Category: Clinical Sciences/Health Conditions
Case Diagnosis: Stiff Person Syndrome
70 year-old Female with PMH of HTN, DM presented to the Emergency Department with 4 weeks progressively worsening bilateral lower extremity weakness, stiffness and inability to ambulate. Physical exam revealed severe rigidity. Extensive neurological workup ruled out myelopathy. EMG revealed no myopathic pathology, but was significant for motor activity at rest in vastus medialis, vastus lateralis, lumbosacral and thoracic paraspinals. Autoimmune workup revealed anti-glutamic acid decarboxylase antibodies. Patient was diagnosed with Stiff Person Syndrome, and started on clonazepam 2mg BID, baclofen 20mg, and dantrolene 25mg BID. Due to persistent symptoms, she underwent a 5 day course of IVIG, and failed to improve. She was then transferred to acute inpatient rehab for continued care. On admission to rehab, she was started on a trial of bromocriptine 2.5mg BID, which resulted in marked improvement of her rigidity. After 2 weeks she ambulated 100 feet with a walker with contact guard assistance.
Stiff Person syndrome (SPS) is rare disorder of CNS characterized by fluctuating muscle rigidity and spasms. There are three subtypes of SPS, classic (most common), partial (aka stiff limb syndrome), and paraneoplastic variant. Diagnosis is based on laboratory findings including anti-GAD antibodies as was seen in this patient. EMG typically shows continuous motor unit activity that decreases with sleep, benzodiazepines, and general anesthesia. Treatment focuses on symptomatic management, including benzodiazepines, baclofen, antiepileptics, IVIG and plasmapheresis. This case was unique due to the notable improvement after trial of bromcriptine, a dopamine agonist not typically used in SPS, but known to work on rigidity due to extrapyramidal symptoms.
SPS is a rare disorder of the CNS hallmarked by marked rigidity. Treatment includes benzodiazepines, baclofen, antiepileptics, IVIG, and plasmapheresis. This patient improved after a trial of bromocriptine. Further studies may be warranted to assess the efficacy of bromocriptine in SPS.