Stiff Person Syndrome With Positive Anti-glutamic Acid Decarboxylase (GAD) Autoantibodies

Area of Science:

• Neurology
• Immunology
• Autoimmune Disorders

Background:

• Stiff person syndrome (SPS) is a rare, progressive autoimmune neurological disorder.
• Characterized by fluctuating muscle rigidity, spasms, and increased startle response.
• Primarily affects women, with increasing evidence linking it to specific autoantibodies.

Observation:

• A 53-year-old female presented with chronic lower back pain, paresthesias, and progressive lower limb rigidity.
• Electromyography confirmed severe muscle rigidity, co-contractions, and spasms triggered by touch.
• Imaging revealed a polymyomatous uterus, ruling out hypermetabolic lesions.

Findings:

• The patient was diagnosed with stiff person syndrome, confirmed by positive anti-glutamic acid decarboxylase (GAD)65 autoantibodies.
• A multimodal treatment regimen included corticosteroids, gabapentin, baclofen, alprazolam, immunoglobulins, and rituximab.
• This therapeutic approach resulted in moderate symptom improvement.

Implications:

• This case underscores the critical association between stiff person syndrome and anti-GAD65 antibodies.
• Highlights the importance of early diagnosis and a comprehensive, multidisciplinary management strategy for SPS.
• Suggests that combined immunotherapies and symptomatic treatments can lead to functional improvements in patients with SPS.