Stiff man-like syndrome and generalized myokymia in spinocerebellar ataxia type 3.
We describe the novel association of spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) phenotype combining classical clinical presentation and semeiology mimicking stiff man syndrome (SMS). The studied pedigree comprises seven affected members in three generations. Their clinical picture consisted of cerebellar ataxia, pyramidal signs, facial myokymia, and ophthalmoplegia. The proband was a 39-year-old man in whom such a clinical picture, 5 years after onset at age 29, evolved to severe SMS and widespread myokymia. Electrophysiological study revealed continuous muscle activity in proximal limb muscles. Molecular study demonstrated the MJD gene mutation in all four examined patients with 73 to 76 CAG repeats in the expanded allele. We conclude that an excess of motor unit activity including stiff man-like syndrome and widespread myokymia may be an integral part of the SCA3 clinical spectrum.
Service of Neurology, University Hospital Marqués de Valdecilla, (UC) Santander, Spain. jaberciano@humv.es
José
J
Berciano
Jon
J
Infante
Antonio
A
García
Carmen
C
de Pablos
Guillermo
G
Amer
José Miguel
JM
Polo
Victor
V
Volpini
Onofre
O
Combarros
D000328:Adult; D000368:Aged; D000483:Alleles; D000067699:Ataxin-3; D001284:Atrophy; D001933:Brain Stem / Q000473:pathology; D002531:Cerebellum / Q000473:pathology; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006801:Humans; D017827:Machado-Joseph Disease / Q000175:diagnosis / Q000235:genetics*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020385:Myokymia / Q000175:diagnosis / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics; D009460:Neurologic Examination; D009687:Nuclear Proteins / Q000235:genetics; D009886:Ophthalmoplegia / Q000175:diagnosis / Q000235:genetics; D010375:Pedigree; D010641:Phenotype; D012097:Repressor Proteins / Q000235:genetics; D016750:Stiff-Person Syndrome / Q000175:diagnosis / Q000235:genetics*; D014057:Tomography, X-Ray Computed
D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012097:Repressor Proteins; C092341:ATXN3 protein, human; D000067699:Ataxin-3