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1.
A bilateral and symmetrical neuronal vacuolation associated with spinal cord white matter degeneration and laryngeal neuropathy was observed in a 12-week-old male mixed-breed dog with a history of progressive pelvic limbs ataxia. On clinical examination, signs included inspiratory stridor, spinal ataxia, tetraparesis, and proprioceptive deficits more severe in the pelvic limbs. Examination of the larynx showed bilateral laryngeal paralysis and electromyography revealed fibrillation potentials restricted to the intrinsic laryngeal muscles. Clinical and pathological findings resembled the syndrome of neuronal vacuolation and spinocerebellar degeneration described in Rottweiler dogs. This is the first report of a similar disorder in a dog different from Rottweiler.  相似文献   

2.
Five Rottweiler puppies from 3 unrelated litters developed inspiratory stridor at 11–13 weeks of age. Physical examination disclosed tetraparesis in all dogs, and bilateral lenticular cataracts in 4 dogs. Laryngeal examination under light anesthesia showed laryngeal paralysis in all dogs. Electrodiagnostic testing revealed denervation potentials in the distal appendicular muscles of 4 dogs tested and in the intrinsic laryngeal muscles of 2 dogs tested. Motor nerve conduction velocity was slightly low in 1 dog. Neurogenic muscular atrophy was found in distal appendicular muscles (n = 3) and intrinsic laryngeal muscles (n = 2), and degenerative changes were found in peripheral nerves (n = 3) and recurrent laryngeal nerves (n = 2). No abnormalities were detected in the spinal cord, spinal nerve roots, or ganglia of 3 dogs autopsied. The clinical, electrophysiologic, and histopathologic findings support a diagnosis of polyneuropathy and resemble the finding reported in young Dalmatians. Young dogs with laryngeal paralysis should be evaluated neurologically to rule out a more generalized polyneuropathy. The condition is suspected to be hereditary in nature and the prognosis is poor.  相似文献   

3.
Nine horses with clinical signs of Australian Stringhalt were killed and tissues collected for a detailed pathological study. Lesions were limited to peripheral nerves and muscles. The most severely affected nerves were the superficial and deep peroneal, distal tibial, plantar digital, volar and recurrent laryngeal nerve with changes characterised by a selective loss of large diameter myelinated fibres with various degrees of demyelination, fibrosis, Schwann cell proliferation and onion-bulb formation. A routine evaluation of the brain and spinal cord by light microscopy failed to reveal any consistent abnormalities. Morphometric analysis of deep peroneal and recurrent laryngeal nerves confirmed the reduced number of large diameter myelinated axons. Teased fibre preparations of these nerves did not show any abnormalities in internodal distance. The most severe muscle lesions were in the long and lateral digital extensors, cranial tibial, dorsal cricoarytenoid, gracilis and lateral deep digital flexor with extensive atrophy of fibres and diffuse fibrosis. Histochemical evaluation of the long digital extensor from 3 affected horses showed an abnormally wide distribution in fibre size and a reduction in type II fibres compared with controls. These lesions are consistent with a distal axonopathy leading to neurogenic muscle atrophy. The distribution of neuromuscular lesions in Australian Stringhalt may be explained by the susceptibility of longer, larger myelinated nerve fibres to injury, but the cause for this distal axonopathy remains unknown.  相似文献   

4.
The recurrent laryngeal nerves were examined by electron microscopy in five control, four subclinical and four clinical laryngeal hemiplegic horses. In addition, the peroneal nerve was examined in two horses in the latter group. The distally distributed loss of large myelinated fibres in the left recurrent laryngeal nerve seen by light microscopy was confirmed. In addition, active axonal pathology was found to be more evident than indicated by light microscopic investigations. The onion bulb formations observed indicated the repetitive nature of the damaging influence to nerve fibres. Although the pathological changes were most obvious in the distal left recurrent laryngeal nerve, alterations similar in type and distribution were present in other areas of the left and right nerves, and in the distal hindlimb nerves. The observation of fibres with inappropriately thick myelin sheaths relative to their axonal calibre, was confirmed statistically by determining the regressions of axis cylinder perimeter against the number of myelin lamellae. In conclusion, the peripheral nerve pathology of equine laryngeal hemiplegia was demonstrated to be a distally distributed loss of myelinated fibres, with considerable active axonal damage, in conjunction with axonal atrophy. These features suggest that this disease may be classified as a distal axonopathy.  相似文献   

5.
This light microscopic investigation of 15 Thoroughbred horses provided substantial evidence for the classification of equine laryngeal hemiplegia as a distal axonopathy. Morphologic and morphometric examinations were performed on resin embedded recurrent laryngeal nerves from control, subclinical and clinical laryngeal hemiplegic animals. In the latter group of animals some distal hindlimb nerves were also examined. A distally graded loss of myelinated fibres selectively affecting those of large diameter was demonstrated in both left and right recurrent laryngeal nerves. Morphologic evidence of similar pathological changes in long hindlimb nerves was also present. An explanation for the early involvement of the cricoarytenoideus lateralis muscle in the course of laryngeal hemiplegia, was offered by the demonstration of more large diameter fibres in the branch of the recurrent laryngeal nerve innervating it, thus making it more susceptible to the disease process.  相似文献   

6.
This study confirmed that neurogenic muscle pathology exists in intrinsic laryngeal muscles supplied by the recurrent laryngeal nerves in horses subclinically and clinically affected with laryngeal hemiplegia. An important additional observation was the occurrence in three out of four laryngeal hemiplegic horses of neurogenic muscle changes in a hindlimb muscle, the extensor digitorum longus, a muscle supplied by another long peripheral nerve. This finding suggests that a polynenropathy exists in laryngeal hemiplegic horses, and supports the classification of this disease as a distal axonopathy. Comparison of the degree of pathology in the intrinsic laryngeal muscles and that of the recurrent laryngeal nerves innervating them, demonstrated a strong correlation between the extent of damage in the distal left recurrent laryngeal nerve and the overall degree of muscle pathology. The muscle damage in clinically affected horses is a reflection of the nerve damage present in the most distal portion of the recurrent laryngeal nerve. The more variable pathological changes found in proximal levels of the left and right recurrent laryngeal nerves probably reflects the ongoing nature of the pathological process affecting nerve fibres. The existence of a subclinically affected group of horses, the earliest involvement of an adductor, the left cricoarytenoideus lateralis muscle, and the presence of changes in the right intrinsic laryngeal muscles all confirmed the findings of previous workers.  相似文献   

7.
A 5-month-old female Border Collie was evaluated because of progressive hind limb ataxia. The predominant clinical findings suggested a sensory neuropathy. Sensory nerve conduction velocity was absent in the tibial, common peroneal, and radial nerves and was decreased in the ulnar nerve; motor nerve conduction velocity was decreased in the tibial, common peroneal, and ulnar nerves. Histologic examination of nerve biopsy specimens revealed considerable nerve fiber depletion; some tissue sections had myelin ovoids, foamy macrophages, and axonal degeneration in remaining fibers. Marked depletion of most myelinated fibers within the peroneal nerve (a mixed sensory and motor nerve) supported the electrodiagnostic findings indicative of sensorimotor neuropathy. Progressive deterioration in motor function occurred over the following 19 months until the dog was euthanatized. A hereditary link was not established, but a littermate was similarly affected. The hereditary characteristic of this disease requires further investigation.  相似文献   

8.
The terminal branches of the recurrent laryngeal nerve (RLN) of three normal ponies and six horses with sub-clinical laryngeal disease were examined qualitatively and quantitatively in an attempt to explain the preferential denervation of the laryngeal adductor muscles in the neuropathy of idiopathic laryngeal hemiplegia (ILH). The myelinated fibre spectra of all the motor nerve fibres in the left and right abductor and adductor branches of the RLN in three normal ponies were measured. The density of myelinated fibres was also calculated. There was no significant difference between the larger group of myelinated fibres in the adductor or abductor branches. In the six horses with laryngeal hemiparesis, however, there was a marked preferential loss of the medium/large size myelinated fibres in the left adductor branch, although nerve fibre densities were not significantly different. While no simple morphometrical feature was found to explain the selective muscle denervation, the greater loss of large diameter myelinated fibres in the adductor branches confirms the earlier observation of adductor muscle susceptibility in the neuropathy of ILH.  相似文献   

9.
A 5-month-old female Rottweiler dog was diagnosed to have a neurodegenerative disease that has been recently report ed in Rottweilers from North America and Europe. The dog was presented with progressive signs of ataxia, tetraparesis and inspiratory stridor. The clinical investigation included analysis of CSF, radiography, myelography and electrophysiolog-ical testing. No evidence of vertebral malformation or inflammatory CNS disease was identified. Bilateral laryngeal paraly sis was identified in the lightly anaesthetised dog. Electromyography showed abnormal spontaneous activity from the intrin sic musculature of the larynx. At necropsy there were no gross abnormalities of the nervous system but there was atrophy of the dorsal cricoarytenoid muscles of the larynx. There were widespread histological abnormalities throughout the ner vous system including neuronal vacuolation, spongiform changes in the neuropil and axonal degeneration which was most prominent in the spinal cord. These clinical and pathological findings are consistent with the diagnosis of a new neurode-generative disease reported from North America and Europe. This diagnosis is of particular significance in Australia where transmissible spongiform encephalopathies have not been identified.  相似文献   

10.
Experimental reinnervation of the equine larynx in healthy ponies was studied after the recurrent laryngeal nerve was crushed, using endoscopic, electromyographic, and microscopic techniques. In 12 ponies, the recurrent laryngeal nerve was crushed unilaterally in the midcervical area. All showed postoperative paralysis of the larynx on the operated side. In 8 ponies, recovery of movement of the vocal folds occurred at different times (2.5 to 8 months) after surgical operation was done. These movements, which were often abnormal, included trembling and asynchronism. In 2 of these ponies, complete return of normal vocal fold function occurred. Return of function was due to reinnervation, as determined by electromyographic examination of the laryngeal muscles and microscopic evaluation of these muscles and the recurrent laryngeal nerves. In the muscles, there was evidence of fiber-type grouping, and the nerves showed regenerative activity. In 3 ponies, there was evidence of aberrant reinnervation, with adductor or abductor muscles discharging during an inappropriate phase of the respiratory cycle. Further evidence that reinnervation occurred in the larynges of these ponies was determined in microscopic sections of the recurrent laryngeal nerves and muscles, which showed regenerative activity and muscle fiber-type grouping, respectively. The endoscopic abnormalities in these ponies were compared with those seen in horses with spontaneous subclinical laryngeal paralysis. However, the possibility that the abnormal endoscopic findings in this latter group of horses are due to aberrant reinnervation is thought to be unlikely.  相似文献   

11.
12.
Clinical and morphologic features of a progressive polyneuropathy in young mature Alaskan Malamutes are described. Clinical signs included progressive paraparesis, synchronous pelvic limb gait, exercise intolerance, hyperesthesia, hypore-flexia, muscle atrophy, and tetraplegia. Electromyographic testing revealed diffuse fibrillation potentials and positive sharp waves in limb muscles, especially in muscles below the elbow and stifle. Pathologic findings in skeletal muscles and peripheral nerves included neurogenic muscle atrophy, focal or diffuse loss of myelinated nerve fibers, myelinoaxonal necrosis, and variable demyelination or remyelination.
Ultrastructural changes included axonal degeneration, presence of numerous Büngner bands, and denervated Schwann cell subunits. The nature and distribution of abnormal electrophysiologic and pathologic findings were suggestive of a distal sensorimotor polyneuropathy, which we have termed idiopathic polyneuropathy of Alaskan Malamutes to distinguish this condition from hereditary polyneuropathy of Norwegian Alaskan Malamutes, last described in 1982.  相似文献   

13.
Familial motor neuron disease in Rottweiler dogs: neuropathologic studies   总被引:1,自引:0,他引:1  
Two 6-week-old female Rottweiler littermates were evaluated for regurgitation, diminished growth, progressive ataxia, and pelvic limb weakness. Clinical examination indicated a progressive, diffuse, lower motor neuron disorder and megaesophagus. The pups were killed at 6 and 8 weeks of age. Lesions included central chromatolysis and swelling of the perikarya in many large motor neurons in the ventral gray matter of the spinal cord. Some involvement of red, oculomotor, trigeminal motor, and ambiguus nuclei of the brainstem was noted. Ultrastructurally, chromatolytic neurons had excess neurofilaments, and an increase in and enlargement of Golgi complexes. Wallerian-like degeneration was prominent in neuropil of spinal cord and in peripheral nerve. Clinical, histological, and ultrastructural findings were consistent with a progressive motor neuron disease.  相似文献   

14.
Four two-year-old Thoroughbreds suffered an acute gastrointestinal illness shortly after dosing with mineral oil which was thought to have been contaminated with an organophosphate compound. Three weeks later all four were noted to be dyspnoeic and endoscopic examination showed that they had developed bilateral laryngeal paralysis. Two of the horses died during severe bouts of dyspnoea six and eight months later and the third was killed shortly thereafter. Examination of the left and right recurrent laryngeal nerves from these horses showed a severe loss of myelinated fibres distally, especially in the left nerve. A similar but less severe lesion was seen in other long peripheral nerves, including the phrenic and digital nerves of the third horse. The spinal cord in two horses showed evidence of mild axonal degeneration which was not related to a particular tract or location. The fourth horse had bilateral laryngeal paralysis two years later. The acute clinical signs and delayed neurological sequelae seen in these horses were strongly suggestive of accidental organophosphate toxicity.  相似文献   

15.
In 25 adult dogs of various breeds, recurrent laryngeal nerve fibers were electrically stimulated at 2 points along their extralaryngeal course. Evoked compound muscle action potentials were recorded in the ipsilateral intrinsic laryngeal muscles, using a percutaneous needle electrode. Latencies, amplitudes, and durations were measured. Latencies were correlated with neck length (r = 0.88 on left and 0.82 on right). Five of the dogs were euthanatized, and the nerve length between the 2 stimulating needle electrodes was measured; calculated conduction velocities (mean +/- SD) were 55 +/- 6 m/s (left) and 57 +/- 6 m/s (right). In 38 additional canine cadavers, the lengths of the exposed left and right recurrent laryngeal nerves were correlated with neck length (r = 0.44 on left and 0.56 on right). A linear regression model is proposed for predicting normal latencies, despite variations in neck length among different breeds of dogs.  相似文献   

16.
AIMS: This study was undertaken in order to determine whether wild Burchell's Zebra (Equus burchelli) are affected by Idiopathic Laryngeal Hemiplegia (ILH). ILH has a high prevalence in the domestic horse and a negative control population has not been identified. METHODS: The work was conducted in two phases on two large farms in central Kenya during routine culls. The larynges of 42 zebra were removed and the left and right intrinsic laryngeal adductor and abductor muscles and recurrent laryngeal nerves were isolated. The muscles were weighed and biopsy samples of left and right recurrent laryngeal nerve and cricoarytenoideus lateralis muscles from 16 animals were taken for histological examination. RESULTS: Left adductor muscles were observed to be significantly lighter than right adductor muscles (p = 0.001). There was no significant difference between the weights of left and right laryngeal abductors (p = 0.260). There was no light microscopic evidence of pathological changes consistent with ILH in any of the muscle or nerve samples. CONCLUSIONS: Zebra do not appear to suffer from ILH and equids unaffected by ILH can have significantly lighter muscles on the left of the larynx. CLINICAL RELEVANCE: Mild asymmetries of the larynx on palpation may not be a reliable indicator of ILH. Zebra may be a potentially useful negative control animal for observational ILH studies.  相似文献   

17.
The spinal nerve roots and dorsal ganglia of 104- to 135-week-old rats with spontaneous radiculoneuropathy were examined by light and electron microscopy. Demyelination was common in myelinated fibers of various diameters of both ventral and dorsal roots. The most striking alteration was wide distention of myelin sheaths, which extended throughout the entire internode. The spaces formed between separated lamellae frequently were invaded by macrophages. Subsequent vesicular degeneration of myelin seemed to be mediated by invading macrophages. These processes caused complete myelin destruction, but most axons showed no degenerative changes except for obvious reduction in diameter. Occasionally, there were clumping and partial degradation of neurofilaments and ruptured axolemma in the severely demyelinated axons. A few fibers also were undergoing wallerian-type degeneration, perhaps secondary to the severe demyelinative changes. Remyelinating fibers in various phases of repair were coexistent with markedly demyelinated ones. Demyelinative changes described above also developed within some of these remyelinated internodes. There were no remarkable changes in neurons of the dorsal root ganglia, though accumulation of lipofuscin was common. Our findings suggest that the changes in the nerve roots are essentially a primary segmental demyelination in aging rats with radiculoneuropathy.  相似文献   

18.
Intoxication by pods of Prosopis juliflora (mesquite beans) causes an impairment of cranial nerve function in cattle and goats. In goats, vacuolation of neurons in the trigeminal motor nuclei has been reported. To study the lesions in cattle caused by consumption of P. juliflora pods and dry ground pods, eight 6- to 12-month-old male cattle were divided into 4 groups: group 1 was fed a ration containing 50% of pods; groups 2 and 3 received a ration containing 50 and 75% of dry ground pods, respectively; group 4 was the control. After 200 days, all cattle were killed and sampled for histologic evaluation. Samples of the trigeminal motor nucleus were examined by electron microscopy. All cattle from groups 1, 2, and 3 showed clinical signs resulting from impaired function of cranial nerves V, IX, X, and XII, starting 45-75 days after consumption of the plant. The main histologic lesions were vacuolation and loss of neurons in trigeminal motor nuclei and other motor cranial nerve nuclei with Wallerian-like degeneration in the cranial nerves. Mild denervation atrophy was observed in the masseter and other masticatory muscles. On electron microscopy, neurons of the trigeminal nuclei had markedly swollen mitochondria, with the mitochondrial cristae displaced peripherally, disoriented and disintegrating. Intoxication by P. juliflora seems to have a novel pathogenesis, characterized by a selective, primary, chronic, and progressive injury to mitochondria of neurons of the trigeminal and other cranial nerve nuclei. Cranial nerve degeneration and denervation atrophy of the muscles occurs as a consequence of the neuronal lesion.  相似文献   

19.
Reasons for performing study: Recurrent laryngeal neuropathy (RLN) is a common and debilitating peripheral nerve disease of horses, but it remains unclear if this disease is a mono‐ or polyneuropathy. An understanding of the distribution of the neuropathological lesions in RLN affected horses is fundamental to studying the aetiology of this very significant disease of tall horses. Objective: To determine whether RLN should be classified as a mono‐ or polyneuropathy. Methods: Multiple long peripheral nerves and their innervated muscles were examined systematically in 3 clinically affected RLN horses Results: Severe lesions were evident in the left as well as right recurrent laryngeal nerves in all horses, both distally and, in one case, also proximally. No primary axonal lesions were evident in other nerves nor were changes found in their innervated muscles. Conclusions: RLN is not a polyneuropathy but should be classified as a bilateral mononeuropathy. Potential relevance: Genetic and local factors specifically affecting the recurrent laryngeal nerves in RLN‐affected horses should now be investigated further.  相似文献   

20.
Stereological techniques have been increasingly employed for assessment and characterization of neuromuscular diseases in humans and animals. As an adjunct to histopathology, morphometrical algorithms provide quantitative evidence of the peripheral nerve composition, thereby shedding light on its fibre characteristics and basic electrophysiological properties. In the horse, stereological investigations already have focussed on the recurrent laryngeal, deep peroneal and lateral palmar nerves (LPN). Of these, only the latter is suitable for taking biopsies in clinical settings, however, it does not contain any motor fibres and Ia-afferents. On account of its virtually mixed fibre qualities, most researchers today recommend the cervical branch of the equine accessory nerve (AN) for harvesting diagnostic samples. Thus, the present study was carried out to gain morphometrical proof of the AN composition and to obtain stereological base values in healthy individuals using state-of-the-art technology. All parameters were compared to the common peroneal nerve (CPN), known to harbour all myelinated fibre classes. As this second biopsy site is located farther distally to the neuro-axis, attention was paid to possible length-dependent features. Taken together, digital image analysis could be accurately applied on all AN samples. Stereology supported the histological and clinical evidence that the AN contains all myelinated fibre types. The huge range and scatter of fibre counts and density (3351-17,812/mm(2)) per fascicle were comparable to that measured in the equine common peroneal, deep peroneal, lateral palmar and recurrent laryngeal nerves. Similar to those, fibre diameter distribution was bimodal with slow Abeta- and Agamma-mechanoceptor afferents outnumbering large myelinated Aalpha-fibres by a factor of about 1.5. With a g-ratio at 0.55 +/- 0.001, the overall degree of myelination in the AN is highly consistent and insignificantly ranges between that of the equine common peroneal and LPNs. Apart from this subtle deviation, a statistically relevant difference between the more proximal AN and the distal CPN could not be documented. By obtaining morphometrical standard parameters and even more sophisticated distribution indices, stereology is a valuable tool for detection of subtle changes that are likely to escape from the investigators' eyes. The AN serves as a reliable source for advanced peripheral nerve research and should be accompanied by farther distal nerve probes for assessment of neuropathies that present with a proximodistal gradient.  相似文献   

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