Peroneal Muscular Dystrophy
Introduction
Introduction to sacral muscle atrophy Peronialmyoatrophy, also known as Charcot-Marie-Tooth disease (CMT), is the most common group of peripheral neuropathies, accounting for approximately 90% of all hereditary neuropathies. The common features of this group of diseases are the onset of childhood or adolescents, chronic progressive sacral muscle atrophy, and the symptoms and signs are relatively symmetrical. Most patients have a family history. Because of the main clinical features of iliac muscle atrophy, it is also called peronealmyoatrophy. ). According to neurophysiological and neuropathological findings, CMT is classified into type I and type II, CMTI type is called hypertrophic type, and type CMTII is called aneuronal type. basic knowledge Sickness ratio: 0.05% Susceptible people: good for children or teenagers Mode of infection: non-infectious Complications: knee varus optic atrophy
Cause
Causes of sacral muscular atrophy
Genetic factors (35%)
The CMT1A pathogenic gene is located at 17p11.2-12, and the nuclear gene encodes peripheral neuromyelin protein 22 (PMP22). Repeated mutation of PMP22 gene leads to overexpression, which increases PMP22 protein. A small number of patients produce abnormal PMP22 protein due to PMP22 gene mutation. And cause illness.
Prevention
Tibial muscle atrophy prevention
Tibial muscular atrophy is a hereditary motor neuropathy with obvious genetic heterogeneity and is a group of hereditary diseases. The only effective preventive measure for sacral muscular atrophy is prenatal genetic diagnosis. The proband's genotype is determined by genetic diagnosis, and the fetal genotype is analyzed by fetal villi, amniotic fluid or cord blood to determine the prenatal diagnosis and terminate the pregnancy.
Complication
Complications of iliac muscle atrophy Complications of knee occlusion nerve atrophy
The disease often has swelling, purpura, ulcers and other neurotrophic disorders, occasionally optic atrophy, pupillary changes, nystagmus and trigeminal neuralgia, late interosseous muscles in the hands, large and small intermuscular muscle atrophy, the formation of ankle deformity, However, the atrophy generally does not exceed the elbow joint. The injury of the leg begins with the gastrocnemius muscle, and then gradually spreads to the interosseous muscle, the calf flexor muscle, and finally the lower third of the thigh muscle, but the upper part is completely normal, forming a "crane leg". Or inverted bottle-like malformation, atrophic muscles may have fasciculation, Achilles tendon reflexes weaken or disappear early, due to dorsiflexion often often horseshoe varus deformity.
Symptom
Symptoms of sacral muscular atrophy Common symptoms Cross-threshold gait muscle atrophy atrophy of the iliac crest muscles... Nutritional dysfunction reflex disappears hand deformity
It is a typical iliac muscle atrophy. The lower limbs are inverted bottle-shaped, or standing legs, and there are high arches, claw-shaped toes, and horseshoe varus deformities. They have a special gait when walking. Deficit muscle weakness, muscle atrophy, muscle tremor, sputum reflex or disappear. First in the hand muscle, forearm muscle atrophy, and the lower extremity distal muscle atrophy is only seen in a few cases. Glove-like, sore-like sensory disturbances and a series of autonomic and dystrophic disorders can occur in the extremities. The local skin is blue-purple, the skin temperature is low, and ulcers are formed.
Examine
Examination of iliac muscle atrophy
Laboratory inspection:
1. Cerebrospinal fluid examination: Most of them are normal, and a few may have increased protein content. Electromyography showed that the atrophic muscles were denervated, the nerve conduction velocity (NCV) of the limbs slowed down or even disappeared, the lower limbs were more obvious than the upper limbs, and the motor nerve conduction velocity changed significantly compared with the sensory nerve conduction velocity. In familial cases, NCV changes are similar in the same family, with many differences in different families. Some patients have abnormalities in visual, auditory and somatosensory evoked potentials, suggesting involvement of the central nervous system.
2. Serum protein electrophoresis: Idiopathic peripheral neuropathy with unknown causes should be routinely performed.
3. There may be a significant increase in serum phytanic acid levels and a 10% to 20% increase in fatty acids. Blood cholesterol, high-density lipoprotein, and low-density lipoprotein are moderately reduced.
4. Detection of point mutations in genes by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) combined with DNA sequence analysis.
Diagnosis
Diagnosis and differentiation of sacral muscle atrophy
diagnosis
1. Distal muscular dystrophy: muscle weakness in the distal extremities of the extremities, muscle atrophy, adult onset of the disease, myogenic damage to myoelectricity, normal NCV, etc. can be identified.
2. Chronic progressive distal spinal muscular atrophy: The muscle atrophy and muscle weakness of the disease and the course of the disease are similar to CMT, but the sensory function is not tired, and EMG shows anterior horn damage.
3, hereditary ataxia with muscle atrophy: also known as Roussy-Lévy syndrome, childhood onset, slow progression, manifestation of iliac muscle atrophy, arched foot, scoliosis, quadriplegia tendon reflex or disappear, motor NCV slow However, there are ataxia, gait, hand tremor and other ataxia performances.
