Spinal muscular atrophy treatment
Spinal muscular atrophy is a progressive genetic disease affecting the motor neurons of the spinal cord. It goes in families from parent to child if both have the damaged gene. The first signs begin with muscle weakness and general loss of strength. Such drugs as Zolgensma, Evrysdi and Spinraza, together with rehabilitation, have a positive effect in treating the disease.
Spinal muscular atrophy (SMA) is a neuromuscular inherited disorder associated with damage to motoneurons (in the anterior horns of the spinal cord) and neurons of the motor nuclei in the brain stem. A spinal motor neuron gene mutation causes this progressive degenerative process. In patients with SMA, it is entirely or partially absent on the 5th pair of chromosomes. The severity and nature of the disease depend on how large the damaged area is and the state of other genes.
Neurologists differ several types of SMA:
- Spinal muscular atrophy type I (Werdnig-Hoffman disease) is an easily recognizable early-onset and the most severe form: fragile newborns with difficulties in controlling the head, soft cry and cough, difficulty swallowing, and inability to sit without support.
- Chronic forms are divided into type II and III:
- Spinal muscular atrophy type II (Dubowitz disease) occurs in 7-18 months. Children can sit, but there are delayed motor development, weight gain, and weak cough. They cannot stand independently.
- Spinal muscular atrophy type III (Kugelberg-Welander disease) manifests with a later onset (after 18 months). The child can stand independently but gradually loses the ability to walk. Other symptoms are muscle weakness of varying degrees and hypermobility of the joints;
- There is also spinal muscular atrophy type IV, characterized by lower leg weakness and typically occurs in adults (over 30th).
The symptoms of all four types have some differences, but they are common in something:
- Weakness and deficient motor activity;
- Involuntary twitching (tremor) of fingers, tongue;
- Slightly flattened chest;
- Symmetrical atrophy of the muscles of the trunk and limbs (especially the lower ones);
- Dysfunction of the pelvic organs.
The initial SMA examination reveals clinical signs such as hypotonia, weakness of the legs and the intercostal muscles, paroxysmal breathing, and other syndromes. The second stage is molecular genetic diagnosis. Genetic analysis for SMN 1/SMN 2 is reliable and belongs to the first-line tests for suspected SMA. An additional diagnosis for spinal muscular atrophy today is electroneuromyography (EMG) - in the later (chronic) forms and tests for the concentration of creatine kinase (CK) in the blood.
Today there are three drugs for effective SMA treatment: Zolgensma® is aimed at introducing a similar healthy gene into the body, replacing the disabled gene for a specific time. Likewise, Evrysdi® and Spinraza® compensate for the incapacity of a broken gene. As a result, all three contribute to the production of the SMN protein in the body, which protects motor neurons. In addition, neurologists usually advise rehabilitation along with medications course.