Encyclopedia of Health and Medicine

226 The Nervous System
a child has acquired a vocabulary of several dozen
to several hundred words and can speak in simple
sentences. Symptoms of verbal apraxia include
• unable to shape the lips and MOUTH to form
words
• appears to hear and understand but does not
verbalize in response
• verbalizes only certain sounds or words
• makes inconsistent mistakes in speech
These characteristic symptoms distinguish verbal
apraxia from developmental delays in speech,
in which the child’s language skills evolve more
slowly than normal but are otherwise typical and
complete. The diagnostic path includes a comprehensive
speech and language evaluation as well as
an assessment for HEARING LOSS. Early recognition
and diagnosis allow appropriate early intervention,
which focuses on training the brain to use different
language pathways. Treatment is more likely to
succeed when the brain is still learning these pathways.
Rerouted language pathways appear to
remain as redirected, becoming the “normal” language
pathways for the individual, and the person
speaks and otherwise manages language skills in an
age-appropriate manner. However, the ultimate
success of treatment depends on the nature, location,
and extent of the injury to the brain, factors
the neurologist often does not know.
Verbal Apraxia in Adults
Acquired verbal apraxia in adults most commonly
results as a consequence of STROKE or TRAUMATIC
BRAIN INJURY (TBI). The person knows what he or
she wants to say but cannot formulate the words,
says the wrong words, or articulates sounds that
are not words (gibberish). The person knows the
right words and is aware his or her words are
wrong but cannot correct them. Often the mistakes
in speech are inconsistent; the person may
one time speak flawlessly and the next be unable
to articulate recognizable words. The person may
also speak with incorrect inflection and intonation,
such that the rhythm of speech does not
match the words. Verbal apraxia is extremely frustrating
for the person who has it.
The diagnostic path typically includes imaging
procedures such as COMPUTED TOMOGRAPHY (CT)
SCAN to identify the area of injury as well as to
determine, when unknown, the cause of the
injury. Aggressive speech therapy may improve
speech over time. However, severe apraxia, especially
when coupled with muscle weakness, may
not respond to treatment. In such circumstances
the emphasis shifts to teaching the person to communicate
through other means such as writing or
pictures. Some people experience spontaneous
recovery from acquired verbal apraxia, though
neurologists do not know what causes this to happen
or how it happens.
See also AGING, NEUROLOGIC CHANGES THAT OCCUR
WITH; SPEECH DISORDERS; SWALLOWING DISORDERS;
VELOPHARYNGEAL INSUFFICIENCY.
ataxia The inability to coordinate voluntary
fine-motor movement. Ataxia may be acquired or
inherited and has varied presentations. Gait and
balance disturbances (difficulty with walking) are
the most common symptoms. Depending on the
form of ataxia, other symptoms may include disturbances
of EYE movements, sensory perception,
and cognition. The diagnostic path includes diagnostic
imaging procedures such as MAGNETIC RESO-
NANCE IMAGING (MRI) and COMPUTED TOMOGRAPHY
(CT) SCAN to rule out other causes of the symptoms.
Personal health history and family medical
history are important.
Acquired ataxia most commonly occurs as a
result of injury to the cerebellum (the division of
the BRAIN responsible for fine motor movement),
SPINAL CORD, or SPINAL NERVES. It may also develop
as a consequence of long-term ALCOHOLISM and
MULTIPLE SCLEROSIS. These forms of ataxia tend to be
persistent or slowly progressive, depending on the
underlying cause. Acute (sudden onset) acquired
ataxia may develop following a viral INFECTION
such as CHICKENPOX and EPSTEIN-BARR VIRUS. No
treatment is necessary for acute acquired ataxia, as
normal movement and coordination generally
return within several months.
Hereditary ataxia may occur in various inheritance
patterns and tends to be slowly progressive.
There are several forms of hereditary ataxia, the
most common of which are ataxia telangiectasia
and Friedreich ataxia. Hereditary ataxia typically
begins to show symptoms in early childhood
when the child begins to walk. Most people retain