also affect the arms and hands. Though the motor
symptoms of CMT are most prominent, CMT also
affects sensory perceptions and can cause tingling
and numbness (PARESTHESIA). Characteristic symp-
toms of CMT include
- apparent clumsiness or difficulty walking, run-
ning, and jumping - progressive weakness in the legs and feet, and
occasionally in the arms and hands - atrophy (wasting) of MUSCLE mass in the
affected extremities - diminished sensory perception in the extremi-
ties, particularly of heat, cold, and PAIN - foot drop and heel slap when walking, indica-
tions of muscle weakness in the lower leg and
foot
The diagnostic path includes a comprehensive
NEUROLOGIC EXAMINATION, detailed PERSONAL HEALTH
HISTORY, nerve conduction studies, and elec-
tromyogram (EMG). The neurologist may also
perform a nerve biopsy to examine the structure
of nerve cells in the muscle tissue and GENETIC
TESTINGfor mutations known to cause CMT. The
neurologic examination typically shows dimin-
ished or absent reflexes at the elbow, knee, and
ACHILLES TENDON.
Treatment Options and Outlook
CMT is a progressive, lifelong condition. Symp-
toms in CMT1 generally stop short of complete
loss of motor function in the affected extremities.
Other forms of CMT, notably CMT4 and CMTX,
may result in inability to walk. PHYSICAL THERAPY
and daily physical activity—STRENGTH exercise,
RESISTANCE EXERCISE, and activities to improve bal-
ance and FLEXIBILITY such as YOGA—can extend
unassisted mobility. Bicycling and swimming are
excellent activities for AEROBIC EXERCISEas well as
for strengthening and flexibility with minimal
impact on the ankles, which are the most vulnera-
ble as CMT progresses. Adaptive devices such as
braces, walkers, and wheelchairs can aid mobility
when motor function deteriorates to a point that
cannot support independent mobility. Some peo-
ple benefit from surgery to rebalance muscles and
tendons, in particular to provide support for the
feet. Despite the progressive nature of CMT, the
condition is not fatal; and with adaptive devices
and environmental modifications, most people
who have CMT can enjoy productive lifestyles.Risk Factors and Preventive Measures
CMT is nearly always an inherited condition, so
the key risk factor is genetics. GENETIC COUNSELING
can assist couples with FAMILY PLANNING. Early diag-
nosis and treatment preserves muscle strength and
function to the greatest extent possible. High-top
shoes and braces to support the ankle extend
mobility and reduce the risk for ankle injuries
such as sprains, strains, and fractures.
See also DISABILITY AND EXERCISE; EXERCISE AND
HEALTH; FRACTURE; GENETIC DISORDERS; INHERITANCE
PATTERN; REFLEX; SPRAINS AND STRAINS.Charcot’s joints See NEUROGENIC ARTHROPATHY.chondritis INFLAMMATIONof CARTILAGE that may
occur anywhere in the body though is most com-
mon in the cartilage of the ribs (costochondritis),
on the ends of the bones (osteochondritis), and
within the external EAR (auricular chondritis).
Chondritis often results from trauma, such as a
blow or, when the external ear is involved, after a
burn injury. Bacterial INFECTION may accompany
the inflammation. Polychondritis is an autoim-
mune disorder in which inflammation affects mul-
tiple locations of cartilage throughout the body.
Some rheumatologists believe polychondritis is a
form of VASCULITIS. NONSTEROIDAL ANTI-INFLAMMA-
TORY DRUGS(NSAIDS) may suppress the inflamma-
tory response. Bacterial infection requires
treatment with ANTIBIOTIC MEDICATIONS. However,
chondritis may respond slowly to treatment
because cartilage does not have a BLOODsupply to
carry medications to the site of the inflammation.
Heat and rest may provide some relief.
See also AUTOIMMUNE DISORDERS; BACTERIA; SYN-
OVITIS; TENDONITIS.clubfoot See TALIPES EQUINOVARUS.congenital hip dysplasia A condition in which
the head of the femur (thigh BONE) does not prop-
erly seat in the acetabulum (pelvic socket) at
birth. Numerous potential causes may account for318 The Musculoskeletal System