Spotlight on Syndromes: An SLPs Perspective on Spinal Muscle Atrophy

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The following is an informational post on the disease SMA (spinal muscle atrophy) by Rose Ann Kesting M.A. CCC-SLP. After reading, please visit her blog post “My Wednesday Morning Wake Up Call,” for a personal account of her experience with a very special boy with Type 1 SMA and his amazingly dedicated family.

What is SMA?

SMA (Spinal Muscle Atrophy) is a collection of different muscle diseases. Grouped together, it is the second leading cause of neuromuscular disease, after Duchenne muscular dystrophy. SMA is a motor neuron disease that affects the voluntary muscles that are used for activities such as crawling, walking, head and neck control, and swallowing. The mind remains unaffected, while the muscles waste away. Often, weakness is first felt in the shoulder and leg muscles. Weakness gets worse over time and eventually becomes severe.

The most severe form is SMA type I, also called Werdnig-Hoffman disease. Infants with SMA type II have less severe symptoms during early infancy, but they become weaker with time. SMA type III is the least severe form of the disease. Rarely, SMA may begin in adulthood. This is usually a milder form of the disease. A family history of spinal muscular atrophy is a risk factor for all types of the disorder.

Here is a break-down of the characteristics for each of the four types of SMA:

Type I: The diagnosis of this type is usually made before 6 months of age, often a lot earlier. Some mothers even notice their baby is moving less in the womb in the final months of pregnancy. Usually a baby with Type I is very “floppy” and is never able to lift his/her head or accomplish the normal motor skills expected in the early months of life. They are never able to sit up unsupported. Swallowing, feeding, and handling of oral secretion are affected before 1 year of age. The tongue may show atrophy and fasciculation. Weakness and hypotonia in the limbs and trunks are eventually accompanied by intercostal muscle weakness. Infants exhibit characteristic a bell-shaped trunk with chest wall collapse and abdominal protrusion. Early morbidity and mortality are most commonly associated with pulmonary complications.

Type II: These children have delayed motor milestones. Some learned to achieve independent sitting, whereas others need help to sit up. The defining characteristic is an ability to maintain a sitting position unsupported. Some children with type II can stand with long leg braces but are not able to walk independently. Swallowing difficulties may lead to poor weight gain in some children. Intercostal muscles are weak, and some are also diaphragmatic breathers. They have difficulty coughing and clearing tracheal secretion.

Type III: This type is also called Kugelberg-Welander disease or juvenile spinal muscular atrophy. These patients have later age of onset. All achieve independent walking. Some patients lose the ability to walk in childhood, yet others maintain walking until adolescence or adulthood. Other symptoms include frequent, increasingly severe respiratory infections, nasal speech and posture that gets worse.

Type IV: The onset of weakness is usually in the second or third decade of life. Motor impairment is mild without respiratory or gastrointestinal problems.

Statistics

SMA is a relatively common “rare disorder” . Approximately 1 in 6000 babies born are affected, and about 1 in 40 people are genetic carriers.

Most of the time, a person must get the defective gene from both parents to be affected. About 4 out of every 100,000 people have the condition. The gene is carried by seven million potential parents, most unknowingly. If both a man and woman carry the gene, the chances are 25% that any of their children will manifest SMA.

Spinal Muscular Atrophy kills more babies than any other genetic disease.

Differential Diagnosis

SMA is sometimes confused with the following diseases:

  • Amyotrophic Lateral Sclerosis (ALS)
  • Congenital Muscular Dystrophy
  • Disorders of Carbohydrate Metabolism
  • Myasthenia Gravis
  • Primary Lateral Sclerosis

Spinal cord disorders, including trauma of the cervical spinal cord, should be considered, especially if the child was born in the breech position.

Physical characteristics/abnormalities of children with SMA

These characteristics vary in severity depending on how advanced the SMA is in each child. Some of these may not show up until later. The common physical characteristics of SMA include:

  • “Frog” shaped legs (knees apart and legs bent)
  • a sunken or narrow chest
  • a big belly
  • breathing with the belly instead of the lungs
  • a weak cry and weak cough
  • poor to no head/neck control; head tilted to one side
  • weak if any movement of the legs and upper arms
  • not able to bear any weight on legs or arms
  • hands that remain clenched or turned the wrong way
  • difficulty sucking and swallowing
  • tongue fasciculations (tongue vibrating rapidly).

The student I worked with had all of the above mentioned characteristics, as well as poor dental structure (missing/pulled teeth due to poor bone growth)

Cognition

Intelligence is unaffected, and in fact many physicians who have worked with hundreds of children with SMA are impressed that these children tend to be unusually alert, interactive, and socially gifted. The child I worked with was fluent in a second language (native to India) and was functioning above grade level in reading and math concepts. He was able to navigate a computer with ease using a special device and was extremely personable and witty.

Medical complications

The leading cause of death for children with SMA is respiratory complications. Because SMA affects all voluntary muscles controlled by the motor neurons in the spinal column, the muscles that aid in breathing are affected. These children breathe in very shallow breaths and coughing effectively on their own is almost impossible. A Bi-level positive airway pressure (BiPAP) and home ventilator are usually necessary to assist children with SMA Type I in breathing , managing secretions and relieving congestion. Laying flat is often helpful during labored breathing. Children with Type I at some point need a feeding tube to maintain a satisfactory nutritional status . Nasogastric (NG) feedings are usually for a short time (tube in nose creates breathing issues.) Gastrostomy (G-tube) is common for long term nutritional support. The student I worked with layed flat on a thick mat and I usually sat on a yoga mat next to him. His nurse generally needed to suction him several times throughout our sessions.

Speech and Language Issues:

A speech therapist will assess treatment goals by first performing one or several of the following: a swallow study, oral motor skills evaluation, alteration of foods (thickeners, texture changes, nipple/bottle changes, positioning). Feeding problems and dysphagia are common, but the underlying mechanisms of these problems are not well defined. Dysphagia is due to a neurologic dysfunction (lower motor neuron problems from the cranial nerves in the brainstem) influencing the muscle force and efficiency of movement of the tongue. An adapted posture during meals and the advice of drinking water after meals to prevent aspiration pneumonias is recommended. Strategies for better respiratory support (inhalation/exhalation exercises) and clarity of articulation are often addressed. A child with Type II or III will have great success in achieving these goals than a child with Type I due to the severity of the disease. Oral-motor exercises for jaw, tongue and lip strengthening may be addressed if the child is a good candidate . Adults with SMA benefit greatly from the use of assistive technology, such as speech recognition software. These devices allow people with even very limited mobility to use a computer to read, write, communicate, play video games, and access environmental controls. The child I worked with had goals related to breath support and speech clarity at a younger age, however as he got older, the progression of the disease made it impossible to address theses areas. My goals began to center around supporting language skills, namely, vocabulary development and comprehension skills.

The multidisciplinary team

The following professionals are generally involved in treatment of children with SMA:

Orthopedic doctor ( Bones and muscles)

Physical Medicine and Rehabilitation doctor (oversees rehabilitation care)

Physical Therapist (PT) – strength, walking, sitting, posture, balance

Occupational Therapist (OT) – adaptive aids, fine motor/hand skills

Speech Therapy (ST) – language, oral-motor issues

Orthotist – makes orthotics or braces

The student I worked with was visited in his home environment weekly by myself (speech tx) , OT and PT. A teacher worked with him on grade level curriculum three times per week for 3 hours each visit. A nurse was present approximately 12 hours per day for feeding, suctioning and other basic needs.

Current Interventions

The United States Senate unanimously passed the National Pediatric Research Network Act (NPRNA) Supporting SMA Research on November 15, 2012. Legislation was headed to the President’s desk for signature, establishing a network of research to focus on pediatric rare diseases, specifically including SMA. (H.R. 225: National Pediatric Research Network Act of 2013).

There are now 15 drugs in the SMA drug pipeline with 3 in clinical trials and several more anticipated to start in 2014.

Research is divided into four areas: Basic Research (projects that identify effective new strategies for SMA drug discovery), Drug Discovery and Therapeutic Development Programs, Clinical Trials and Research, Care Research . Millions of dollars are currently being invested into seeking a cure.

Families of SMA funds and directs the leading SMA research programs to develop a treatment and cure for the disease. The charity has invested over $55 million in research and has been involved in funding half of all the ongoing novel drug programs for SMA. There are currently 31 chapters throughout the United States and over 105,000 members and supporters in this collaborative organization of families, friends and researchers.

Conclusion

Spinal Muscle Atrophy is a degenerative disease that affect muscle control, including the ability to walk, move limbs and in many cases the ability to eventually swallow, speak and breathe. Various interventions from a supportive therapeutic team can help facilitate communication and mobility. Children with this condition are usually very bright and social , as one’s intelligence is not affected by the condition. Millions of dollars in research are currently in progress, however at this time there is no know cure for this disease which kills more babies than any other genetic disease.

References

Dysphagia in spinal muscular atrophy type II L. van den Engel-Hoek, MSc, C. E. Erasmus, MD, H. W. van Bruggen, MSc, B.J.M. de Swart, PhD, L. T.L. Sie, MD, PhD, M. H. Steenks, DDS, PhD and I. J.M. de Groot, MD, PhD

Families of SMA http://www.fsma.org/Home/

http://www.spinalmuscularatrophy.info/

SMA Support Inc. http://www.smasupport.com/

pict 3 Rose Ann Kesting , M.A., CCC-SLP is an ASHA certified speech-language pathologist. She has been practicing for 18 years in schools and clinics with the preschool and K-12 population in both public and private school settings. She received her B.A. from Loyola University in Maryland and M.A. from The College of New Jersey. Presently she works at The Bridge Academy, a private school for children ages 8-18 with language based learning disabilities located in Lawrence Township, New Jersey. Rose Ann is also the author of the  Cooking Up Good Speech…with SpeechSnacks blog where she combines her interest in nutrition and healthy cooking with her professional knowledge as a speech-language pathologist. You can also follow her in her TeachersPayTeachers store where she has created products that accompany her kid-friendly , speech-language inspired recipe posts and find her on facebook at www.facebook.com/speechsnacks

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