Distal Spinal Muscular Atrophy Research Articles

Werdnig-Hoffmann: Dominant Inheritance

A family in which both Werdnig-Hoffmann disease and chronic distal spinal muscular atrophy occurred, with apparent autosomal dominant inheritance, is reported from the Department of Neurology, Mayo Clinic Jacksonville, FL and Johns Hopkins University School of Medicine, Baltimore, MD.

Werdnig‐Hoffmann disease and chronic distal spinal muscular atrophy with apparent autosomal dominant inheritance

We report on a family in which both Werdnig-Hoffmann disease (severe infantile-onset spinal muscular atrophy) and chronic distal spinal muscular atrophy occurred, with apparent autosomal dominant inheritance. The female proband clinically had Werdnig-Hoffmann disease and died at 10 months. In their second decade of life, the proband's father and his 2 brothers developed bilateral progressive atrophy and weakness of the hands and mild weakness in the distal parts of the legs. Their mother had no symptoms or signs of motor neuron disease but electromyography revealed distal denervation of the limbs. While the family studies suggest autosomal dominant inheritance, it is possible that the proband's condition was influenced by a maternally derived allelic or modifying trait.

Juvenile distal spinal muscular atrophy of upper extremities in Chinese males: a single fibre electromyographic study of arms and legs.

Single fibre electromyography (SFEMG) was performed on six young Chinese males with distal spinal muscular atrophy of the upper extremities. Abnormal SFEMG findings of increased fibre density, jitter and blocking were recorded over both arms and legs in all patients, suggesting a more generalised disturbance than would appear clinically.

Continuous Muscle Activity and Distal Spinal Muscular Atrophy

A young man presented with myokymias, cramp-like difficulty in muscle relaxation and peroneal atrophy. EMG studies revealed continuous muscle activity (CMA) manifested as grouped potentials and high frequency discharges. Sensory nerve conduction studies and sural nerve biopsy gave normal results, and he was thought to suffer from distal spinal muscular atrophy with CMA. This association suggests that the lower motor neuron may have an important role in the generation of the continuous muscle activity.

Sensory axonopathy in hereditary distal spinal muscular atrophy

A girl of 14 year is presented with a distal spinal muscular atrophy (SMA) with autosomal recessive inheritance. The technical findings are in agreement with the diagnosis. Light microscopical examination of sural nerve biopsy, including teased fiber studies and morphometry, showed no abnormalities. Electron microscopical investigation however demonstrated axonal pathology. The question arises if distal SMA is a distal axonopathy mainly of motor nerves, but to some extent also of sensory nerves.

Distal infantile spinal muscular atrophy associated with paralysis of the diaphragm: A variant of infantile spinal muscular atrophy

We report the clinical, electrophysiological, and morphological observations of five infants with an unusual form of spinal muscular atrophy (SMA). In these infants muscular weakness and atrophy were initially restricted to the distal limbs and this pattern was associated with paralysis of the diaphragm. The difference between the clinical manifestations of this syndrome and the classical form of infantile spinal muscular atrophy (SMA type 1) as well as other congenital hereditary neuropathies is discussed.

Non familial juvenile distal spinal muscular atrophy of upper extremity.

An uncommon variety of non familial, juvenile onset, spinal muscular atrophy with asymmetric distal upper extremity affection is described. One hundred and two patients with a one to 14 year follow up are analysed. Spinal muscular atrophies with a distal distribution are rare. However, in the past three decades, previously unrecognised varieties of neurogenic muscular atrophy have been described in Asia (Japan, India, Sri Lanka and Singapore) under a variety of names. These provide interesting data for discussion of Asian neurogenic muscular atrophies with distal affection, in the context of diseases of the motor neuron.

Hereditary distal muscular atrophy with vocal cord paralysis and sensorineural hearing loss: a dominant form of spinal muscular atrophy?

In 1980 Young and Harper described a family with an unusual form of distal spinal muscular atrophy associated with vocal cord paralysis. We report a family with three similarly affected...

Chronic distal spinal muscular atrophy in adults (involving the hands) — clinical and electrophysiological studies: [formula omitted] (City Hospital, Dept. of Neurology, Nemocnicnì 20, Czechoslovakia)

The exercise test is one of the most widely used challenge tests for asthma. It is not clear if the sensitivity of this test is lower when patients with asthma are not symptomatic. Since asthma activity is season dependent, with lower activity in the summer, we sought to determine if the percentage of positive exercise test results for asthma is lower in the summer as well.In this retrospective study, the proportion of positive exercise test results for asthma during each of the four seasons of the year, over a 5-year period, was compared.The study was conducted at the pediatric respiratory clinic and pulmonary function laboratory of Shaare Zedek Medical Center.The study group consisted of 532 consecutive patients, all 17 years of age, who were referred for exercise testing for evaluation of suspected asthma. All had normal baseline FEV1 levels, and none received maintenance asthma treatment.Spirometry was performed before and after a standard exercise regimen. A decrease of ≥ 10% in FEV1 after exercise was considered positive; 141 patients (26%) had a positive test result. The percentage of positive results in the summer (July to September quartile) was 12.9%, less than half the percentage of positive results during any of the other three quartiles (January to March, 28.9%, p < 0.05; April to June, 30.6%, p < 0.05; October to December, 29.1%, p < 0.05).This study shows that the percentage of positive exercise challenge test results in the summer is half that of any other season. It is likely that the lower percentage of positive results for asthma in the summer reflects the lower sensitivity of the test during this season due to decreased asthma activity. We suggest performing exercise challenge testing only when patients are symptomatic. Physicians caring for patients with symptoms suggestive of exercise-induced asthma whose exercise test results are negative while asymptomatic should consider repeat exercise testing when their patients are symptomatic.

Hereditary distal spinal muscular atrophy with vocal cord paralysis.

A large kindred is described in which an unusual form of spinal muscular atrophy is segregating in an autosomal dominant manner. The disease presents most commonly in the teens with small muscle wasting in the hands, particularly involving median nerve musculature. Subsequently distal muscle wasting and weakness occur in the lower limbs. Vocal cord paralysis is a characteristic and potentially hazardous feature. No previous report of this condition has been found.

Hereditary distal spinal muscular atrophy: A report on 34 cases and a review of the literature

A description is given of 34 patients with the distal form of hereditary spinal muscular atrophy. This disorder constitutes one form of “peroneal muscular atrophy”. It resembles types I and II hereditary motor and sensory neuropathy but differs from them in displaying less upper limb weakness, relative preservation of the tendon reflexes and an entirely normal clinical sensory examination. Motor nerve conduction velocity and sensory nerve action potentials are normal. Previous reports of this disorder are reviewed and compared with the present series.

Distal spinal muscular atrophy: A clinical and genetic study of 8 kindreds

Twelve patients (8 kindreds) with distal SMA are described, and an analysis presented of their clinical and genetic features. Distal SMA accounted for 10% of all patients with SMA in a total population survey of this disease in North-East England. The parental consanguinity rate is high, occurring in 3 of the 8 kindreds reported; the sex ratio was 1.0; the segregation ratio of sibs did not differ from 0.25. Intrafamilial concordance for clinical features of the disease is high. This current data is consistent with a suggested aetiology of two separate autosomal recessive genes. Clinical features are discussed and a review of the literature presented. The disease is only slowly progressive, but one of the genetic types may present with infantile or early juvenile onset; there is no evidence that it shortens life. 50% of cases did not have a normal gait after 4 years of age; 50% could not run after 17 years of age; and 50% could not walk unaided after 28 years of age. Details of prognosis, and principles of genetic counselling in this disease are discussed.