We report on 2 patients who presented stiffness and spasms similar to
those of stiff-man syndrome (SMS) that were limited to one leg for up
to 11 years. Patients had serum glutamic acid decarboxylase (GAD) auto
antibodies in high titer, clinical evidence of organ-specific autoimmu
nity, and electromyographic pattern of continuous motor unit activity
with abnormally enhanced exteroceptive reflexes. The clinical and immu
nological profile suggests that this disorder may be a focal form of S
MS.