BMH Med. J. 2014;1(1):17-18   Images

Unilateral Hemispheric Encephalitis

Mohan Leslie Noone MD, DM¹; Shaji Thomas John MD<sup>2

1</sup>Department of Neurology, Baby Memorial Hospital, Calicut, India
²Department of Paediatrics, Baby Memorial Hospital, Calicut, India

Address for Correspondence: Dr. Mohan Leslie Noone MD, DM, Department of Neurology, Baby Memorial Hospital, Indira Gandhi Road, Calicut - 4, India.  E-mail: mlnoone@fastmail.in

Presented as a poster at European Neurology Society Conference 2013

Abstract

A 10 year old boy presented with history of mild fever and upper respiratory symptoms followed by recurrent seizures and loss of consciousness on the next day. Normal blood counts and abnormal hepatic transaminases were noted.  MRI of the brain, done on the fourth day of illness, showed extensive involvement of the cortex in the right hemisphere.  Lumbar CSF was normal.  The EEG showed bilateral slowing with frontal sharp wave discharges and marked attenuation over the entire right hemisphere.  The patient succumbed to the illness on the ninth day.  A similar pattern of acute unilateral hemispheric cortical involvement is described in the hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome, which is typically described to occur in children below 4 years of age. This case of fulminant acute unilateral encaphilitic illness could represent the acute phase of HHE syndrome.

Key Words:  encephalitis, MRI, status epilepticus, hemiconvulsion-hemiplegia-epilepsy

A 10 year old boy presented with history of mild fever and upper respiratory symptoms followed by recurrent seizures and loss of consciousness on the next day. Normal blood counts and abnormal hepatic transaminases were noted.  MRI of the brain, done on the fourth day of illness, showed extensive involvement of the cortex in the right hemisphere (Figure 1).  Lumbar CSF was normal.  The EEG showed bilateral slowing with frontal sharp wave discharges and marked attenuation over the entire right hemisphere (Figure 2).  The patient succumbed to the illness on the ninth day.  A similar pattern of acute unilateral hemispheric cortical involvement is described in the hemiconvulsion-hemiplegia-epilepsy (HHE) syndrome, which is typically described to occur in children below 4 years of age [1]. This case of fulminant acute unilateral encaphilitic illness could represent the acute phase of HHE syndrome.

Figure 1: MRI of the brain showing extensive gyral edema in the right hemisphere on T1 (A) with hyperintensity of the cortex on T2 (B) and restricted diffusion (C & D).  A few scattered areas of restricted diffusion are also noted on the left side.

 

Figure 2: EEG with referential (A) and bipolar (B) montages showing bilateral slowing with frontal sharp wave discharges and marked attenuation over the entire right hemisphere.

 
References


1. D W Kim,  K K Kim, K Chu, C K Chung,  S K Lee. Surgical treatment of delayed epilepsy in hemiconvulsion-hemiplegia-epilepsy syndrome. Neurology 2008;70:2116-2122.