Glycine receptor Ab as a marker of stiff-person syndrome spectrum disorder
Clinical cases: Neurology
Background
A 54-year-old man presents with a subacute onset of double vision, whole-body spasms with startle, and balance problems. Clinical exam reveals ophthalmoparesis and myelopathic signs. Further evaluation via imaging, spinal fluid testing, and bloodwork fails to yield a clear diagnosis; however, an autoimmune cause is suspected. Negative GAD65 antibody testing assumes exclusion of stiff-person syndrome.
After a neuroimmunology subspecialty opinion is sought, glycine receptor (GlyRa1) antibody testing is undertaken in serum and cerebrospinal fluid (CSF). Both are positive. The patient is diagnosed with progressive encephalomyelitis with rigidity and myoclonus (PERM), a variant of stiff-person syndrome. The patient improves with immunotherapy.
Teaching points
- The Mayo Clinic Neuroimmunology Laboratory’s testing includes a profile of neurological phenotype-pertinent antibodies to minimize delay in obtaining diagnosis and to initiate early appropriate treatment.
- GAD65, GlyRa1, amphiphysin, and DPPX antibody tests should be considered in patients with stiff-person spectrum disorders, including PERM.
Key testing
- Turnaround time: 10 days
- Turnaround time: 7 days
Find out how we use glycine receptor Ab as a marker of stiff-person syndrome spectrum disorder.
