DIRECTION-CHANGING GAZE-EVOKED NYSTAGMUS WITH PERSISTENT OSCILLOPSIA IN A PATIENT WITH HASHIMOTO’S THYROIDITIS: A CASE REPORT AND REVIEW OF VESTIBULO-OCULAR DYSFUNCTION IN AUTOIMMUNE THYROID DISEASE

Abstract

Background: Direction-changing gaze-evoked nystagmus with persistent oscillopsia is an unusual neuro otological manifestation and may indicate dysfunction of central or peripheral vestibulo-ocular pathways. Autoimmune thyroid disease, particularly Hashimoto’s thyroiditis, has been increasingly recognised as a contributor to vestibular and ocular-motor abnormalities. The coexistence of disabling oscillopsia, mixed-pattern nystagmus, and markedly elevated thyroid autoantibody titres remains rarely documented. Case Presentation: A 31-year-old woman presented with a 10-month history of oscillopsia and shaking of images on lateral gaze, preceded by blurring of lateral vision during the fifth month of pregnancy. Her antenatal period had been complicated by severe hyperemesis and neurological symptoms for which she was treated as Wernicke’s encephalopathy earlier in the year. Despite partial improvement, oscillopsia and intermittent headaches persisted. She had a known history of hypothyroidism for four years on levothyroxine 100 mcg/ day On examination, she was conscious and afebrile, with stable vital signs. Neurological evaluation revealed bilateral gaze-evoked nystagmus with rotatory, direction-changing, upbeat, and downbeat components. Motor, sensory, and cerebellar functions were largely normal except for mild difficulty in tandem walking. MRI brain showed small bilateral frontoparietal T2/FLAIR hyperintensities of nonspecific etiology, and VEMP  (vestibular evoked myogenic potential ) testing was normal. Laboratory workup demonstrated markedly elevated thyroid peroxidase antibodies (>1000 IU/mL) and mildly raised alkaline phosphatase. Thyroid ultrasonography revealed a hypoechoic nodule in the left lobe.Endocrinologist opined to start intravenous pulse dose steroids. The patient was initiated on intravenous methylprednisolone 1g for five days along with thiamine and supportive therapy. She tolerated treatment well, with mild subjective improvement in oscillopsia, and was discharged in stable condition with a tapering steroid regimen, continuation of levothyroxine, and structured follow-up. Conclusion: This case highlights a rare presentation of direction-changing gaze-evoked nystagmus and persistent oscillopsia in the context of autoimmune thyroid disease. The findings emphasise the importance of evaluating thyroid autoimmunity in patients with atypical nystagmus patterns, even when vestibular testing is normal. Early neuro-vestibular assessment and timely immunomodulatory therapy may improve outcomes. This report contributes to the emerging evidence linking thyroid autoimmunity with vestibulo-ocular dysfunction and underscores the need for heightened diagnostic vigilance.