Charcot-Marie-Tooth disease (CMT)

Overview

Charcot-Marie-Tooth disease (CMT), also called hereditary motor and sensory neuropathy, affects the peripheral nerves that carry movement and sensory signals, rather than the muscles directly — it isn't a form of muscular dystrophy, though it's often grouped alongside neuromuscular conditions because nerve damage leads to muscle weakness as a knock-on effect. There are two broad types: type 1, affecting the protective myelin sheath around nerves, and type 2, affecting the nerve fibre (axon) itself.

Symptoms

CMT usually starts in childhood, sometimes later. An early sign is often mild difficulty walking, caused by weakness or reduced sensation in the feet. Foot drop — difficulty lifting the front of the foot — is common and increases the risk of trips, and the lower legs can become noticeably thinner over time. Weakness gradually extends up toward the knees, though the ability to walk is rarely lost entirely, even if aids become useful. Hand weakness tends to develop much later, affecting fine tasks like writing.

Sensory changes — numbness or tingling in the feet and hands, sometimes described as feeling like poor circulation — are common. Muscle imbalance often leads to very high-arched or very flat feet and curled ('hammer') toes; hip dysplasia is more common than average, and severe cases can develop scoliosis. Both mechanical joint/muscle pain and nerve-related pain (burning, tingling, sharp sensations) are frequently reported.

Inheritance

Most CMT type 1 and type 2 subtypes are autosomal dominant, needing just one changed gene copy from a parent. A less common form, CMTX, is X-linked.

Getting a diagnosis

A GP refers on to a neurologist or geneticist, who combines a physical exam, family history, nerve/muscle electrical testing, and a genetic blood test to identify the specific subtype.

Management and outlook

Care is typically led by a neurologist as part of a wider team. Gentle exercise helps with balance and strength, and regular stretching — particularly of the calf/heel — helps prevent muscles tightening further; low-impact aerobic exercise like swimming or walking is generally recommended, and keeping to a steady weight matters since extra load falls on already-weakened muscles. Orthotics — insoles, ankle or leg braces, adapted shoes — improve walking safety and reduce falls; a wheelchair for longer distances can help manage fatigue without meaning walking ability is lost altogether.

Foot care deserves real attention, since reduced sensation means injuries or sores can go unnoticed — a podiatrist is worth involving if infections become frequent. Pain relief helps manage both the mechanical and nerve-related pain, and foot surgery can sometimes correct deformities that are affecting balance or causing pain. One important safety note: certain medications — chemotherapy drugs like vinca alkaloids and taxanes especially, but a number of others too — carry a meaningful risk of worsening CMT, so any new prescriber should know about the diagnosis before starting treatment.