Head Injury

The hard skull protects the soft brain (consistency of porridge) from many minor injuries. The scalp/skull may suffer bruising, lacerations and fractures, but apparently no damage to the neurological tissue that it covers. Head injuries usually mean damage to the brain even though this may only be transitory (concussive). Most head injuries are minor, though neurological injuries are the principal cause of death or lasting disability in the younger age groups who still play football, ride motorcycles and engage in contact sports. Head injuries are the main cause of death in the under 35's in America. In Britain, over one million people attend hospital each year with head injury with over 50% of these arising from road traffic accidents (RTAs) and 120,000 are classified each year as having suffered brain damage. The brain may be directly injured after the skull has been fractured, but may also be damaged by rapid acceleration or deceleration injuries.

The brain is able to slop about within the skull as gruel does in a bucket. When the brain moves violently to and fro, it suffers injury at two points: the impact site and at the opposite side of the brain as a result of rebound. The general shaking a brain receives (after a heavy blow or deceleration injury), causes widespread, but lesser damage throughout the frontal and temporal lobes. Further destruction of the brain is caused by the tearing of its covering (meninges) and blood vessels. Any subsequent haemorrhages cause extensive neurological damage, which is also accompanied by oedema and swelling. As the skull is rigid, any swelling can produce a dangerous rise in the intracranial pressure.

After any brain damage severe enough to cause unconsciousness, brain cells will have been permanently destroyed and therefore complete recovery is not possible. Even after concussion, patients may suffer for a time from ill-defined symptoms such as depression, apathy, headaches and dizziness. Many find the zest for life lessened. And difficulty in concentration. Serious head injuries with an apparent good recovery can be associated with loss of memory. Retrograde amnesia (loss of memory of events before an accident) is usually less extensive compared to loss afterwards.

It is unusual to suffer head injuries in accidents without associated injuries usually to the chest. This confuses the clinical picture after a head injury as damage to the lungs frequently reduces the oxygen supply to the brain. Likewise, difficulty in respiration and swelling within the lungs are sometimes the result of damage to the respiratory centre within the brain. Or injury to the spine.