Histological changes in thalamus in short term survivors following traumatic brain injury: An autopsy study

Abstract

BACKGROUND: Severe traumatic brain injury (TBI) is a major cause of morbidity and mortality. Reduction of thalamic volumes were seen in upto 80% of patients who survived for more than 3 months after TBI. However, the same may not be true in patients who died earlier following TBI. AIMS: To to study the thalamus for evidence of any injury in short term survivors of TBI (<5 days) using immunohistochemistry to look for evidence of acute thalamic injury. MATERIALS AND METHODS: A cross sectional prospective study was done in which autopsy specimens of short term survivors of TBI (<5 days) were studied for histopathological changes. RESULTS: A total of 16 patients with a mean age of 37.8 years were included in the study. CT scan revealed acute subdural haematoma in 10, contusions in 4 patients, extradural haematoma and depressed fracture in 1 each, and diffuse axonal injury in 1 patient. Seven patients required surgery in the form of a decompressive hemicraniectomy. The histopathological analysis of the bilateral thalami showed evidence of congestion of the cerebral capillaries in 8 patients. Axonal retraction balls were seen in 8 patients, myelin breakdown products were seen in 14 patients and axonal swelling was seen in 14 patients. CONCLUSIONS: Thalamic injury is universal in the setting of severe TBI in patients who have decreased survival and may be a significant factor for the poor outcome in these patients.