Aggravation of Stiff-Person Syndrome With Ophthalmoplegia After Tandospirone Initiation: A Case

02 Apr 20264 min read0 viewsJournal Feed

GIST

BackgroundStiff-person syndrome (SPS) is a rare neuroimmune disorder that is associated with a variety of symptoms and varying degrees of disability. SPS has multiple phenotypes and different immunological bases, and the lack of clinical awareness of these various clinical phenotypes often leads to misdiagnosis and inappropriate treatment of SPS patients in the early stage of the disease course.Case descriptionWe report a distinctive case of SPS with a 4-year follow-up.

The patient was a 56-year-old middle-aged woman who initially presented with diplopia and atypical muscle tension. Treatment with baclofen and lorazepam showed poor efficacy, and she was once misdiagnosed with anxiety and depression as well as oculomotor nerve palsy.

During the 4-year follow-up period, the patient gradually developed typical clinical manifestations and signs of SPS and was diagnosed with positive GAD antibodies. In the later stage, the patient’s symptoms were exacerbated by the serotonin receptor partial agonist tandospirone; further testing revealed a significant increase in GAD antibody titer.ResultsAs the patient could not tolerate hormone pulse therapy, she was administered rituximab and two sessions of intravenous immunoglobulin (IVIG).

Clinical Editorial

Clinical portrait and study context

The report documents a distinct case of stiff-person syndrome (SPS) with a four-year clinical course in a 56-year-old woman, illustrating diagnostic challenges and evolving symptomatology.
SPS is described as a rare neuroimmune disorder with heterogeneous phenotypes and immunological underpinnings, contributing to misdiagnosis and delayed appropriate management in early disease stages.

Study design and patient trajectory

This case follows a single patient over four years, detailing initial presentation, diagnostic evolution, and treatment responses.
Early symptoms included diplopia and atypical muscle tension, with initial therapy using baclofen and lorazepam yielding limited benefit.
Misclassification occurred as anxiety/depression and oculomotor nerve palsy before later recognition of SPS features and positive glutamic acid decarboxylase (GAD) antibodies.

Laboratory and diagnostic evolution

Over time, the patient developed characteristic SPS signs and tests revealed positivity for GAD antibodies.
A notable later development was an exacerbation of symptoms associated with tandospirone, a serotonin receptor partial agonist, accompanied by a marked rise in GAD antibody titers.

Therapeutic course and outcomes

Hormone pulse therapy was not tolerated, prompting alternative strategies.
Rituximab was pursued, supplemented by two rounds of intravenous immunoglobulin (IVIG).
Following treatment adjustments, the patient experienced substantial symptomatic improvement.

Clinical implications and limitations

The report underscores the diagnostic ambiguity of SPS and the potential for misdiagnosis in its early stages.
It highlights the potential for certain pharmacologic agents to influence symptom severity and antibody dynamics, though mechanistic explanations are not elaborated.