Case Description—A 9-year-old 19.7-kg (43.3-lb) spayed female Australian Shepherd was examined for an increase in frequency of episodic neurologic signs, often occurring upon exercise.
Clinical Findings—Between episodes of neurologic signs, the dog was considered clinically normal on the basis of findings on physical and neurologic examinations. An episode of ataxia with central vestibular signs was induced by exercising the patient in the hospital. All clinicopathologic values were within reference ranges, as were findings on magnetic resonance imaging of the brain and peripheral vestibular system. Systolic blood pressures of 180 to 200 mm Hg were recorded, and systemic hypertension was diagnosed.
Treatment and Outcome—While the dog received amlodipine and enalapril, blood pressure returned to within reference range, and episodes of neurologic signs no longer occurred. When clinical signs later recurred, systolic blood pressure was again found to be high. Following an increase in medication dosage, blood pressure normalized, and only 4 further episodes of neurologic signs were observed during a follow-up period totaling 30 months.
Clinical Relevance—Transient ischemic attack is a common diagnosis in humans but has not been described for dogs. In humans, it is defined as focal brain dysfunction caused by vascular disease that resolves completely in less than 24 hours and is often recurrent. Systemic hypertension is one of the most common preexisting conditions. We propose that the dog in the present report had clinical signs and diagnostic test results supportive of a diagnosis of transient ischemic attack.
Case Description—A 12-month-old castrated male Boxer was examined because of signs of acute, progressive intracranial disease.
Clinical Findings—Cytologic and histologic findings were consistent with an intracranial fungal granuloma in the right cerebral hemisphere. Fungal culture yielded a Cladophialophora sp.
Treatment and Outcome—The granuloma was surgically debulked to remove infected brain tissue and the avascular purulent core. Postoperatively, the patient was treated with fluconazole (2.3 mg/kg [1 mg/lb], PO, q 12 h) for 4 months, followed by voriconazole (3.4 mg/kg [1.5 mg/lb], PO, q 12 h) for a further 10 months. The outcome was considered excellent on the basis of resolution of neurologic signs and a lack of evidence of recurrence of the granuloma during magnetic resonance imaging and CSF analysis 8 months after surgery. Magnetic resonance imaging and CSF analysis 9 weeks after administration of antifungal medications was discontinued (16 months after surgery) confirmed resolution.
Clinical Relevance—Intracranial phaeohyphomycosis in small animals is rare and is most commonly associated with Cladophialophora infection. Phaeohyphomycosis frequently causes a focal granuloma, whereas other fungal infections typically cause diffuse meningoencephalitis. In all previous reports of phaeohyphomycosis of the CNS in dogs, treatment has been limited to medical management with conventional antifungal drugs and had failed to prevent death. The present report suggested that combined management of granulomas with surgery and newer triazole medications such as voriconazole may represent a novel strategy that improves the prognosis for this disease.
OBJECTIVE To evaluate the association between ultrasonographically measured optic nerve sheath diameter (ONSD) and acute increases in intracranial pressure (ICP) as measured by an epidural intracranial pressure monitoring system (EICPMS) in healthy dogs.
ANIMALS 6 young healthy dogs.
PROCEDURES An EICPMS connected to a pressure monitor was used to generate a continuous pressure waveform in each anesthetized dog. A 22-gauge IV catheter was inserted into the brain parenchyma through the contralateral parietal bone, and 0.5 to 2.0 mL of anticoagulated autologous blood was injected at predetermined intervals. At baseline (immediately after EICPMS placement) and following each injection, the ICP as indicated by EICPMS was recorded, and 3 ultrasonographic images of the optic nerve sheath of each eye were obtained. The ONSD was measured at maximum diameter and at 5 mm caudal to the optic disk.
RESULTS In linear models, the maximum ONSD was positively associated with increasing ICP. Specifically, the rate of maximum ONSD increase was greater for pressures ≤ 20 mm Hg above baseline (0.0534 mm/1 mm Hg ICP increase) than for pressures > 40 mm Hg above baseline (0.0087 mm/1 mm Hg ICP increase). The relationship of ICP to maximum ONSD was slightly nonlinear and best explained by comparison of fractional polynomial regression models.
CONCLUSIONS AND CLINICAL RELEVANCE ICP was positively and nonlinearly associated with increasing maximum ONSD, especially when ICP was ≤ 20 mm Hg above baseline, supporting the conclusion that ultrasonographic measurement of maximum ONSD may provide a noninvasive monitoring tool for evaluation of ICP in dogs. Further research is needed to assess the utility of these measurements in clinical patients.