Case of the month

December 2006

Irish Setter, m, 4y

For more than two years irregular seizure attacks of about 1 min duration. One week ago cluster of 2 h duration. Since then the dog is in lateral recumbency, unable to get up.

History

Referral to the Neurology division of the Vetsuisse Faculty Berne

Results of neurologic examination

• Lateral recumbency, severe tetraparesis• Generalized missing proprioception• Menace response and palpebral reflex bilaterally

reduced

Localisation diffuse, intracranial

MRI

FSE T2 transverse

MRI of the brain

dorsal

right

dorsal

right

dorsal

right

FLAIR DOR

MRI of the brain

rostral

right

rostral

right

rostral

right

rostral

right

rostral

right

plain contrast enhanced

MRI of the brain

FE 3D MPR (T1) dorrostral

right

rostral

right

rostral

right

rostral

right

Findings

?

Findings

In T2 and FLAIR there is a symmetric increase in signal intensity of the gray matter from the areas rostral to the lateral ventricles going caudally to the gyrus dentatus (yellow arrows). The T1-weighted images are unremarkable, there is no contrast uptake.

The distribution of the lesions is typical for polioencephalomalacia. The etiology of this rare condition is unclear. A toxic/metabolic genesis is assumed. It is progressive and cannot be improved by any known therapy. Prognosis is infaust.

Symmetric changes either of white or gray matter or both usually are caused by toxic/metabolic conditions. These include hypooxygenism, hepatoencephalopathy or renal failure, storage diseases and intoxications. Some of them show a typical distribution; e.g. hypooxygenism typically leads to signal enhancement of the basal ganglia. However, the available veterinary medical database of these conditions is still small.

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