Spinal Muscular Atrophy (SMA) is a disease characterized by damage to one’s specialized nerve cells in the brain and spinal cord. Since these nerve cells regulate voluntary muscle movement, patients with this condition experience severe muscle weakness and restricted mobility. The disease affects one’s central as well as peripheral nervous systems and is reported to affect 1 in 6,000 to 10,000 individuals at birth nationwide. Here’s everything to know about SMA:

Types of spinal muscular atrophy
Here are a few types to know about:

• Type I
  Also called Werdnig-Hoffman disease or infantile-onset SMA, type-I SMA begins before six months of age and severely affects a child’s movement. It is also characterized by chronic shrinkage of muscles and tendons. Without treatment, many children with this disease may not be able to survive beyond the age of two. Conversely, timely treatment can help manage its symptoms and prolong life expectancy. This is the most common type of SMA.
• Type II
  This type of SMA shows up between 6 and 18 months of age. Here, affected children can sit up independently but require assistance to stand up and walk. They may also experience respiratory problems. Children with this condition may live into adolescence or even adulthood, although their lifespan is considerably shorter due to the disease.
• Type III
  Also called Kugelberg-Welander disease, type III SMA progresses after 18 months of age. In this case, children may be able to walk independently but face difficulties in running, climbing, etc. Most people with type III SMA typically have a normal life expectancy.
• Type IV
  Classified as the rarest type of SMA, this condition appears after 21 years of age and is characterized by moderate leg muscle weakness, breathing difficulties, etc. These individuals have a normal lifespan.

What causes spinal muscular atrophy?
Except in rare cases, SMA is a genetic condition inherited in an autosomal recessive pattern, which implies that individuals affected by the disease inherit two mutated genes, one from each parent. Individuals with only one such mutated gene are carriers of the disease and are not affected by it.

Symptoms of spinal muscular atrophy
Here are a few symptoms of spinal muscular atrophy:

• Restricted mobility
  Since SMA affects muscles responsible for voluntary movement, it restricts one’s mobility considerably, posing difficulties with sitting up, crawling, standing, climbing stairs, and walking.
• Muscle tremors or twitching
  Early stages of SMA involve muscle twitching under one’s skin or tremors when one’s hand is outstretched. Muscle tremors and twitching may be signs of muscle weakening due to SMA.
• Scoliosis
  Scoliosis refers to the unusual curving of one’s spine, a common symptom of SMA. This symptom stems from damage to nerve cells in the spinal cord.
• Breathing problems
  Patients with SMA typically have weak intercostal muscles or muscles situated within the rib cage, which often leads to underdeveloped lungs. Consequently, they may face severe breathing difficulties.
• Problems with chewing and swallowing
  Weakness of the mouth and throat muscles may cause patients with SMA to experience problems swallowing. SMA also involves damage to the bulbar motor neurons, which are responsible for chewing and swallowing.
• Numbness or tingling in the hands and legs
  Muscle weakness due to SMA may lead to numbness or a tingling sensation in the hands and legs of patients with the disease.

Diagnostic tests for SMA
Doctors typically recommend comprehensive testing to diagnose SMA and prescribe timely interventions to manage its symptoms. Here are some common ways in which SMA is diagnosed:

• Genetic test
  A genetic test may be carried out to detect mutations in the SMN1 gene, which is responsible for this condition. A genetic test is estimated to be 95% effective in detecting this mutation. Sometimes, this test may even be carried out on infants without apparent symptoms as part of the genetic screening process for newborns. These tests can also help identify whether infants are carriers of the disease.
• Enzyme and protein blood test
  Weakened muscles due to SMA typically release the enzyme creatine kinase into the bloodstream. Therefore, an enzyme and protein blood test can help measure the levels of this enzyme in the blood and diagnose the onset of SMA.
• Muscle biopsy
  In rare cases, doctors may carry out a muscle biopsy, which involves extracting a small portion of one’s muscle tissue and examining it in a laboratory. A biopsy is often effective in revealing a loss of muscle mass or atrophy.
• Nerve conduction test
  This test involves the use of an electromyogram (EMG) to study electrical activity in one’s nerves and nerve muscles.
• Ultrasound
  Ultrasound may be an effective technique to study fasciculations or spontaneous muscle contractions affecting certain muscle fibers, as well as muscle tremors and twitches, to identify the presence of SMA.

Remedies and management tips
Besides following the prescribed treatment course systematically, SMA patients or caregivers should be aware of certain remedies and management tips to control its symptoms:

• Try interventions to improve posture
  Patients with SMA, particularly those with types II, III, and IV, may benefit from posture-improvement exercises and therapies such as occupational therapy, physical therapy, and rehabilitation.
• Engage in strengthening exercises and stretches
  Stretches and strengthening exercises can help reduce muscle tremors and twitching, increase range of motion, and enhance blood circulation among patients with SMA.
• Have nutrient-rich foods
  Patients with SMA should have nutrient-rich foods rich in healthy carbohydrates and fats, proteins, vitamins, and minerals, which can boost immunity and help manage symptoms of SMA better. Toddlers with SMA may do well with mashed bananas and other soft fruits, yogurt, milk (if not lactose-intolerant), hummus, mashed rice and lentils, and nut butter.
• Engage in physical activity
  While SMA involves muscle degeneration and restricted mobility, a sedentary lifestyle can aggravate its symptoms. Therefore, patients with SMA should be assisted to sit and rise, walk, climb, and move about as much as possible.
• Ensure adequate rest
  This condition involves progressive muscle weakening, which can cause severe pain and discomfort. Therefore, one should ensure that patients with SMA rest adequately and have their daily tasks delegated.