Page 825 - Problem-Based Feline Medicine

36 – THE CAT WITH SEIZURES, CIRCLING AND/OR CHANGED BEHAVIOR 817

onset of high-frequency seizures, often cluster seizures Diagnosis
or status epilepticus, and other diffuse neurological
Diagnosis is based on finding a total serum calcium
and/or systemic signs before and in between the
concentration < 1.6 mmol/L (6.5 mg/dl) and ionized
seizures.
calcium level < 0.6 mmol/L (2.5 mg/dl).
Active brain diseases often cause a higher seizure fre-
Other historical, clinical and laboratory abnormalities
quency, interictal neurological signs and deficits, and
may reflect the underlying cause, including idiopathic
abnormal findings upon CSF analysis or brain imaging.
or post-thyroidectomy hypoparathyroidism, puerperal
Likely symptomatic epilepsy may sometimes be distin- tetany, renal failure and phosphate enema.
guished from idiopathic epilepsy only by the occur-
rence of partial seizures and/or the presence of focal Differential diagnosis
neurological deficits because CSF analysis and MRI
Other causes of neuromuscular hyperexcitability such
may also be normal.
as intoxications should be considered. With organophos-
phate toxicity, muscarinic signs are usually present
Treatment (miosis, salivation, vomiting, bradycardia). Fenthion
has few muscarinic signs and mainly produces muscle
Symptomatic anti-epileptic drug therapy for life
weakness.
(see Likely symptomatic epilepsy, page 801).
Tetany must be differentiated from convulsive status
Prognosis epilepticus of hypocalcemia. The cat with tetany is con-
scious although it is very anxious.
Good seizure control should be obtained in most cases,
although some cats can progress toward refractoriness, Treatment
despite adequate anti-epileptic drug treatment.
Calcium supplementation and specific treatment of
the underlying cause is required.
HYPOCALCEMIA* ● Use 0.5–1.5 ml/kg IV of 10% calcium gluconate.
Infuse slowly over 10 minutes while monitoring
Classical signs heart rate. Stop if bradycardia develops. See
Hypocalcemia, page 962 in “The Cat With
● Muscle fasciculation, especially involving
Generalized Weakness” for treatment.
the head and ears.
● Generalized weakness.
● Stiffness, tremors, tetany. HEAD TRAUMA
● Rarely, convulsive status epilepticus.
Classical signs
● Vomiting.
● Peracute onset of cerebral signs ±
See main reference on page 962 for details (The Cat seizures.
With Generalized Weakness). ● Signs of head trauma, including
hemorrhage in eyes, ears, nose.
● Delayed onset epilepsy.
Clinical signs
Symptomatic hypocalcemia is rare in cats. It is usu-
ally iatrogenic following bilateral thyroidectomy. Clinical signs

Signs are episodic or persistent and include multi- Concussion manifests with immediate and brief (a few
focal muscle fasciculations, which often involves the seconds to minutes) mental confusion or loss of con-
face and ears. This may progress to generalized weak- sciousness. Recovery is rapid and complete with no
ness with stiffness, panting, tremors and tetany. residual neurological signs as there are no parenchymal
Terminally, convulsive status epilepticus may occur. lesions.