Helena Rylander

Evaluation of therapeutic phenobarbital concentrations and application of a classification system for seizures in cats: 30 cases (2004-2013).

OBJECTIVE To determine the percentage of cats with a phenobarbital (PB) concentration between 15 and 45 μg/mL that had a ≥ 50% reduction in the number of seizures and to investigate applicability of the 2011 International League Against Epilepsy (ILAE) classification system in cats. DESIGN Retrospective case series. ANIMALS 30 cats with suspected or confirmed epilepsy. PROCEDURES Medical records for 2004 to 2013 at 3 veterinary hospitals were searched. Information collected included signalment, duration of observation before treatment, frequency of seizures before PB administration, seizure phenotype, dose of PB, serum PB concentration, number of seizures after PB administration, duration of follow-up monitoring, and survival time. A modified 2011 ILAE classification system was applied to all cats. RESULTS Seizure control was achieved in 28 of 30 (93%) cats with a serum PB concentration of 15 to 45 μg/mL. This comprised 10 of 11 cats with structural epilepsy, 14 of 15 cats with unknown epilepsy, and 4 of 4 cats with presumptive unknown epilepsy. Thirteen cats had no additional seizures after initiation of PB treatment. CONCLUSIONS AND CLINICAL RELEVANCE Seizure control was achieved in most cats with a serum PB concentration between 15 and 45 μg/mL, regardless of the cause of the seizures. A modified 2011 ILAE classification was applied to cats with seizures and enabled classification of cats without specific genetic testing and without identified structural or inflammatory disease. This classification system should be incorporated into veterinary neurology nomenclature to standardize communication between veterinarians and improve comparisons among species.

Clinical and magnetic resonance imaging features of central nervous system blastomycosis in 4 dogs.

A 4-year-old female spayed Golden Retriever was evaluated after generalized seizures for 2 days and a 1-month history of decreased appetite, conjunctivitis in the left eye (OS), and pyoderma. Therapy with oral cephalexin (25.6mg/kg PO q12h), neopolydex ophthalmic solution (OS q6h), and oral phenobarbital (1.6mg/ kg PO q12h) did not improve clinical signs. Physical examination revealed multifocal nodular skin lesions, granulomatous fundic lesions in both eyes (OU), and uveitis OS. Neurologic examination abnormalities included an absent menace response and direct pupillary light reflex OS, delayed conscious proprioception in all limbs and generalized ataxia. Neuroanatomic localization was forebrain. CBC and serum biochemistry profile results were within reference intervals. On thoracic radiographs, a bilateral interstitial pulmonary pattern was present in the caudal dorsal lung fields with a round, soft tissue opacity (2.5 2 cm) in the left caudal lung. Magnetic resonance imaging (MRI) of the brain was performed with a 1.0 T magnet. Images included T2weighted (T2W), fluid-attenuated inversion recovery (FLAIR), and T1-weighted (T1W) images before and after intravenous contrast administration (0.1mmol/kg gadodiamide). Multifocal intraand extra-axial lesions causing a mild left midline shift were identified in the right cerebrum, thalamus, and midbrain). Lesions were also present in the left ocular posterior chamber and temporalis muscles adjacent to affected brain region. Brain lesions were hypointense to grey matter on T1W images and mildly hyperintense with marked perilesional edema on T2W and FLAIR images. After contrast administration, there was enhancement of lesions and meninges (Fig 1). Radiological diagnosis was multifocal brain disease with secondary meningitis and left ocular granuloma or retinal hemorrhage. Cisternal cerebrospinal fluid (CSF) analysis showed 15 white blood cells/mL (reference range, 5), 2 red blood cells/mL, and 25.9mg/dL protein (reference range, 25). The differential cell count was 30% neutrophils, 60% lymphocytes, and 10%macrophages. CSF immunoflourescence antibody titer (IFAT) for Neospora caninum was 10 (reference, 10 positive). Microscopic examination of an aspirate of the pulmonary mass showed pyogranulomatous inflammation and Blastomyces dermatitidis organisms. Disseminated blastomycosis was presumptively diagnosed and the dog was treated with fluconazole (5mg/kg PO q12h); phenobarbital (2.5mg/kg PO q12h), cephalexin (20mg/ kg PO q12h), and neopolydex (OU q8h) were continued. The dog represented for examination because of acute obtundation 2 weeks later. Inflammation secondary to death of Blastomyces organisms in the central nervous system (CNS) was suspected. After therapy of dexamethasone sodium phosphate (0.07mg/kg IV once) and prednisone (0.25mg/kg PO q12h), the dog’s clinical signs rapidly improved. Clindamycin (10mg/kg PO q12h) was added based on a N. caninum serum titer of 400 (reference, 100 indicates exposure). One month later, neurologic examination was normal except for absent menace response and direct pupillary light reflex OS. On MRI examination there was resolution of the muscle granuloma, persistence of intracranial granulomas and parenchymal edema, and lateral ventriculomegaly. Cisternal CSF analysis was within reference intervals. Prednisone therapy was tapered and discontinued. The dog had recurrence of ataxia and conscious proprioception deficits 10weeks later. OnMRI, there was resolution of 2 forebrain granulomas; however, a new granuloma From the Department ofMedical Sciences (Lipitz, Rylander, Foy) and the Department of Surgical Sciences (Forrest), School of Veterinary Medicine, University of Wisconsin—Madison, Madison, WI. The original MRI for Case 3 was performed at the Veterinary Specialty Center in Buffalo, Grove, IL, and the images in Figure 3 are from this examination. All work for the other 3 cases was done at University of Wisconsin-School of Veterinary Medicine, Madison, WI. This paper has not been previously presented at a meeting. It has been accepted as an abstract scheduled for oral presentation at the 2010 ACVIM Forum in Anaheim, CA. Corresponding author: Helena Rylander DVM, Dip. ACVIM (Neurology), Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-School of Veterinary Medicine, 2015 Linden Drive, Madison, WI 53706; e-mail: rylander@svm.vet med.wisc.edu. Submitted March 17, 2010; Revised June 19, 2010; Accepted July 1, 2010. Copyright r 2010 by the American College of Veterinary Internal Medicine 10.1111/j.1939-1676.2010.0581.x Abbreviations:

Diagnosis and surgical treatment of an intracranial cyst in an alpaca cria.

CASE DESCRIPTION A 7-day-old female alpaca was examined because of an acute onset of diffuse central neurologic deficits. CLINICAL FINDINGS Diagnostic imaging with CT and MRI identified an intracranial cyst occupying approximately one-third to one-half of the dorsal portion of the cranial cavity, markedly displacing the cerebral hemispheres bilaterally. TREATMENT AND OUTCOME Initial surgical management via trephination and needle drainage was only transiently effective at resolving the neurologic signs. Craniotomy and drainage and removal of the cyst lining resulted in a sustained improvement in neurologic status, and the cria remained clinically normal and well grown at follow-up 5 months after surgery. CLINICAL RELEVANCE This report represented the first description of the successful treatment of an intracranial cyst in a New World camelid.

Feline ischemic myelopathy and encephalopathy secondary to hyaline arteriopathy in five cats

Five cats presented with acute-onset neurological signs. Magnetic resonance imaging in four cats showed a T2-weighted hyperintense spinal cord lesion that was mildly contrast-enhancing in three cats. Owing to inflammatory cerebrospinal fluid changes three cats were treated with immunosuppression. One cat was treated with antibiotics. All cats improved initially, but were eventually euthanased owing to the recurrence of neurological signs. Histopathology in all cats showed hyaline degeneration of the ventral spinal artery, basilar artery or associated branches with aneurysmal dilation, thrombosis and ischemic degeneration and necrosis of the spinal cord and brain. Two cats also had similar vascular changes in meningeal vessels. Vascular hyaline degeneration resulting in vascular aneurysmal dilation and thrombosis should be a differential diagnosis in cats presenting with acute central nervous system signs.

Surgical management of vertebral synovial cysts in a rabbit (Oryctolagus cuniculus).

CASE DESCRIPTION An approximately 8-month-old female Miniature Lop rabbit (Oryctolagus cuniculus) was evaluated because of an acute onset of progressive paraparesis. CLINICAL FINDINGS The rabbit was ambulatory paraparetic, and results of neurologic examination were consistent with a myelopathy localizing to the T3-L3 spinal cord segments. Evaluation with CT myelography revealed focal extradural spinal cord compression bilaterally at the level of the articular process joints of T12-L1. TREATMENT AND OUTCOME A Funkquist type A dorsal laminectomy was performed at T12-L1, and the vertebral column was stabilized with pins and polymethylmethacrylate-based cement. Multiple vertebral synovial cysts were confirmed on histologic evaluation of the surgically excised tissues. The rabbit was nonambulatory with severe paraparesis postoperatively and was ambulatory paraparetic at a recheck examination 7 weeks after surgery. Fourteen weeks after surgery, the rabbit appeared stronger; it walked and hopped slowly but still fell and dragged its hindquarters when moving faster. Thirty-seven weeks after surgery, the neurologic status was unchanged. CLINICAL RELEVANCE Although thoracolumbar myelopathy in rabbits is commonly secondary to vertebral fracture, vertebral synovial cysts should be considered a differential diagnosis for rabbits with slowly progressive paraparesis. Decompressive surgery and stabilization can result in a good outcome for rabbits with this condition.

Neurological examination in healthy chinchillas (Chinchilla lanigera)

Chinchillas are popular as laboratory models and companion animals, and they can be affected by a variety of infectious and non-infectious neurological diseases. Little information is available on making a neurological diagnosis in this species, in part because the neurological examination has not been standardized in chinchillas and the expected physiological findings in healthy chinchillas have not been reported. In this study, a standardized neurological examination was performed on 30 clinically normal chinchillas. The perineal reflex and the menace response were absent in all chinchillas evaluated and so should not be used as functional tests. Several tests were consistently positive, such as the oculocephalic reflex, maxillary, mandibular and auricular sensations, withdrawal reflexes, thoracic limb paw replacement, and the wheelbarrow test. Other tests, such as the cutaneous trunci reflex and pelvic limb paw replacement, had variable responses. Based on these findings, it is advised that clinicians prioritize tests that can be easily performed without undue stress to the animal, and give consistent results in a healthy patient.

Antemortem diagnosis of hydrocephalus in two Congo African grey parrots (Psittacus erithacus erithacus) by means of computed tomography

CASE DESCRIPTION A 7-year-old and a 10-year-old Congo African grey parrot (Psittacus erithacus erithacus; parrots 1 and 2, respectively) were evaluated because of neurologic deficits. CLINICAL FINDINGS Parrot 1 had an 8- to 9-month history of lethargy and anorexia, with a recent history of a suspected seizure. Parrot 2 had a 6-month history of decreased activity and vocalizing, with an extended history of excessive water intake; a water deprivation test ruled out diabetes insipidus, and psychogenic polydipsia was suspected. Both birds had ophthalmologic asymmetry, with anisocoria detected in parrot 1 and unilateral blindness in parrot 2. Metal gastrointestinal foreign bodies were observed on whole-body radiographs of both birds, but blood lead concentrations were below the range indicated for lead toxicosis. Findings on CT of the head were consistent with hydrocephalus in both cases. TREATMENT AND OUTCOME Parrot 1 received supportive care and died 3 months after the diagnosis of hydrocephalus. Parrot 2 was treated with omeprazole and prednisolone for 10 days without any improvement in neurologic deficits; euthanasia was elected, and hydrocephalus was confirmed on necropsy. No underlying or concurrent disease was identified. CLINICAL RELEVANCE Hydrocephalus should be considered a differential diagnosis for parrots evaluated because of CNS signs. Computed tomography was an excellent screening tool to diagnose hydrocephalus in these patients. Compared with MRI, CT is more frequently available and offers reduced scanning times, reduced cost, and less concern for interference from metallic foreign bodies.