Flashcards in SA Neuro Deck (244)
Which diagnostic tests can you use to diagnose neuro conditions?
Blood, urine, faecal, microbiology
Imaging (US, radiographs, myelography, CT, MRI)
Muscle and nerve biopsies
What would you look for on a haematology test when diagnosing neuro disease?
Infectious and inflammatory dx
Inclusions (lysosomal storage dx)
What would you look for on a biochemistry test when diagnosing neuro disease?
Liver function (bile acid stimulation test, ammonia)
Glucose and fructosamine (weakness, seizures)
Electrolytes (Na, K, Ca-weakness, seizures)
CK, AST (muscle damage)
Which endocrine tests may you run when investigating neuro disease (mainly for neuromuscular disease)?
Give some markers for immune-mediated diseases
-Acute phase proteins (eg C-reactive protein, good for steroid-responsive meningitis arteritis SRMA)
-Acetylcholine receptor antibodies titres (gold standard for acquired myasthenia gravis)
-Type IIM antibodies titres (gold standard for masticatory muscle myositis)
How does immune-mediated acquired myasthenia gravis work?
Forms circulating antibodies against Ach receptors
Which test would you use to diagnose myasthenia gravis?
Acetylcholine receptor Ab test= gold standard
IV administration of edrophonium chloride (often called tensilon) which is a fast-acting cholinesterase inhibitor
Can have false + and -
Give a potential problem with using the edrophonium test to diagnose myasthenia gravis
How would you resolve it?
Can cause a cholinergic crisis: bradycardia, salivation, miosis, dyspnoea, tremors
Which infectious diseases could cause neuro conditions in dogs?
Which infectious diseases could cause neuro conditions in cats?
Why might you carry out metabolic urine screening?
To identify genetic diseases causing errors of metabolism
Most abnormal metabolites are concentrated in urine
Metabolic defects that produce organic acid accumulation often affect neuronal and muscle metabolism
Why should you always do a CSF analysis before doing a myelography?
The contrast material in the myelogram is irritable and will cause inflammation, which will affect the results of the CSF analysis
Where should you collect a CSF sample from relative to the lesion?
Caudal to lesion
When is a CSF analysis contraindicated?
Increased intra-cranial pressure (brain could herniate through skull)
Clotting problems (could cause bleeding into spine -> death)
Chiari-like malformations (syringomyelia)
Atlantoaxial instability or trauma
What shoud you never do when taking a CSF sample?
How much CSF should you take when obtaining a sample?
When taking a CSF sample, why should you use a plastic rather than glass tube?
Cells adhere to glass -> may get falsely low counts
What should you look at in a CSF analysis?
Differential cell count
What would you expect in a normal CSF sample?
What are the 2 places you can take a CSF sample from?
Cerebellomedullary cistern (atlanto-occipital joint) or lumbar subarachnoid space (L5-L6)
What position should a dog be when you take a CSF sample?
Head 90 degrees, nose parallel to table
Where would you take a cervical CSF sample?
Imaginary line between occipital protuberance and wings of atlas (cerebellomedullary cystern)
Where would you take a lumbar CSF sample?
L5-L6 in dogs
L6-L7 in cats and small dogs (end of spine) (lumbar subarachnoid space)
What size needle should you use when taking a CSF sample?
Cervical: 1.5 inch needle, 21-22G
Lumbar: 1.5-3.5 inch needle, 21-22G
What is a pleocytosis?
An increased cel count, usually WBCs
For which conditions may you see a neutrophilic pleocytosis in a CSF sample?
SRMA (steroid-responsive meningitis arteritis)
Post-myelography, haemorrhage, trauma, neoplasia
For which conditions may you see a mononuclear pleocytosis in a CSF sample?
Bacterial and steroid-responsive meningitis arteritis
For which conditions may you see a mixed pleocytosis in a CSF sample?
Bacterial and steroid-responsive meningitis arteritis
Non-inflammatory disease (infarction)
For which conditions may you see an eosinophilic pleocytosis in a CSF sample?
What is myeography?
Administration of contrast agent to subarachnoid space to outline the spinal cord
Highlights space-occupying lesions as deviations or thinning of contrast column
CT is good for diagnosing what?
Haemorrhage and middle ear disease
Fair for tumours and IVDD
What is electrodiagnostics?
Recording of electrical activity of muscles or neuronal structures
Can be spontaneous or in response to stimulation
What is electromyography (EMG)?
Records spontaneous muscle electrical activity
Normal muscle at rest is electrically silent
Destabilisation of the muscle cell membrane results in spontaneous discharge and so identifies damaged or denervated muscles and lesions
What do nerve conduction velocities (NCV) do?
Evaluate peripheral nerve function by stimulating a nerve at 2 different locations and recording:
-Amplitude of response (strength)
-Latency of response (how long it takes to get there-to calculate velocity)
What do velocities and amplitude represent on an nerve conduction velocity test?
What do repetitive nerve stimulation tests do?
Evaluate neuromuscular junctions (eg myasthenia gravis)
If amplitude decreases by >10%, suggestive of disease
What do F wave tests do?
Evaluate nerve roots and proximal part of peripheral nerves
(Lost/delayed F waves if nerve roots are damaged)
What do electroencephalography (EEG) tests do?
Record spontaneous electrical activity in cerebral cortex. 5-12 electrodes on head.
-Localising seizure focus
-Monitoring response to AEDs (automated external defibrillators) in cases with epilepsy
What do brainstem auditory evoked response (BAER) tests do?
Screening tool for detection of congenital sensorineural deafness
Determines hearing threshold in adults
Assess neural lesions on CNVIII or brainstem
Assess for brain death
Why do we take muscle and nerve biopsies when diagnosing neuro disease?
Mainly to differentiate between inflammatory and non-inflammatory (metabolic, degenerative) disaese
How big should a muscle biopsy be?
0.5 x 0.5 x 1.0cm
How big should a nerve biopsy be?
1/3 the width for 1cm
Which nerve is commonly biopsied?
Peroneal nerve (cranial tibia mucsle) (easily identified, is both motor and sensory)
Give some neurological deficits of the forebrain
-Altered mental status (depressed/disorientated)
-Contralateral blindness (decreased menace but normal PLR)
-Circling (ipsilateral), head turn, head pressing, pacing
-Reduced postural responses in contralateral limb (tells you the lesion is rostral to midbrain)
-Normal to increased spinal reflexes and muscle tone
-Seizures, behavioural changes, hemineglect syndrome
How would you identify the location of a lesion using postural reactions?
-Lesions rostral to the midbrain (eg forebrain) -> contralateral reduced responses
-Lesions caudal to the midbrain (eg SC) -> ipsilateral reduced responses
Give some neurological deficits of the midbrain
-Depression, stupor, coma
-Cranial nerve deficits, possible vestibular signs
-Paresis of all or ipsilateral limbs
-Possible decerebrate rigidity
-Reduced postural responses in all/ipsilateral limbs
-Normal to increased spinal reflexes and muscle tone
-Resp or cardiac abnormalities
Opisthotonus with hyperextension of
all four limbs reflects a lesion where?
Give some neurological deficits of the cerebellum
-Ipsilateral menace deficit, normal vision, possibly vestibular signs
-Possibly decerebellate rigidity (hyperextended FLs, spastic flexion of hips)
-Truncal ataxia, broad-based stance, hypermetria
-Delayed then hypermetric postural responses
-Normal spinal reflexes and muscle tone
-Rarely increased frequency of urination
Hyperextension of the forelimbs and spastic flexion of the hips reflects a lesion where?
What is meant by 'white shakers'?
-Idiopathic cerebellitis, idiopathic tremor syndrome
-Mostly small breeds, young dogs
-Fine tremor, worse with stress/excitement
+/- head tilt/decreased menace/ leaning and falling, ataxia
How do you diagnose white shakers?
How do you treat white shakers?
What is the prognosis like?
Corticosteroids for 4-6 months +/- other immunosuppressive drugs
Good prognosis, may relapse
What are the 3 main methods of infection of bacterial meningitis?
-Direct invasion (eg inner ear, eyes, bite wounds)
Give some clinical signs of bacterial meningitis
-Obtundation and cranial nerve deficits
-Neutrophilia (50% of cases)
How would CSF be affected by bacterial meningitis?
-Increased protein concentration
-Pleocytosis (increased lymphocytes)
-Phagocytosed organisms (rare)
How do you treat bacterial meningitis?
Give some clinical signs of increased intracranial pressure
-Altered mental status: obtunded, stupor, coma
-Altered pupil function: anisocoria, miosis, mydriasis
-Posture: decerebrate or decerebellate
-Bradycardia and hypertension (Cushing's reflex)
What is the oculocephalic reflex?
-When you move head, eyes should follow
-May be absent in comatose patients with brainstem dysfunction eg head trauma
How should you treat a patient with head trauma?
-Restore blood pressure
-Fluid therapy (avoid glucose)
How would you treat raised intracranial pressure?
-Mannitol (decreases blood viscosity) followed by crystalloid fluid therapy to prevent dehydration eg normal 0.9% saline (CI in hypovolaemia)
-Or hypertonic saline (4mg/kg 7.5% as slow bolus) (CI in hyponatremia)
Give some general care you should consider when treating a patient with head trauma
-Keep head elevated
-Avoid jugular compression
-Turn every 4-6 hours
-Nutritional support (tube feeding)
What should you not give to patients with head trauma?
What is hydrocephalus?
Abnormal dilation of the ventricular system within the cranium
Which kinds of dogs are affected by hydrocephalus?
Toy breeds, young age
Give some clinical signs of hydrocephalus
How do you treat hydrocephalus?
-Medical: corticosteroids, furosemide, anti-epileptic drugs
-Surgical: ventriculoperitoneal shunt (drains fluid from ventricles into abdomen)
What is lissencephaly?
Which breeds are predisposed to it?
-No development of gyri and sulci
-Llasa apso, Korat cats
Give some clinical signs of lissencephaly
-Seizures and behavioural changes
What are hydronencephaly and porencephaly?
Presence of cerebral cavities, usually communicating with subarachnoid space and/or lateral ventricles
Give the clinical signs of hydronencephaly and porencephaly
-1st few months: circling, abnormal behaviour
-Up to a few years: seizures
What is hepatic encephalopathy?
Liver dysfunction -> toxins in blood -> brain dysfunction
-Caused by acute liver failure or congenital portosystemic shunt
Give some clinical signs of hepatic encephalopathy
Mostly signs of forebrain dysfunction:
-Mentation changes (obtundation)
How do you diagnose hepatic encephalopathy?
-Blood ammonia levels
-Liver US or CT
How do you treat hepatic encephalopathy?
-Lactulose (reduces absorption of ammonia from gut)
-Restricted protein diet
Give the clinical signs of hypocalcaemia
-Muscle spasm and cramping
-Muscle twitching, trembling, stiffness
Give the clinical signs of hypercalcaemia
-Muscle spasm and cramping, muscle twitching -Trembling
Give some causes of hypernatremia (high blood sodium)
-Excess water loss
-Excess salt intake
-Insufficient water intake
Give the clinical signs of hypernatremia (high blood sodium)
-Changes in mentation and seizures
How do you treat hypernatremia (high blood sodium)?
Correct sodium levels slowly over 48-72 hours
What is a storage disease?
-Defect of a lysosomal hydrolase enzyme
-Accumulation of storage substrates within the cytoplasm (mainly of neurons) -> cellular dysfunction -> diffuse neurological dysfunction -> progressive -> death
How do you manage storage diseases?
-Symptomatic treatment eg anti-epileptic drugs, anti-anxiety drugs
Give some causes of hypoglycaemia
Insulinoma, hepatic dysfunction
Give some clinical signs of hypoglycaemia
-Anxiety, lethargy, depression
-Ravenous appetite, exercise intolerance
-Tremors, visual deficit, seizures, coma
How do you diagnose hypoglycaemia?
Blood glucose <3mmol/L and clinical signs
How do you treat hypoglycaemia?
-Direct administration of glucose in emergency
-Frequent feeding in chronic cases
-Treat underlying cause
Give some primary neoplasms of the brain
-Intra-axial glial cell tumours
-Extra-axial meningiomas, choroid plexus tumours
How do you diagnose brain tumours?
-MRI (sometimes CT)
-CSF analysis (to rule out inflammatory disease)
How do you treat brain tumours?
-AEDs (anti-epileptic drugs)
-Anti-inflammatory dose of corticosteroids to reduce cerebral oedema
-Surgery +/- radiotherapy
What is Lafora's disease?
-Progressive myoclonic epilepsy
-Jerking (myoclonic) which is induced by flashing lights, sudden sounds and movements
-Wire-haired Dachshund and Basset Hound; rare
How do you treat Lafora's disease?
-Avoid starchy/sugary treats
-Treat epilepsy symptomatically (eg KBr)
Give some clinical signs of vestibular disease
-Head tilt (ipsilateral)
-Vestibular ataxia and wide-based stance
-Leaning and falling, sometimes tight circling
Is a vertical nystagmus normally caused by a defect in the central or peripheral vestubular system?
What is a cerebrovascular accident?
-Rapid loss of brain function due to a disturbance in blood supply to the brain
What are the 2 types of cerebrovascular accident (stroke)?
-Ischaemic (majority; results from aterial/venous obstruction)
-Haemorrhagic (results from rupture of blood vessels)
How do you diagnose a cerebrovascular accident (stroke)?
Give some concurrent medical conditions that could lead to a cerebrovascular accident (stroke)?
What is an MUO?
Meningoencephalomyelitis of unknown origin
What are the 3 types of MUO?
-GME= granulomatous meningoencephalomyeitis
-NME= necrotising meningoencephalomyelitis
-NLE= necrotising leucoencephalomyelitis
Which kind of dogs are more affected by GME (granulomatous meningoencephalomyelitis)?
Young adults, toy and terrier breeds
What are the 3 forms of GME (granulomatous meningoencephalomyelitis)?
-Disseminated: multifocal signs involving forebrain, cerebellum, brainstem, spinal cord
-Ocular: acute onset visual impairment, papillary changes, optic disc oedema
Which dog breeds are prone to NE (necrotising meningoencephalitis and leucoencephalitis)?
Toy breeds eg pugs, maltese, chihuahua, pekinese
How do you treat MUOs?
-Immunosuppression: corticosteroids, cytosine arabinoside, cyclosporin, lomustine
Neurological signs associated with FIP are usually localised to which brain region?
Give some neurological clinical signs that can be associated with FIP
Tetraparesis, ataxia, nystagmus, loss of balance, sometimes behavioural changes or seizures +/- iritis/anterior uveitis/chorioretinitis
Which cranial nerves pass by the middle ear?
Give some clinical signs of otitis media/interna
-Pain opening the mouth
Give some examples of ototoxic drugs
-Antibiotics (aminoglycosides, tetracyclines)
-Chemotherapy agents (vincristine, cisplatin)
-Chlorhexidine -> perforated ear drum
What is the only thing you should lavage the middle ear with?
How can you investigate peripheral vestibular disease?
-Examine ear canal
-If tympanic membrane broken -> swabs, C&S
-Myringotomy if indicated (small hole in tympanic membrane)
-Lavage if indicated (warm saline)
How can you investigate central vestibular disease?
-Blood pressure/urine analysis/caogulation profile
-Abdominal US/thoracic radiographs
-Serology for infectious diseases
What is the difference between sensorineural and conductive deafness?
-Sensorineural: failure to conduct sound from cochlea to auditory cortex of brain
-Conductive: failure to conduct sound from outer ear to inner ear
Which dogs and cats are affected by sensorineural deafness?
Breeds with white pigmentation and blue eyes eg dalmation
How can you assess hearing in dalmation puppies?
-BAER test (brainstem auditory evoked response)
-Done at 8 weeks old
Which cranial nerve does a BAER test assess?
Which nerve plexus supplies the HLs?
Which nerve plexus supplies the FLs?
Which nerve plexus supplies the neck?
What is discospondylitis?
Infection and inflammation of intervertebral disc and adjacent vertebrae
Give the clinical signs of discospondylitis
Significant spinal pain, may have systemic signs of illness
Discospondylitis is most likely to occur where along the spinal cord?
Discospondylitis is most commonly caused by which infectious agent?
How do you diagnose discospondylitis?
-Imaging: radiographs, MRI or CT (narrowing of IVD space, roughening of endplates, proliferation of adjacent bone)
-Bacteriology: blood, urine, CSF
How do you treat discospondylitis?
-Long-term antibiotics (based on sensitivity)
-NSAIDs initially when painful
What is chiari-like malformation?
-Malformation of the skull- cerebellum protrudes through foramen magnum
How do ischaemic myelopathies usually occur?
-Fibrocartilage from nucleus pulposus embolises in spinal cardvasculature- fibrocartilagenous embolism
-Hypertension in cats
Which dog breed is more affected by ischaemic myelopathies?
How do you diagnose an ischaemic myelopathy?
How do you treat an ischaemic myelopathy?
-Supportive care, physio
-Usually takes 10 days to walk again (max. 3-4 months)
What is SRMA?
-Immune-mediated inflammation of the blood vessels in the meninges lining the spine
What are the clinical signs of SRMA?
-Spinal pain, pyrexia, lethargy
-Occasionally neurological deficits
Which dog breeds are more affected by SRMA?
-6-18 months old
How do you treat SRMA?
-Corticosteroids for 4-6 months +/- other immunosuppressive drugs (azathioprine)
How do you diagnose SRMA?
-Leucocytosis with neutrophilia
-CSF analysis: increased neutrophils and protein
-Increased IgA in CSF and serum
Atlanto-axial (AA) instability occurs in which dog breeds?
-Young dogs, toy breeds
-Failure of ligamentous support between the two vertebrae, usually asociated with aplasia/hypoplasia of the dens
Give some clinical signs of atlanto-axial intability
-Ataxia or tetraplegia
How do you treat atlanto-axial instability?
-Conservative splint for 6-12 weeks
Give some clinical signs of chiari-like malformation
-Thoracic limb weakness and atrophy
How do you treat chiari-like malformation?
-Medical: NSAIDs, furosemide, gabapentin, corticosteroids, amantadine
What is the difference between Hansens type I and II IVDD (intervertebral disc disease)?
-Type I: herniation of nucleus pulposus through annular fibres and extrusion into the spinal canal (chondrodystrophic breeds)
-Type II: annular protrusion but no extrusion of nuclear material (large breed dogs)
Intervertebral disc disease typically affects which vertebrae?
How would you diagnose IVDD?
-Radiography: narrowed IVD space (spondylosis with type II)
How would you treat IVDD?
-Conservative: strict rest for 6-8 weeks for type I, 4-6 weeks for type II, NSAIDs
-Surgical: if neurological deficits/ severe or recurrent pain
Give some clinical signs of cervical spondylomyopathy ('Wobbly dog')
-Large breeds and Basset hounds
-Progressive ataxia, tetraparesis, sometimes pain
-Signs worse in the pelvic limbs (paresis, ataxia)
-Short stilted gait and muscle atrophy in thoracic limbs
What might hyperviscosity of blood indicate?
What might inclusion bodies indicate on a haematology?
Lysosomal storage disease
What is the gold standard diagnostic tool for the acquired form of Myasthenia Gravis?
Acetylcholine receptor antibodies titres
What is the gold standard diagnostic tool for masticatory muscle myositis?
Type 2M antibody titres
Seizures occur due to a change in activity where?
Give some deficits associated with a forebrain lesion
Head turn (to side of lesion)
Give the 4 stages of a seizure
1. Prodrome (any predicting events)
2. Aura (initial manifestation of seizure)
3. Ictal (seizure event- involuntary muscle tone or movement +/- abnormal sensations or behaviour)
4. Post-ictal (can have unusual behaviour or neurological deficits for minutes to days after)
How long does the ictal stage of a seizure normally last?
Occurs most commonly at sleep or rest
What are the 2 major categories of seizure?
Generalised (involvement of both cerebral hemispheres simultaneously; consciousness is impaired)
Focal (activation of one part of one cerebral hemisphere)
What are the phases of a generalised seizure?
Tonic-clonic (most common)
Tonic (conraction of all skeletal muscles, legs out, head back)
Clonic (rhythmic movements eg jerking, clamping jaw, paddling of legs)
Myoclonic (sudden jerking motions
Atonic (sudden and general loss of muscle tone -> collapse)
What are the forms of a focal seizure?
What are audiogenic reflex seizures?
Cats, late onset (15yrs)
Myoclonic seizures caused by high-pitched sounds (can progress to tonic-clonic)
How do you control audiogenic reflex seizures?
What are the criteria for a diagnosis of idiopathic epilepsy?
2 or more seizures (24 hours apart)
Age of onset 6m to 6y
Unremarkable inter-ictal examination (period between seizures)
No clinically significant abnormalities on minimum database (haem/biochem/fasting bile acids/urinalysis)
Unremarkable MRI and CSF analysis
When should you start treatment for epilepsy?
Status elipticus or cluster seizures
6 months or less between seizures
Post-ictal signs are severe or last longer than 24 hours
Seizure frequency and/or duration is increasing
1st seizure is within 1 month of a traumatic event
Are any seizure medications licensed in cats?
Which are the 3 licensed seizure medications?
Bromide (Potassium or sodium bromide salts)
What is the mechanism of action of phenobarbitone?
Enhances GABA (inhibitory neurotransmitter of CNS)
What are the initial doses for phenobarbitone in cats and dogs?
Dogs: 3mg/kg BID
Cats: 2mg/kg BID
Give some side effects of phenobarbitone
Haematological abnormalities (anaemia, neutropenia, thrombocytopenia)
When is phenobarbitone contra-indicated?
Dogs with hepatic dysfunction
What is the mechanism of action of bromide (anti-seizure medication)?
Raises the seizure threshold by inhibiting transport of Na+
What are the initial doses for bromide in cats and dogs?
Dogs: 30mg/kg SID
DON'T USE IN CATS
Give some side effects of bromide
Ataxia and HL weakness
What is the dose for imepitoin in dogs?
What is status elipticus?
Seizure lasting >5 mins, or >2 seizures without full recovery
What are cluster seizures?
2 or more seizures within 24 hours
Give some causes of status elipticus seizures in dogs
CNS inflammatory disease
Why are status elipticus and cluster seizures an emergency?
Stage 1: increased autonomic activity (tachycardia, hypertension, hyperglycaemia)
Stage 2: irreversible neuronal damage (after 30 mins; hypotension, hypoglycaemia, hyperthermia, hypoxia, brain damage)
How do you stop a seizure?
Diazepam 1mg/kg per rectum
What is meant by 'breakthrough seizures'?
When an epileptic dog is medicated and still has seizures, we call them “breakthrough seizures”
How would you begin medicating a dog that is experiencing cluster seizures/status elipticus?
Place iv catheter
Phenobarbital 3mg/kg BID
If seizures don't stop/there are further seizures over the next 1-3 hours: phenobarbital iv loading (boluses)
If further seizures: levetiracetam loading
Give a side effect of using potassium bromide as an anti-seizure medication in cats
Give a side effect of using diazepam as an anti-seizure medication in cats
Hepatic necrosis (oral administration)
Give some differentials for acute onset non-ambulatory tetraparesis
Junctionopathy: myasthenia gravis, botulism, organophosphate toxicity
Myopathy: severe polymyositis, electrolyte abnormalities eg Addisons
Which markers do we use for acquired myasthenia gravis?
Acetylcholine receptor antibodies
Which markers do we use for masticatory myositis?
What is polyradiculoneuritis?
Inflammation of nerve and roots
Give some causes of polyradiculoneuritis
Idiopathic/rabies vaccine, immune-mediated?
Breed predisposition in Bengal cats
Give some clinical signs of polyradiculoneuritis
Acute onset, rapidly progressive (days)
Tetra/paraparesis -> non-ambulatory tetraparesis/plegia
Flaccid, reduced motor fuction (inc absent reflexes)
Can affect respiratory muscles
How do you diagnose polyradiculoneuritis?
Electrophysiology (f waves will be lost/delayed) and CSF analysis (lumbar)
How do you treat polyradiculoneuritis?
Supportive: nursing, physio, ventilatory support if necessary
What is myasthenia gravis?
Muscle weakness due to reduced neuromuscular transmission
What causes the 2 forms of myasthenia gravis?
Acquired: immune-mediated; Ab-mediated destruction of acetylcholine receptors
Congenital: deficiency of acetylcholine receptors
>80% of dogs with myasthenia gravis also have what?
Megaoesophagus (only 15% in cats)
Which cat breed is predisposed to myasthenia gravis?
25% of cats with myasthenia gravis also have what?
How do you treat myasthenia gravis?
Anti-cholinesterase (pyridostigmine po)
Postural feeding if mega-oesophagus
What is meant by the 'fulminant' form of myasthenia gravis?
Sudden onset of megaesophagus and frequent regurgitation of large volumes of fluid
How does botulism affect nerves?
Toxins prevent acetylchline release at nerve junctions
Give some clinical signs of botulism
Acute onset rapidly-progressing tetraparesis
Cranial nerves may be affected: facial paralysis, megaoesophagus, altered jaw tone
Respiratory muscles may be affected
Urinary dysfunction, GI dysmotility, mydriasis, reduced tear production
How do you treat botulism?
Give some clinical signs of immune-mediated polymyositis
Exercise intolerance, generalised weakness, muscle atrophy
Pyrexia, stiffness, non-ambulatory tetraparesis, reluctance to move, lowered head carriage, myalgia (muscle pain)
How do you diagnose immune-mediated polymyositis?
Inflammatory leucogram, elevated CK/AST
How do you treat immune-mediated polymyositis?
Prednisolome +/- other immunosuppressives
Are cats or dogs affeced by masticatory myositis?
Why does masticatory myositis occur?
Antibodies to 2M myosin -> myositis
Give some clinical signs of acute and chroninc masticatory myositis
Acute: swollen/painful masticatory muscles, exophthalmos
Chronic: trismus (pain/fibrosis), mastictory muscle atrophy
How do you diagnose mastictory myositis?
CK (may be slightly elevated)
How do you treat masticatory myositis?
Prednisolone +/- other immunosuppressive drugs
What is the most likely cause of an infectious myositis?
Protozoa eg Toxoplasma, Neospora
Give some clinical signs of Neosporosis in puppies
Radiculoneuritis and polymyositis
Pelvic limb hyperextension
Ascending paralysis of pelvic limbs with muscle contracture and arthrogryposis
How do you diagnose Neosporosis in puppies?
Clinical signs, biopsy, CK/AST. serology
How do you treat Neosporosis in puppies?
Clindamycin/TMPS and pyrimethamine
What is neuropraxia?
Temporary nerve damage but no disruption of the nerve or myelin sheath
Good prognosis, will return to normal function in a few days
What is axonotmesis?
Disruption of the axon but intact myelin sheath
Good prognosis but slow recovery
What is neurotmesis?
Partial/complete transection of the nerve
Partial recovery is possible
Give some clinical signs of brachial plexus avulsion
Monoparesis, cutaneous trunci absent ipsilaterally, Horner's syndrome
Give some clinical signs of a brachial plexus tumour?
Malignant peripheral nerve sheath tumour
Chronic progressive thoracic limb lameness, pain, muscle atrophy
How do you diagnose a brachial plexus tumour?
Imaging (MRI best)
How do you treat a brachial plexus tumour?
How do you differentiate central from peripheral vestibular disease?
Central: may have paresis and prorioceptive deficits, nystagmus may be vertical, horizontal or rotatory
Peripheral: may have Horner's syndrome, nystagmus may be horizontal or rotatory
Give some causes of acute onset vestibular disease
Idiopathic vestibular dz
Trauma to middle/inner ear
Give some causes of chronic onset vestibular disease
Brain and middle ear tumours
Lysosomal storage dz
Congenital vestibular dz
Give some causes of vestibular disease that can be acute or chronic onset
How do you diagnose MUOs?
How do you diagnose FIP in cats?
Lymphopenia, neutrophilia, non-regenerative anaemia
Increased serum alpha-1-acid glycoprotein
High serum titres of feline coronavirus Ab
MRI: ventricular dilation
Give some signs of metronidazole toxicity
When does it occur?
Seizures, tremors, rigidity, hypermetria
Usually when doses are >60mg/kg/day
How do you treat metronidazole toxicity?
Give some clinical signs of a thiamine deficiency
Bilateral central vestibular signs, seizures
Give some clinical signs of bilateral vestibular disease
Crouching low to the ground
May fall to both sides
Wide lateral excursions of the head
What age of dogs are affected by idiopathic vestibular disease?
Adult to geriatric
How do you treat idiopathic vestibular disease?
No tx needed-will resolve spontaneously
How do you diagnose idiopathic vestibular disease in dogs?
Diagnosis of exclusion
What are the 2 forms of feline idiopathic vestibular disease?
Acute onset, non-progressive, improves over 2-4 weeks
Atypical form: acute onset but clinical signs progress over 3 weeks; recover after 3 months but milk residual head tilt may remain
How do ischaemic myelopathies occur?
Fibrocartilage from nucleus pulposus embolises in the spinal cord vasculature -> fibrocartilagenous embolism -> blocks off blood supply to part of spinal cord
When do clinical signs of ischaemic myelopathies occur?
What signs do you see?
Vary from mild weakness or incoordination, to inability to walk
What is chiari-like malformation?
Mismatch between caudal fossa volume and its contents, with caudal displacement of the cerebellum through foramen magnum
Can develop syringomyelia (fluid-filled 'cyst' in spinal cord)
How do you diagnose cervical spondylomyelopathy?
Myelography +/- CT, MRI
How do you treat cervical spondylomyelopathy?
What is 'cauda equina' syndrome?
Degenerative lumbosacral stenosis
Arthritis of the joint between the last lumbar vertebra and the sacrum -> narrowing of spinal canal -> pressure on nerves coming off spinal cord
Give some clinical signs of 'cauda equina' syndrome?
Reluctance to exercise, rise, jump into car, do stairs
Proprioceptive deficits, reduced withdrawal reflex, muscle atrophy
Urinary and/or faecal incontinence
How do you treat cauda equina syndrome?
Conservative: rest and NSAIDs
Surgery: dorsal laminectomy/ dorsal fusion-fixation/ foraminotomy
Give some clinical signs of degenerative myelopathy
Insidious, progressive ataxia and paresis of pelvic limbs -> paralysis
Age of onset: 5-9y
Are there any treatment options for degenerative myelopathy?
No therapeutical options
How do you perform a hemilaminectomy?
Remove one half of the vertebral arch (lamina, articular process and pedicle) and expose spinal cord -> remove ruptured disc material
Used to correct slipped or herniated discs in the thoracolumbar spine
How do you perform a dorsal laminectomy?
Remove dorsal spinous process and laminae -> access to spinal cord
Which drug can you give to dogs with canine cognitive dysfunction?
Give some clinical signs of canine cognitive dysfunction?
Disturbances in sleeping; pacing/vocalising at night
Getting stuck in corners, staring into space
Loss of house-training ability
New behavioural problems
What is myelography?
Injection of positive contrast into subarachnoid space