Laceration Of The Brain

The brain may be injured directly or indirectly. In injuries involving fracture of the skull the brain is often simultaneously wounded, or the bone may be carried inwards and impinge upon the brain. On the other hand, the brain is often lacerated without a corresponding external wound or fracture of the skull, by so-called contre coup. When a person falling from a height alights on the head the solid cranium is suddenly arrested. The more mobile contents impinging against the internal surface of the skull are pitched back in the opposite direction. Hence in such cases there is often laceration both at a point corresponding with the injury to the skull and at a point more or less diagonally opposite. The latter is called laceration by contre coup, and it is sometimes more severe than the other.

The lacerated brain substance is torn and softened and there is more or less haemorrhage. The haemorrhage may be serious if any considerable vessel in the meninges be injured, but is not usually great from the brain substance itself. The injured parts are afterwards affected by inflammation, which in the case of compound fracture with a septic wound may be acute, leading to abscess, but in most cases is chronic. Such chronic inflammations, affecting brain and meninges, may persist for long periods, even enlarging their area and producing extensive destruction and shrinking of the cerebral substance. In the affected part the membranes are adherent and thickened, and the brain substance is indurated by new-formed connective tissue. Important nervous and mental phenomena may follow such lesions even when the injury to the head has not been great.