Quantifying pathological disorders of consciousness. Reliability criteria, aims, feasibility

Within a survey of coma scales we distinguish scales of clinical findings (Glasgow Coma Scale [GCS], Glasgow Liège Scale [GLS], Innsbruck Coma Scale [ICS], Comprehensive Level of Consciousness Scale [CLOCS]), grading tests (Vigilance Scale [VS], Funktionspsychose-Skala-B [FPBS-B]) and level-scales (Reaction-Level-Scale [RLS-85], Munich Coma Scale [MCS]). With regard to the purpose we differentiate a classification of depth, the prediction of prognosis and the monitoring of changes. For the purpose of classification of depth, the RLS-85 because of its superior objectivity is preferable, but the GCS is of comparable validity and more widely used. The GLS differentiates the deeper states of coma better than either of these because brainstem-reflexes in cranio-caudal order are added. Within the prediction of prognosis all coma-scales have only limited validity and for the purpose of resource economy require additional criteria in the individual case. For the purpose of monitoring changes the level-scales primarily do not fit, the GCS is not sensitive enough. The Glasgow-Cologne-List is better suited; it is more than one-dimensional, but can be expressed through the GCS numbers for comparative purposes. The ICS is not widely used and the prognostic validity has not been proven to the same extent. The Glasgow-Cologne-List could be amplified for the less severe disturbances of consciousness according to Price (32,33), and for the lower levels according to the GLS (2,3,4). In both cases the expense is slightly higher.