The scapuloperoneal syndromes (SPSs) are heterogeneous disorders characterized by weakness of both shoulder girdle and peroneal muscles. Both a neurogenic form (scapuloperoneal spinal muscular atrophy [SPSMA]) and a myopathic form (scapuloperoneal muscular dystrophy [SP MD]) have been identified. The neurogenic SPSMA was linked to chromosome 12q24.1-q24.31, which is a region about 20 cM telomeric to the location of the gene for the myopathic SP MD. y
These are uncommon disorders, with heated debate as to whether the scapuloperoneal syndromes are all distinct
Figure 36-6 Facioscapulohumeral dystrophy in a 15-year-old boy. There is marked facial weakness on frontal view and dramatic scapular winging with arm abduction on the postericfFrom Dubowitz V: Muscle Disorders in Childhood. London, W.B. Saunders, 1995.)
entities. Autosomal dominant, autosomal recessive, and sex-linked recessive patterns of inheritance have been reported, as well as sporadic cases. Genetic studies will undoubtedly eventually clarify the situation.
The clinical features of both the myopathic and neurogenic types are similar. Age of onset reported ranges from infancy to adulthood, most commonly late childhood or young adulthood. The usual presentation is weakness in shoulder girdle muscles, progressing to weakness in the anterior tibial muscles, followed by weakness in pelvic girdle muscles. When facial involvement occurs, it is mild and late in onset.
Although there are a few neuromuscular disorders that may present with weakness in the scapuloperoneal distribution, particularly Charcot-Marie-Tooth disease and FSH MD, a comprehensive neuromuscular work-up based primarily on EMG and muscle and nerve biopsies screens out most of them.
Davidenkow's syndrome, which includes scapuloperoneal weakness, may be confused with the SPSs. However, it also has pes cavus deformities and progressive distal sensory loss with early depression of reflexes, as well as impaired sensory and motor nerve conduction velocities. y
ED MD may also produce weakness in the scapulohumeral distribution, but it has characteristic contractures and cardiac conduction abnormalities not present in the SPSs. The weakness tends to progress very slowly, and patients become only mildly disabled. It generally does not affect the lifespan. y
Was this article helpful?
Headache Happiness! Stop Your Headache BEFORE IT STARTS. How To Get Rid Of Your Headache BEFORE It Starts! The pain can be AGONIZING Headaches can stop you from doing all the things you love. Seeing friends, playing with the kids... even trying to watch your favorite television shows. And just think of how unwelcome headaches are while you're trying to work.