Polioencephalomalacia and Heart Failure Secondary to Presumptive Thiamine Deficiency, Hepatic Lipidosis, and Starvation in 2 Abandoned Siamese Cats.

Two 4-year-old spayed female Siamese cats were seized by the British Columbia Society for the Prevention of Cruelty to Animals after confinement to an abandoned housing unit without food for 9 weeks. One cat was found dead, and the second was euthanized within 24 hours due to neurologic deterioration despite therapy. Polioencephalomalacia of the caudal colliculus, hepatic lipidosis, cachexia, and congestive heart failure with cardiomyocyte atrophy were identified in both cats through postmortem examination and attributed to a prolonged period of starvation. Brain lesions were likely the result of thiamine deficiency (Chastek paralysis), which can be associated with both malnutrition and liver disease. This case highlights the importance of thiamine supplementation during realimentation of cats with hepatic lipidosis. Heart failure resulting from cachexia may have contributed to the death of the first cat and the morbidity of the second cat.

Focal symmetrical encephalomalacia in a goat.

Focal symmetrical encephalomalacia (FSE) is the most prominent lesion seen in the chronic form of enterotoxemia caused by Clostridium perfringens type D in sheep. However, this lesion has not been reported in goats. The current paper reports a case of FSE in a goat from the state of Paraíba in the Brazilian semiarid region. As reported by the farmer, 30, 4-48-month-old animals from a flock of 150 goats died after showing nervous signs, including blindness and recumbence, for periods varying between 1 and 14 days. The flock was grazing native pasture supplemented with wheat and corn bran. Additionally, lactating goats were supplemented with soybeans. A 4-month-old goat with nervous signs was examined clinically and then necropsied 3 days after the onset of clinical signs. Bilateral, focal, and symmetrical areas of brown discoloration were observed in the internal capsule and thalamus. Histologic lesions in these areas consisted of multifocal, bilateral malacia with a few neutrophils; endothelial cell swelling; perivascular edema; and hemorrhages. The etiology of these lesions was not determined. However, FSE is considered pathognomonic for C. perfringens type D enterotoxemia in sheep, and it is speculated that this microorganism was the etiologic agent in the present case. The flock had been vaccinated against type D enterotoxemia only once, approximately 3 months before the beginning of the outbreak. Insufficient immunity due to the incorrect vaccination protocol, low efficacy of the vaccine used, and a diet including large amounts of highly fermentable carbohydrates were suspected to be predisposing factors for this outbreak.

Toxicology of Astragalus lusitanicus Lam.

Astragalus lusitanicus is a toxic legume grown in Morocco and in some other Mediterranean countries. In small ruminants, poisoning by this plant is dominated by nervous signs characterized by many cycles of excitement-depression. Macroscopic examination of poisoned animals showed congestive lesions and oedema in the brain and lungs. Microscopic lesions consisted mainly of vacuolar degeneration in neurons, hepatocytes and in spleen and kidney cells. Serum activity of AST and CK as well as blood glucose and urea were increased as a result of poisoning. However, serum activity of alpha-mannosidase was not modified as is the case in locoism. Chemical investigations showed that A. lusitanicus does not contain swainsonine or miserotoxin and its selenium concentration is very low. However, this legume contains indolizidin alkaloids and a first compound was purified and identified.

Polioencephalomalacia associated with the ingestion of ammonium sulphate by sheep and cattle.

In the latter part of 1991 an unusual neurological disease was recognised on several farms in England. This report describes the case histories and clinical, biochemical and pathological findings in six calves and two lambs aged from two to 44 weeks obtained from five of these farms. Laminar cerebrocortical necrosis and severe bilateral necrosis of the thalamus and/or striatum progressing to cavitation were recognised in their brains. These changes are similar to those of experimental sulphate toxicity. Morbidity rates of 16 to 48 per cent and mortality rates of 0 to 8 per cent were recorded. The affected animals did not respond to vitamin B1 treatment; the erythrocyte transketolase levels of in-contact cattle and of one untreated affected calf and one untreated lamb were within the normal range. All five farms had recently introduced a proprietary concentrate ration containing ammonium bicarbonate. After this ration was withdrawn no new cases of nervous clinical disease were observed. It is suggested that, in at least some cases, the morphology and topography of lesions may distinguish sulphate induced polioencephalomalacia from that of sporadic thiamine-dependent cerebrocortical necrosis.

Sonography of the internal capsule and basal ganglia in infants. Part II. Localization of pathologic processes in the sagittal section through the caudothalamic groove.

Sagittal sonograms through the caudothalamic groove routinely display a gangliothalamic ovoid delimited by the lateral ventricle, the perimesencephalic cistern, and the radiations of the corpus callosum. The caudothalamic groove divides the superior surface of the ovoid into an anterior caudate arc and a posterior thalamic arc. The cerebral peduncle divides the inferior surface of the ovoid into an anterior ganglial arc, a middle peduncular arc, and a posterior thalamic arc. The genu of internal capsule constantly courses from the anterior end of the caudothalamic groove down to the peduncular arc and is easily identified. The gangliothalamic ovoid exhibits four obliquely oriented bands of increased and decreased echogenicity. The anteriormost hyperechoic band 1 corresponds to the head of the caudate nucleus. Hypoechoic band 2 corresponds to the globus pallidus, genu of the internal capsule, and cerebral peduncle. Hyperechoic band 3 corresponds to the ventral and lateral thalamic nuclei (exclusive of the pulvinar). Hypoechoic band 4 corresponds to the pulvinar. Lesions of the medial nucleus of the globus pallidus appear as hyperechoic foci that abut on the anterior surface of genu just above the peduncle and that have a narrow convex caudal margin. Lesions of the lateral nucleus of globus pallidus abut on the genu distant from the peduncle, spare the medial nucleus adjacent to the peduncle, and have a broad caudal border. Lesions of the head of caudate nucleus affect the anterior pole of the ovoid; those of the body affect the caudate arc superior to the caudothalamic groove. Thalamic lesions increase the echogenicity of bands 3 and 4.

[Staged or bilateral malacias in the area of the middle cerebral or posterior cerebral arteries. Comparative study of the risk of multifocal stroke in 120 patients]. / Les ramollissements étagés ou bilatéraux du territoire des artères cérébrales moyennes ou cérébrales postérieures. Etude comparative du risque d'atteinte multifocale chez 120 patients.

We studied and compared 120 cases with an infarction in the superficial area of the middle cerebral artery (MCA) or the posterior cerebral artery (PCA). Among the patients with an infarction of the MCA area, 8% had a capsular involvement and 3% a delayed contralateral sylvian infarction. Among the patients with an infarction of the PCA area, 35% had a thalamo-mesencephalic involvement and 23% a delayed contralateral occipital infarction. Thus, multifocal infarction was significantly more frequent in the PCA area than in the MCA area. No particular vascular risk factor could explain this difference, which may be related to general constitutional factors, such as the type of collateral supply or the vascular anatomy itself. In the PCA area only, we found a significant association between the severity of risk factors and occurrence of multifocal infarction.

Avian encephalomalacia in Barbados, West Indies: a description of spontaneous field cases with feed analyses.

The clinical, necropsy and histopathological findings in four natural outbreaks of encephalomalacia are reported. Feed analyses implicated low levels of vitamin E as the probable cause of the condition. Treatment with vitamin E has proved to be very effective. The instability of vitamin E in animal feed ingredients during long periods of shipment into the Caribbean may be important in the pathogenesis of the disease.

Avian encephalomalacia in Barbados, West Indies: a description of spontaneous field cases with feed analyses

The clinical, necropsy and histopathological findings in four natural outbreaks of encephalomalcia are reported. Feed analyses implicated low levels of vitamin E as the probable cause of the condition. Treatment with vitamin E has proved to be very effective. The instability of vitamin E in animal feed ingredients during long priods of shipment to the Caribbean may be important in the pathogenesis of the disease. (AU)

The cortical form of subacute necrotizing encephalopathy of the Leigh type. A light- and electron-microscopic study.

The present paper is a clinico-pathological study of a 14-year-old boy with a chronic, progressive occipital syndrome for which he was operated upon. Postoperatively, metabolic acidosis developed. Pathological anatomy revealed spongy necrosis of the thalamus and corpora quadrigemina with the typical histological features of Leigh's necrotizing encephalopathy. Similar necrotic lesions had developed in the occipital cortex. At this level apart from the typical foci, cavitating necrosis was found as well as involvement of the smaller vessels of the pial circulation. Electron microscopy revealed vascular and glial changes suggestive of primary mesenchymoglial dystrophy. The histiocytes presented intracytoplasmic multiplication of lysosomes and their transformation into lipofuscin pigment. The changes demonstrate a juvenile cortical form of Leigh's subacute necrotizing encephalopathy.

Spontaneous thrombosis of deep cerebral veins: a complication of arteriovenous malformation.

An uncommon type of stroke in children is presented. An intracranial arteriovenous malformation in a 13-year-old boy spontaneously occluded about 22 months after surgical intervention. Precipitating factors, such as bacterial infections, could not be demonstrated in this patient, who had been attending school since the time of the craniotomy. The histological features of venous encephalomalacia in the galenic territory are contrasted with hemorrhagic encephalomalacia as seen after arterial occlusions: in the former, hemorrhages are more widespread and edema is more pronounced.