Progressive spinal muscular atrophy

Introduction to progressive spinal muscular atrophy Progressive spinal muscular atrophy lesions in the lower motoneurons, also mostly sporadic cases, duration of disease for several months to 2 years. The cause of the disease is unclear. In addition to the theory of poisoning, the theory of lentivirus, etc., it is also found that the androgen receptor gene mutation has a certain relationship with the disease. Infant progressive spinal muscular atrophy is a childhood monogenic genetic disease, which is called childhood type I, with a prevalence of 0.1 to 1/100,000 population, most of which are from June to December after birth. Internal morbidity, the disease progresses rapidly, and the patient often dies within 1 year after the onset of illness. Juvenile familial progressive spinal muscular atrophy is also known as childhood motor neuron disease type III, which is more common in adolescents, with an onset age of 2 to 17 years, and KWD accounts for 48% of proximal limb spinal atrophy. Above, the disease progresses slowly, and the course of disease is 10 to 40 years. Most of the disease is long-term recessive inheritance, and a few are long-macro-dominant inheritance, with more male patients than females. basic knowledge The proportion of illness: 0.004% Susceptible people: infants and young children Mode of transmission: mother-to-child transmission Complications: progressive spinal muscular atrophy

Causes of progressive spinal muscular atrophy

Progressive spinal muscular atrophy is caused only by degeneration of the anterior horn cells of the spinal cord. Although many studies have proposed hypothesis of lentiviral infection, immune dysfunction, genetic factors, heavy metal poisoning, nutritional and metabolic disorders, and environmental factors, they have not been confirmed.

Progressive spinal muscular atrophy prevention

Prenatal diagnosis of SMA is carried out with the deepening of SMA gene research. The advantage of this method is that prenatal diagnosis can also be performed in families that do not have a proband sample. The pregnancy should be terminated if necessary.

Progressive spinal muscular atrophy complications Complications progressive spinal muscular atrophy

Muscular atrophy, lung infection, motor neuron function deficit.

Symptoms of progressive spinal muscular atrophy Common symptoms Muscle atrophy Arm muscle strain Thigh muscle atrophy Ineffective medullary numbness Neck back muscles Muscle tremor tremors Scapular muscles Atrophy gluteal muscle contraction Arm muscle atrophy

More than 30 years old, more common in men, motor neuron degeneration is limited to the anterior horn cells of the spinal cord, showing signs of muscle dysfunction, muscle atrophy and fasciculation, such as impaired motor neurons, insidious onset, starting with a hand or hands Small muscle atrophy, weakness, gradually affect the forearm, upper arm and shoulder strap muscles, but also from the lower limbs atrophy, but rare, distal atrophy, muscle tension and tendon reflex reduction, barrier-free, sphincter function is not tired, involving the medulla oblongata Survival, often died of lung infection.

Progressive spinal muscular atrophy

1. Neuroelectrophysiology: Electromyography is a typical neurogenic change. At rest, the fibrillation potential and positive sharpness can be seen, and sometimes the tremor potential can be seen. When the small force contracts, the motor unit potential time is widened, the amplitude is increased, and the multiphase wave is increased. The vigorous contraction presents a simple phase. Nerve conduction. Motor evoked potentials help to determine upper motor neuron damage.

2, muscle biopsy: helpful, but no specific, early neurogenic muscle atrophy, late in the light microscopy and myogenic muscle atrophy is not easy to identify.

3, blood biochemistry, CSF, no abnormalities, creatine phosphokinase (CK) activity can be mildly abnormal, MRI can show that some cases of spinal cord and brain stem atrophy become smaller.

Diagnosis and differentiation of progressive spinal muscular atrophy

Most cases are autosomal recessive and appear to be allelic mutations at a single locus on chromosome 5. There are four main variants.

Type I spinal muscular atrophy (Werdnig-Hoffmann's disease) is present in the fetus or develops symptoms 2 to 4 months after birth. Most sick babies have a manifestation of hypotonia at birth; before the 6-month-old, all sick babies have shown significant delays in motor function development. 95% of sick children die before and after 1 year of age, and no cases can survive more than 4 years of age, usually dying of respiratory failure.

Most children with type II (intermediate) spinal muscular atrophy develop symptoms during 6 to 12 months, and all cases have obvious symptoms before the age of 2 years. Less than 25% of cases can learn to sit, but they can't walk or climb. All children showed hypotonia, with loose muscle weakness, sputum reflexes and muscle tremors, which were not easily detectable in young children. Can have difficulty swallowing. Children often die in the early years due to respiratory complications, but there are also spontaneous progression of the disease, making the child in a permanent non-progressive state of weakness.

Type III spinal muscular atrophy (Wohlfart-Kugelberg-Welander disease) develops between the ages of 2 and 30. Pathological changes and hereditary patterns are similar to the first two variants, but the disease progresses slowly and the life expectancy is longer. The weakness of the legs and muscle atrophy were most pronounced, with the earliest symptoms of the quadriceps and hip flexors. The arm can be involved later. Powerlessness often spreads from the proximal end to the distal end. Certain familial cases may be secondary to defects in specific enzymes (eg, hexosaminoglycosidase deficiency).

Type IV spinal muscular atrophy is inherited (autosomal recessive, autosomal dominant, sexually linked), adulthood (age 30 to 60 years), and the disease progresses slowly. It may not be possible to follow the underlying sports of amyotrophic lateral sclerosis. People follow the laws of the growth and development of the human body and the laws of the body's activities. Through physical exercise, technology, training, competitive competitions, etc., the physical fitness can be enhanced and the level of exercise technology can be improved. Social activities for the purpose of enriching cultural life.

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