Treatment of nonconvulsive status epilepticus.

Nonconvulsive status epilepticus (NCSE) is relatively common; it comprises at least one third of all cases of status epilepticus. NCSE may be an even more common, yet more elusive, condition in the elderly population. NCSE can be divided into complex partial status epilepticus (CPSE), NCSE in coma, and typical absence status epilepticus (TAS). The clinical manifestations may be subtle, and thus the diagnosis of these conditions is critically dependent on electroencephalography (EEG). When EEG demonstrates typical ictal patterns, the diagnosis is usually straightforward. However, in many circumstances the EEG pattern has to be differentiated from other encephalopathic patterns, and this differentiation can prove troublesome; clinical and electrographic response to treatment can prove helpful in these situations. The prognosis for NCSE in the elderly is generally poor due to the underlying etiology rather than the persistence of electrographic discharges. Whether the neuronal damage that occurs in convulsive status epilepticus and in animal models of limbic status epilepticus also occurs in NCSE in humans is still a matter of debate. Intravenous treatment is not benign, especially in the elderly, who may be at greater risk of systemic complications from hypotensive and sedative agents. Therefore, a more conservative approach to the treatment of NCSE in the elderly is warranted. Oral benzodiazepines should be used for the treatment of TAS and CPSE in noncomatose patients with a prior history of epilepsy, and in some circumstances, intravenous medication may be necessary. Generally, anesthetic coma should not be advised in either of these conditions. A more aggressive approach may be required with NCSE in coma, in the hope of improving a very poor prognosis. Treatment regimens will remain largely speculative until there are more relevant animal models and controlled trials of conservative versus aggressive treatment.