- ringing in the ears (TINNITUS)
- progressive loss of cognitive function and mem-
ory - seizures
- personality changes
The diagnostic path begins with an assessment
of any history of trauma to the head, such as falls
or MOTOR VEHICLE ACCIDENTS. When a single event is
not apparent, the doctor will look for cumulative
injury. A NEUROLOGIC EXAMINATION can identify
signs of sensory or motor disturbances that suggest
the areas of the brain where there may be injury.
Diagnostic imaging procedures, such as COMPUTED
TOMOGRAPHY(CT) SCANor MAGNETIC RESONANCE IMAG-
ING(MRI), often reveal signs of injury such as sub-
dural or intracranial HEMATOMA, cranial FRACTURE,
or altered brain structure. ELECTROENCEPHALOGRAM
(EEG) may provide further evidence in the form of
abnormal electrical activity in certain areas of the
brain.
Treatment Options and Outlook
Treatment depends on the cause and extent of the
injury. Surgery is often necessary to drain col-
lected BLOOD (hematoma), relieve pressure,
remove BONE fragments or other matter when
there is an open wound, or repair damaged blood
vessels. Most treatment targets maintaining and
restoring brain function through PHYSICAL THERAPY,
OCCUPATIONAL THERAPY, and speech therapy. A per-
son may need to relearn basic activities of daily
living, or to use his or her nondominant hand.
Rehabilitation may also target lost abilities such as
reading or writing. The extent of recovery
depends on the nature of the injury and the per-
son’s overall health status and age. Though trau-
matic brain injury typically results in some degree
of permanent symptoms, many people are able to
recover enough to return to an acceptable level of
independent living.
Significant injury may result in COMA(UNCON-
SCIOUSNESS that extends for a few hours to a
month) or persistent vegetative state (uncon-
sciousness that persists beyond a month). Though
CT scan or MRI can help the neurologist monitor
the state of physical damage within the brain, it is
difficult to project the likelihood for recovery. A
person can remain in a persistent vegetative state
for months to years.Risk Factors and Preventive Measures
Blows to the head are the primary risk factor for
traumatic brain injury. Preventive measures
include wearing seat belts, helmets, and other pro-
tective equipment. Appropriate training and meth-
ods reduce the risk for head injuries that occur
during sporting events and competitive athletics.
See also COGNITIVE FUNCTION AND DYSFUNCTION;
MEMORY AND MEMORY IMPAIRMENT; SEIZURE DISORDERS;
STROKE.tremor disorders Conditions in which there is
damage to the areas of the BRAINthat regulate or
coordinate movement, resulting in involuntary,
rhythmic back-and-forth movements of the
extremities (most commonly the hands) and
sometimes the head. Such damage may result
from STROKE; injury; or, some researchers specu-
late, the cumulative effect of NEURONloss over the
course of the lifetime. Tremor disorders become
increasingly common with advancing age. The
most common tremor disorder is benign essential
tremor, which affects about five million Americans
most of whom are age 60 or older.BENIGN ESSENTIAL TREMOR
VERSUS PARKINSON’S DISEASE
Though tremor is a symptom of PARKINSON’SDIS-
EASE, Parkinson’s disease is not a tremor disorder
and tremor disorders do not indicate a person
has Parkinson’s disease. The tremors that charac-
terize Parkinson’s disease are most intense when
the hands are still and diminish with activity.
Tremors of benign essential tremor are most
intense during activity and may entirely disap-
pear when the affected limbs are at rest.Symptoms and Diagnostic Path
Tremors tend to develop gradually and may
worsen during times of stress or anxiety. They first
appear as mild and intermittent trembling. Over
time the movement becomes more clearly rhyth-
mic and begins to interfere with tasks such as
holding a pen to write. Tremors may also affect
the VOCAL CORDS, making the voice sound waver-
ing. This is the point at which people tend to seek288 The Nervous System