Acute disseminated encephalomyelitis (ADEM) is a postinfectious autoimmune demyelinating disease of the central nervous system. ADEM typically presents with non-specific symptoms including nausea, vomiting, fever and headache. This then progresses to neurological deficits such as motor weakness, altered sensorium and often significant morbidity or mortality. Typically the infectious insult is thought to be a transient viral infection or vaccination. We describe a case of ADEM in a 50 yearold woman who presented to a rural emergency department fifteen days after surgery to remove a gangrenous appendix. She presented febrile and with signs of encephalopathy. Initial computed tomography (CT) findings showed a left parietal lesion with mass effect, and there was a moderate neutrophilia and lymphocytosis. Empirical therapy for a viral or bacterial cerebral infection was commenced including dexamethasone.
After transfer to a tertiary referral center, and after five days of investigation and treatment and LP was performed and the diagnosis of ADEM was reached. Given the lack of response to steroids a course of intravenous immunoglobulin (IVIG) was commenced. Our patient responded extremely well on IVIG, showing substantial recovery within 24 hours. ADEM is a rare condition but is poorly understood in comparison to other diseases of similar incidence. Currently there is insufficient pathophysiological understanding and primary evidence to guide the use of treatment options even when the diagnosis is reached in a timely manner. Further case series or small trials are eagerly awaited. They may allow us to better formulate a treatment approach that can reduce the morbidity associated with even the best outcomes of our current therapies.
White LD, White LK, Baxter DF and Melhuish TM