Facial Onset Sensory and Motor Neuronopathy with Neurotrophic Keratitis: A Case Report

Main Article Content

Rozita Khalili Ahmad M. A. Abualhayjaa Tulio E. Bertorini


Facial-onset sensory and motor neuronopathy (FOSMN) is a rare, progressive neurodegenerative disorder characterized by sensory loss and motor deficits, primarily affecting the face and upper extremities. The condition begins with sensory impairments in the trigeminal nerve distribution, extending to involve the scalp, neck, upper limbs, and trunk. Symptoms include facial weakness, bulbar disturbances (dysphonia, dysarthria, dysphagia, and sialorrhea), and lower motor neuron signs (weakness, atrophy, fasciculation, and cramps) in the limbs. A hallmark of FOSMN is the diminished or absent corneal reflex, indicating trigeminal nerve involvement and leading to potential complications like neurotrophic keratitis (NK), which can cause corneal ulceration and blindness. The etiology of FOSMN remains uncertain, with theories proposing autoimmune or neurodegenerative origins. Diagnosis is challenging due to the overlap with other ocular surface disorders, necessitating careful examination and differential diagnosis. Management focuses on symptomatic relief, including eye protection to prevent corneal complications. Awareness and early detection of ocular symptoms in FOSMN are crucial for preventing severe outcomes like NK and blindness.

Keywords: Facial-onset sensory and motor neuronopathy, Corneal reflex, Neurotrophic keratitis

Article Details

How to Cite
KHALILI, Rozita; ABUALHAYJAA, Ahmad M. A.; BERTORINI, Tulio E.. Facial Onset Sensory and Motor Neuronopathy with Neurotrophic Keratitis: A Case Report. Medical Research Archives, [S.l.], v. 12, n. 3, mar. 2024. ISSN 2375-1924. Available at: <https://esmed.org/MRA/mra/article/view/5119>. Date accessed: 13 apr. 2024. doi: https://doi.org/10.18103/mra.v12i3.5119.
Case Reports


1. Vucic S, Tian D, Siao Tick Chong P, Cudkowicz ME, Hedley-Whyte ET, Cros D. Facial onset sensory and motor neuronopathy (FOSMN syndrome): a novel syndrome in neurology. Brain. 2006;129(Pt 12):3384-90. Doi: 10.1093/brain/awl258.
2. Watanabe M, Shiraishi W, Yamasaki R, et al. Oral phase dysphagia in facial onset sensory and motor neuronopathy. Brain Behav 2018;8:e00999.
3. de Boer EMJ, Barritt AW, Elamin M, et al. Facial Onset Sensory and Motor Neuronopathy: New Cases, Cognitive Changes, and Pathophysiology. Neurology Clinical Practice. 2021;11(2):47-157. Doi:10.1212/CPJ.0000000000000834.
4. Bertorini TE. Treatment and management of adult motor neuron diseases. In: Bertorini TE, ed. Neuromuscular Disorders. 2nd ed. Elsevier; 2011:253.
5. Vucic S, Stein TD, Hedley-Whyte ET, et al. FOSMN syndrome: Novel insight into disease pathophysiology. Neurology. 2012;79(1):73-9. Doi: 10.1212/WNL.0b013e31825dce13.
6. Fluchere F, Verschueren A, Cintas P, et al. Clinical features and follow-up of four new cases of facial-onset sensory and motor neuronopathy. Muscle and Nerve 201;43:136–140.
7. Knopp M, Vaghela NN, Shanmugam SV, Rajabally YA. Facial onset sensory motor neuronopathy: an immunoglobulin-responsive case. J Clin Neuromuscul Dis 2013;14:176–179.
8. Broad R, Leigh PN. Recognising facial onset sensory motor neuronopathy syndrome: insight from six new cases. Practical Neurology. 2015;15(4):293-7. Doi: 10.1136/practneurol-2014-000984. Epub 2015 May 19.
9. Hokonohara T, Shigeto H, Kawano Y, Ohyagi Y, Uehara M, Kira J. (2008). Facial onset sensory and motor neuronopathy (FOSMN) syndrome responding to immunotherapies. Journal of the Neurological Sciences. 2008;275(1-2):157-8.
Doi: 10.1016/j.jns.2008.07.021.
10. Simmons Shaheen B, Bakir M, Jain S. Corneal nerves in health and disease. Survey of Ophthalmology. 2014;59(3):263-85. Doi: 10.1016/j.survophthal.2013.09.002.
11. Preston, David C., and Barbara E. Shapiro. Electromyography and neuromuscular disorders e-book: clinical-electrophysiologic-ultrasound correlations. 4th ed. Elsevier Health Sciences; 2020:54.
12. Ruys‐Van Oeyen, Astrid EWM, and J. Gert Van Dijk. "Repetitive nerve stimulation of the nasalis muscle: technique and normal values." Muscle & Nerve: Official Journal of the American Association of Electrodiagnostic Medicine 26.2 (2002): 279-282. doi.org/10.1002/mus.10201.
13. Dobrev D, Barhon RJ, Anderson NE, et al. Facial onset sensorimotor neuronopathy syndrome: a case series. J Clin Neuromuscul Dis 2012;14:7–10
14. Zheng Q, Chu L, Tan L, Zhang H. Facial onset sensory and motor neuronopathy. Neurological Sciences. 2016;37(12):1905-1909. Doi: 10.1007/s10072-016-2686-7.
15. Barca E, Russo M, Mazzeo A, Terranova C, Toscano A, Girlanda P. Facial onset sensory motor neuronopathy: not always a slowly progressive disorder. J Neurol 2013;260:1415–1416.
16. Pinto WBVR, Naylor FGM, Chieia MAT, de Souza PVS, Oliveira ASB. New findings in facial-onset sensory and motor neuronopathy (FOSMN) syndrome. Revue neurologique. 2019;175(4):238-246. Doi: 10.1016/j.neurol. 2018.04.010.
17. Grudzińska M, Kierdaszuk B, Lipowska M, Rosiak E, Kostera-Pruszczyk A. Facial onset sensory and motor neuronopathy syndrome - a rare variant of motor neurone disease. Neurol Neurochir Pol. 2021;55(3):325-327. Doi: 10.5603/PJNNS.a2021.0018.
18. Peterson DC, Hamel RN. Corneal Reflex. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023. PMID: 30480980. Bookshelf ID: NBK534247.
19. Heigle TJ, Pflugfelder SC. Aqueous tear production in patients with neurotrophic keratitis. Cornea. 1996;15(2):135-8. Doi: 10.1097/00003226-199603000-00005.
20. Labetoulle M, Baudouin C, Calonge M, et al. Role of corneal nerves in ocular surface homeostasis and disease. Acta Ophthalmol. 2019;97(2):137-145.
Doi: 10.1111/aos.13844.
21. Versura P, Giannaccare G, Pellegrini M, Sebastiani S, Campos EC. Neurotrophic keratitis: current challenges and future prospects. Eye Brain. 2018; 28:10:37-45. Doi: 10.2147/EB.S117261.
22. Nishida T, Chikama TI, Sawa M, Miyata K, Matsui T, Shigeta K. Differential contributions of impaired corneal sensitivity and reduced tear secretion to corneal epithelial disorders. Jpn J Ophthalmol. 2012;56(1):20-5.
Doi: 10.1007/s10384-011-0105-4.
23. Smith JH, Cutrer FM. Numbness matters: A clinical review of trigeminal neuropathy. Cephalalgia. 2011;31(10):1131-1144. Doi: 10.1177/0333102411411203.