SA neurology Flashcards
Describe the changes associated with forebrain lesions. (x8)
Altered mental status, normal gait, compulsive pacing, circling, reduced postural response, behavioural changes, normal to increased spinal reflexes/ muscular tone, decerebate rigidity
In which direction would a dog circle with a forebrain lesion? Why?
Towards the lesion - decreased activity on that side!
On which side of the body would a dog with a forebrain lesion show postural deficits? What would the deficits be like?
Knuckling on the contralateral side to the lesion
Describe decerebrate rigidity.
No mentation, extended fore and hindlimbs with extended neck
Describe decerebellate rigidity.
Mentation present, extended neck and forelimbs and flexed hindlimbs
Describe the changes associated with cerebellum (x9).
Normal mentation, hypermetric gait/ delayed initiation, intention tremors, circling, truncal ataxia, reduced postural responses, normal spinal reflexes/ muscle tone, altered urination, decerebellate rigidity
In which direction would a dog circle with a cerebellar lesion? Why?
Away from the lesion - increased activity on the lesion side (less inhibition)
On which side of the body would a dog with a cerebellar lesion show postural deficits? What would the deficits be like?
Ipsilateral side - wide-based stance/ splayed
Describe the path of neurones leading to the PLR.
Optic to hindbrain to occulomotor nerve
Describe the path of neurones leading to the menace.
Optic to forebrain to facial
What changes may be seen with a lesion of the hindbrain? (x7)
Depression/ stupor/ coma, CNS deficits/ vestibular signs, Paresis, decerebrate rigidity, reduced postural response, normal to increased reflexes/ tone, respiratory/ cardiac abnormalities
What changes may be seen with a lesion of the vestibular system? (x6)
Ipsilateral head tilt, atazia, wide-based stance, nystagmus, tight circling, positional stabismus.
What changes would be seen with a neuropathy?
Flaccid paresis, reduced reflexes
What signs would be seen with an UMN lesion?
Ataxia, slow propagation, normal to increased reflexes, normal muscle tone/ bulk
What signs would be seen with an LMN lesion?
Stiff/ bunny hop gait, normal propagation, reduced reflexes, muscle atrophy/ reduced tone
What signs may be seen with a junctionopathy?
Exercise intolerance, sensory normal, intact tendon reflexes
What signs may be seen with a myopathy?
Atrophy/ hypertrophy, normal sensory, generalised/ focal signs
What breeds are predisposed to an idiopathic tremor?
Small breeds - terriers/ toys - worsening head tremor with stress
What treatment is used for an idiopathic tremor syndrome
Steroids + other immunosuppressives - may relapse
What clinical signs are seen with bacterial meningioencephalitis
Pyrexia, obtunded, CN deficits
What pressures make up the overall intra-cranial pressure?
Brain volume , vascular and CSF pressure
An increase in ICP may be characterised by what clinical signs?
Changes in mentation, occular (anisocoria, miosis, mydriasis), bradycardia/ hypertension, impaired vestibular eye movements, decerebrate/ cerebellar rigidity, abscent oculocephalic reflex
How do you treat an increase in intracranial pressure?
Oxygenation, fluid therapy, diuresis (mannitol/ hypertonic saline), assess temperature and blood pressure, general nursing
Which breeds are associated with hydrocephalus? How can it be treated?
Toy breeds -steroids, furosemide, AEDs, ventriculoperitoneal
What clinical signs are associated with hydrocephalus?
Domed head, persistent fontanellae, abnormal behaviour, cognitive dysfunction, obtund, circling, seizures, vestibular disease
Which breeds are predisposed to lissencephaly?
Lhasa apso/ korat cats
What metabolic product can cause encephalopathy? What clinical signs are associated?
Ammonia (no conversion to urea) - seizure, circling, head pressing, mentation changes. Give lactulose, antibiotics and low protein diet
Hypernautraemia can be characterised by what clinical signs?
Mentation and seizures - gradually correct levels
What neurological signs characterise hypocalcaemia?
- Muscle spasm/ twitching/ cramps
- Trembling
- Stiffness
- Mental depression
- Tonic-clonic
- Episodic regidity
- Tetraparesis
- Seizures
What neurological signs characterise hypercalcaemia?
- Muscle spasm/ twitching/ cramps
- Trembling
- Mental depression
- PUPD
- Constipation
What neurological signs characterise hypoglycaemia?
Anxiety, lethargy, PP, tremors, seizures, coma - caused by hepatic dysfunction and insulinoma
Laforas disease may be seen in which dog breed?
Daschund - causes progressive myoclonic epilepsy. Feed antioxidant rich diets
Beta-amyloid plaque accumulation causes what disease?
Cognitive dysfunction
Define cerebrovascular accident.
Rapid loss of brain function due to vascular disturbance, usually ischemia
What conditions may predispose dogs to a cerebrovascular accident?
Chronic kidney disease, hyperadrenocorticism, hypertension
MUO
Meningioencephalomyelitis of unknown origin
What breeds are predisposed to granulomatous MUO?
Young adult toy and terrier breeds
What breeds are predisposed to necrotising MUO?
Pug, chihuahua, yorkie, ST - treated with immunosuppressive doses of corticosteroid/ cytosine
What neurological signs may be associated with FIP?
Cerebellomedullary signs - paresis/ ataxia, progressive, ocular lesions
What nervous structures may be affected by otitis media/ interna?
Facial nerve, vestibulocochlear nerve, sympathetic trunk
Which parts of the brain may be damaged with a thiamine deficiency?
Lateral genticulate nucleus, caudal colliculo, vestibular and facial nucleus
What antibiotics may be associated with ventibular toxicity/ ototoxicity?
Metronidazole, gentamycin, streptomycin (remember to check tympanic membrane before putting drugs down an ear!!)
What is idiopathic vestibular disease?
Peracute vestibular signs which improve gradually over a few weeks
Facial and vestibular neuropathy of unknown origin may be seen in which breed of dog?
Cockers
What generalised signs may be seen with a neuromuscular disorder?
Tetraparesis, exercise intolerance, stiff/ stilted gait, muscular atrophy, altered reflexes, tremors/ fasciculations
What is myaesthenia gravis?
Immune-mediated attack against acetylcholine receptors leading to AP blockage
What is the most prominent clinical outcome of myaesthenia gravis in dogs? How is it managed?
Megaoesophagus
Why are cats with myaesthenia gravis less likely to suffer with megaoesophagus?
They have less smooth muscle in their oesophagus
What test is used to diagnose MA?
Edrophonium, gold standard = antibody test, electrodiagnostics
What treatment options are their for MA?
Anticholinesterases (pyridostigmine), immunosuppression, thymectomy, postural feeding
What clinical signs are associated with botulism
NACh - acute tetraparesis + CN deficits + resp muscle problems. MACh - urinary, GI dysmotility mydriasis, reduced tear production
Paraneoplastic myositis may occur as a result of which types of tumour?
Thymoma/ lymphoma
What parasites can cause myositis?
Neospora/ toxoplasma
What can lead to an ischemic myelopathies?
Fibrocartilagenous embolism of spinal vasculature - leading to per-acute, non-painful weakness +/- proprioceptive deficits and decreased reflexes
What breeds are predisposed to ischemic myelopathies?
Mini schnauzers, cats
SRMA
Steroid-responsive meningitis arthritis
What breeds are predisposed to SRMA?
Young dogs, boxers and beagles - pyrexia, pain, lethargy - steroids/ immunosuppressive
What bacterial may cause discospondylitis?
Staph intermedius
Discospondylitis
Discospondylitis is an infection of the vertebrae and intervertebral disc spaces
Describe chiari-like malformation.
Toxic CSF accumulations (syringomyelia) and dilated central canal (hydromyelia) - NSAIDS, steroids, gabapentic, surgical decompression
What is the difference between extrusion and protrusion IVDD?
Extrusion the annulus through the spinal cord (dasch) and protrusion in large breed dogs
