Page 804 - Problem-Based Feline Medicine

796 PART 10 CAT WITH SIGNS OF NEUROLOGICAL DISEASE

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WHERE?
● Most cats with seizures, compulsive circling or changed behavior from neurological disease
have a forebrain (thalamocortex) lesion.
WHAT?
● Seizures are most often associated with tumors, encephalitides and inactive lesions (e.g. glial
scar), while extracranial causes (metabolic and toxic) and idiopathic epilepsy are rare.
● Compulsive circling is caused by any kind of lesion located in the frontal lobe or rostral thala-
mus, although trauma, tumors and ischemic encephalopathy are the most common causes.
Circling is usually toward the side of the lesion.
● Changed or abnormal behavior usually consists of subtle personality changes, and is most
often associated with tumors, head trauma, ischemic encephalopathy, congenital and inherited
forebrain anomalies, hepatic encephalopathy, feline infectious peritonitis, and feline immunod-
eficiency encephalopathy.

QUICK REFERENCE SUMMARY
Diseases causing seizures, circling and/or changed behavior
DEGENERATIVE

● Likely symptomatic epilepsy*** (p 800)
Recurrent seizures typically beginning as single seizures at intervals of several weeks to months.
Frequency may remain low or progressively increase over time. Seizures are partial in onset (±
aura, unilateral or localized motor activity, ± localized post-ictal motor deficits) with or without
secondary generalization (to violent tonic-clonic motor activity involving the whole body) which
may obscure the partial signs.
● Feline ischemic encephalopathy*** (p 804)
Peracute onset of unilateral forebrain signs (mental depression and confusion, compulsive circling,
hemiparesis) and rarely, severe cluster seizures or status epilepticus. Personality changes and/or
post-ischemic epilepsy may be the only manifestation of the milder atypical form.
● Cerebrovascular accidents** (p 808)
Peracute onset of focal cerebral signs attributable to the forebrain (confusion, circling, pacing) or
brainstem (depression, head tilt, loss of balance, nystagmus, facial paresis) or cerebellum (hyper-
metria, intentional tremors). Occasionally, seizures occur either as immediate cluster seizures or
status epilepticus, or later as secondary epilepsy.

ANOMALY
● Congenital and inherited forebrain anomalies*** (p 805)
Developmental abnormalities, such as mental retardation, learning disability or loss of training are
often evident historically in kittens and young adult cats (< 2 years old) presenting with abnormal
mentation and behavior, central visual deficits and occasionally, secondary epilepsy.