Fisher’s “One and a half syndrome” in myasthenia gravis – a case report
DOI:
https://doi.org/10.67667/NEU.v27i1.226Keywords:
myasthenia gravis, “one and a half“ syndromeAbstract
Fisher’s “One and a half syndrome” is a rare oculomotor lesion characterized by conjugate gaze palsy with contralateral internuclear ophthalmoplegia. The syndrome is due to a unilateral pontine lesion affecting the ipsilateral paramedian pontine reticular formation and/or the abducens nucleus and the adjacent medial longitudinal fasciculus interneurons. It is described in brain stem lesions with different etiology—vascular, demyelinating, neoplastic, inflammatory, and other causes. We present an 81-year-old patient with acutely developed one and a half syndrome, accompanied by unilateral mild ptosis as a debut symptom of myasthenia gravis. The myasthenic symptoms mimic a structural pontine lesion in the patient.
References
1. Чернинкова, С. Характеристика на очедвигателните паретични лезии при болни с множествена склероза. В: Невроофталмологична диагностика при някои заболявания на нервната система и окото. Монография, София, 2009, Издателство Булвест, 61-85. ISBN 978-954-18-0690-6. [Ckerninkova, S. Harakteristika na ocedvigatelnite pareticni lezii pri bolni s mnojestvena skleroza Nevrooftalmologicna diagnostika pri niakoi zaboliavania na nervnata Sistema I okoto. M0n0grafia, Sofia, 2009, Izdatelstvo Bulvest, 61-85.]
2. Abuzaid, Z., Alutaibi, M., Alsarawi, A., Al-Harbi, T. One and a half syndrome and bilateral cerebellar ataxia as an uncommon brainstem stroke. J Neurol Sciences, 2021, 429, Suppl., 119619.
3. Allbon, D., La Hood, B. Thirteen-And-A-Half Syndrome. J Neuroophthalmol, 2016, 36, 191-192.
4. Azzopardi, M., Agius, D. One-and-a-half syndrome. Malta Med Journal, 2023, 35, 1, Section Case reports.
5. Bandini, F., Faga, D., Simonetti, S. Ocular myasthenia mimicking a one and a half syndrome. J. Neuroophthalmology, 2001, 21, 210-211.
6. Behbehani, R. Ocular Myasthenia Gravis: A Current Overview. Eye Brain, 2023, 5, 15, 1-13.
7. Bolanos, I., Lozano, D., Cantu, C. Internuclear ophthalmoplegia: causes and long-term follow-up in 65 patients. Acta Neurologica Scandinavica, 2004, 110, 161-165.
8. Chai, E., Cardoza, S., Rosado, I., Manes, P., Rivero, H., Bernstein, A. Juxtaposition of One and a Half Syndrome with Pseudo One and a Half Syndrome. Annals of Clinical Case Reports, 2018, 3, 1565, 1-3.
9. Fisher, C. Some neuro-ophthalmologic observations. J Neurol Neurosurg Psychiatry, 1967, 30, 383-392.
10. Ford, H. Clinical presentation and diagnosis of multiple sclerosis. Clin Med (Lond), 2020, 20, 4, 380-383.
11. Khalili, M., Badiei, M., Jahanbani-Ardakani, H. One- and-a-half syndrome as first clinical manifestation of multiple sclerosis – a case report and literature review. Polish J Neurology Neurosurgery, 2022, 56, 5, 451-452.
12. McClard, C., Lyons, L., Yalamanchili, S. Bilateral pseudointernuclear ophthalmoplegia in a patient with myasthenia gravis. Am J Ophthalmol Case Rep, 2018, 12, 76-78.
13. Menon, V., Gogoi, M., Sahena, R., Singh, S., Kumar, A. Isolated “one and a half syndrome” with brainstem tuberculoma. Indian J Pediatr, 2004, 71, 469-471.
14. Minagar, A., Schatz, N., Glaser, J. Case report: one and a half syndrome and tuberculosis of the pons in a patient with AIDS. AIDS Patient Care STDS, 2000, 14, 9, 461-464.
15. Nair, S., Subha, L., Raj, K. One and a half syndrome (OAHS) – A case report. J Evid Based Med Healthc, 2017, 77, 4, 4571-4573.
16. Ranjith, M., Divya, R., Sahni, A. Isolated one and a half syndrome: an atypical presentation of neurocysticercosis. Indian J Med Sci, 2009, 63, 119-120.
17. Shao, K., Dong, S., Guo, J., Wang, Sun, Z. Eight and a half syndrome caused by tuberculous meningitis: a case report. Acta Neurol Belg, 2021, 121, 2, 591-593.
18. Toorn, R., Schoeman, J., Donald, P. Brainstem tuberculoma presenting as eight-and-a-half syndrome. Eur J Paediatr Neurol, 2006, 10, 41–44.
19. Tsuda, H., Ishikawa, H., Matsunaga, H., Mizutani, T. A neuroophthalmological analysis in 80 cases of multiple sclerosis. Rinsho Shinkeigaku, 2004, 44, 513-521.
20. Wall, M., Wray, S. The one and a half syndrome – an unilateral disorder of the pontine tegmentum: A study of 20 cases and review of the literature. Neurology, 1983, 33, 971-980.
21. Xue, F., Zhang, L., Zhang, L., Ying, Z., Sha, Ou, Ding, Y. One-and-a-half syndrome with its spectrum disorders. Quantitative Imaging in Medicine and Surgery. 2017, 7, 6, 691–697.
Downloads
Published
How to Cite
Issue
Section
ARK
License
Copyright (c) 2026 Sylvia Cherninkova, Kristina Kastreva, Yavor Zhelev, Ivailo Tournev

This work is licensed under a Creative Commons Attribution 4.0 International License.