DeLahunta Chapter 5 - GSE - LMN, spinal nerves 2nd (p.130-158) Flashcards
What is the cause of acquired equine motor neuron disease in horses? Which are the usual circumstances that this occurs? Which are the main clinical signs?
Lack of vitamin E in the diet
It occurs usually in a riding stable when fed hay and some
grain, with no access to pasture.
Generalised weakness, fatigue, BW loss (better walking, trembly and weak with dancing sign on standing)
In which breed of dogs brachial plexus neuritis has been reported and what was the suspected trigger?
Great Dane
Diet with horse meat (allergic reaction?)
Which nerve is affected when the dog is unable to support his weight in one of the thoracic limbs – and which SCS is this originated from?
Loss of function of radial nerve (C7,C8,T1)
Involved in antigravity extension of both elbow & carpus
In brachial plexus injury, how miosis and 3rd eyelid protrusion could be explained?
Avulsion of the ventral roots of T1 or of the T1 spinal nerve –> miosis
because of the interruption of the GVE preganglionic neuronal axons
located there that provide sympathetic innervation to the eye.
An elevated third eyelid and ptosis require interruption of the ventral roots
of the T2 and T3 spinal cord segments.
Dog with left thoracic limb lameness AND left thoracic limb protracted with medial rotation of the elbow and a lateral position of the paw. What is your diagnosis?
Infraspinatous contracture - Traumatic (overextension)
State the nerve delivering LMN and GSA function to each region
-Tail
-Anus and perineum
-Caudal thigh
-Caudal thigh muscles and all crural muscles and skin of crus and paw except for medial surface
-Tail: caudal nerves
-Anus/perineum: pudendal nerve
-Caudal thigh: femoral nerve (caudal cutaneous femoral nerve)
-Caudal thigh muscles and all crural muscles etc..:sciatic nerve
Which species is mostly affected by auto-immune polyneuritis equi ? Most common neuro signs? Where the lesions are situated histopathologically? What the CSF tap shows? What is the prognosis?
What is its DDx for cauda equina syndrome in horses?
-horses
-Atonia, areflexia, and analgesia of the tail, anus, and perineum
+/- facial neuropathy, or vestibulocochlear, or trigeminal (rarely).
Histopath:
-Intradural spinal nerve root lymphoplasmatic inflammation PLUS additional extradural granulomatous lesion at the nerves (mass lesion – compressive) which makes it different from canine PRN
CSF: elevated TP +/- nonsuppurative pleocytosis
Poor prognosis
DDx:
-sarcocystis neurona
-diskospondylitis
less likely neoplasia, Cryptococcus
Which Brucella species have been reported to cause diskospondylitis in dogs and which is the most common?
B. canis (most common) but also B.abortus and B.suis
Dog came with paralysed tail after swimming. What is your diagnosis? In which dogs and breeds has this been reported? Which is the clinical hallmark? Potential triggers? What is the main suggested pathogenesis?
-Limber tail syndrome or caudal myopathy
-Hunting dogs (e.g. pointers) and labradors
signs:
- completely flaccid tail or a tail that is held in a dorsal plane (horizontally) for several inches from the tail base and then hangs ventrally with no tone
-vigorous exercise/swimming
pathogenesis:
-ischaemic myopathy
Large puppy dog cannot stand and walk as is growing up. Joint deformities and ankylosis are evident. What could be a potential diagnosis? Why this is caused and how can we overcome it?
-Swimmer puppy syndrome
-Developmental abnormality - This is not a neurologic problem or a primary muscle disorder. It is the result of a disparity in growth between the muscles and the bones
and soft tissues.
-Breeders should loosely tying their limbs together to prevent the abduction
and by providing nonskid surfaces during this critical growth period.
-
A 3mo Tibetan mastiff with acute progressive (started between 7-12 weeks) paresis of the pelvic limbs with obvious plantigrade, loss of patellar reflexes, decreased withdrawal reflexes and intact nociception. EMG showed denervation potentials, but MNCV were markedly prolonged. What is your dx? What is the classic appearance of the nerves in histopath?
-inherited hypertrophic neuropathy
-myelin disorder
-plantigrade because of tibial neuropathy
-inherited hypertrophic neuropathy (Schwann cell hyperplasia but cannot produce myelin–-> onion-bulb formations)
A mutation in which gene is associated with the development of exercise-induced collapse in Labrador Retrievers?
Mutation in DNM1 (dynamiine 1) gene
What is anatomically/functionally different in the horse’s brachial plexus?
Radial nerve more subcutaneous (?)
In horses, brachial plexus injuries are often due to trauma (e.g., falls or collisions) and can lead to significant issues like “dropped elbow” syndrome due to radial nerve damage
What is the aetiology of poliomyelomalacia a young pigs?
Toxicosis from excessive Se in diet
Unique syndrome
Hyperacute toxic myelopathy
Degeneratin of the ceneter of the ventral gray column in cervical and lumbar intumescense, and few in brainstem GSE nuclei –> neuronal cell bodies spread at the border of the lesion (they have a periphery of immune cells - characteristic histopath pic)
In which condition is the posture of tip toeing of the pelvic lim typically seen in cows?
tibial neuropathy due to trauma
Which 2 inherited neuropathies you know in dogs?
-inherited hypertrophic neuropathy in Tibetan Mastiffs
-inherited Giant axonal neuropathy in GSDs
What is stringhalt in horses, and which forms are recognized?
-Equine reflex hypertonia
-lession at CPGs at L4-S2 SCS, rotts or nerves or ganglia or sciatic or femoral , or peroneal or tibial nerves
-Forms
1) classic or sporadic: sudden, uni or bilateral, can have no CNS/PNS lesions
2)epidemid or plant-associated: pastured horses on false dandelion (Hypochaeris radicata)–> bilateral, onset in few weeks, pathology: dying-back axonopathy of branches of sciatic nerves
What is the aetiology of ‘stiff lamb disease’? State also DDx
-Vitamin E deficiency myopathy (most common myopathy in young RUM & HORSE)
-accompanied by Se feciciency
-causes myopathy & rhabdomyolysis
-semiology: stiffness (especialy in goats) via myotonia or pseudomyotonia (but no EMG has been done)
-elevated CK/AST
DDx:
1) inherited myotonia
2) muscular dystrophy (dystrophinopathy/Duschene)
3) tetanus
What is spinal muscular atrophy, and what is the hallmark of this condition?
It is the motor neuron disease in young animals. The hallmark of the disease is an abiotrophy of GSE neurons in the spinal cord ventral grey horn and brainstem nuclei.
What is abiotrophy? Which cells usually affect?
Premature degeneration of neurons:
Most commonly affects Purkinje cell in cerebellum and GSE neurons in the spinal cord and brainstem.
In which canine breeds congenital motor neuron disease occurs?
Which calves have been reported?
1) Brittany spaniel
2) Sweedish lapland dogs (this is multisystemic which means also cerebllum)
Maybe: labs, saluki, rotties, dobermans
–>Swiss calves
What enzyme would be beneficial to test in horses with equine motor neuron disease?
Superoxide dismutase in CNS and blood. This enzyme normally converts the highly toxic superoxide radical into hydrogen peroxide.
