Peripheral cranial neuropathies consistent with cavernous sinus syndrome caused by extracranial nasopharyngeal lymphoma in a cat.

Cavernous sinus syndrome is a unique constellation of cranial nerve deficits occurring typically as a result of pathologic infiltration of the cavernous sinus, which is located in the lateral sellar compartment of the calvarium. This case report describes a polyneuropathy consistent with cavernous sinus syndrome as a result of a lesion outside of the cavernous sinus. The cat was presented with right internal and external ophthalmoplegia, loss of right corneal sensation, inspiratory stridor, dysphagia, dysphonia, tongue weakness, and weight loss. Magnetic resonance imaging identified a large nasopharyngeal mass along the base of, but without extension into, the calvarium. The histologic diagnosis was nasopharyngeal lymphoma. Focal extracranial masses should be considered as differential diagnoses for multiple cranial nerve deficits, including the constellation of clinical signs recognized as cavernous sinus syndrome.

Neuropathies crâniales périphériques compatibles avec un syndrome du sinus caverneux causé par un lymphome nasopharyngé extra-crânial chez un chat. Le syndrome du sinus caverneux est une constellation unique de déficits des nerfs crâniens se produisant typiquement comme le résultat d'une infiltration pathologique du sinus caverneux, qui est situé dans le compartiment sellaire latéral du calvarium. Le présent rapport de cas décrit une polyneuropathie compatible avec un syndrome du sinus caverneux résultant d'une lésion à l'extérieur du sinus caverneux. Le chat fut présenté avec une ophtalmoplégie interne et externe droit, perte de sensation au niveau de la cornée droite, stridor inspiratoire, dysphagie, dysphonie, faiblesse de la langue, et perte de poids. Un examen d'imagerie par résonnance magnétique permis d'identifier une large masse nasopharyngée suivant la base du calvarium, mais sans extension à l'intérieur. Le diagnostic histologique en fut un de lymphome nasopharyngé. Les masses focales extra-crâniales devraient être considérées dans le diagnostic différentiel lors de déficits de plusieurs nerfs crâniens, incluant la multitude de signes cliniques reconnus comme le syndrome du sinus caverneux.(Traduit par Dr Serge Messier).

Pathological classification of equine recurrent laryngeal neuropathy.

Recurrent Laryngeal Neuropathy (RLN) is a highly prevalent and predominantly left-sided, degenerative disorder of the recurrent laryngeal nerves (RLn) of tall horses, that causes inspiratory stridor at exercise because of intrinsic laryngeal muscle paresis. The associated laryngeal dysfunction and exercise intolerance in athletic horses commonly leads to surgical intervention, retirement or euthanasia with associated financial and welfare implications. Despite speculation, there is a lack of consensus and conflicting evidence supporting the primary classification of RLN, as either a distal ("dying back") axonopathy or as a primary myelinopathy and as either a (bilateral) mononeuropathy or a polyneuropathy; this uncertainty hinders etiological and pathophysiological research. In this review, we discuss the neuropathological changes and electrophysiological deficits reported in the RLn of affected horses, and the evidence for correct classification of the disorder. In so doing, we summarize and reveal the limitations of much historical research on RLN and propose future directions that might best help identify the etiology and pathophysiology of this enigmatic disorder.

Clinico-pathological findings in natural cases of "mascadera" in goats.

"Mascadera" is a chronic emaciating neuropathy affecting goats; it produces significant economic losses in many regions and its cause is unknown. Here, the histological lesions found in 15 animals naturally affected by the disease are described. Complete necropsy was performed and tissue samples were collected for histopathological study. Severe atrophy of the masseter and buccinator muscles and tongue was observed, as well as vacuolar degeneration of neurons in the nuclei of the trigeminal, facial, and glossopharyngeal nerves. No relevant lesions were observed in other tissues. These findings and the clinical signs are consistent with those observed by other authors in animals spontaneously and experimentally intoxicated with Prosopis juliflora. The disease may be due to consumption of a similar species present in our country that is still unknown. Further research on the etiology and pathogenesis of this disease is needed to establish appropriate prevention guidelines.

Brainstem and Cranial Nerve Disorders of Ruminants.

Asymmetrical signs of brainstem disease occur relatively infrequently in ruminants. The most common differential diagnoses include listeriosis, otitis media/interna, and pituitary abscess syndrome. Although these conditions produce signs of brainstem dysfunction, the diseases can usually be differentiated based on historical findings and subtle clinical differences. Basic laboratory diagnostic tests are often not specific in the definitive diagnosis but may be supportive. Advanced imaging techniques have proven to be useful in the diagnosis of otitis media/interna. Presumptive clinical diagnosis is confirmed at necropsy. Treatment involves a prolonged course of antibiotic therapy but is unrewarding in cases of pituitary abscess syndrome.

Imaging the cranial nerves.

An understanding of the normal course of the cranial nerves (CN) is essential when interpreting images of patients with cranial neuropathies. CN foramina are depicted best using computed X-ray tomography, but the nerves are depicted best using magnetic resonance imaging. The function and anatomy of the CN in the dog are reviewed and selected examples of lesions affecting the CN are illustrated.

Recovery of divergent avian bornaviruses from cases of proventricular dilatation disease: identification of a candidate etiologic agent.

BACKGROUND: Proventricular dilatation disease (PDD) is a fatal disorder threatening domesticated and wild psittacine birds worldwide. It is characterized by lymphoplasmacytic infiltration of the ganglia of the central and peripheral nervous system, leading to central nervous system disorders as well as disordered enteric motility and associated wasting. For almost 40 years, a viral etiology for PDD has been suspected, but to date no candidate etiologic agent has been reproducibly linked to the disease. RESULTS: Analysis of 2 PDD case-control series collected independently on different continents using a pan-viral microarray revealed a bornavirus hybridization signature in 62.5% of the PDD cases (5/8) and none of the controls (0/8). Ultra high throughput sequencing was utilized to recover the complete viral genome sequence from one of the virus-positive PDD cases. This revealed a bornavirus-like genome organization for this agent with a high degree of sequence divergence from all prior bornavirus isolates. We propose the name avian bornavirus (ABV) for this agent. Further specific ABV PCR analysis of an additional set of independently collected PDD cases and controls yielded a significant difference in ABV detection rate among PDD cases (71%, n = 7) compared to controls (0%, n = 14) (P = 0.01; Fisher's Exact Test). Partial sequence analysis of a total of 16 ABV isolates we have now recovered from these and an additional set of cases reveals at least 5 distinct ABV genetic subgroups. CONCLUSION: These studies clearly demonstrate the existence of an avian reservoir of remarkably diverse bornaviruses and provide a compelling candidate in the search for an etiologic agent of PDD.

Bilateral cavernous sinus syndrome in dogs: 6 cases (1999-2004).

OBJECTIVE: To determine clinical features, diagnostic imaging abnormalities, underlying disease, disease progression, and outcome in dogs with bilateral cavernous sinus syndrome. DESIGN: Retrospective study. ANIMALS: 6 dogs. PROCEDURE: Dogs were included if clinical signs consistent with bilateral cavernous sinus syndrome (i.e., deficits of the third, fourth, and sixth cranial nerves and at least 1 of the first 2 branches of the fifth cranial nerve) were present and a lesion of the cavernous sinus was identified by means of diagnostic imaging or postmortem examination. RESULTS: 5 dogs were evaluated because of problems referable to abnormal ocular motility or pupillomotor dysfunction, and 1 dog was evaluated because of partial motor seizures involving the face and bilateral mydriasis. Four dogs had neurologic signs referable to an extrasinusoidal lesion at the time of initial examination, and the remaining 2 dogs eventually developed extrasinusoidal signs. Besides neuroanatomic location, the only consistent neuroimaging feature was variably intense, heterogeneous enhancement of cavernous sinus lesions. Neoplasia was histologically confirmed as the underlying cause in 5 of the dogs and was suspected in the remaining dog. Median survival time for the 4 dogs that were treated was 199 days (range, 16 to 392 days). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that bilateral cavernous sinus syndrome is rare in dogs but should be suspected in dogs with compatible clinical signs. Affected dogs have a poor prognosis, and dogs with clinical signs of bilateral cavernous sinus syndrome should be systematically evaluated for neoplastic disease.

Brainstem and cranial nerve abnormalities: listeriosis, otitis media/interna, and pituitary abscess syndrome.

This article reviews three disorders associated with multiple asymmetric cranial nerve deficits in ruminants: encephalitic listeriosis,otitis media/interna, and pituitary abscess syndrome. Emphasis is placed on encephalitic listeriosis, an infectious disease of the brainstem and cranial nerves caused by Listeria monocytogenes. The epidemiology, pathophysiology, clinical manifestations, diagnosis,and treatment of encephalitic listeriosis are reviewed, and differences between cattle and small ruminants are noted. Physical and neurologic examination findings that distinguish otitis media/interna and pituitary abscess syndrome from encephalitic listeriosis are highlighted.

A study of an electrodiagnostic technique for the evaluation of equine recurrent laryngeal neuropathy.

The electrodiagnostic measurement of the thoracolaryngeal reflex (TLR) ('slap test') latency was compared to 5 other diagnostic techniques used for evaluation of laryngeal function, namely laryngeal muscle palpation, resting and immediately postexercise endoscopic examinations, and palpable and endoscopic responses to the TLR. Compared to resting endoscopy, the electrodiagnostic measurement of TLR latency was not found to be an accurate test for the evaluation of recurrent laryngeal neuropathy (RLN), nor was laryngeal muscle palpation or the endoscopic response to the TLR. Twenty-five (71%) of 35 Clydesdale horses examined were affected by RLN; 16 (46%) had mild, 5 (14%) moderate, 3 (9%) severe hemiparesis and 1 (3%) had total laryngeal paralysis. Within these 35 horses, physical traits such as height or neck length did not correlate with the incidence or severity of RLN. Ten control ponies showed no evidence of abnormal laryngeal function.

[Multiple cranial nerve deficits after eye injury and eye enucleation. A case report]. / Multiple Kopfnervenausfälle nach Augenverletzung und Bulbusexstirpation. Ein Fallbericht.

A 12-year old Simmental x Red Holstein cow was admitted to the clinic eight months after an eye laceration followed by eye extirpation. The region of the excised eye had healed, however, the cow had additional trigeminal and facial nerve palsy. Nevertheless, the cow was in good general condition, and therefore, was sent home without therapy. After delivering a sound calf, her physical condition deteriorated and she was slaughtered. Histologic examination of the brain revealed degeneration of the right optic nerve and right half of the chiasma opticum as well as left tractus opticus (opposite side); furthermore, degenerative changes with slight inflammation of the right vestibular nuclei were observed. Possible pathogenesis is discussed.

Recognition and localization of intracranial disease.

Clinical recognition and localization of disease within the nervous system is paramount to effective diagnosis and treatment of animals with neurologic disease. Thorough examination of the nervous system is based upon an understanding of normal neuroanatomy and physiology. Once a disease process is established to involve the nervous system, localization of the abnormalities within the nervous system is imperative for formulation of a differential diagnosis and diagnostic plan. This article reviews important aspects of the neurologic examination that lead to neuroanatomical localization.

A retrospective study of cavernous sinus syndrome in 4 dogs and 8 cats.

Cavernous sinus syndrome (CSS) is characterized by deficits in more than one of the cranial nerves (CN) that traverse the cavernous sinus at the base of the cranial vault: CN III (oculomotor), IV (trochlear), VI (abducens), and the first two branches of CN V (trigeminal). Records from 4 dogs and 8 cats with CSS diagnosed over a 14-year period were reviewed. The most common clinical signs were ophthalmoparesis or ophthalmoplegia, mydriasis with no direct or consensual pupillary light reflexes, ptosis, decreased corneal sensation, and decreased retractor oculi reflex. All cats had initial signs referable to a left CSS lesion (one had bilateral CSS), whereas in all dogs the lesions were localized to the right cavernous sinus. Median ages at diagnosis were 9 and 10 years of age for dogs and cats, respectively. Cerebel lomedullary cisternae cerebrospinal fluid analysis in 6 animals was useful as a sensitivebut nonspecific diagnostic test of an intracranial inflammatory or neoplastic lesion. Magnetic resonance imaging scans provided a more definitive diagnostic test in all dogs, revealing a contrast-enhancing mass on T1 weighted scans in the region of the cavernous sinus. A definitive pathological diagnosis was obtained in 2 dogs: a primary intracranial neoplasm and a metastatic intracranial neoplasm. A definitive diagnosis was obtained in 6 cats: metastatic neoplasm (n = 1), primary intracranial neoplasm (n = 1), primary intracranial infectious disease (n = 2), and associated systemic infectious disease (n = 2). The prognosis associated with CSS in dogs and cats was considered guarded to poor.

Evaluation of the pathogenesis of vagus indigestion in cows with traumatic reticuloperitonitis.

OBJECTIVE--To evaluate the functional importance of impaired reticular contractions attributable to inflammatory adhesions in the pathogenesis of vagus indigestion in cows with traumatic reticuloperitonitis (TRP). DESIGN--Case control study. ANIMALS--42 dairy cows with TRP were compared with 10 healthy control cows. Cows with TRP were assigned to 3 groups: cows with uncomplicated TRP (n = 15), cows with TRP and a disturbance of digesta passage through the reticular-omasal orifice (TRP-AD; n = 17), and cows with TRP and a disturbance of digesta passage through the pylorus (TRP-PD; n = 10). PROCEDURE--Cows were evaluated, using routine clinical methods, biochemical analysis of blood and ruminal fluid samples, exploratory rumenotomy, and postmortem examination. RESULTS--Damage of thoracic and abdominal parts of the main vagal branches were not evident in cows with TRP. Parareticular inflammatory adhesions were more extensive in cows with TRP-AD and in cows with TRP-PD than in cows with uncomplicated TRP. Reticular motility was decreased in cows with TRP-AD and TRP-PD, compared with cows with uncomplicated TRP and control cows. In contrast to cows with uncomplicated TRP and cows with TRP-AD, the abomasum was impacted with large amounts of long fibrous material in most of the cows with TRP-PD. CLINICAL IMPLICATIONS--We believe that disturbances of digesta passage in cows with TRP represent distinct stages of a common pathogenetic course. The primary disease mechanism was a disturbance in particle-separating processes in the reticulum/rumen attributable to mechanical inhibition of reticular motility that was the result of extensive inflammatory parareticular adhesions.

The effect of reversible left recurrent laryngeal neuropathy on the metabolic cost of locomotion and peak aerobic power in thoroughbred racehorses.

The effect of left recurrent laryngeal neuropathy (LRLN) on the metabolic cost of locomotion (MCL) and peak aerobic power (VO2peak) was evaluated in four trained Thoroughbred racehorses. Oxygen consumption (VO2), carbon dioxide production (VCO2), venous lactate concentrations (LAC), and heart rate (HR) were measured during a treadmill exercise test (TET). Each horse performed the exercise test four times, alternating between normal upper airway function and reversibly induced LRLN. Subcutaneous infusion of 2% mepivicaine, a local anesthetic, into the region were the left recurrent laryngeal nerve passes caudal to the cricoid cartilage was used to induce LRLN. The induction of LRLN did not alter the relationship between VO2 and treadmill speed at exercise intensities where VO2 was less than VO2peak (< 9 m/sec). However, a 15.3% reduction in VO2peak (Normal = 165.3 +/- 3.4, LRLN = 140.0 +/- 3.2 mL/kg/min +/- SE, P < .001) occurred at higher treadmill speeds in horses with induced LRLN. A significant group (Normal v LRLN) by treadmill speed effect was found for LAC and R only at treadmill speeds where VO2 = VO2peak. Peak lactate (LACpeak) did not change after the induction of LRLN. The relationship between HR and treadmill speed increased in horses with induced LRLN at exercise intensities where VO2 < VO2peak. Peak heart rate (HRpeak) remained unchanged. Performance as indicated by the maximum number of speed intervals completed (STEPmax) decreased 7% in horses with induced LRLN (Normal = 9.1 +/- 0.04, LRLN = 8.5 +/- 0.2 minutes +/- SE, P < .04). A comparison of paired exercise test measurements showed no evidence of a training effect, or decreased performance caused by a learned response, over the course of the experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscular pathology in equine laryngeal neuropathy.

Three adductor muscles of the larynx, the cricoarytenoideus lateralis (CAL), the arytenoideus transversus (AT) and the ventricularis (Ve), from 36 horses were examined histologically. The neurogenic changes seen in each muscle were evaluated qualitatively. In addition, in 6 horses with clinical and subclinical signs of neurogenic atrophy, measurements of muscle fibre area were performed. Neurogenic changes observed in the Ve were less than in CAL and AT. Measurements of muscle fibre area also demonstrated that CAL and AT showed a wider range of pathological changes than did Ve. The results show that denervation does not uniformly affect all adductor muscles of the larynx. On the other hand, the appearance in some animals of fibre type grouping in the right AT to the same or to a greater extent than in the left AT supports the classification of equine laryngeal neuropathy as a distal axonopathy.

Immunohistological study of encephalomalacia in pigs infected with Aujeszky's disease virus.

Seven hysterectomy-derived colostrum-deprived pigs aged 4 weeks were inoculated intranasally with 10(3) plaque-forming units (1 ml) of the Yamagata YS-81 strain of Aujeszky's disease virus. One pig died and five developed encephalomyelitis and trigeminal ganglionitis. Three pigs killed on days 12-16 showed prominent malacic degeneration. Associated with the malacic foci were many lysosome-positive cells. IgG- and IgM-containing cells in the perivascular cuffs and glial nodules were first detected on day 7, after which they increased in number. They were thought to be closely associated with the presence of neutralizing antibody. These findings suggest that inflammatory cells in the brain are of haematogenous origin.

Monoparesis (monoplegia) and cranial mononeuropathy. Peripheral/cranial nerve and nerve root diseases.

Monoparesis (monoplegia) refers to partial (monoparesis) or complete (monoplegia) loss of voluntary motor function in a single limb. Cranial mononeuropathy implies that there is dysfunction referable to a single cranial nerve. These neurologic problems are generally associated with peripheral and cranial nerve lesions, respectively. These problems are discussed together here because similar, if not identical, diseases are involved.