Neuropathology of prolonged unresponsive wakefulness syndrome after blunt head injury: Review of 100 post-mortem cases

Objectives: Recently, 'unresponsive wakefulness syndrome' (UWS) was coined for challenging conditions previously termed vegetative state or apallic syndrome. Materials and methods: In a post-mortem series of 630 patients who sustained a blunt traumatic brain injury, 100 (59 men and 41 women, aged 5-86 years; 77% traffic accidents, 23% falls and others) showed various disorders of consciousness which were compared with neuropathology with focus on brainstem lesions. Results: In the total autopsy series (n = 630), the incidence of cortical contusions, diffuse axonal injury (DAI) and intracranial haemorrhages was 41, 55 and 73%, respectively, of diencephalic, hypothalamic and hippocampal lesions 62% each, brainstem lesions 92%. Clinical prognosis was related to the location and extent of brainstem damage. Lesions in central parts of the rostral brainstem, frequently associated with extensive DAI, allowed no recovery from coma or UWS (n = 67), which occurred only with damage to the dorso-lateral brainstem tegmentum or pontine basis (n = 33). Only two of 11 patients with minimally conscious state (MCS), in addition to haemorrhages (n = 4), contusions (n = 10) and DAI (n = 7), showed small lesions in dorsolateral pontine tegmentum or diffuse pontine gliosis. Conclusions: These and other data confirm the importance of the pattern and extent of brainstem damage for the prognosis of UWS, only small peripheral lesions in pontine tegmentum allowing progressive remission.