As in all other areas of medicine, effective treatment of status epilepticus (SE) is facilitated tremendously by the correct diagnosis! Convulsive SE is rarely a diagnostic difficulty, but nonconvulsive forms, including episodes after generalized seizures, may be difficult to recognize or missed altogether.
Shaking and responding poorly do not always indicate epilepsy. The differential diagnosis of apparent SE includes movement disorders, psychiatric disorders, and other conditions. Treating these conditions as SE may result in significant harm.Table: Differential Diagnosis of SE
Nonepileptic seizures ("pseudoseizures" or "pseudo status") are particularly troublesome. These episodes often occur in patients who also have epileptic seizures. Features that suggest nonepileptic spells include:
Iatrogenic morbidity is common in these patients, and spells may persist until treatment causes respiratory arrest. The spells often recur. Thorough psychiatric evaluation and treatment are appropriate but not always successful.
The patient's history often reveals the cause of a patient's SE. Factors such as trauma, drug overdose, alcohol use, medical illness, stroke, or epilepsy may be uncovered through discussions with the patient's family members and companions or the patient's medical bracelet and personal possessions.
Physical examination focuses on the ascertaining the underlying cause of SE, localizing the neurologic abnormality, and determining whether complications have occurred. Vital signs are crucial given the cardiovascular complications. (Respiratory failure is an occasional complication of SE but more often results from medications.) The general examination can show signs of infection (by fever, nuchal rigidity, or skin lesions) or systemic illness, such as kidney or liver disease. Signs of head injury or coagulopathy are also important. The neurologic examination also assesses whether seizures are actually continuing in subtle ways.
Appropriate laboratory studies include:
Generalized convulsive SE is diagnosed without an EEG, and treatment begins without it. An EEG is necessary for the diagnosis of nonconvulsive SE, although treatment may begin based on clinical suspicion. EEGs are mandatory when a patient does not respond to initial treatment, because it may be impossible to ascertain clinically whether the patient is postictal or whether electrographic status epilepticus is continuing, requiring further aggressive treatment.
Reviewed and revised January 2004 by Thaddeus Walczak, MD, MINCEP® Epilepsy Care, Minneapolis, MN
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