Page 824 - Problem-Based Feline Medicine

816 PART 10 CAT WITH SIGNS OF NEUROLOGICAL DISEASE

Differential diagnosis Clinical signs

Other infectious and non-infectious causes of Recurrent primary generalized tonic-clonic seizures
encephalomyelitis including FIP and non-suppurative should be the only sign.
meningoencephalitis should be considered. ● There is no aura, no localized or unilateral signs
during the ictus and in the post-ictal phase.
The initial seizure frequency should be low with iso-
Treatment
lated single seizures at more than 6–8 week intervals.
Clindamycin 12.5 mg/kg PO q 12 h doses for a mini- ● The subsequent seizure frequency could remain
mum of 4 weeks. low or progressively increase, perhaps to the point of
intractability, but this should not occur before several
Clarithromycin (7.5 mg/kg PO q 12 h) and azithro-
months to a few years from the seizure onset.
mycin (7–15 mg/kg q 12 h) are newer macrolides which
may be useful. Onset of seizures should be during adolescence or
young adulthood (probably between 6 months and
5 years).
Prognosis

Prognosis is guarded with CNS involvement. Diagnosis
Clinical signs of systemic illness usually begin to
Diagnosis is by exclusion of other causes.
resolve within 24–48 h of beginning therapy but neu-
rological signs may take weeks to improve and major Physical and ophthalmological examinations should
neurological abnormalities may remain. Response be normal. Abnormal findings would indicate the pres-
may be poor, slow, incomplete, and recurrence may ence of another pathological process possibly related to
occur. the seizure disorder (e.g. fever, chorioretinitis).
Neurological examination should be normal. Other
neurological signs or deficits would indicate that an
IDIOPATHIC EPILEPSY*
active or inactive structural brain lesion is present.
Classical signs CSF analysis should be normal. Abnormalities would
reveal the presence of an active or a resolving brain
● Recurrent primary generalized tonic-clonic
disease.
seizures.
● The initial seizure frequency is low (< 1 Brain imaging (MRI) should be normal. Any abnor-
single seizure every 6–8 weeks) but may mality could be related to the seizure disorder (e.g.
later increase. active or inactive lesions).
● Seizures begin in young adult cats
Idiopathic epilepsy should be excluded when there
(6 months to 5 years of age) that
are partial seizures (including seizures that appear to
have no other neurological signs and
be generalized from their onset but that are preceded by
deficits.
an aura or followed by localized post-ictal signs),
a seizure onset before 6 months or after 5 years of
age, an initially high seizure frequency, a rapid
Pathogenesis increase of the seizure frequency within the first few
weeks or months, other neurological signs or deficits,
This is believed to result from a diffuse imbalance
CSF changes or MRI abnormalities.
between neuronal excitatory and inhibitory mecha-
nisms that has no underlying cause other than a genetic
predisposition. Differential diagnosis

Idiopathic epilepsy is rare and poorly documented in Extracranial causes of seizures such as metabolic,
cats. toxic and hypoxic causes usually produce a sudden