Preserved auditory cognitive ERPs in severe akinetic mutism: a case report

Akinetic mustism is a dramatic deficit in spontaneous initiation of voluntary motor and speech acts, usually secondary to bilateral lesions of the anterior cingulate cortices and supplementary motor areas [Principles of Neurology, McGraw-Hill, New York, 1989]. Given the obvious limitations of traditional neuropsychological testing in this clinical context, the use of neurophysiological tools such as bedside auditory cognitive event-related potentials (ERPs), recently proven to be relevant to evaluate comatose and vegetative patients [Clin. Neurophysiol. 110 (9) (1999) 1601; News Physiol. Sci. 17 (2002) 38], may constitute an interesting alternative. Here, we present the ERPs of a 38-year-old right-handed woman with severe akinetic mutism recorded in a passive auditory odd-ball paradigm. In spite of this severe clinical state, we could observe the presence of a "Mismatch Negativity", and of a larger P300 in rare trials than in frequent ones. By revealing a high level of cognitive integration of environmental auditory information, our study emphasizes the potential clinical relevance of MMN and P300 recordings in akinetic mutism to assess patient cognitive functioning. (C) 2004 Elsevier B.V. All rights reserved.