Charcot-Marie-Tooth disease (CMT) is named after the three doctors who first described the disease in 1886: Jean-Martin Charcot (shar-coh), Pierre Marie, and Howard Henry Tooth. Today, CMT refers to any peripheral neuropathy with a genetic cause, whether or not the specific genetic mutation is known.
CMT is a rare multisystem, multiorgan disease that causes lifelong, progressive symptoms, including muscle weakness and atrophy in the arms and legs, sensory loss, and other complications. These symptoms often lead to challenges with balance, walking, hand use, and other daily activities.
While CMT affects everyone differently, understanding the range of possible symptoms can help individuals and families identify and manage challenges early.
Early CMT Symptoms
Early signs of CMT often appear subtly but can significantly affect daily life. In children, toe walking or frequent tripping may be among the first signs caused by a weakening of the muscles that lift the front of the foot—a condition called foot drop. Other early symptoms include frequent ankle rolls or sprains, persistent muscle cramps in the legs, and difficulties with fine motor tasks, such as writing, using zippers or buttons, and using utensils.
Muscle Weakness and Atrophy
Muscle weakness and atrophy are common symptoms of CMT. The muscles farthest away from the spinal cord (distal) are usually affected first and more severely than those closer to the spinal cord (proximal). As muscles weaken and atrophy, tasks like walking, climbing stairs, or gripping objects can become increasingly difficult.
Numbness and Sensory Symptoms
CMT often causes numbness, particularly in areas farthest from the spinal cord such as the hands and feet. This numbness can be episodic, with some individuals waking up with painfully numb hands that may clear within hours or persist for weeks or months and can vary widely in intensity.
Balance and Proprioception
CMT frequently causes challenges with balance due to weakened muscles and impaired proprioception (the body’s ability to sense the position and movement of its limbs in space). These can make it challenging to navigate uneven surfaces, maintain stability during movement, or recover from minor stumbles, leading to an increased risk of trips and falls.
Reduced or Absent Deep Tendon Reflexes
Reduced or absent deep tendon reflexes (areflexia) are common symptoms of CMT. Reduced or absent reflexes are often diffuse, affecting multiple areas of the body equally. Reduced reflex activity can contribute to muscle weakness and a reduced ability to respond to sudden movements or maintain stability.
Hand Weakness and Finger Contractures
CMT often leads to progressive weakness in the hands and wrists, making everyday tasks like gripping objects, writing, or buttoning clothing increasingly difficult. Over time, this weakness can contribute to finger contractures, commonly called clawed fingers, where the fingers become curled or stiff due to muscle imbalance and tendon tightening. These contractures can further limit fine motor skills and dexterity, impacting independence in daily activities.
Foot Drop
Foot drop is a common symptom of CMT, caused by weakness in the muscles responsible for lifting the front of the foot. This weakness makes it difficult to clear the toes when walking, leading to a characteristic “steppage gait” where individuals may raise their knees higher than usual to avoid catching their toes on the ground. Over time, the strain from compensating for foot drop can contribute to additional complications, such as ankle instability or joint pain, underscoring the importance of early diagnosis and tailored support to maintain mobility.
Foot Deformities
CMT frequently leads to foot deformities such as high arches (cavovarus deformity) or flat feet (pes planus), significantly impacting mobility and quality of life. Cavovarus foot deformity results from imbalanced muscle weakness that twists the foot outward and downward, creating a high arch and causing individuals to stand or walk on the outer edges of their feet. This imbalance often contributes to ankle instability, frequent sprains, trips, and falls; and can lead to degenerative changes in the ankles, knees, hips, and lower back over time.
In contrast, pes planus foot deformity, or flat feet, involves inward-turning feet caused by different muscle imbalances. While opposite in presentation, pes planus can be equally painful and challenging, mobility difficult for many with CMT.
Pain and Fatigue
Chronic pain is a common and often debilitating aspect of CMT. Pain can stem from neuropathic pain, muscle and joint pain, or both. This combination can significantly impact one’s quality of life.
Chronic fatigue is common in CMT, as the physical demands of weakened muscles and impaired mobility can make even simple tasks exhausting, leaving individuals feeling drained after minimal activity.
Spine Deformities
Spine deformities, such as scoliosis and kyphosis, can occur in CMT. They can develop as a result of muscle weakness and imbalances along the spine. Scoliosis, a sideways curvature of the spine, and kyphosis, an exaggerated forward rounding of the upper back, are usually mild in CMT but can become severe in some cases, requiring corrective surgery.
Kneecap Dislocations
Kneecap dislocations can occur in CMT, particularly in children, and are often linked to a condition called patella alta. Patella alta describes a kneecap that sits higher than usual, often due to weakened leg muscles.
Less Common Symptoms
Though less common, some individuals with CMT experience neurogenic bladder and bowel issues, optic atrophy or pupil abnormalities, and vestibular challenges that worsen balance. Speech, swallowing, hearing, and breathing difficulties can also occur.
While the symptoms listed here represent common challenges faced by individuals with CMT, they are not an exhaustive list. Each person’s experience with CMT is unique, and symptoms can vary widely. Expert guidance and resources are available to help at CMTA Centers of Excellence.
CMTA Centers of Excellence are multidisciplinary clinics specializing in CMT care, where patients and their families can receive comprehensive care that includes genetic counseling and tailored management plans.
