Spinal muscular atrophy (SMA) is a progressive genetic disorder that affects the nervous system and muscles. It is estimated to affect 1 in every 6,000 to 10,000 people. It is caused by a loss of specialized nerve cells, called lower motor neurons, leading to muscle weakness and muscle cell death.

There are five subdivisions of SMA (type 0, 1, 2, 3, 4), classified according to a person’s age at onset (before birth to young adulthood) and the disease’s clinical course. A number of specialists, however, do not consider type 0 as a separate type, referring only to types 1-4.

Lower motor neurons run from the spinal cord to muscle cells, making muscle-controlled movements as crawling and walking, grasping or reaching, breathing and swallowing difficult for patients.

Nutritional care for SMA patients 

Nutrition is a primary concern for SMA patients. The progression of the disease usually leads to a loss of lean body mass and an increase in fat mass, gastrointestinal dysmotility, bulbar dysfunction, dysphagia (difficulty swallowing), and osteoporosis.

Correct nutritional care is an essential factor to the health and growth of everyone, but it carries special importance for SMA patients, especially children.

Children with SMA who have good nutritional care obtain many benefits such as improved growth, better breathing, respiratory illness prevention, and improved motor function.

Typical SMA gastrointestinal problems

  • SMA type 1: Undernutrition, low or high blood sugar, gastroesophageal reflux disease (GERD), aspiration (food and drink entering the airways), and constipation;
  • SMA type 2: Undernutrition, obesity, GERD, constipation, feeding issues;
  • SMA type 3: Obesity, GERD, and constipation.

How to assess correct nutrition?

Typical methods to assess infant nutrition (measurements of weight for age, height for age, weight for height, and head circumference) are usually not suited for SMA patients.

A physician may suggest other tests to assess nutrition in these patients, such as skinfold thickness, DEXA scan, blood tests, swallow study, and UGI Series.

Calories needed by SMA patients

Children with SMA usually have lower physical activity than other children, possess lower muscle mass, and use less energy in their daily life. Therefore, they need fewer calories to achieve a normal gain in weight and growth.

In general, children with SMA need 20 to 50 percent fewer calories than healthy children.

Troublesome foods

Nutritional content is not the only problem caregivers have to worry about regarding food for SMA patients. The consistency of food and the fluidity of the liquids may be a cause for concern regarding chewing and swallowing.

All foods that prove to be difficult to chew and swallow must be avoided. Excessively fluid liquids, such as water or juices, have a propensity for being inhaled into the airways. Thicker liquids, like milkshakes, are better suited for these children.

Although it’s not easy balancing nutrition and gastrointestinal problems in SMA patients, a good pediatric doctor and a dietitian may help caregivers respond to challenges that develop.

Note: SMA News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.