Although favorable outcomes may be possible in young patients with post-traumatic coma even after prolonged coma and with radiographic evidence of brainstem injury, an editorial published in Neurology says it is difficult to predict the prognosis of these patients.
Post-traumatic coma is often associated with white matter injury, resulting in loss of network connectivity and impaired axonal transport. Technological advances, including improved magnetic resonance imaging techniques, enable better assessment of brain lesions. Advanced imaging studies can provide evidence of microbleeding, which is considered a surrogate marker for diffuse axonal injury and suggests a poor prognosis in this population.
In the current issue of Neurology, Bianciardi and colleagues reported on the results of their study, which aimed to examine the patterns of microbleeding associated with post-traumatic coma and to examine the relationship between the distribution of microbleeds and the restoration of consciousness in young patients who were responsive again after being in a coma for less than 10 days. .
The data suggested that multiple nuclei in the brain stem and diencephalon were affected by microbleeding and that there was no single lesion that caused a coma. However, microhemorrhages in the brain stem occurred more frequently in comatose (severe head trauma) than in non-comatose (moderate head trauma) patients.
Study results showed that despite acute damage to deep excitation nuclei, the patients regained consciousness and in some cases achieved good functional recovery after 6 months.
The study had several limitations, including the inability to extrapolate the results to elderly patients or those in prolonged coma, possible selection bias, a small sample size, and the limitations of susceptibility-weighted images. The study researchers found that diffuse axonal injuries can occur without microbleeding and vice versa, and that additional techniques are required to determine the impact of the severity of the axonal injury on the chances of regaining consciousness.
“The submission of a nihilistic prognosis should therefore be avoided in the acute phase in the treatment of young patients with coma after severe brain trauma,” the study researchers conclude.
Rabinstein AA. A good recovery is possible in young patients with post-traumatic coma and brainstem microbleeding. Neurology. Published online May 28, 2021. doi: 10.1212 / WNL.0000000000012197