| disease | Fibular Muscular Atrophy |
| alias | Charcot-Marie-Tooth Syndrome |
Also known as Charcot-Marie-Tooth syndrome. It is a hereditary peripheral neuropathy primarily affecting the peroneal muscles and other distal muscles of the lower limbs. It is usually autosomal dominant, with a minority being recessive. It is classified into two types: demyelinating and axonal.
bubble_chart Pathological Changes
In the demyelinating type, the motor and sensory nerve conduction velocities are 65% lower than normal, with prolonged latency. Nerve biopsy reveals partial demyelination and Schwann cell proliferation. In the axonal type, the motor and sensory nerve conduction velocities are 65% higher than normal, but the amplitude of evoked responses is reduced. Nerve biopsy shows Wallerian degeneration, most pronounced in the distal nerve segments.
bubble_chart Clinical Manifestations
Demyelinating type onset occurs before the age of 20, presenting with foot drop and a steppage gait. Distal muscle atrophy leads to a "frog-leg" deformity, intrinsic hand muscle atrophy, weakened or absent distal tendon reflexes, and frequent stocking-like sensory disturbances. High-arched feet are also common. Peripheral nerves become enlarged. In some cases, tremor is prominent. Axonal type Charcot-Marie-Tooth disease symptoms begin in adulthood, but foot deformities occur earlier. Distal muscle weakness and atrophy, stocking-like sensory disturbances, and suppressed tendon reflexes are similar to the demyelinating type, but symptoms are milder, and there is no nerve enlargement.
bubble_chart Treatment Measures
There is no specific treatment; for foot drop, braces can be used to help patients maintain walking ability.
Lumbosacral radiculopathy or tumors may present with muscle atrophy, sensory and reflex abnormalities, which need to be differentiated from this condition. The sensory disturbances often follow dermatomal distributions and may involve radicular pain, but there is no family history. The upper limbs are asymptomatic, and myelography, CT, or MRI can help confirm the diagnosis.
