Music as a diagnostic tool in low awareness states: considering limbic responses.

PRIMARY
OBJECTIVE: Examining the evidence from contrasting epistemological sources a case is made for the use of music as an assessment medium with patients in low awareness states. Profound brain damage can result in long-term states of altered consciousness such as vegetative and minimally conscious states. Differential diagnosis with this population is immensely complex requiring diverse approaches. Neuroimaging alone is not, as yet, sufficient to establish diagnosis in this population and must be supplemented by repeated behavioural observation methods from a skilled and diverse treatment team, as there are enormous medico-legal and ethical implications. Evidence from research in neuroimaging and the behavioural health sciences indicates that auditory stimulation can reveal residual functioning and elicit optimal behaviours in such patients, particularly when the stimulation has emotional significance. MAIN OUTCOMES AND
RESULTS: Behavioural assessment is complicated by limbic behaviours which can be misinterpreted as purposeful emotional responses. A case vignette using music therapy in a complex case illustrates such complications.
CONCLUSIONS: Given the evidence for residual auditory functioning in patients in low awareness states, music is recommended as a medium for assessment. However, professionals involved in diagnosis must take caution against misinterpreting limbic responses and attributing greater meaning to such behaviours.