Status Epilepticus

Status epilepticus is a state in which seizures are of sufficient length or are repeated frequently enough to produce a fixed and lasting epileptic condition. From a practical standpoint, status epilepticus can be identified as seizure activity lasting 30 minutes or longer. Status epilepticus is a medical emergency requiring prompt therapy guided by the clinical situation. Untreated status leads to profound, life-threatening, systemic metabolic and physiologic disturbances. Status epilepticus, independent of systemic and metabolic disturbance, also leads to persistent brain dysfunction and damage.

Status epilepticus rarely if ever occurs as the initial manifestation of idiopathic epilepsy. It more generally occurs as a complication in the course of a chronic, uncontrolled epileptic state, especially in animals experiencing cluster seizures. Symptomatic status epilepticus is associated with acute insult to the central nervous system (trauma, systemic metabolic disease, infection, or inflammation) and with static or chronic progressive neurologic disorders (neoplasia, hydrocephalus, degeneration, anoxia, and prior encephalitis). In evaluating the animal for the cause of status epilepticus, it is important to distinguish between these categories as the prognosis for each may be significantly different.

An important factor that is frequently identified as a precipitating cause of status epilepticus is manipulation and/ or withdrawal of medication. The primary factors leading to errors in medication include failure to achieve an effective therapeutic level of anticonvulsant medication because of incorrect dosage by the veterinarian, use of the wrong drug, failure of the owner to comply with the labeled directions with respect to dosage and frequency of administration, abrupt discontinuation of the drug, or abruptly changing from one anticonvulsant drug to another.

A wide array of cellular disturbances are believed to play a role in the injury caused to selectively vulnerable neurons during status, including calcium influx into cells, the production of oxygen free radicals, and lipid peroxidation of neuronal membranes. [...]