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Full Outline of UnResponsiveness

Wijdicks et al. (2005) have recently presented the Full Outline of UnResponsiveness (FOUR) scale as an alternative to the Glasgow Coma Scale (GCS, Teasdale and Jennett 1974) in the evaluation of consciousness in severely brain-damaged patients. They studied 120 patients in an intensive care setting (mainly neuro-intensive care). FOUR is an acronym for the number of components tested (eye, motor, brainstem reflexes and respiratory function) and for the maximum score assigned to each of these (eyes 4, motor 4, brainstem 4, respiration 4). The scale explicitly tests for eye movements or blinking on command - requesting to open the eyes manually if closed. This facilitates the early detection of a locked-in syndrome and is in our view very much welcomed given that recent studies have shown that medical caregivers failed to recognise signs of consciousness during the first weeks of the locked-in syndrome in more than half of the cases (Laureys et al. 2005). In contrast to the GCS, the scale also tests for eye tracking of a moving object. Most frequently, this is the first sign heralding the transition from a vegetative to a minimally conscious state (Majerus et al. 2005). The rest of the FOUR’s E-score is identical to the GCS.
Mostly innovating is the hand-position test where the patient is asked to make a fist (as for hitting) or a “thumbs-up” sign, or a “victory” V-sign. This is a smart alterative to the V-score of the GCS and remains testable in intubated patients. The rest of the M-score is taken from the GCS with the exception that no difference is made between abnormal stereotyped flexion and normal flexion to pain (similar to the early version of the GCS, Teasdale and Jennett 1974). This difference indeed is hard to appreciate by inexperienced observers but might ensue in lower prognostic power. Generalized myoclonus status epilepticus, known to be a poor prognostic sign in anoxic coma, is scored identical as absent motor response to pain. Amending the GCS’s lack of brainstem-reflexes assessment, the FOUR tests pupil, cornea and cough reflexes and separately scores respiration. For untrained users, evaluation of the brainstem component probably is the most complex as it proposes different combinations of the presence or absence of each of its three reflexes. Unilateral fixed mydriasis, alerting uncal herniation, has a separate score. To avoid corneal trauma by repeated testing, it is cleverly proposed to instil some drops of saline on the cornea. The last category of the FOUR scores respiration as spontaneous regular, irregular, Cheyne-Stokes, ventilator-assessed patient-generated breaths or absent. It remains to be seen how pulmonary disease and respirator settings might bias the assessment and how reliably Cheyne-Stokes can be separated from irregular respiration by inexperienced users. With all categories graded zero, the FOUR equates with brain death.

REFERENCES (Text adapted from Laureys et al. 2005)

Laureys, S., F. Pellas, P. Van Eeckhout, S. Ghorbel, C. Schnakers, F. Perrin, J. Berre, M. E. Faymonville, K. H. Pantke, F. Damas, M. Lamy, G. Moonen and S. Goldman (2005). "The locked-in syndrome : what is it like to be conscious but paralyzed and voiceless?" Prog Brain Res 150: 495-511.
Laureys, S., S. Piret and D. Ledoux (2005). "Quantifying consciousness." Lancet Neurol 4(12): 789-90.
Majerus, S., H. Gill-Thwaites, K. Andrews and S. Laureys (2005). Behavioral evaluation of consciousness in severe brain damage. The boundaries of consciousness: neurobiology and neuropathology. S. Laureys. Amsterdam, Elsevier. 150: 397-413.
Teasdale, G. and B. Jennett (1974). "Assessment of coma and impaired consciousness. A practical scale." Lancet 2(7872): 81-4.
Wijdicks, E. F., W. R. Bamlet, B. V. Maramattom, E. M. Manno and R. L. McClelland (2005). "Validation of a new coma scale: The FOUR score." Ann Neurol 58(4): 585-93.