is IVDD type 1 a protrusion or extrusion?
extrusion
Is IVDD type 2 a protrusion or extrusion?
protrusion
What is conservative Tx for IVDD?
Rest 4-6w
Analgesia
When should surgery be used for IVDD?
Grade 3-5 neuro deficits
severe pain
lack of improvement
What signs of wobblers are present in the pelvic limbs?
paresis/ataxia (worse)
What signs of wobblers are present in the thoracic limbs?
Short gait
Atrophy
What is the cause of CSM?
Multifactorial: Type II IVDD Hypertrophy of ligaments or synovial membrane Spinal Canal Stenosis DJD of facets
How can CSM be treated conservatively?
Anti-inflammatories
Rest
How can CSM be treated surgically?
Decompression
OR
Distraction-stabilisation
What is the main presenting sign for lumbosacral degenerative stenosis?
reluctant to exercise, rise, jump, do stairs
How is lumbosacral degenerative stenosis treated?
Anti-inflammatories/gabapentin
OR
Surgery
How do vertebral body abnormalities present?
Chronic & slow progression
non-painful
How are vertebral body abnormalities diagnosed?
Myelography
How are vertebral body abnormalities treated?
Decompression +/- stabilisation
How does spinal neoplasia present?
Chronic
Progressive
Painful
Where are the 3 possible locations for a spinal neoplasia?
Extradural
Intradural Extramedullary
Intramural Intramedullary
How are spinal neoplasms treated?
Decompression
Radiation
Palliate
How does Degenerative Myelopathy present?
Progressive ataxia/paresis of PLs leading to paralysis
NO Tx!
What is a hemilaminectomy?
Removal of half of the vertebral arch
Allows IVD fenestration
Where is a hemilaminectomy used?
TL spine
What is a Dorsal Laminectomy?
Removal of DSPs and laminae
When should a Dorsal Laminectomy be used?
Anywhere - mostly at LS area.
IVDD, malformations and neoplasia common uses
What is a ventral slot surgery?
slot ventrally through IVD and cranial/caudal endplates of cervical vertebrae
What is the limitation to a ventral slot surgery?
Limited View
What analgesia may be used post-spinal surgery?
NSAID Gabapentin Paracetamol Tramadol Opioids
How does a UMN bladder lesion present?
Distended
Difficult to express
How does a LMN bladder lesion present?
Distended
Continually dribbling
Where is the lesion for a UMN bladder lesion commonly found?
Cranial to Sacral SC
Where is the lesion for a LMN bladder lesion commonly found?
Within sacral SC/plexus
or in pelvic/pudendal nerve
Which drugs increase detrusor contraction?
Bethanecol
Cisapride
Which drugs decrease detrusor hyperreflexia?
Propantheline
Oxybutinin
Which drugs increase urethral tone?
phenylpropanolamine
imipramine
diethylstilbestrol
testosterone
Which drugs decrease urethral tone?
phenoxybenzamine
prazosin
diazepam
dantrolene
What is a seizure?
transient symptoms of an abnormal excessive/synchronus neuronal activity in the brain
Where in the brain would a lesion cause seizures?
Forebrain
Explain the pathogenesis of a seizure.
Imbalance in excitation and inhibition.
Excitation inc
|nhibition dec
What is the Prodrome phase of a seizure?
A predicting event
What is the Aura phase of a seizure?
The initial manifestation
What is the Ictal phase of a seizure?
the seizure event: involuntary tone/movement/behaviour
What is the Post-ictal phase of a seizure?
mins to days after: strange behaviour/neuro deficits
How long is the ictal event normally?
60-90s
When do ictal events commonly occur?
at sleep or rest
What are the two major phenotypic categories of seizure?
Generalised
Focal
What are the two major phenotypic categories of seizure?
Generalised
Focal
Which generalised seizure activity is most common?
tonic-clonic
What is the characteristic feature of a generalised seizure?
loss of consciousness
What is a focal seizure?
Activation of one part of one cerebral hemisphere/forebrain region
What are the 3 forms of focal seizure?
Motor
Autonomic
Behavioural
What are the 5 forms of Generalised seizure?
Tonic-clonic Tonic Clonic Myoclonic Atonic
What are the main predisposing factors for audiogenic reflex seizure?
Cat Late onset (15y+)
What are the characteristics of an audiogenic reflex seizure?
Myoclonic progressing to tonic-clonic in some
Which drug is best used to control audiogenic reflex seizures in cats?
Levetiracetam
Which seizure drugs are licensed in cats?
none
What are common Ddx for seizures?
Narcolepsy/cataplexy Neuromuscular collapse Syncope Movement Disorders Metabolic /vestibular disease
What are the 3 categories of seizure cause?
Reactive Seizure
Idiopathic epilepsy
Structural Epilepsy
What two things usually cause reactive seizures?
Metabolic or toxic derrangements
What is often present with a reactive seizure or structural epilepsy?
concurrent neurological signs
What is the cause of idiopathic epilepsy?
Genetic
What neurological signs are associated with idiopathic epilepsy?
NONE
No inter-ictal signs
What are the causes of structural epilepsy?
Inflammatory
Neoplastic
Traumatic
What are the causes of structural epilepsy?
Inflammatory
Neoplastic
Traumatic
How is idiopathic epilepsy diagnosed?
Exclusion
How does idiopathic epilepsy commonly present?
6m-6y
Normal between seizures
What are the tier I confidence intervals for idiopathic epilepsy?
2+ seizueres 24h apart
6m-6y onset
Normal inter-ictal exam
Haem/biochem normal
What are the tier II confidence intervals for idiopathic epilepsy diagnosis?
Unremarkable fasting/bile acids
MRI of brain
CSF analysis
+ tier I
When is KBr NOT licensed?
Cats
Mono therapy in dogs
When is KBr NOT licensed?
Cats
Monotherapy in Dogs
What 2 seizure types are an emergency?
Cluster Seizures
Status Epilepticus
What are the tier III confidence intervals for idiopathic epilepsy diagnosis?
Tier I & II PLUS
Ictal or inter ictal ECG abnormalities
At what age should a dog with idiopathic epilepsy have an MRI?
<6m or >6y
What abnormal seizure patterns may make an MRI an appropriate investigation?
Inter-Ictal abnormalities
Status Epilepticus
Cluster Seizure
What seizure features would warrant Tx initiation?
SE/Cluster seizures
post-ictal signs >24h
Which are the 3 anti-seizure drugs licenced in dogs?
Phenobarbitone
KBr
Imepitoin
Which anti-seizure drugs are licenced in cats?
NONE
What is the MOA of phenobarbitone?
Augments GABA - prolongs Cl channel opening
What is the appropriate dose of phenobarb for seizures in:
a) Cats
b) Dogs?
a) 2mg/kg BID
b) 3 mg/kg BID
When should we monitor phenobarbitone levels?
2w, 3m, and 6m after starting
What level of phenobarbitone in the blood is ideal?
25-30mg/L
What are common SEs of phenobarbitone?
Sedation/Ataxia
PUPD & polyphagia
Neutropenia/Anaemia/TCP
When is phenobarbitone CI’ed?
Liver disease due to Cp450 metabolism
What is the MOA of KBr?
Competes with Cl- at nerve, inhibts Na (membrane hyperpolarisation, seizure threshold raised)
What is the appropriate dose of KBr for seizures in:
a) Cats
b) Dogs?
a) DO NOT GIVE
b) 30mg/kg SID
When do we monitor KBr levels?
12w PLAIN SERUM
What is our therapeutic level of KBr in the blood?
10-15mmol/L if w/pheno
12.5-37.5 if monotherapy
What are the SEs of KBr?
Sedation, Ataxia, PL weakness
How is KBr metabolised/excreted?
Unchanged in urine.
What is the MOA of Imepitoin?
GABA Benzodiazepine receptor partial agonist
What is the therapeutic dose for Impeitoin in dogs?
10-30mg/kg BID
When should we monitor imepitoin?
N/A - not required
What are the SE’s of imepitoin?
Same as pheno but lesser
Which 2 AEDs are not licenced but commonly used?
Levetiracetam
Zonisamide
Which unlicenced AED must be given at a dose of 20mg/kg TID?
Levetiracetam
What is the MOA of levetiracetam?
SV2a modulator - prevents vesicle mobilisation
What is the AE dose for zonisamide?
10mg/kg BID
What must be done if giving phenobarbitone and zonisamide concurrently?
reduce phenobarbitone dose by 25%
What is the MOA of zonisamide?
Blocks Na and Cl- channels.
What are the SEs of diazepam in cats?
Fulminant Hepatic Necrosis
What are the SEs of Propofol in cats?
Heinz Body Anaemia
What are the SEs of KBr in cats?
Eosinophilic Bronchitis
How do we classify a cluster seizure?
2+ in 24h
how common are cluster seizures in IE?
1/3-2/3 of dogs with IE
How do we classify status epilepticus?
seizure lasting >5min
>2 seizure w/o recovery
Why are Clusters and Status E emergencies?
irreversible neuronal damage after 30-60min due to excitotoxic cell injury
What is Stage 1 in the pathogenesis of excitotoxic cell injury?
Inc Autonomic Activity
What is Stage 2 in the pathogenesis of excitotoxic cell injury?
Irreversible neuronal damage due to increased glutamate
What are 6 major causes of Canine Status Epilepticus?
Idiopathic Epilepsy Neoplasia CNS inflammatory Dz Trauma Metabolic Disorders Toxicities
What is the FIRST thing you do with a case of status epilepticus?
STOP SEIZURE:
rectal diazepam 1mg/kg
What should you do whilst assessing a case of status epilepticus?
IV catheter placement
Examine
Bloods (Glucose, Na, Ca, Renal/Hepatic Fct)
What is the primary medical Tx for a stable patient that has been in status epilepticus?
Phenobarbital
What is the secondary medical Tx for a stable patient that has been in status epilepticus?
Levetiracetam
Which 3 drugs can be given as infusions to seizure cases?
Diazepam
Midazolam (not hep dysfct)
Propofol
What unique management changes should be but in place for seizure patients?
Monitor for pressure sores
Lubricate Eyes
What Neuropathy may cause sudden tetraparesis?
Polyradiculoneuritis
What Junctionopathy may cause sudden tetraparesis?
Myasthenia Gravis
Botulism
OP toxicity
What Myopathy may cause sudden tetraparesis?
Polymyositis
Electrolyte abnormalities
What is Polyradiculoneuritis?
Inflammation of nerves and roots
Which breed is predisposed to Polyradiculoneuritis?
Bengal Cats
Where is most of the pathology located in Polyradiculoneuritis?
Ventral Spinal Roots (causes pure motor deficits)
Apart from Cx, how can Polyradiculoneuritis be diagnosed?
Electrophysiology (f waves)
How is Polyradiculoneuritis treated?
Spintaneous recovery - give supportive care over days-weeks
What are the two forms of myasthenia gravis?
Generalised
Fulminant (fast onset)
Focal
What is the underlying pathology of myasthenia gravis?
Acquired/Congenital antibodies against AChR
how common is megaoesophagus in dogs with myasthenia gravis?
80% of dogs with Mg have megaoesoph
What is the gold standard tests for MG?
nAChR Ab
Apart from the gold standard, what two tests are available for MG?
Electrodiagnosis
Tensilon edrophonium response test
How is MG treated?
ACh-esterase
Immunosuppression
Postural Feeding
What is the pathogenesis of botulism?
Blocks vesicle fusion of pre-synaptic membrane & Ach Release
What are the two categories of clinical presentation of botulism?
Nicotinic - Junctionopathy
Muscarinic - Dysautonomia
How does nicotinic botuloism present?
Acute onset tetraparesis
Poss CN involvement
Poss resp muscle involvement
How does muscarinic botulism present?
urinary dysfunction
GI dysmotility
mydriasis
reduced tear production
