Acute disseminated encephalomyelitis and dengue fever: comment.

We read with interest the case of dengue encephalopathy by Kanade and Shah1 and have the following comments to offer: The authors have correctly listed the three types of neurological manifestations associated with dengue infection1. We would like to add ‘acute disseminated encephalomyelitis’ (ADEM) to the list of post-infection neurological manifestation of dengue fever. ADEM is a monophasic, post-infectious or post-vaccine acute inflammatory demyelinating disorder of central nervous system2. The pathophysiology involves transient autoimmune response directed at myelin or other self-antigens, possibly by molecular mimicry or by non-specific activation of autoreactive T-cell clones2. ADEM is often preceded by a viral or bacterial infection; usually in the form of a non-specific upper respiratory tract infection3. Neurologic symptoms of ADEM commonly appear 4 to 13 days after the infection. ADEM can affect any part of the nervous system and thus the clinical presentation is variable. Patients can present with altered mental status, seizures, pyramidal dysfunction, cerebellar ataxia, brainstem syndromes, optic neuritis, myelitis, and rarely myeloradiculopathy and extrapyramidal syndromes2. The diagnosis of ADEM is based on clinical presentation and neuroimaging2,3. ADEM following dengue infection has been described in literature4,5. Although, ADEM following dengue infections is rare, it deserves mention as the management and prognosis depend on early recognition and treatment. It has been seen that the recovery is incomplete in patients with ADEM not receiving any form of immune modulation treatment (high dose methylprednisolone, intravenous immunoglobulin or plasmapheresis)2,3. The clinical presentation of the infant and cerebrospinal fluid analysis described by Kanade and Shah1 is similar to that of ADEM. However, the normal magnetic resonance imaging findings and the complete recovery without immune modulation treatment goes against ADEM. In conclusion, we would like to highlight that ADEM should be suspected in a child who develops multifocal neurologic abnormalities with encephalopathy, especially if onset occurs one to two weeks after dengue fever. REFERENCES