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Pearls & Oy-sters: Tonic eye deviation in stiff-person syndrome

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Abstract

Stiff-person syndrome (SPS) is an autoimmune disease characterized by muscle rigidity, episodic muscle spasms, as well as continuous cocontraction of agonist and antagonist muscles.

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... Multiple ocular abnormalities have been described in association with anti-GAD antibodies including nystagmus (up/down-beat, periodic alternating nystagmus) [4], abduction deficits in association with myasthenia and thymoma, slowed and impaired saccade initiation [5], opsoclonus [6], and even ocular flutter [7]. There has been one report of tonic eye deviation associated with SPS [8], but there have been no reports of isolated ophtalmoplegia in association with anti-GAD antibodies. ...
... Tonic eye deviation has rarely been reported in conjunction with SPS [8]. It has been hypothesized that tonic eye deviation associated with anti-GAD might be secondary to continuous discharge in gaze holding neurons in the brainstem, similar to what occurs in spinal motor neurons in SPS. ...
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Anti-GAD ataxia is one of the most common forms of immune-mediated cerebellar ataxias. Many neurological syndromes have been reported in association with anti-GAD. Ophthalmoparesis has been described in stiff person syndrome. We report a case of anti-GAD ataxia presenting initially with isolated ophthalmoplegia and showing complete resolution after immunotherapy. A 26-year-old male patient presented with ophthalmoparesis characterized by tonic upwards deviation of the right eye. In the following month, he developed progressive ataxia with anti-GAD titers of 1972 UI/mL. After treatment with methylprednisolone and immunoglobulin, there was complete resolution of symptoms and anti-GAD titers decreased. This is the first report of isolated ophthalmoparesis due to tonic eye deviation associated with anti-GAD antibodies without stiff-person syndrome. Tonic eye deviation has been reported in SPS, possibly secondary to continuous discharge in gaze holding neurons in the brainstem (similar to what occurs in spinal motor neurons). With growing evidence for ocular abnormalitites in SPS, anti-GAD associated neurological syndromes should be included in the differential diagnosis of isolated ophthalmoplegia.
... A review of the literature has however revealed several case reports which have highlighted neuro-ophthalmic problems patients with SPS may present with (Chakravarthi, Table 2). Nystagmus and defective saccades appear to be the most common presentation (Ances et al. 2005;Brokalaki et al. 2015;Chakravarthi, Goyal & Lal V 2015;Dubbioso et al. 2013;Economides & Horton 2005;Tilikete et al. 2005;Zivotofsky et al. 2006). Our patient had both of these problems. ...
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Aim: To report a case of sudden onset vertical diplopia, blurred vision, and muscle spasms. Methods: This is a case report of a 57-year-old female who presented to the accident and emergency department with a one day history of vertical diplopia and a two week history of lower limb spasticity secondary to muscle spasms. Results: The patient had no significant medical or ocular history. Orthoptic investigation initially revealed a left inferior rectus (IR) underaction. Possible diagnoses at this point were thought to be isolated IR weakness, myasthenia gravis or skew deviation. An urgent MRI scan was arranged and blood tests were taken. MRI showed no abnormalities. Blood tests were normal, however, the acetylcholine receptor antibody serum test (ACH-R) was 0.43 nmol/L, which is at the high end of normal. At the follow-up visit, the IR weakness had deteriorated and the patient had also developed gaze-evoked nystagmus. An appointment with the neurologist and neuro-ophthalmologist was expedited. When the patient returned, she reported that her neurologist had diagnosed her with stiff-person syndrome (SPS). The patient had also developed a laterally alternating skew deviation and reported that she had undergone a course of intravenous immunoglobulin (IVIG). The patient was prescribed diazepam and gabapentin. Due to the lack of recovery, persistent diplopia and oscillopsia, monthly IVIG have been prescribed. Conclusion: There is currently a paucity of literature relating to ophthalmic problems with SPS and how they are best treated. Previous reports have established that there is a link with myasthenia gravis, with many patients going on to develop myasthenia. Treatment of SPS is lacking large evidence-based studies. However, treatment with muscle relaxants and anticonvulsants has provided a good outcome for some. Further research is required to develop an evidence-based approach to treating the ophthalmological problems patients with SPS experience. This case report highlights the importance and value of orthoptists in investigating and monitoring patients with stiff-person syndrome.
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The authors describe a 38-year-old woman with stiff person syndrome (SPS) and gaze-holding nystagmus, limited abduction, vertical and horizontal ocular misalignment, deficient smooth pursuit, and impaired saccade initiation. There was no evidence of ocular myasthenia, indicating that abnormalities of ocular motor function can occur as a primary manifestation of SPS, perhaps from depletion of GABA.