POSTTRAUMATIC APALLIC SYNDROME FOLLOWING HEAD-INJURY .1. CLINICAL CHARACTERISTICS

Epidemiological studies made within the western countries indicate an incidence of 200-300 traumatic head injuries per 100 000 residents eac h year. Severe head injuries account for 5-25% of all head injuries; 1 0-14% of all severe head-injured patients develop into a vegetative st ate, in which a sleep-wake rhythm is apparent, but however in which th ere is no evidence of awakeness or reactivity to the environment. The most commonly used labels, in the German and international literature, for these patients are 'vegetative state', 'apallic syndrome' and 'co ma vigile'. This clinical characterization is not sufficient. It is ne cessary to employ additional criteria to distinguish subsets of vegeta tive patients e.g. computerized tomography, magnetic resonance imaging , single photon emission tomography, electroencephalography, brainstem reflexes, evoked potentials, assessment scales, age, premorbid brain disorders. Diagnostic and prognostic parameters must form the basis fo r various decisions relating to patients' care and intervention.