Recurrence of acute disseminated encephalomyelitis at the previously affected brain site.
BACKGROUND
Acute disseminated encephalomyelitis (ADEM) is a usually monophasic demyelinating disorder of the central nervous system. Recurrences pose a diagnostic challenge because they can be overlooked or suggest an alternative diagnosis.


OBJECTIVE
To examine the frequency, nature, and outcome of recurrent ADEM.


METHODS
Review of the medical records of patients diagnosed in our institution as having ADEM between January 1, 1983, and May 31, 1998. Recurrences were defined as appearance of new symptoms and signs at least 1 month after the previous episode.


RESULTS
Five (24%) of 21 patients with ADEM developed recurrent disease episodes. In all, diagnosis was confirmed by brain biopsy. One patient had 4 disease episodes, 2 had 3, and the other 2 each had 2. Recurrence appeared 1.5 to 32 months after initial presentation and involved the same brain territory in 6 of 9 recurrences in 3 of 5 patients. In 2 patients, recurrences included neuropsychiatric signs. A good response to corticosteroid therapy was observed in 10 of 13 of treated ADEM attacks: in 3 of the 4 treated initial events and in 7 of 9 recurrences.


CONCLUSIONS
Recurrent ADEM may be more prevalent than previously recognized. Patients who relapse tend to have more than 1 recurrence that usually involves, clinically and radiologically, a brain territory that was affected before and can simulate a space-occupying lesion that requires histologic diagnosis. Neuropsychiatric features may be the main presentation of a relapse. Since recurrent ADEM is a corticosteroid-responsive condition, awareness and early diagnosis are mandatory.
Cohen
O
O
Department of Neurology, Hadassah University Hospital, PO Box 12000, Ein Karem, Jerusalem 91120, Israel.
Steiner-Birmanns
B
B
Biran
I
I
Abramsky
O
O
Honigman
S
S
Steiner
I
I
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D001706:Biopsy; D001921:Brain / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D004673:Encephalomyelitis, Acute Disseminated / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D001523:Mental Disorders / Q000209:etiology; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology; D012008:Recurrence
D000305:Adrenal Cortex Hormones