Adult spinal muscular atrophy is a genetic neurodegenerative disorder characterized by muscle wasting and weakness. In adults, normal life expectancy is achieved, as only mild weakness may be encountered. The diagnosis rests on confirming genetic mutations.
Presentation
Adult spinal muscular atrophy or spinal muscular atrophy (SMA) type 4 usually begins to appear at 30 years of age and has a relatively benign course [1]. The clinical features of this disease are very similar to SMA type 3, although the adult version is less severe. Life expectancy is normal in such patients [2]. Type 1 and type 2 SMA can occur at any age between birth and 2 years.
Patients classically present with an asymmetric weakness of the proximal muscles of the arms and legs, resulting in hampering of the quality of life [3]. Over time, the muscle wasting spreads to the other limb muscles before involving the central portions of the body. The weakness is associated with pain, in both the normal and affected muscles. Tremors and twitchings are also known to occur [4].
Involvement of the muscles of the thorax may result in respiratory compromise. The affliction of the brainstem may lead to bulbar symptoms such as dysphagia and dysarthria. There are usually no other central nervous system manifestations present. Reports have shown that these patients exhibit a higher degree of intelligence.
The examination may show all the characteristic findings of a lower motor neuron disease, namely absent/decreased reflexes, hypotonia, flaccid paralysis and muscle fasciculations.
Entire Body System
- Difficulty Walking
People with the condition: are able to stand and walk without help, although they may find walking or getting up from a sitting position difficult may have balance problems, difficulty running or climbing steps, and a slight shaking in their fingers may [nhs.uk]
These children show signs of clumsiness, difficulty walking, mild muscle weakness, and may be developmentally delayed. These children live long into their adult years. [chw.org]
These children show signs of clumsiness, difficulty walking, mild muscle weakness, and may be developmentally delayed. These children live long into their adult years. Type IV. [texaschildrens.org]
[…] unaided, though many find it difficult to walk or get up from a sitting position Balance problems Difficulty walking Breathing and swallowing difficulties are very rare and the condition does not usually affect life expectancy Over time, muscles become [thehumanthebody.com]
- Pathologist
As a designated Muscular Dystrophy Association Care Center, we provide a team-based approach to care that brings together many specialists, including neurologists, geneticists, pulmonologists, and physical, occupational, speech and language pathologists [stanfordhealthcare.org]
- Mobility Impairment
Spinal muscular atrophy manifests itself in diverse severity degrees, though general muscle atrophy and mobility impairment are common symptoms in all degrees of severity. [bionews-tx.com]
Respiratoric
- Respiratory Distress
Distress Spinal Muscular Atrophy with Respiratory Distress Type 1 spinal muscular atrophy, adult form spinal muscular atrophy, congenital benign, with contractures spinal muscular atrophy, distal, congenital non-progressive spinal muscular atrophy, mild [medical-dictionary.thefreedictionary.com]
Early diaphragmatic palsy → elevation of the right or both hemidiaphragms → Early onset of respiratory distress Progressive distal weakness → early distal contractures (e.g., finger deformities, pes equinus ) Spinal muscular atrophy with pontocerebellar [amboss.com]
These conditions include: Spinal muscular atrophy with respiratory distress (SMARD) —SMARD has similar symptoms to infant-onset spinal muscular atrophy, though it affects the upper spinal cord neurons instead of the lower motor neurons. [togetherinsma.com]
distress Age of onset between 1 to 6 months of age A predominant symptom is severe respiratory distress due to the involvement of diaphragm muscles Distal muscle weakness Sensory and autonomic nervous system may also be involved Amyotrophic lateral sclerosis [thehumanthebody.com]
SMA with respiratory distress type 1(SMARD1) Age of onset : 1-6 months. Features : similar to SMA types I-IV but the predominant symptom is severe respiratory distress due to involvement of the diaphragm muscles. [patient.info]
Gastrointestinal
- Dysphagia
The affliction of the brainstem may lead to bulbar symptoms such as dysphagia and dysarthria. There are usually no other central nervous system manifestations present. Reports have shown that these patients exhibit a higher degree of intelligence. [symptoma.com]
Dysphagia may be present. Most children are confined to a wheelchair by age 2 to 3 yr. The disorder is often fatal in early life, frequently resulting from respiratory complications. [merckmanuals.com]
As the condition progresses, it may cause other symptoms, including: weakness of the facial and tongue muscles, which may cause difficulty swallowing ( dysphagia ) and slurred speech recurring pneumonia (infection of lung tissue) Some people with Kennedy [your.md]
[…] associated with names of investigators such as Santavuori-Haltia, Jansky-Bielschowsky, Batten, Spielmeyer-Vogt, Kufs Opitz G/BBB Syndrom ( 1 Files ) Erkrankung : Opitz G/BBB Syndrom ICD 10: Q87.8 Synonyme : Hypertelorism-hypospadias syndrome, hypospadias-dysphagia [orphananesthesia.eu]
Jaw & Teeth
- Fasciculation of the Tongue
They will see if the muscles are floppy or flaccid, to check for deep tendon reflexes and muscle fasciculation of the tongue muscle. [medicalnewstoday.com]
[…] of the tongue Weakness and hypotonia in the limbs and trunk Intercostal muscle weakness (note, the diaphragm is initially spared) Paradoxical breathing Bell-shaped trunk with chest wall collapse and abdominal protrusion To learn how different aspects [togetherinsma-hcp.com]
Musculoskeletal
- Muscular Atrophy
Differential diagnosis usually involves the other spinal muscle atrophies which include the X-linked spinal muscular atrophy, distal spinal muscular atrophy, autosomal dominant spinal muscular atrophy and juvenile asymmetric segmental spinal muscular [symptoma.com]
muscular atrophy Spinal muscular atrophy Spinal muscular atrophy Spinal muscular atrophy Spinal muscular atrophy Spinal Muscular Atrophy 3 Spinal Muscular Atrophy Association of Australia Inc. spinal muscular atrophy I spinal muscular atrophy III spinal [medical-dictionary.thefreedictionary.com]
Diagnosis - Adult-onset spinal muscular atrophy Prognosis - Adult-onset spinal muscular atrophy Treatment - Adult-onset spinal muscular atrophy Resources - Adult-onset spinal muscular atrophy Not supplied. [checkorphan.org]
About Spinal Muscular Atrophy (SMA) About SMA Spinal Muscular Atrophy (SMA) refers to a group of genetic conditions that cause muscle weakness and atrophy in children and adults. “Atrophy” means that the mass and size of muscles is reduced. [griswoldhomecare.com]
What is spinal muscular atrophy adult type? Spinal Muscular Atrophy Adult Type is a condition that affects the nerve cells (motor neurons) in your spinal cord. Onset of this condition is usually after 30 years of age. [patientslikeme.com]
- Muscle Weakness
SMA4 is usually considered in an adult who begins to have proximal muscle weakness. Genetic testing of the SMN1 gene is used to confirm the diagnosis. Muscle weakness seen in SMA4 is similar to the muscle weakness seen in other genetic conditions. [resourcerepository.org]
SMAPAD is characterized by proximal muscle weakness that begins in the lower limbs and then progresses to upper limbs, onset in late adulthood (after third decade) and a benign course. [uniprot.org]
Weakness and atrophy in the lower extremities are usually followed by problems with the pectoral girdle, facial muscles, distal limb, and bulbar muscles. Muscle cramps on exertion often precede the weakness by several years. [encyclopedia.com]
The weakness tends to be more severe in the muscles that are close to the center of the body (proximal) compared to muscles away from the body's center (distal). The muscle weakness usually worsens with age. [ghr.nlm.nih.gov]
[…] muscular atrophy Initial symptoms may include: Tremor of the hands Muscle cramps when performing physical activities Muscle twitches and weakness of limb muscles As the condition progresses: Weakness of the face and tongue muscles which may cause difficulties [thehumanthebody.com]
- Myopathy
Multicore myopathy, Multiminicore myopathy, Minicore myopathy with hand involvement, antenatal onset minicore myopathy with arthrogryposis, Minicore myopathy with external ophthalmoplegia, Multicore myopathy with external ophthalmoplegia, Multiminicore [orphananesthesia.eu]
Over the years, patients labeled earlier as SMA have had their diagnoses revised to more treatable conditions including syringomyelia, amyotrophic lateral sclerosis, myopathy, axonal neuropathies and herniated lumbar discs. [symptoma.com]
Differential diagnosis Motor neurone disease Primary lateral sclerosis Muscular dystrophy Congenital myopathies Disorders of carbohydrate metabolism ( glycogen storage diseases ) Myasthenia gravis Poliomyelitis Investigations Blood tests Creatine kinase [patient.info]
The symptoms of spinal muscular atrophy may resemble other problems or medical conditions and can be confused with other muscle or nerve conditions, including muscular dystrophy, myopathy, other spinal muscular atrophy variants or even forms of amyotrophic [massgeneral.org]
The database (known as the UMD-SMN1 France database) is financed by AFM (Association Française contre les Myopathies) and is a result of a major national effort involving all French molecular diagnostic laboratories and reference centers for neuromuscluar [treat-nmd.eu]
- Muscle Twitch
The disorder slowly progressed to include cramps and muscle twitches. [ncbi.nlm.nih.gov]
[…] atrophy, with the gradual onset of weakness, tremors, and muscle twitching first noted in late teens or early adulthood There are other diseases that are similar to spinal muscular atrophy, but have different genetic causes. [togetherinsma.com]
[…] atrophy Initial symptoms may include: Tremor of the hands Muscle cramps when performing physical activities Muscle twitches and weakness of limb muscles As the condition progresses: Weakness of the face and tongue muscles which may cause difficulties [thehumanthebody.com]
twitching first noted in late teens or adulthood To learn how different aspects of care may relate to the signs and symptoms of SMA, click here. [togetherinsma-hcp.com]
The initial symptoms of Kennedy’s syndrome may include tremor (shaking) of the hands, muscle cramps on exertion, muscle twitches and weakness of the muscles of the limbs. [your.md]
Neurologic
- Tremor
The nerve cells tend to cause muscle weakness, tremor, and twitching. Common symptoms reported by people with spinal muscular atrophy adult type Reports may be affected by other conditions and/or medication side effects. [patientslikeme.com]
[…] usually able to sit unattended, but cannot stand or walk without assistance Weak respiratory muscles, which can inhibit coughing Breathing problems Weakness in the muscles of the arms and especially of the legs Swallowing and feeding problems Slight tremor [thehumanthebody.com]
Other symptoms include tremors, twitching, and mild breathing issues. SMA4 is caused by changes (mutations) in the SMN1 gene. This gene provides the instructions to make a protein that helps motor neurons work. [resourcerepository.org]
Tremors and twitchings are also known to occur. Involvement of the muscles of the thorax may result in respiratory compromise. The affliction of the brainstem may lead to bulbar symptoms such as dysphagia and dysarthria. [symptoma.com]
Fine tremors of the face are present in over 90% of patients. Type 2 diabetes mellitus, hand tremor, and infertility can also occur. [encyclopedia.com]
- Limb Weakness
As the disease progresses patients may notice limb weakness starting in the pelvis or shoulders, or weakness of the facial and tongue muscles. Symptoms of SMA-LED often develop in infancy or early childhood. [cedars-sinai.edu]
Patients typically present during infancy or early childhood with progressive weakness, hypotonia, muscle atrophy, hyporeflexia /areflexia, and varying degrees of bulbar weakness. [amboss.com]
In addition to muscle weakness, clinical features include head lag, poor sucking and swallowing, weak cry, proximal limb weakness, and lack of reflexes. Affected children never raise their head, roll over, or walk. [encyclopedia.com]
- Average Intelligence
The brain is not affected, and they have been tested to have at least average to above average intelligence. Please do not make the mistake of treating them as mentally impaired!! [smasupport.com]
- Flaccid Paralysis
The examination may show all the characteristic findings of a lower motor neuron disease, namely absent/decreased reflexes, hypotonia, flaccid paralysis and muscle fasciculations. Diagnosis of this disease is dependent on the anamnestic data. [symptoma.com]
- Dysarthria
The affliction of the brainstem may lead to bulbar symptoms such as dysphagia and dysarthria. There are usually no other central nervous system manifestations present. Reports have shown that these patients exhibit a higher degree of intelligence. [symptoma.com]
Workup
Diagnosis of this disease is dependent on the anamnestic data. Amongst laboratory tests that may be performed, creatine kinase is the most useful, with elevated levels of the enzyme found. In some patients, the enzyme levels may be normal.
Genetic tests may be performed both prenatally and postnatally to check for deletions involving the SMN1 gene [5].
Electrocardiograms (ECGs) are usually normal in these patients [6].
A variety of other neuromuscular diseases may present in a similar manner. Differentiation is done by electrophysiological tests that demonstrate a reduction of transmitted nerve signals [7] [8]. Sensory signals are usually normal in adult spinal muscular atrophy. Tests involving compound motor action potential may also be performed for diagnosis.
Muscle biopsy is another test that may help in differentiating adult spinal muscular atrophy from other similar muscular diseases [9] [10]. These characteristically show atrophy of the muscle fibers with compensatory hypertrophy.
Differential diagnosis usually involves the other spinal muscle atrophies which include the X-linked spinal muscular atrophy, distal spinal muscular atrophy, autosomal dominant spinal muscular atrophy and juvenile asymmetric segmental spinal muscular atrophy. Postpolio syndrome and multifocal motor neuropathy are the other conditions that may present in a similar fashion.
There is a potential for patients with adult spinal muscular atrophy to be misdiagnosed due to the overlapping of clinical features. Over the years, patients labeled earlier as SMA have had their diagnoses revised to more treatable conditions including syringomyelia, amyotrophic lateral sclerosis, myopathy, axonal neuropathies and herniated lumbar discs. It is hence, recommended that patients be followed up for a long duration to establish the correct diagnosis.
Treatment
It is important for all those interested to know that not all patients will be eligible for treatment, that treatment could be discontinued if a patient does not respond to the drug, and that treatment services are dependent upon availability of resources [columbianeurology.org]
We are at the forefront of developing and validating new treatment approaches, such as Spinraza, the only treatment available for spinal muscular atrophy. [stanfordhealthcare.org]
Treatment options focus on addressing the muscle weakness and can include physical therapy. If you or your child has been diagnosed with SMA4, talk with a doctor about all treatment options. [resourcerepository.org]
They are here to respond to the urgent need for support, education, mainstream awareness and treatments. [avexis.com]
The sponsor is receiving a rare pediatric disease priority review voucher under a program intended to encourage development of new drugs and biologics for the prevention and treatment of rare pediatric diseases. [news-medical.net]
Prognosis
prognosis of these patients 7,8. [radiopaedia.org]
The prognosis is poor for babies with SMA Type I: most die within the first two years. [bionews-tx.com]
Diagnosis - Adult-onset spinal muscular atrophy Prognosis - Adult-onset spinal muscular atrophy Treatment - Adult-onset spinal muscular atrophy Resources - Adult-onset spinal muscular atrophy Not supplied. [checkorphan.org]
These subgroup classifications are useful for prognosis and management. [en.wikibooks.org]
If a child reaches 18 months of age before symptoms begin, the prognosis is good. Symptoms will include reduced muscle strength and eventually, patients will lose the ability to walk. [babymed.com]
Etiology
Etiology Pathophysiology Clinical features The most common causes of death among patients with SMA are respiratory insufficiency (due to respiratory muscle weakness ) and aspiration pneumonia (due to bulbar weakness)! [amboss.com]
Etiology As for the other forms of SMA, SMA4 has been associated with deletions in the SMN1 gene (5q12.2-q13.3) encoding the SMN (survival motor neuron) protein. [orpha.net]
Etiology [ edit ] Mode of inheritance: SMA is an autosomal recessive disorder Chromosome location: Chromosomal locus 5q11-q13 Molecular Genetics: SMN (survival motor neuron) has been identified as the primary SMA-determining gene The SMN gene is very [en.wikibooks.org]
Epidemiology
Epidemiology References: [1] [2] [3] Epidemiological data refers to the US, unless otherwise specified. [amboss.com]
Summary Epidemiology Prevalence is estimated at around 1/300,000. Clinical description SMA4 usually manifests in the second or third decade of life. [orpha.net]
SMA with respiratory distress (SMARD1) Inheritance is autosomal recessive due to mutations in the IGHMBP2 gene on chromosome 11q13. [ 9 ] Epidemiology The estimated incidence is between 1 in 6,000 and 1 in 10,000 live births and the carrier frequency [patient.info]
Epidemiology of spinal muscular atrophies in a sample of the Italian population. Neuroepidemiology. 1992; 11 :34–8. [ PubMed : 1608493 ] Moutou C, Gardes N, Viville S. [ncbi.nlm.nih.gov]
Pathophysiology
Etiology Pathophysiology Clinical features The most common causes of death among patients with SMA are respiratory insufficiency (due to respiratory muscle weakness ) and aspiration pneumonia (due to bulbar weakness)! [amboss.com]
Pathophysiology Spinal muscular atrophy (SMA) types I-III Inheritance is autosomal recessive. Affected individuals have two copies of the altered gene. Those who carry one copy are usually unaffected carriers. [patient.info]
Pathophysiology In 1995, the spinal muscular atrophy disease-causing gene, termed the survival motor neuron ( SMN ), was discovered. [9] Each individual has 2 SMN genes, SMN1 and SMN2. [emedicine.medscape.com]
Prevention
Prevention - Adult-onset spinal muscular atrophy Genetic counseling is recommended for people with a family history of spinal muscular atrophy who want to have children. [checkorphan.org]
SMA cannot be prevented, but prospective parents can request genetic testing if they may be carriers. Types There are different types of SMA. [medicalnewstoday.com]
Improve Your Chances by Hiring a Disability Attorney If you've been denied benefits for muscular atrophy that prevents you from working, an experienced disability attorney can help you navigate the confusing disability appeals process. [disabilitysecrets.com]
Orthopedic surgical interventions such as tendon transfer or spinal surgery can prevent disability in patients with expected prolonged survival. [encyclopedia.com]
Two major decisions must be made with Type I children...whether or not to insert a feeding tube to prevent pneumonia and prevent starvation when they have lost their ability to suck or swallow; and whether or not to put them on a ventilator or other breathing [smasupport.com]
References
- Wang CH1, Finkel RS, Bertini ES, et al. Consensus statement for standard of care in spinal muscular atrophy. J Child Neurol. 2007;22(8):1027-1049.
- Baioni MT, Ambiel CR. Spinal muscular atrophy: diagnosis, treatment and future prospects. J Pediatr (Rio J). 2010;86(4):261-270.
- Prior TW, Russman BS. Spinal Muscular Atrophy. 2000 Feb 24 [Updated 2013 Nov 14]. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2016.
- Joynt R, Griggs R. Clinical Neurology. Philadelphia: Lippincott; 1997. Vol 4: 11-5.
- Arnold WD, Kassar D, Kissel JT. Spinal Muscular Atrophy: Diagnosis and Management in a New Therapeutic Era. Muscle Nerve. 2015;51(2):157-167.
- Palladino A, Passamano L, Taglia A, et al. Cardiac involvement in patients with spinal muscular atrophies. Acta Myol. 2011 Dec. 30(3):175-8.
- Hausmanowa-Petrusewicz I, Karwanska A. Electromyographic findings in different forms of infantile and juvenile proximal spinal muscular atrophy. Muscle Nerve. 1986 Jan. 9(1):37-46.
- Krivickas LS. Electrodiagnosis in neuromuscular disease. Phys Med Rehabil Clin N Am. 1998 Feb. 9(1):83-114, vi.
- Buchthal F, Olsen PZ. Electromyography and muscle biopsy in infantile spinal muscular atrophy. Brain. 1970. 93(1):15-30.
- Dubowitz V. Muscle disorders in childhood. Major Probl Clin Pediatr. 1978. 16:iii-xiii, 1-282.