Veränderungen des Blinkreflexes (Orbicularis-oculi-Reflexes) im Koma: lokalisatorische und prognostische Bedeutung

Abstract

Alteration of the early component of the blink reflex (delayed latency or abolished reflex) is considered to be relatively specific for pontine lesions (multiple sclerosis, vascular lesions of the brain-stem, neoplasms, syringes); provided, the trigeminal and facial nerve are unaffected. In comatose patients the electrically, by stimulation of the supraorbital nerve elicited blink reflex was super-imposed (50 or 100 responses) with the LAB 8/e-computer (off-line). It was found that the R1 component was abolished even in cases with supratentorial lesions and secondary brain-stem alterations, while no specific pontine lesions were demonstrated by neuropathological examination. Therefore it is suggested that delayed or abolished blink reflexes in coma due to supratentorial mass lesions are not conclusive for pontine lesions: they rather may reflect an unspecific secondary brain-stem alteration. Recording of the EEG reveals that in some cases the extinction of the early blink reflex precedes corresponding EEG alterations; this may be a matter of prognostic value.