The brain could be regarded as being in three parts. The brain stem is the most primitive part and supports the most basic functions of breathing, blood circulation and digestion. It is also involved in some of the basic aspects of behaviour, mating, aggression and anger. It sits above the spinal cord at the base of the rest of the brain.

Probably the greatest practical challenge facing the physician is the maintenance of vital functions in the acute stage of brainstem encephalitis. With the present capacity of physiologic support and close observation offered by intensive care units, such patients may be tided over the acute phase. Many cases of apparently devastating brainstem encephalitis recover significantly if supported through the acute phase. Yet others will survive with devastating disability remaining in a "locked-in" state.

Long term damage to any area of the brainstem will result in problems that are associated with that area. Examples include problems with temperature control, digestion and anger management.

The second and third parts of the Brain

Wrapped around this basic brain is the "limbic brain" or intermediate brain. It includes the hippocampus, thalamus, hypothalamus and amygdale which are involved in memory an much of the behaviour related to sex, hormones, food, the perception of pleasure and competition with others. The limbic brain is the seat of higher emotions including the protection of the young and feelings such as love, sadness and jealousy.

The third and major part of the brain is the neocortex, the rational brain. The neocortical brain provides logic and thought, it is the seat of processes such as speaking, planning and writing.

Last modified: 15/11/2006