Diagnosis: Cerebral contusions
• Contusions are superficial bruises of the brain after head injury, due to damage to small blood vessels and neural parenchyma.
• Contusions occur commonly in the inferior aspect of frontal lobes, inferolateral parts of the temporal lobes, temporal poles, the cortex adjacent to the Sylvian fissure, and, occasionally, the cerebellar hemispheres. Rotational movement of the brain over the rough base of the skull is one factor in producing contusions in inferior aspects of the frontal and temporal lobes.
• Initially, a contusion appears as a superficial microhemorrhage occasionally extending into the overlying leptomeninges and with variable brain swelling. Over time, a brown or orange discoloration is present and the involved gyri become indented or superficially cavitated. Old contusions often have a triangular shape with the point in the depths of the cortex.
• Damage to the blood vessels (like thrombosis), can lead to ischemic infarcts within the lesion.
• Superficial lobar hematomas can occur overlying contusions, and are mainly seen in the frontal and temporal lobes and in the cerebellum.
• Coup contusions are contusions that occur beneath the site of impact in the absence of a fracture. Contrecoup contusions occur opposite or away from the site of impact.
