Approximately
half of severely head-injured patients will need surgery to remove or
repair hematomas (ruptured blood vessels) or contusions (bruised brain
tissue). Disabilities resulting from a TBI depend upon the severity of
the injury, the location of the injury, and the age and general health
of the individual. Some common disabilities include problems with
cognition (thinking, memory, and reasoning), sensory processing (sight,
hearing, touch, taste, and smell), communication (expression and
understanding), and behavior or mental health (depression, anxiety,
personality changes, aggression, acting out, and social
inappropriateness). More serious head injuries may result in stupor, an
unresponsive state, but one in which an individual can be aroused
briefly by a strong stimulus, such as sharp pain; coma, a state in which
an individual is totally unconscious, unresponsive, unaware, and
unarousable; vegetative state, in which an individual is unconscious and
unaware of his or her surroundings, but continues to have a sleep-wake
cycle and periods of alertness; and a persistent vegetative state (PVS),
in which an individual stays in a vegetative state for more than a
month.