To present a case of anti-glycine receptor antibody (anti-GlyR Ab) positive stiff person spectrum disorder (SPSD) with oculomotor involvement.

SPSD classically presents with rigidity, spasms, hyperreflexia, and hyperekplexia, but a growing body of evidence shows a range of associated neurologic deficits, including oculomotor dysfunction. High GAD65 Ab titers have been associated with nystagmus, impaired abduction and saccades, opsoclonus, ocular flutter, and gaze deviation. Progressive encephalomyelitis with rigidity and myoclonus (PERM), a severe phenotype of SPS commonly associated with anti-GlyR Ab, is well established to have brainstem findings, including ophthalmoplegia. However, there is a dearth of reports of ophthalmoplegia in SPSD with anti-GlyR antibodies alone.

A 70-year-old female was recently diagnosed with stiff limb syndrome (CSF positive for anti-GlyR Ab and negative for GAD65; serum with GAD65 Ab 0.07 nmol/L and negative for anti-GlyR Ab). She was treated with IVIG and methylprednisolone, with improvement in her lower extremity symptoms. She represented 6 weeks later with aphasia and left gaze deviation. She had no recurrence of her previous lower extremity stiffness or hyperreflexia. MRI brain and MR perfusion were negative for stroke. EEG had no epileptiform abnormalities. CSF GAD65 Ab remained negative. Her aphasia resolved within a day but the ophthalmoplegia persisted. Repeat MRI brain with thin cuts through the brainstem again confirmed no infarct, thus her presentation was treated as an exacerbation of stiff person syndrome. After a repeat course of high dose steroids and IVIG, her ophthalmoplegia gradually resolved over the course of 4 weeks.

Anti-GlyR antibody positive SPSD can present with ophthalmoplegia even in the absence of GAD65 Ab or features of PERM. While care should be taken to rule out other etiologies of oculomotor dysfunction, the possibility of oculomotor consequences of anti-GlyR antibodies should not be missed in patients with a history of SPSD.