Bruxism in awake dogs as a clinical sign of forebrain disease: 4 cases.

BACKGROUND: Bruxism is a repetitive masticatory muscle activity characterized by clenching or grinding of the teeth, or by bracing or thrusting of the mandible, or both. OBJECTIVES: To investigate whether bruxism in awake dogs could be associated with brain lesions. ANIMALS: Four dogs with episodic bruxism in the awake state. METHODS: Observational retrospective single-center case series. Inclusion criteria were dogs examined between 2010 and 2021 with episodic bruxism as a presenting complaint or observed during the examination or hospitalization, complete medical records and magnetic resonance imaging or computed tomography of the brain. Bruxism during epileptic seizures as oroalimentary automatism was an exclusion criterion. RESULTS: Four dogs met the inclusion criteria. Two dogs had bruxism while awake as a presenting complaint, whereas in the remaining 2 it was a clinical finding. All dogs had neuroanatomical localization consistent with a forebrain lesion, with diencephalic involvement in 3/4. The diagnostic evaluation was consistent with neoplasia (n = 2) and meningoencephalitis of unknown origin (n = 2), in 1 case accompanied by corpus callosum abnormality affecting the forebrain, in 3 dogs advanced imaging findings were suggestive of increased intracranial pressure. All dogs were euthanized. CONCLUSIONS AND CLINICAL IMPORTANCE: Our results suggest that the presence of bruxism in the awake state associated with other neurological deficits might indicate a forebrain lesion.

Clinical features, diagnosis, and survival analysis of dogs with glioma.

BACKGROUND: Gliomas in dogs remain poorly understood. OBJECTIVES: To characterize the clinicopathologic findings, diagnostic imaging features and survival of a large sample of dogs with glioma using the Comparative Brain Tumor Consortium diagnostic classification. ANIMALS: Ninety-one dogs with histopathological diagnosis of glioma. METHODS: Multicentric retrospective case series. Signalment, clinicopathologic findings, diagnostic imaging characteristics, treatment, and outcome were used. Tumors were reclassified according to the new canine glioma diagnostic scheme. RESULTS: No associations were found between clinicopathologic findings or survival and tumor type or grade. However, definitive treatments provided significantly (P = .03) improved median survival time (84 days; 95% confidence interval [CI], 45-190) compared to palliative treatment (26 days; 95% CI, 11-54). On magnetic resonance imaging (MRI), oligodendrogliomas were associated with smooth margins and T1-weighted hypointensity compared to astrocytomas (odds ratio [OR], 42.5; 95% CI, 2.42-744.97; P = .04; OR, 45.5; 95% CI, 5.78-333.33; P < .001, respectively) and undefined gliomas (OR, 84; 95% CI, 3.43-999.99; P = .02; OR, 32.3; 95% CI, 2.51-500.00; P = .008, respectively) and were more commonly in contact with the ventricles than astrocytomas (OR, 7.47; 95% CI, 1.03-53.95; P = .049). Tumor spread to neighboring brain structures was associated with high-grade glioma (OR, 6.02; 95% CI, 1.06-34.48; P = .04). CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with gliomas have poor outcomes, but risk factors identified in survival analysis inform prognosis and the newly identified MRI characteristics could refine diagnosis of tumor type and grade.

Network analysis of canine brain morphometry links tumour risk to oestrogen deficiency and accelerated brain ageing.

Structural 'brain age' is a valuable but complex biomarker for several brain disorders. The dog is an unrivalled comparator for neurological disease modeling, however canine brain morphometric diversity creates computational and statistical challenges. Using a data-driven approach, we explored complex interactions between patient metadata, brain morphometry, and neurological disease. Twenty-four morphometric parameters measured from 286 canine brain magnetic resonance imaging scans were combined with clinical parameters to generate 9,438 data points. Network analysis was used to cluster patients according to their brain morphometry profiles. An 'aged-brain' profile, defined by a small brain width and volume combined with ventriculomegaly, was revealed in the Boxer breed. Key features of this profile were paralleled in neutered female dogs which, relative to un-neutered females, had an 11-fold greater risk of developing brain tumours. Boxer dog and geriatric dog groups were both enriched for brain tumour diagnoses, despite a lack of geriatric Boxers within the cohort. Our findings suggest that advanced brain ageing enhances brain tumour risk in dogs and may be influenced by oestrogen deficiency-a risk factor for dementia and brain tumours in humans. Morphometric features of brain ageing in dogs, like humans, might better predict neurological disease risk than patient chronological age.

Feline meningioma with extensive nasal involvement.

CASE SUMMARY: A 9-year-old male neutered domestic longhair cat was presented with a 3 week history of lethargy and pain of unknown origin. A large extra-axial mass was demonstrated on MRI of the head, with cribriform plate destruction, extensive nasal invasion and intracranial expansion, producing a severe mass effect. The mass was isointense on T1-weighted imaging, predominantly hypointense with some hyperintense areas on T2-weighted imaging and fluid attenuation inversion recovery, markedly contrast enhancing, and caused transtentorial and cerebellar herniation. Histopathological evaluation confirmed a transitional (mixed) meningioma. RELEVANCE AND NOVEL INFORMATION: To our knowledge this is the first report of a meningioma with extensive nasal involvement in a cat. Based on this case, meningioma should be considered as a differential diagnosis for tumours involving the nasal cavity and frontal lobe with cribriform plate destruction.

Feline hyperaesthesia syndrome with self-trauma to the tail: retrospective study of seven cases and proposal for an integrated multidisciplinary diagnostic approach.

CASE SERIES SUMMARY: This was a retrospective study on the clinical features and response to treatment in seven cats with feline hyperaesthesia syndrome (FHS) and tail mutilation. FHS is a poorly understood disorder characterised by skin rippling over the dorsal lumbar area, episodes of jumping and running, excessive vocalisation, and tail chasing and self-trauma. The majority of the cats were young, with a median age of 1 year at the onset of clinical signs, male (n = 6) and with access to the outdoors (n = 5). Multiple daily episodes of tail chasing and self-trauma were reported in five cats, with tail mutilation in four cats. Vocalisation during the episodes (n = 5) and rippling of lumbar skin (n = 5) were also reported. Haematology, serum biochemistry, Toxoplasma gondii and feline immunodeficiency virus/feline leukaemia virus serology, MRI scans of brain, spinal cord and cauda equina, cerebrospinal fluid analysis and electrodiagnostic tests did not reveal any clinically significant abnormalities. A definitive final diagnosis was not reached in any of the cats, but hypersensitivity dermatitis was suspected in two cases. A variety of medications was used alone or in combination, including gabapentin (n = 6), meloxicam (n = 4), antibiotics (n = 4), phenobarbital (n = 2), prednisolone (n = 2) and topiramate (n = 2); ciclosporin, clomipramine, fluoxetine, amitriptyline and tramadol were used in one cat each. Clinical improvement was achieved in six cases; in five cats complete remission of clinical signs was achieved with gabapentin alone (n = 2), a combination of gabapentin/ciclosporin/amitriptyline (n = 1), gabapentin/prednisolone/phenobarbital (n = 1) or gabapentin/topiramate/meloxicam (n = 1). RELEVANCE AND NOVEL INFORMATION: This is the first retrospective study on a series of cats with FHS. The diagnostic work-up did not reveal any significant abnormalities of the central or peripheral nervous system; dermatological and behavioural problems could not be ruled out. We propose an integrated multidisciplinary diagnostic pathway to be used for the management of clinical cases and for future prospective studies.

Expression of microRNAs in cerebrospinal fluid of dogs with central nervous system disease.

In this pilot study we investigated the expression of 14 microRNAs in the cerebrospinal fluid (CSF) of dogs with neoplastic, inflammatory and degenerative disorders affecting the central nervous system (CNS). CSF microRNA (miRNA) expression profiles were compared to those from dogs with neurological signs but no evidence of structural or inflammatory CNS disease. Seven miRNAs were easily detected in all samples: miR-10b-5p, miR-19b, miR-21-5p, miR-30b-5p, miR-103a-3p, miR-124, and miR-128-3p. Expression of miR-10b-5p was significantly higher in the neoplastic group compared to other groups. There was no relation between miRNA expression and either CSF nucleated cell count or CSF protein content. Higher expression of miR-10b-5p in the neoplastic group is consistent with previous reports in human medicine where aberrant expression of miR-10b is associated with various neoplastic diseases of the CNS.

Restored vision in a young dog following corticosteroid treatment of presumptive hypophysitis.

BACKGROUND: Hypophysitis is an umbrella term for a group of disorders involving inflammation of the pituitary gland. A rare occurrence in humans, hypophysitis can produce a range of clinical signs including (but not limited to) visual deficits and diabetes insipidus. Only five cases of canine hypophysitis exist in the literature, all presenting in mature dogs with no visual deficits and a grave outcome. This case report describes the clinical and advanced imaging features of blindness-inducing presumptive hypophysitis in a dog, which rapidly resolved with medical management. CASE PRESENTATION: A 1-year-and-seven-month-old neutered male Standard Poodle presented with subacute blindness, ataxia, and polyuria/polydipsia (PUPD). Magnetic resonance imaging (MRI) detected a contrast-enhancing pituitary mass with perilesional oedema compromising the optic chiasm. Suspecting neoplasia, anti-inflammatory corticosteroid was commenced prior to radiation therapy planning. Complete resolution of neurological and visual deficits occurred within 12 days of starting steroid treatment. Repeated advanced imaging indicated macroscopic resolution of the lesion. An extended thyroid panel with insulin-like growth factor-1 analysis supported a diagnosis of hypophysitis. Resolution of PUPD was achieved with tapering courses of prednisolone and desmopressin; the dog has since been clinically normal for 14 months and treatment-free for 11 months. CONCLUSIONS: To the authors' knowledge, this is the first instance in which a canine pituitary mass has demonstrated long-term resolution with palliative medical treatment alone, alongside reversal of associated blindness and presumptive diabetes insipidus. We suspect this lesion to be a form of hypophysitis, which should be included among differential diagnoses for pituitary masses, and for subacute blindness in dogs. Where possible, we advocate biopsy-confirmation of hypophysitis prior to timely intervention with anti-inflammatory treatment.

Idiopathic sclerosing orbital inflammation mimicking a malignant spindle cell tumor in a dog.

A dog presented with a retrobulbar mass, diagnosed histopathologically as malignant spindle cell neoplasia. Emergence of analogous findings in the contralateral orbit prompted extended immunohistochemistry of the original mass and reassignment to idiopathic sclerosing orbital inflammation. Early incisional biopsy with extended immunohistochemical analysis should be considered for canine orbital tumors.

Chronic hypertrophic ganglioneuritis mimicking spinal nerve neoplasia: clinical, imaging, pathologic findings, and outcome after surgical treatment.

OBJECTIVE: To report the clinical, imaging, pathologic findings, surgical planning, and long-term outcome after surgery in a dog with neurologic deficits because of a hypertrophic ganglioneuritis that compressed the spinal cord. STUDY DESIGN: Clinical report. ANIMAL: An 8-year-old male intact Yorkshire terrier. METHODS: The dog had ambulatory tetraparesis and neurologic examination was consistent with a C1-C5 myelopathy. Magnetic resonance imaging (MRI) revealed enlargement of the left C2 spinal nerve causing compression of the spinal cord. The main differential diagnosis was spinal nerve neoplasia with compression and possibly spinal cord invasion. On ultrasonography, there was enlargement of the spinal nerve and fine needle aspiration did not show evidence of neoplasia. Fascicular biopsy of the spinal nerve was consistent with enlargement because of chronic inflammation (hypertrophic neuritis). RESULTS: Hemilaminectomy followed by durotomy and rhizotomy allowed resection of an intradural-extramedullary mass that was the enlarged left C2 spinal nerve. Histopathology was consistent with a hypertrophic ganglioneuritis. Thirteen months later the dog remained free of clinical signs. CONCLUSION: Hypertrophic neuritis affecting the spinal nerves may be misdiagnosed as spinal nerve neoplasia that in dogs is usually malignant with a poor prognosis. Focal spinal nerve lesions with compression of the spinal cord evident on MRI may be inflammatory and are not necessarily a neoplastic condition.

Feline spinal cord diseases.

The objective of this article is to review the recent literature that reports on the most common diseases affecting the spinal cord of cats, and to draw some general conclusions that will be useful to formulate diagnosis and prognosis for feline spinal patients. The most common types of feline spinal cord diseases documented were inflammatory/infectious diseases, and feline infectious peritonitis was the most common disease, representing approximately 50% of all feline myelitis. Neoplasms were documented in approximately 25% of cases; lymphosarcoma was the most common tumor affecting the spinal cord of cats, with reported prevalence between 28% and 40%. Cats diagnosed with spinal lymphosarcoma were significantly younger (median age 4 years) than cats with other spinal cord tumors (median age 10 years). Cats with clinical signs of intervertebral disc disease had a median age of 8 years, and 67% had Hansen type I disc protrusions. The most commonly affected intervertebral disc was at the L4 to L5 intervertebral disc space. Fibrocartilaginous embolism-affected older cats (median age 10 years), seemed to predominate in the cervicothoracic intumescence, and clinical signs were markedly lateralized, especially when the cervical region was affected.

Myelography vs. computed tomography in the evaluation of acute thoracolumbar intervertebral disk extrusion in chondrodystrophic dogs.

Myelography and/or computed tomography (CT) are commonly used to evaluate acute intervertebral disk extrusion in chondrodystrophic dogs. The purpose of this study was to evaluate the sensitivity of myelography and two different CT protocols in determining level and lateralization of acute thoracolumbar intervertebral disk extrusion in comparison with surgical findings, investigate interobserver variability, and determine examination duration times. Results of conventional CT, helical CT, and myelography were compared with surgical findings in 19 chondrodystrophic dogs with acute thoracolumbar intervertebral disk extrusion. Agreement among investigators was determined for different imaging modalities, and examination times were recorded. In the diagnosis of level of disk extrusion there was agreement of myelography, conventional CT, and helical CT with surgical findings in 94.7%, 100%, and 94.7% of dogs, respectively (P = 0.144). In the diagnosis of level and lateralization of disk extrusion there was agreement of myelography, conventional CT, and helical CT with surgical findings in 78.9%, 87.4%, and 85.3% of dogs, respectively (P = 0.328). Interobserver agreement was very good for all imaging modalities (myelography K = 0.87; conventional CT K = 0.86; helical CT K = 0.95). There were significant differences in median examination duration times between helical CT (4 min), conventional CT (8 min), and myelography (32 min) (P < 0.001). Both helical and conventional CT appear to be accurate for evaluation of acute thoracolumbar intervertebral disk extrusion in chondrodystrophic dogs and are faster to perform than myelography.

Tumors affecting the spinal cord of cats: 85 cases (1980-2005).

OBJECTIVE: To determine the prevalence of lymphosarcoma and other tumors affecting the spinal cord of cats and to relate specific types of tumors with signalment, history, and clinical findings. DESIGN: Retrospective case series. ANIMALS: 85 cats with tumors affecting the spinal cord. PROCEDURES: Medical records of cats with histologically confirmed primary or metastatic tumors of the spinal cord or tumors causing spinal cord disease by local extension from adjacent tissues examined between 1980 and 2005 were reviewed. Data on signalment; clinical history; results of neurologic examination, diagnostic imaging, and clinical pathologic evaluation; and location of tumor within the spinal cord were obtained from medical records and analyzed by use of logistic regression models. RESULTS: Lymphosarcoma was the most common tumor and affected the spinal cord in 33 (38.8%) cats, followed by osteosarcoma in 14 (16.5%) cats. Cats with lymphosarcoma were typically younger at initial examination, had a shorter duration of clinical signs, and had lesions in more regions of the CNS than did cats with other types of tumors. In 22 of 26 (84.6%) cats with lymphosarcoma, the tumor was also found in extraneural sites. CONCLUSIONS AND CLINICAL RELEVANCE: Data for spinal cord tumors in this population of cats were analyzed by logistic regression analysis, which effectively distinguished cats with lymphosarcoma from cats with other types of tumors. Additional clinical information reported here will help to increase the index of suspicion or definitive antemortem diagnosis of spinal cord tumors of cats.

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.

Prevalence of diseases of the spinal cord of cats.

A retrospective review of records of 205 cats with histologically confirmed disease of the spinal cord was performed to identify the prevalence of disease in this nonrandomly selected population of cats. Clinical records were reviewed, and age, duration of neurologic illness, and clinical and histopathologic findings in cats with spinal cord disease were abstracted. Disease processes were classified into 7 categories and 23 groups. The most common diseases affecting the spinal cord of cats were feline infectious peritonitis (FIP), lymphosarcoma (LSA), and neoplasia of the vertebral column secondarily affecting the spinal cord. Information on age, onset and duration of clinical signs, and lesion localization at the postmortem examination in cats belonging to the 7 categories of disease were analyzed to create a practical list of differential diagnoses. Cats were also subcategorized into 3 groups based on their age at death. FIP was the most common disease of cats younger than 2 years of age. LSA and vertebral column neoplasia were the most common diseases affecting cats between 2 and 8 years of age. Vertebral column neoplasia was the most common disease affecting cats older than 8 years of age. Results of this histopathologic study showed that FIP and LSA were the most common disease processes affecting the spinal cord of cats. However, at least 21 other groups of diseases and their relative prevalence were identified.