Publication

Abstract : Dear Sir, We read with great interest the article by Nukui et al. on clinical characteristics of acute encephalopathy with acute brain swelling [1]. Authors have pertinently discussed four patients with this entity, three of whom had seizure clustering or status epilepticus in the clinical course. Authors tried to provide recognition to this clinico-radiological entity since it is not well recognized among the clinicians. However, this is not an uncommon entity in Asian countries. We would like to share our experience and propose a unified diagnosis of “Acute encephalopathy with brain swelling (AEBS)” for different entities with varied presentations but with common underlying pathophysiology for brain swelling. We have seen several patients with this entity. They either had a pre-existing epilepsy or developmental delay or were premorbidly normal. They developed acute encephalopathy with brain swelling (diffuse cerebral edema on CT brain) and elevated intracranial pressure either with associated febrile non-encephalitic illness, status epilepticus or trivial trauma. The outcome was variable in the form of death, consequent refractory epilepsy, and developmental delay or near normal with variable cognitive deficits. Zhang et al recently reported another distinctive entity “focal status-epilepticus related unilateral brain edema (FSE-UBE)”, separate from Infantile hemiconvulsion-hemiplegia-epilepsy syndrome (IHHE) in terms of age-group, preexisting epilepsy and/or developmental delay and absence of fever [2]. We contemplate that IHHE, FSE-UBE and acute encephalopathy with diffuse brain swelling with febrile infection are nothing but a continuum of AEBS. They share common pathophysiology- a varying combination of vasogenic and cytotoxic brain swelling with neuronal damage secondary to inflammatory cascade, neuronal hypoxia, status epilepticus, cortical spreading depression etc [3]. Genetic predisposing factors may include channelopathies such as CACNA1A, SCN1A etc [4]. The outcome in AEBS, likely depends on the degree of CNS inflammation, neuronal hypoxia, cortical spreading depression and proportions of vasogenic and cytotoxic edema.