Pathogenesis (disease development) Spinal muscular dystrophy is an autosomal recessive inherited disorder that affects the “survival motor neuron” (SMN1) gene on chromosome 5. The SMN (Survival of Motor Neuron) protein expressed by the gene is essential for the function of alpha-motoneurons (the basis of active contractions of skeletal muscle). More than 90% are caused by … Spinal Muscular Atrophy: Causes
Endocrine, nutritional, and metabolic diseases (E00-E90). Disorders of carbohydrate metabolism Musculoskeletal system and connective tissue (M00-M99). Polymyositis – autoimmune disease; inflammatory systemic disease of skeletal muscle. Psyche – nervous system (F00-F99; G00-G99). Amyotrophic lateral sclerosis (ALS) – progressive, irreversible degeneration of the motor nervous system. Emery-Dreifuss muscular dystrophy (synonym: Hauptmann-Thannhauser syndrome) – autosomal dominant or … Spinal Muscular Atrophy: Or something else? Differential Diagnosis
The following are the most important diseases or complications that may be contributed to by spinal muscular atrophy: Respiratory system (J00-J99) Aspiration pneumonia – pneumonia caused by inhalation of foreign substances (in this case, stomach contents). Pneumonia (pneumonia) Respiratory insufficiency – isolated arterial hypoxemia (oxygen deficiency) with reduction of partial pressure of oxygen below a … Spinal Muscular Atrophy: Complications
A comprehensive clinical examination is the basis for selecting further diagnostic steps: General physical examination – including blood pressure, pulse, body temperature, body weight, body height; further: Inspection Skin (Normal: intact; abrasions/wounds, redness, hematomas, scars) and mucous membranes. Posture [free sitting possible?, standing possible?, frog leg posture (bending of legs, angling of knees outward as … Spinal Muscular Atrophy: Examination
1st order laboratory parameters – obligatory laboratory tests. Molecular genetic testing – analysis for mutations in the SMN1 gene on chromosome 5. Muscle biopsy (an incision about 7.5 cm long and removal of part of the muscle tissue from the thigh) – if atrophy of type 1 (faster twitching) and type 2 (slow twitching) muscle … Spinal Muscular Atrophy: Test and Diagnosis
Therapy goals Alleviation of symptomatology and discomfort Slowing of the progression Healing Therapy recommendations Nusinersen (Spinraza; drug from the antisense oligonucleotide class; available in Germany since July 2017): This is a single-stranded nucleic acid that binds to the complementary intron (noncoding region of a pre-RNA transcript) 7 of SMN2 pre-mRNA (mRNA subject to processing), preventing … Spinal Muscular Atrophy: Drug Therapy
Obligatory medical device diagnostics. Electromyography (EMG; measurement of electrical muscle activity). Electrophysiological examination – due todifferential diagnosis of other neurogenetic diseases. Measurement of nerve conduction velocity (NLG) – to determine the total activity of muscle fibers. Optional medical device diagnostics – depending on the results of the history, physical examination and obligatory laboratory parameters – … Spinal Muscular Atrophy: Diagnostic Tests
Newborn screening for spinal muscular atrophy (SMA) would be desirable to make the diagnosis early so that the sufferer can then be treated.
The following symptoms and complaints may indicate spinal muscular dystrophy (SMA): In the spontaneous course, i.e., without therapy, SMA is characterized by proximal and leg-emphasized, usually symmetrical muscle weakness and atrophy. The following is a presentation of the symptomatology of 5q-associated spinal muscular atrophy: SMA type Synonyms Start Motor skills Clinical findings 0 neonatal form … Spinal Muscular Atrophy: Symptoms, Complaints, Signs
The medical history represents an important component in the diagnosis of spinal muscular atrophy (SMA). Family history Are there any hereditary diseases in your family? Are there any neurological diseases in your family? Social anamnesis Current anamnesis/systemic anamnesis (somatic and psychological complaints) [usually as foreign anamnesis]. Subsequently query motor or clinical findings depending on the … Spinal Muscular Atrophy: Medical History
General measures Nicotine restriction (abstaining from tobacco use) [due toharmfulness to lungs and heart]. Limited alcohol consumption (men: max. 25 g alcohol per day; women: max. 12 g alcohol per day) [due topotential increase in damage to myocytes (muscle fiber cell)] Limited caffeine consumption (max 240 mg of caffeine per day; equivalent to 2 to … Spinal Muscular Atrophy: Therapy