A 20-year-old man remains comatose (GCS 6) after a high-speed accident with no focal neurological deficit. CT brain shows only small petechial haemorrhages at the grey white junction and in the corpus callosum, with no surgically drainable collection. Which statement best describes this injury?

• A It is caused by contusion of the temporal poles against the sphenoid wing and typically needs surgical evacuation
• B It represents venous bleeding into the subarachnoid space and requires lumbar puncture for confirmation
• C It carries an excellent prognosis with full recovery expected within weeks
• D It results from rotational acceleration deceleration forces shearing axons, and MRI is more sensitive than CT for its detection ✓

Explanation

Diffuse axonal injury follows high speed rotational shearing of axons, classically affecting the corpus callosum, dorsolateral brainstem, and grey white junction. CT may show only subtle petechial haemorrhages while MRI with susceptibility weighted sequences demonstrates far more lesions. Prognosis is guarded, not excellent, and there is no surgical target since the pathology is parenchymal rather than a compressive clot.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.