Stiff-Person Syndrome and Psychiatric Comorbidities: A Systematic Review

Background: Stiff-person syndrome (SPS) is a rare autoimmune neurologic disease characterized by painful rigidity and muscle spasms. Patients with SPS may present with psychiatric symptoms, and little is known about the presence of psychiatric comorbidities.

Objective: The objective of this study was to provide an overview of the association between SPS and psychiatric illnesses.

Methods: The protocol is registered in PROSPERO (Registration ID CRD42020159354). Peer-reviewed articles on adults with SPS and psychiatric comorbidities published before May 26, 2020, were selected by 2 independent reviewers. Qualitative summary data and relative risk of psychiatric disorders in patients with SPS compared with the general population and multiple sclerosis were calculated.

Results: After screening 909 articles, 52 full texts were assessed for eligibility and 27 were ultimately included, 5 of which were selected for quantitative analysis. Although limited by small sample sizes leading to large confidence intervals, the relative risk of any psychiatric comorbidity in SPS was higher than that of the general population, ranging from estimates of 6.09 (95% confidence interval: 4.09, 9.08) to 11.25 (95% confidence interval: 3.27, 38.66). There was no statistically significant difference in the risk of any psychiatric comorbidity between SPS and multiple sclerosis. The review also highlighted delays in SPS diagnosis, often related to misattribution of symptoms as being solely secondary to a psychiatric cause.

Conclusions: The higher risk of psychiatric comorbidities emphasizes the important role of psychiatrists in recognizing the symptoms of SPS to reach timely diagnosis and treatment. The presence of psychiatric symptoms should support rather than delay the diagnosis of SPS.