Mismatch of neurophysiological findings in partial recovery of cosciousness: a case report

Aim: Electroencephalography (EEG) and somatosensory potentials (SEP) are regarded as useful tools for exploring residual brain activity and providing information for recovery in patients with anoxic encephalopaty. However, the diagnoses of vegetative and minimally conscious states can only be made by means of repeated specific neurological examinations. In this respect, this study describes the case of a patient with mismatch of neurophysiological findings despite partial recovery to a minimally conscious state. Case report: A 52-year-old man was admitted to the Post-Coma Intensive and Rehabilitation Care Unit with a diagnosis of anoxic encephalopathy. EEG, according to Hockaday, was severely abnormal (Grade IVa). SEP showed bilateral loss of all cortical components. Four weeks after admission the Coma Recovery Scale Revised (CRS-R) score moved from 7/23 to 13/23. Conclusions: This patient persistently showed a mismatch of neurophysiological findings which did not anticipate the slight but discriminating improvement ascertained through the neurological examination. This observation confirms that electrophysiological evaluations can only be regarded as ancillary tools since level of consciousness may be reliably evaluated only by means of repeated specific neurological assessments. As this case-report suggests, neurophysiological findings may turn out to be inconclusive and misleading in relation to the assessment of consciousness and may lead to an underestimate of minimal signs of recovery across the grey-zone from the vegetative to the minimally conscious state.