シンポジウム14：てんかん新規治療の動向
てんかん診断における新しい進歩
2021 年 38 巻 4 号 p. 559-562
詳細
2021 年 38 巻 4 号 p. 559-562
No diagnostic test can substitute for a detailed history in the diagnosis of epilepsy. Obtaining eyewitness reports is imperative as patients can be unaware of their seizures. Past similar episodes should be identified to elucidate the characteristics of seizures. Alternative diagnoses such as cardiogenic causes should be ruled out. If the events are suggestive of epileptic seizures, patients should be evaluated for underlying etiology.
Electroencephalography (EEG) may show interictal epileptiform discharges when the history is suggestive of epileptic seizure. It is also useful to exclude or identify seizure activity, especially nonconvulsive status epilepticus, in older patients in the hospital for altered mental status of unclear etiology, and their neurological prognosis may be improved. A routine interictal EEG has limited diagnostic utility for older patients when the history is more suggestive of syncope.
A brain imaging study should be obtained in older individuals with possible seizures or epilepsy, given the higher frequency of stroke and other structural disease as possible etiologies. Magnetic resonance imaging, more sensitive than computed tomography, is preferred especially when ictal symptoms are focal, or neurological examination or EEG shows abnormal findings. Contrast–enhanced imaging increases the ability to identify tumors, inflammatory disease, and abscesses.
Because metabolic abnormalities can precipitate seizures in patients with and without epilepsy, patients with acute seizures should have blood analyzed for levels of electrolytes including calcium and magnesium, renal and liver function tests, and glucose. Metabolic causes should be excluded with laboratory evaluation also in older individuals suspected of epileptic seizures or epilepsy. Complete blood count with differential should be also performed in anticipation of initiating antiseizure drugs.
Because of the atypical symptomatology, seizures in older patients are frequently misdiagnosed, or the diagnosis is delayed.
