Stiff Eyes in Stiff-Person Syndrome

Abstract

The clinical findings of stiff-person syndrome (SPS) include trunk and limb muscle stiffness and paroxysmal cramps. Antibodies directed against glutamic acid decarboxylase (GAD) has been associated with SPS. We report a patient with SPS and anti-GAD antibodies (antiGAD-Abs) with a prominent supranuclear gaze palsy and bradykinesia mimicking progressive supranuclear palsy (PSP). Case report.A 45-year-old former fighter pilot presented with an 18-month history of stiffness and gait problems that began with several falls backwards while training for a marathon. Six months later, she noted stiffness of the left arm and leg. She reported painful back and limb spasms when startled by touch. Her history was notable for pernicious anemia.Examination (video) including head thrust revealed a supranuclear vertical gaze palsy and vertical greater than horizontal saccade hypometria with prolonged saccade latency. Vertical pursuits were saccadic, but horizontal pursuits were normal. Convergence was impaired. She had a mildly masked facies, asymmetrically increased axial and limb tone, bradykinetic gait and limb movements, and no arm swing while walking. The remainder of the examination was unremarkable.Brain and spinal cord MRI scans showed mild cortical atrophy. EMG showed continuous motor activity at rest, normal 3-Hz repetitive stimulation, and a mild sensory neuropathy. CT of the chest, abdomen, and pelvis were normal. An extensive evaluation including paraneoplastic, amphiphysin, antigliadin, and intrinsic factor antibodies, rheumatologic markers, hemoglobin A1c, and fasting glucose were normal. Serum antiGAD-Abs were abnormally elevated at 71.6 U/mL (Ͻ1.45 U/mL). During the course of the next year, serum antiGAD-Abs were measured several times and were markedly elevated on all occasions. CSF analysis was acellular with protein of 48 mg/dL (Ͻ45 mg/dL), and antiGAD-Abs were absent.Videonystagmography (Synapsys Ulmer VNG C4-12.2, image frequency 30/s) initially revealed normal saccade latencies to horizontal and vertical targets,

Cognitive dysfunction associated with anti-glutamic acid decarboxylase autoimmunity: a case-control study

“…Full range of motion and conjugate movement indicate preserved integrity of the neural pathway from the frontal eye field to the cranial nerves, but a difficulty in unilateral gaze-holding suggests a dysfunction of the cerebello-vestibular system [29]. A similar phenomenon was described in SPS, and disruption of GABAergic neurons was proposed as a pathogenic mechanism [30]. Therefore, subtle horizontal eye motion disturbance may be a specific (but not sensitive) sign suggesting the involvement of GADA in cognitive decline.…”

Stiff-person syndrome: insights into a complex autoimmune disorder

“…Oculomotor disturbances including dysconjugate gaze, horizontal and vertical supranuclear gaze palsy, hypometric and slow saccades, impaired smooth pursuit, nystagmus and abduction deficits have been described in patients with SPS 11 12. Exaggerated startle responses, abnormally-enhanced extereoceptive reflexes and disinhibition of brainstem reflexes such as the head-retraction reflex are not uncommon features of SPS 13.…”

Ocular Motility of Aging and Dementia

“…It can, however, be very useful for clinical characterization of eye movements, especially because bedside examination alone may be insensitive to certain pathologic eye movement changes (eg, velocity abnormalities or extremely brief pauses between eye movements). The ENG/VNG results might lead to diagnoses other than those considered by bedside examination alone [2].…”