Magnetic resonance imaging in two dogs with central nervous system disease

Accurate localization of the lesions in two dogs with progressive neurological disease was demonstrated with magnetic resonance imaging (MRI). The first dog had unilateral cerebellar signs with associated paradoxical vestibular symptoms. The CSF tap and clinical localization suggested a right-sided cerebellar tumour and this was confirmed with MRI scanning. The second dog had predominantly asymmetrical fore-brain signs with circling, personality changes, seizures and contralateral proprioceptive deficits. CSF analysis suggested an inflammatory or neoplastic condition. MRI showed a diffuse oedematous lesion of the left cerebral hemisphere which corresponded exactly with the lesions seen at necropsy. The advantages of MRI over CT scans are discussed.     

Magnetic resonance imaging of a cerebral cavernous haemangioma in a dog

A 13-month-old, neutered, male Golden retriever presented with seizures and progressive depression. Clinical and neurological assessment was consistent with severe intracranial disease. The neurological condition progressively deteriorated and magnetic resonance imaging (MRI) revealed the presence of a large, contrast-enhancing, space-occupyingmass in the right cerebral hemisphere. Therapy with corticosteroids, mannitol and furosemide ameliorated the signs of depression and ataxia, but the owner elected euthanasia after 1 week. Post mortem examination of the brain confirmed the presence of a large haemorrhagic lesion in the right olfactory lobe, the histopathological appearance of which was consistent with cerebral cavernous haemangioma. This is the 1st case describing the MRI appearance of a cavernous haemangioma of the cerebrum in the veterinary literature.     

Porencephaly in dogs and cats: relationships between magnetic resonance imaging (MRI) features and hippocampal atrophy

Porencephaly is the congenital cerebral defect and a rare malformation and described few MRI reports in veterinary medicine. MRI features of porencephaly are recognized the coexistence with the unilateral/bilateral hippocampal atrophy, caused by the seizure symptoms in human medicine. We studied 2 dogs and 1 cat with congenital porencephaly to characterize the clinical signs and MRI, and to discuss the associated MRI with hippocampal atrophy. The main clinical sign was the seizure symptoms, and all had hippocampal atrophy at the lesion side or the larger defect side. There is association between hippocampal atrophy or the cyst volume and the severe of clinical signs, and it is suggested that porencephaly coexists with hippocampal atrophy as well as humans in this study.     

Bilateral focal cerebral angiomatosis associated with nervous signs in a cat

A case of cerebral angiomatosis in a cat was associated with neurologic signs characterized by clusters of severe generalized seizures. Bilaterally in the gray matter, most prominent in the cingulate gyrus, there was focal accumulation of garlandlike arrangements of blood vessels. Vessels exhibited activated, hypertrophic endothelial cells and thickening and progressive dystrophic mineralization of the basement membrane, with complete luminal obstruction of some affected vessels. Thickening of the basement membrane was due to accumulation of endothelium-derived proteins such as laminin and von Willebrand factor. Furthermore, moderate diffuse astrogliosis was observed. Findings indicate an idiopathic angiomatosis, with clinical signs possibly due to ischemia resulting from narrowing or complete obliteration of vessel lumina. Changes represent a unique endothelial cell-derived lesion within the brain not previously described in humans or domestic animals.     

An isolated cryptococcal urinary tract infection in a cat

A male domestic shorthaired cat was presented for evaluation of stranguria and pollakiuria. A cryptococcal urinary tract infection (UTI) was diagnosed cytologically and via fungal culture. No evidence of systemic involvement was found. Chronic renal failure was a concurrent disease in this cat. Treatment consisted of oral fluconazole. Clinical signs resolved after 2 weeks of therapy, and fluconazole was discontinued after 6 months when negative urine culture results indicated resolution of the infection. This case demonstrates that correct identification of cryptococcal UTI allows for administration of therapy that can be associated with resolution of clinical signs.     

Magnetic resonance imaging of a giant frontal hemorrhagic mucocele with intracranial extension in a cat

A 6‐year‐old domestic short‐haired cat was presented with an acute onset of right cortical encephalopathy. Magnetic resonance imaging (MRI) performed 4 days after the onset of clinical signs revealed a lesion originating from the right frontal sinus with intracranial extension and compression of the right frontal lobe. The lesion was T1‐weighted hypointense and T2‐weighted and fluid‐attenuated inversion recovery hyperintense. Signal voids within the lesion were observed on T2* images, consistent with hemorrhage. Peripheral ring enhancement was visible on postcontrast sequences. These features were consistent with a giant hemorrhagic mucocele. To the authors’ knowledge, this is the first report of MRI characteristics of this lesion in a cat.     

Cutaneous cryptococcosis in three cats

Cutaneous cryptococcosis was diagnosed in 3 cats. No other organ involvement was found. One cat has remained healthy after surgical excision of the cryptococcal skin lesion. One cat was euthanatized after diagnosis. The third cat was treated successfully with a 5-month course of ketoconazole.     

Pyogranulomatous meningoencephalitis associated with dematiaceous fungal (Cladophialophora bantiana) infection in a domestic cat.

A 6-month-old, castrated male domestic cat with progressive neurological signs of 2-3 weeks duration was necropsied. Macroscopic findings were restricted to the brain and included irregularly shaped, well-delineated but unencapsulated areas of intense black pigmentation involving the rostral portion of both cerebral hemispheres. Microscopically, numerous brown, oblong, segmented branching hyphae and conidial-like structures and extensive pyogranulomatous inflammation were identified throughout the cerebral lesion and in adjacent blood vessels. Hyphae and oval conidia were best demonstrated with either Gomori methenamine silver or periodic acid-Schiff stain. Fungal infection in the brain of this cat was unrelated to any concurrent immunodeficiency syndrome or immunosuppressive treatment. This report deals with a case of cerebral phaeohyphomycosis from which a different species of dematiaceous fungus, Cladophialophora bantiana, was isolated and identified.     

Congenital external hydrocephalus in a dog

A 4-year-old female Chihuahua was presented with progressive seizures, blindness and lethargy. Neurolocalisation was consistent with a diffuse brain lesion affecting the forebrain and cerebellum. MRI demonstrated dilation of the subarachnoid space dorsolaterally surrounding the cerebrum, filled with cerebrospinal fluid (CSF). Ventricular system size was normal, but mild cerebral atrophy was suspected. There was pachymeningeal contrast enhancement, but CSF analysis was unremarkable. This lesion was interpreted to be an external hydrocephalus of suspected congenital origin.     

Rostral cerebellar arterial infarct in two cats

A 10-year-old female neutered domestic shorthair (DSH) cat and a 6-year-old female neutered Siamese cat were presented following a peracute onset of decerebellate rigidity and a cerebellar vestibular syndrome, respectively. In both cats, physical examination and routine blood tests were unremarkable, as was routine analysis of cerebrospinal fluid obtained from the DSH cat. Based on the magnetic resonance imaging (MRI) features - focal wedge-shaped lesion in the cerebellum characterised by hyperintensity in T2-weighted, T2( *)-gradient echo and fluid attenuated inversion recovery (FLAIR) images - a presumptive diagnosis of cerebellar infarct was made in both cases. In the DSH cat, the post-mortem examination confirmed the diagnosis of cerebellar infarct and additionally found acute renal infarcts and a pulmonary neoplasia. In the Siamese cat, ultrasonographic evaluation of the heart revealed a probable low-grade chronic valvular endocarditis which was thought to be a potential source of thromboembolism. This paper describes the first two cases - one confirmed and the other suspected - of cerebellar infarct in the cat. The in vivo potential diagnostic value of the MRI study is highlighted. Cerebellar infarcts should be included in the differential diagnosis of cat with a peracute onset of cerebellar signs regardless of the severity of neurological deficits.     

Cerebral vascular hamartoma in a geriatric cat

An 11-year-old castrated male domestic medium hair cat was presented with neurological signs consistent with a right thalamocortical lesion. Computed tomography (CT) images revealed a heterogeneously, hyperattenuating, poorly contrast enhancing intra-axial mass within the right lateral ventricle. The histological diagnosis at post-mortem examination was vascular hamartoma with hemorrhage and necrosis. This is the first report of a vascular hamartoma affecting the thalamocortex in a geriatric cat. Also, this is the first time that CT images of a feline cerebral vascular hamartoma have been reported.     

MRI characteristics of suspected acute spinal cord infarction in two cats, and a review of the literature

A 10-year-old neutered male Persian cat and a 4-year-old spayed female domestic shorthair (DSH) cat were evaluated for acute-onset severe lateralising tetraparesis and hemiplegia, respectively. Both cats also had left-sided Horner's syndrome. Neurological examination of the cats localised the lesion to cranial to C5 in the Persian and the left cervical intumescence (C6-T2) in the DSH. Physical examinations were otherwise generally unremarkable. Routine laboratory tests and spinal radiography were normal for the Persian cat and were not performed for the DSH cat. A cerebrospinal fluid (CSF) tap was attempted for the Persian cat but aborted because of gross blood contamination, and was not performed for the DSH cat. Magnetic resonance imaging (MRI) of the Persian cat revealed a lesion within the spinal parenchyma at segments C1 to C3 (slightly more left-sided) which was iso- to hypointense on T1-weighted scans and hyperintense on T2-weighted scans, and which enhanced slightly with gadolinium. MRI of the DSH cat revealed a lesion within the spinal parenchyma at segment C7 (predominantly left-sided) which was hypointense on T1-weighted scans and hyperintense on T2-weighted gradient echo scans. Contrast was not administered. The MRI findings in both cases were highly suggestive of acute spinal cord infarction, based upon comparison to human cases. Both cats made full neurological recoveries with supportive treatment only. This paper describes two cases of suspected acute spinal cord infarction in the cat, demonstrates the potential diagnostic value of MRI, and discusses the clinical syndrome of this condition with a brief review of published cases.     

Two cases of feline visceral and cutaneous leishmaniosis in Spain

This paper describes clinical signs and lesions in two cases of leishmaniosis--one visceral and one cutaneous in the cat (Felis catus domesticus). The diagnosis was achieved by a combination of serology, light and electron microscopic studies. The vague nature of the clinical signs observed in both cases was particularly striking, and clinical features were similar to many other diseases commonly found in cats. Therefore, the use of various investigations to detect leishmaniosis (serum chemistry, serology and histopathology) is highly recommended in cases where clinical signs do not respond to conventional treatment.     

Two cases of feline leishmaniosis in Switzerland

Two cats with Leishmania species infections were investigated. The first had been imported from Spain with a non-healing, ulcerated nodule on a hindleg. The presence of Leishmania species was detected by histopathology and pcr on samples of skin. The lesion was unresponsive to treatment with allopurinol for three months but the cat was treated successfully by removing the lesion surgically. The second cat had lived in both Spain and Switzerland, and had a history of recurrent skin lesions on its head and neck. A diagnosis of pemphigus foliaceus was made on the basis of histopathology, but Leishmania species serology (elisa) and pcr of skin were positive, leading to a diagnosis of a Leishmania species infection combined with pemphigus foliaceus.     

Chiari‐like malformation in two cats

Two male, neutered, domestic, shorthaired cats were evaluated for progressive paresis and ataxia. Neurological examinations suggested a spinal cord lesion in each case. Complete blood examination and cerebrospinal fluid analysis were unremarkable in both cats. MRI revealed malformation of the occipital bone with herniation of the cerebellar vermis through the foramen magnum but without syringomyelia. Chiari‐like malformation was suspected in both patients. MRI repeated one year later in both cats because of progression of clinical signs yielded the same findings as the initial scans. Foramen magnum decompression in one cat was associated with resolution of clinical signs.     

Chylothorax associated with cryptococcal mediastinal granuloma in a cat

A 10-year-old neutered female cat had chylothorax, precaval syndrome, and a mediastinal granuloma resulting from infection with Cryptococcus neoformans. Diagnosis of a chylous effusion was made by cytologic examination of pleural fluid and by finding higher triglyceride levels in the effusion than in serum (825 vs. 64 mg/dl, respectively). Postmortem examination revealed cryptococcal organisms in the mediastinal granuloma, lungs, cerebral meninges, and connective tissues adjacent to the thyroid gland. Chylous effusion in a cat associated with cryptococcosis has not been reported previously. Cryptococcosis should be included in the differential diagnosis in chylous effusions in cats.     

Porencephaly and hydranencephaly in six dogs

A retrospective study was performed to identify dogs with cerebrospinal fluid-filled cavitatory lesions on MRI. Six dogs were included and the lesions were classified. In the three dogs in the present study with hydranencephaly, unilateral but complete loss of the temporal and parietal lobes was noted and had almost complete loss of the occipital and frontal lobes of a cerebral hemisphere. In the three dogs with porencephaly, there was unilateral incomplete loss of the parietal lobe and one dog had additional partial loss of the temporal and frontal lobes. Two of the dogs with porencephaly had seizures; the third showed no associated clinical signs. The dogs with hydranencephaly had mentation changes and circled compulsively. The two porencephalic dogs with seizures were treated with phenobarbitone. One of the dogs with hydranencephaly showed increased frequency and duration of circling; one dog's clinical signs did not progress and the third dog was euthanased due to increasing aggression. The dog with increased circling had ventriculoperitoneal shunt placement and the circling frequency reduced.     

Toxoplasma gondii brain granuloma in a cat: diagnosis using cytology from an intraoperative sample and sequential magnetic resonance imaging

A cat with a history of seizures and clinical suspicion of forebrain disorder underwent a brain magnetic resonance imaging. A space-occupying lesion was identified in the left temporal lobe. The mass was surgically removed, and cytological, histological and immunohistochemical examinations documented the presence of Toxoplasma gondii. A definitive diagnosis of an intracranial T gondii granuloma was made. The cat was treated with clindamycin and phenobarbital and the seizures did not recur. After 10 months, a second magnetic resonance imaging showed severe brain atrophy, but T gondii granuloma recurrence was not noted. Twenty-one months after surgery, the cat's condition deteriorated, and another magnetic resonance imaging showed a presumptive recurrence of T gondii granuloma. In cats, T gondii granuloma must be considered as a differential diagnosis even when only a single intracranial mass is present. Cytology and magnetic resonance imaging can be useful in making a definitive diagnosis and to follow the evolution of the lesion.     

Cystic nasal adenocarcinoma in a cat treated with piroxicam and chemoembolization

A 13-year-old, castrated male Siamese cat was presented with a 4-month history of recurrent seizures and bilateral conjunctivitis and rhinitis. Computed tomography of the brain and nose revealed a cystic lesion in the cranial cavity that compressed the brain and invaded the nose. Nasal biopsy revealed a nasal adenocarcinoma. The cat was treated with intermittent antibiotics, phenobarbital, piroxicam, and chemoembolization; it survived for 2 years after diagnosis.