Chronic vegetative state after severe head injury: clinical study; electrophysiological investigations and CT scan in 15 cases.

Abstract

Fifteen cases of chronic vegetative state (CVS), following severe head injury and lasting for two years or more, are reported. Vegetative state, in most instances after a period of coma, consists of a return of wakefulness accompanied by an apparent total lack of higher mental activity. A protracted period of vegetative state has been chosen to ensure that the possibility of further recovery could virtually be excluded. The term of CVS could therefore be reasonably used to designate these cases. Moreover, cerebral lesions were then thought to be the same as in neuropathological studies. Severe head injury, responsible for CVS, initially affected adults in 11 cases and children in four cases. The range of duration of the vegetative state was 2 to 14 years, with a mean of five years. The data of clinical study and electrophysiological investigations (EEG, brain stem auditory evoked potentials, somatosensory evoked potentials) are reported. A CT scan was carried out in each case to study the impairment of cerebral hemispheres and brain stem, with particular attention to the ventricular size. The results confirm that in the CVS, lesions affect mainly the hemispheres, while brain stem functions are mainly preserved. Vegetative State (VS) is the term proposed by Jennett and Plum (1972) to describe the condition that sometimes emerges after a period of coma, after a severe head injury (SHI). This condition consists of a return of wakefulness accompanied by an apparent total lack of higher mental activity. A practical definition of this state characterised by wakefulness without responsiveness is that the eyes open spontaneously and/or in response to verbal stimuli. Sleep-wake cycles exist. The patients can neither obey simple orders nor locate painful stimuli. They utter no comprehensible words. Blood pressure and breathing remain steady. It is much more difficult to specify exactly how long such a state must persist before it can be confidently declared permanent. Persistent vegetative state, or chronic vegetative state (CVS) is one of the five categories of the Glasgow Outcome Scale (Jennett and Bond, 1975). Bricolo et al (1980) think that the term CVS should never be applied before completion of the first year after the onset of traumatic coma. It actually seems possible to exclude the possibility of any further recovery after unresponsiveness for one year. The term CVS may then be rightfully used to denote this condition. For such protracted periods of VS, we have tried to state in a retrospective study the clinical and electroencephalographic (EEG) course.(ABSTRACT TRUNCATED AT 400 WORDS)