Objective: To describe a rare presentation of a young-onset Stiff Person Syndrome patient.

Background: The Stiff-Person syndrome (SPS) is classically characterized by progressive stiffness with muscle spasms, involving the axial and limb muscles, and exaggerated startle responses (Hyperekplexia). The phenotypic spectrum is broad and can be expressed as classical SPS, Stiff limb syndrome, and other variants that combine additional neurological symptoms (Stiff person plus), or even as Progressive encephalomyelitis with rigidity and myoclonus (PERM). The diagnosis of this disease in clinical practice is difficult, and may sometimes mimic other disorders.

Methods: Case-report.

Results: A 27-year-old young woman develops intermittent paroxysmal distal muscle contractions of the left lower limb (LLL), initially during exercise, but latter present also at rest. About 6 months’ latter the lower limb dystonic postures started to be more frequent and characterized by left foot inversion, with progressive gait limitation. At this time, the patient starts to experience anxiety and depressive symptomatology and begins escitalopram 20 mg. About 1 month later, she suffered a subacute rapid worsening of the dystonic postures, becoming fixed, more painful and with complete loss of gait. After initiation of benzodiazepines and trihexyphenidyl in progressive titration and SSRI suspension, there was a progressive improvement of the dystonic symptomatology. From the remaining personal history, it was relevant for the presence of type 1 Diabetes Mellitus, insulin-treated. A therapeutic trial with levodopa/carbidopa (until 400 mg/day) was performed without benefit. Brain MRI did not reveal any structural abnormalities. Brain PET-BetaCIT was unremarkable. Genetic NGS panel for dystonia (58 genes) was negative. About 2 months later the patient develops hyperreactivity to auditory and tactile stimuli and myoclonus of the right hand. The Serum anti-glutamic acid decarboxylase (GAD65) was positive and subsequently confirmed its presence in CSF. EMG was also compatible with SPS.

Conclusions: This case report describes a rare presentation of SPS, at the beginning resembling a dystonic syndrome with focal onset of the left lower limb, with subsequent generalization. The presence of a rapid​ progression, the presence of startle response, the disproportion between the amount of pain and the degree of the dystonic posturing and the striking hypersensitivity to the SSRIs, are all red flags that make us rethink the initial diagnosis.

« Back to 2018 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/stiff-young-woman-case-report/