OBJECTIVE: To report an association between two autoimmune conditions, Graves' 
disease and stiff-person (stiff-man) syndrome, and discuss the relevant 
literature.
METHODS: We present a case of a 52-year-old white woman with stiff-person 
syndrome who also had Graves' disease, discuss her management, and review the 
related literature. Pertinent published reports from 1950 through 2004 were 
researched with use of MEDLINE and PubMed, and cross-references to other 
articles were reviewed.
RESULTS: A 52-year-old white woman presented with symptoms of hyperthyroidism 
due to Graves' disease. Laboratory data were as follows: thyrotropin <0.005 m 
IU/mL, thyroxine 11.1 microg/dL, free thyroxine index (FTI) 10.7, and 
triiodothyronine 170 ng/dL. Thyroid-stimulating immunoglobulins (TSI) and 
thyrotropin-binding inhibitory immunoglobulins (TBII) were positive at 1,986% 
and 82.5 U/L, respectively. The hyperthyroidism was treated with propranolol. 
She had a long-standing history of musculoskeletal complaints and was ultimately 
diagnosed with stiff-person syndrome. During her thyroid evaluation, she had 
severe neurologic deterioration that necessitated hospitalization and treatment 
with clonazepam, baclofen, intravenous immunoglobulin, and subsequently 
prednisone and azathioprine for appreciable symptomatic relief. The aggressive 
immunosuppression had a profound effect on her symptoms of hyperthyroidism, 
results of thyroid function tests, and thyrotropin receptor antibodies (TRABs). 
Thyrotropin was 0.52 microIU/mL, thyroxine was 6.9 microg/dL, and FTI was 5.7. 
The TSI decreased from 1,986% to 248%, and her TBII normalized from 82.5 U/L to 
<5 U/L. She was clinically and biochemically euthyroid at last follow-up in May 
2004.
CONCLUSION: This case illustrates the association between TRAB-positive Graves' 
disease and stiff-person syndrome and the improvement of Graves' disease with 
immunosuppressive therapy.