Version Changes
Revised. Amendments from Version 1
We added the information about the sensitivity and specificity of anti-GQ1b antibody in MFS patients in the 1st paragraph of introduction. We added the data of oligoclonal bands and myelin basic protein in the diagnostic assessment section. Since abnormal enhancement was occasionally observed in patients with diabetic oculomotor palsy, we deleted the corresponding sentence in the first paragraph of the discussion. In addition, we described the possible mechanism by which mRNA-based vaccine produce anti-GQ1b antibody and subsequent neurological deficits in the second paragraph of the discussion. We added the patient's photographs of the last follow-up when he completely recovered on day 77 in Figure 1 C.
Abstract
Neurological complications following vaccinations are extremely rare, but cannot be eliminated. Here, we report the first case of unilateral oculomotor nerve palsy (ONP) with anti-GQ1b antibody after receiving the Pfizer-BioNTech COVID-19 (BNT162b2) mRNA vaccine.
A 65-year-old man developed diplopia and ptosis in the right eye 17 days after vaccination, without preceding infection. Neurological examination revealed mild blepharoptosis, limitation of adduction, and vertical gaze on the right side. Increased levels of anti-GQ1b ganglioside antibody in the serum and albuminocytologic dissociation in the cerebrospinal fluid were detected. Cranial magnetic resonance imaging showed swelling and enhancement of the right oculomotor nerve. The patient was diagnosed with right ONP accompanied with anti-GQ1b antibody, and intravenous immunoglobulin (IVIG) therapy for 5 days was administered. The limitation of adduction and vertical gaze improved, and ptosis markedly resolved after IVIG treatment. Given the temporal sequence of disease progression, laboratory findings, and a favorable response to IVIG, a causal relationship cannot be ruled out between the occurrence of ONP and COVID-19 immunization. Since immunomodulatory treatments significantly hasten the recovery and minimize the residual symptoms in anti-GQ1b antibody syndrome, clinicians should be aware of this clinical condition following COVID-19 vaccination.
Keywords: oculomotor nerve palsy, Miller Fisher syndrome, anit-GQ1b antibody, ganglioside, COVID-19, vaccination, IVIG
Introduction
Oculomotor nerve palsy (ONP) is a neurological condition that manifests as diplopia, ptosis, and pupillary mydriasis. The various etiologies of ONP include cerebrovascular disease, cerebral aneurysm, diabetes, tumor, infection, collagen disease, hyperthyroidism, and Tolosa-Hunt syndrome 1 . In some cases, ONP can be caused by an aberrant immune response that develops directly against ganglioside GQ1b, a sialic acid-containing glycosphingolipid enriched in the paranodal region in the III (oculomotor), IV (trochlear), and VI (abducens) cranial nerves 2 . The para-infectious, immune-mediated ONP, along with ataxia and loss of tendon jerks, was originally described by Charles Miller Fisher as a variant of Guillain-Barré Syndrome (GBS) 3 . Compared to control subjects without neurological complications, the sensitivity and specificity of anti-GQ1b antibody in the patients with MFS are very close to 100% 2, 4 . Since there are incomplete or atypical forms of Miller Fisher syndrome (MFS), an umbrella term, “anti-GQ1b antibody syndrome” has emerged to encompass these clinical conditions 5 .
In addition to an antecedent infectious illness, vaccine-mediated immunization can trigger GBS and MFS 6– 9 , for example, MFS following influenza 7– 9 , pneumovax 8 , and DPT (diphtheria, pertussis, tetanus toxoid) vaccination 6 has been reported. GBS has been listed as a very rare neurological complication of the COVID-19 vaccine 10– 16 . However, to the best of our knowledge, there have been no case reports of isolated, unilateral ONP with anti-GQ1b antibody following vaccination. Here, we report an adult case of acute-onset right ONP with anti-GQ1b antibody following COVID-19 vaccination with a literature review.
Case description
A 65-year-old Asian male office worker began to notice persistent double vision without preceding upper respiratory or gastrointestinal infection. The diplopia worsened in the left gaze, and three days later, he developed right ptosis. He was vaccinated with a second dose of Pfizer-BioNTech COVID-19 (BNT162b2) mRNA vaccine 17 days before his presentation. His medical history included a seven-year history of diabetes, glaucoma, and benign paroxysmal positional vertigo. He did not have diabetic retinopathy or neuropathy in his right eye. His medication included one tablet per day of Canalia ® (teneligliptin and canagliflozin), a diabetic combination drug which the patient had been taking for one year and one drop per day of prostaglandin analogue eye drops for glaucoma (time taken for unknown).
The general medical condition of the patient on admission (day 22) was unremarkable. Neurological examination revealed mild blepharoptosis, limitation of adduction, and vertical gaze on the right side ( Figure 1A) with convergence insufficiency. Pupils were slightly asymmetric (right: 3.5 mm, left: 3.0 mm) and the right pupil was slightly slowly reactive to light. The other cranial nerves were preserved normally. These findings were consistent with the diagnosis of right ONP. Gait was normal, with no evidence of muscle weakness, ataxia, or sensory disturbances. Deep-tendon reflexes are normally elicitable.
Figure 1. Eye movement of the patient demonstrating right oculomotor nerve palsy.

( A) Mild blepharoptosis, limitation of adduction and vertical gaze on the right side on day 30. ( B) The limitation of adduction and vertical gaze improved and ptosis completely resolved after IVIG treatment (day 52). ( C) He completely recovered on day 71.
Diagnostic assessment, therapeutic intervention, follow-up, and outcomes
Routine hematological and biochemical analyses, including thyroid function, were normal except for the elevation in glucose concentration 162 mg/dL (normal range: 78–109 mg/dL) and HbA1c level 7.8% (normal range: 4.6–6.2%). Serological tests identified the presence of anti-GQ1b IgG antibody (1.82, normal cut-off index <1), a pathognomonic marker for MFS. Other antibodies against glycoconjugates, including ganglioside GM1, antinuclear antibodies, perinuclear antineutrophil cytoplasmic antibody (ANCA), cytoplasmic ANCA, and acetylcholine receptor antibodies were negative. Cerebrospinal fluid showed mild albuminocytologic dissociation with protein levels of 52 mg/dL (normal range: 10–40 mg/dL) and 2 mononuclear cells/mm 3 (normal range: 0–5 cells/mm 3). Oligoclonal bands were negative and myelin basic protein was less than 31.3 pg/mL (normal range: < 102 pg/mL). High-resolution, constructive interference in steady-state magnetic resonance imaging (CISS-MRI) showed swelling with gadolinium enhancement in the right cavernous segment of the oculomotor nerve ( Figure 2), but no signs of aneurysm, tumor, and inflammation in the cavernous sinus and orbital apex were noted. A nerve conduction study in the limbs was normal.
Figure 2. Contrast-enhanced CISS-MRI demonstrates the swelling and enhancement in the right oculomotor nerve (indicated by white dotted lines).

Based on these clinical and laboratory findings, we diagnosed the patient with isolated, unilateral ONP associated with anti-GQ1b antibody and administered intravenous immunoglobulin (IVIG, 400 mg/kg) for consecutive 5 days. On the fourth day of IVIG administration (day 36), the limitation of the vertical gaze and ptosis mildly improved. There were no adverse events during or after the IVIG treatment. The patient was discharged on day 40 and was followed up at an outpatient clinic on day 52. The limitation of the adduction and vertical gaze markedly improved and ptosis completely resolved on day 52 ( Figure 1B). The patient also noticed an improvement in his diplopia. He completely recovered on day 71 ( Figure 1 C). The patient was afraid of receiving further vaccinations, including the COVID-19 vaccine. We explained to him that the incidence of GBS and MFS caused by vaccinations are extremely rare and the causal link between neurological complication and COVID-19 vaccinations is still unclear. It is undoubtedly true that benefits of vaccination outweigh the risks and the truth of the matter is that rare side effects shouldn't rule out vaccines. If he is going to be vaccinated in the future, we will carefully watch his condition and seek medical attention as soon as possible if he experiences any complications.
Discussion
We report the first case of isolated unilateral ONP with anti-GQ1b antibody following COVID-19 vaccination. Clinically, there were many similarities between our case and the previous four cases of unilateral ONP with anti-GQ1b antibody ( Table 1) 17– 19 . First, all cases, including ours, had ptosis without ataxia, and three cases showed normal deep tendon reflexes. Second, three patients demonstrated albuminocytologic dissociation in the CSF. Third, all of the cases showed a normal pattern in the nerve conduction studies. Finally, four patients were successfully treated with IVIG and/or steroids, with different recovery periods ranging from 22 days to 6 months 17– 19 . From an etiopathological point of view, two cases of isolated ONP with anti-GQ1b antibody were preceded by acute upper respiratory tract infection or gastroenteritis within two weeks of onset 18, 19 . On the other hand, there have been no case reports of vaccine-induced, isolated ONP with anti-GQ1b antibody. Similar to GBS, the majority of MFS and other anti-GQ1b antibody-associated disorders showed a good response to immunotherapy, such as IVIG and plasmapheresis. However, if ONP is the sole manifestation of anti-GQ1b antibody syndrome, it can be difficult to diagnose, leading to a substantial therapeutic delay.
Table 1. Summary of previous reports and present case.
| Author and year | Lee 2008 | Lee 2008 | Ichikawa 2002 | Ueno 2017 | Present case |
| Age (year) | 27 | 30 | 47 | 68 | 65 |
| Sex | Female | Male | Male | Male | Male |
|
Preceding
vaccination |
(-) | (-) | (-) | (-) | COVID-19 (Pfizer) |
| Preceding infection | Gastroenteritis | URI | URI | Gastroenteritis | (-) |
|
Time between
preceding event and onset |
NA | NA | 14 days | 8 days | 17 days |
| Affected eye side | Right | Right | Left | Right | Right |
| Ptosis | (-) | (+) | (+) | (+) | (+) |
| Gage limitation | Vertical | Adduction and vertical | Adduction and vertical | Adduction and vertical | Adduction and vertical |
| Ataxia | (-) | (-) | (-) | (-) | (-) |
| Deep tendon reflex | Normal | Decreased | Normal | Decreased | Normal |
| CSF | Normal | Albuminocytologic
dissociation |
Albuminocytologic
dissociation |
Normal | Albuminocytologic
dissociation |
| NCS | Normal | Normal | Normal | Normal | Normal |
|
Contrast-enhanced
MRI |
NA | NA | NA | NA | Enhancement in
oculomotor nerve |
| Treatment | IVIG or Steroid | IVIG or Steroid | IVIG and Steroid | No | IVIG |
| Recovery period | Follow up loss | 6 months | 28 days | 44 days | 36 days (mild
improvement) |
URI, upper respiratory infection; CSF, cerebrospinal fluid; NCS, Nerve conduction study; MRI, magnetic resonance imaging; NA, Not available; IVIG, intravenous immunoglobulin.
A growing concern among recent coronavirus vaccines is vaccine-related side effects. The most commonly observed adverse events with COVID-19 vaccines are fatigue, headache, muscle and joint pain, fever, pain at the site of injection, and to a much lesser degree, severe allergic reactions including anaphylaxis. The occurrence of these side effects can be predicted based on what is already known about the clinical trials of other vaccines. While not all reported side effects are directly related to vaccine administration, life-threatening side effects such as thromboembolism and neurological complications, including GBS, have also been reported following COVID-19 vaccines. In the United States, as of July 13, 2021 there were 100 preliminary reports of GBS after receiving the Janssen COVID-19 vaccine and 1 death after 12.5 million vaccine doses administered. GBS usually develops 3–22 days after the administration of COVID-19 vaccines 10– 16 . Although MFS following COVID-19 vaccination has not been reported so far, MFS can be observed from 5 to 21 days after immunization with influenza 7– 9 , pneumovax 9 , and DPT vaccines 6 . Similarly, our case also presented with unilateral ONP with elevated anti-GQ1b antibody 17 days after Pfizer-BioNTech COVID-19 (BNT162b2) vaccination without any preceding infection. Based on the temporal sequence of disease progression, laboratory findings, and a favorable response to immunotherapy, the possibility that preceding COVID-19 vaccination may provoke unfavorable immune responses, leading to ONP in our patient, cannot be ruled out. BNT162b2 vaccine of messenger RNA enter the body and export spike proteins on the cell, which provoke the production of antibodies and T cell reactions 20 . These immunological alterations may produce neutralizing antibodies as well as anti-GQ1b antibody, thereby leading to unfavorable neurological complications.
It should be noted that ONP is the most common cranial neuropathy in patients with diabetes 21 . Diabetes not only causes ischemic neuropathy, but also induces chronic low-level inflammation in peripheral nerves through the elevation of various inflammatory markers such as C-reactive protein, tumor necrosis factor, and interleukin-6 21 . Thus, one can imagine that the pre-existing diabetes in our case might impair oculomotor nerve function, thereby aggravating demyelinating oculomotor damage by the anti-GQ1b antibody. Indeed, diabetes has been reported as a risk factor for the exacerbation and poor outcomes of GBS 22– 24 .
Conclusion
Unilateral, isolated ONP with anti-GQ1b antibody was observed following COVID-19 vaccination. Insufficient recognition of this treatable condition often leads to misdiagnosis, which delays the receipt of adequate immunomodulatory therapy. Physicians should consider this rare clinical entity, even when the classical triad of MFS is absent. While the benefits of COVID-19 vaccination substantially outweigh the rare, possible adverse events, healthcare professionals should carefully monitor the hazardous effects of all COVID-19 vaccines and continue to work closely to manage potential risks and to harness science and big data to drive feedback and recommendations.
Consent
Written informed consent was obtained from the patient for the publication of this case report and any associated images.
Data availability
All data underlying the results are available as part of the article and no additional source data are required.
Acknowledgments
We thank all the neurology medical wards and department staff of Tohoku University Hospital.
Funding Statement
The author(s) declared that no grants were involved in supporting this work.
[version 2; peer review: 2 approved]
References
- 1. Raza HK, Chen H, Chansysouphanthong T, et al. : The aetiologies of the unilateral oculomotor nerve palsy: a review of the literature. Somatosens Mot Res. 2018;35(3–4):229–239. 10.1080/08990220.2018.1547697 [DOI] [PubMed] [Google Scholar]
- 2. Chiba A, Kusunoki S, Shimizu T, et al. : Serum IgG antibody to ganglioside GQ1b is a possible marker of Miller Fisher syndrome. Ann Neurol. 1992;31(6):677–679. 10.1002/ana.410310619 [DOI] [PubMed] [Google Scholar]
- 3. Fisher M: An unusual variant of acute idiopathic polyneuritis (syndrome of ophthalmoplegia, ataxia and areflexia). N Engl J Med. 1956;255(2):57–65. 10.1056/NEJM195607122550201 [DOI] [PubMed] [Google Scholar]
- 4. Willison HJ, Veitch J, Paterson G, et al. : Miller Fisher syndrome is associated with serum antibodies to GQ1b ganglioside. J Neurol Neurosurg Psychiatry. 1993;56(2):204–206. 10.1136/jnnp.56.2.204 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Panda S, Tripathi M, Odaka M, et al. : Anti-GQ1b IgG antibody syndrome: clinical and immunological range. J Neurol Neurosurg Psychiatry. 2002;72(3):418–419. 10.1136/jnnp.72.3.418 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. Krämer HH, Niemöller U, Döring K, et al. : Postvaccination Miller Fisher syndrome after combined pertussis, diphtheria and tetanus toxoid vaccine. J Infect. 2013;66(5):460–461. 10.1016/j.jinf.2012.11.014 [DOI] [PubMed] [Google Scholar]
- 7. Shoamanesh A, Chapman K, Traboulsee A: Postvaccination Miller Fisher syndrome. Arch Neurol. 2011;68(10):1327–9. 10.1001/archneurol.2011.236 [DOI] [PubMed] [Google Scholar]
- 8. Blanco-Marchite CI, Buznego-Suárez L, Fagúndez-Vargas MA, et al. : [Miller Fisher syndrome, internal and external ophthalmoplegia after flu vaccination]. Arch Soc Esp Oftalmol. 2008;83(7):433–435. 10.4321/s0365-66912008000700008 [DOI] [PubMed] [Google Scholar]
- 9. Thaler A: Miller Fisher syndrome in a 66-year-old female after flu and pneumovax vaccinations. J Am Med Dir Assoc. 2008;9(4):283–4. 10.1016/j.jamda.2008.01.013 [DOI] [PubMed] [Google Scholar]
- 10. Trimboli M, Zoleo P, Gennarina A, et al. : Guillain-Barré syndrome following BNT162b2 COVID-19 vaccine. Neurol Sci. 2021;42(11):4401–4402. 10.1007/s10072-021-05523-5 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11. Waheed S, Bayas A, Hindi F, et al. : Neurological Complications of COVID-19: Guillain-Barre Syndrome Following Pfizer COVID-19 Vaccine. Cureus. 2021;13(2):2–5. 10.7759/cureus.13426 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12. Razok A, Shams A, Almeer A, et al. : Post-COVID-19 vaccine Guillain-Barré syndrome; first reported case from Qatar. Ann Med Surg (Lond). 2021;67:102540. 10.1016/j.amsu.2021.102540 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13. Min YG, Ju W, Ha YE, et al. : Sensory Guillain-Barre syndrome following the ChAdOx1 nCov-19 vaccine: Report of two cases and review of literature. J Neuroimmunol. 2021;359:577691. 10.1016/j.jneuroim.2021.577691 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14. Introna A, Caputo F, Santoro C, et al. : Guillain-Barré syndrome after AstraZeneca COVID-19-vaccination: A causal or casual association? Clin Neurol Neurosurg. 2021;208:106887. 10.1016/j.clineuro.2021.106887 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15. McKean N, Chircop C: Guillain-Barré syndrome after COVID-19 vaccination. BMJ Case Rep. 2021;14(7):e244125. 10.1136/bcr-2021-244125 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16. Chan M, Han SC, Kelly S, et al. : A case series of Guillain-Barré Syndrome following Covid-19 infection in New York. Neurol Clin Pract. 2021;11(4):e576–e578. 10.1212/cpj.0000000000000880 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17. Lee SH, Lim GH, Kim JS, et al. : Acute ophthalmoplegia (without ataxia) associated with anti-GQ1b antibody. Neurology. 2008;71(6):426–429. 10.1212/01.wnl.0000324266.95814.74 [DOI] [PubMed] [Google Scholar]
- 18. Ichikawa H, Kamiya Y, Susuki K, et al. : Unilateral oculomotor nerve palsy associated with anti-GQ1b IgG antibody. Neurology. 2002;59(6):957–958. 10.1212/wnl.59.6.957 [DOI] [PubMed] [Google Scholar]
- 19. Ueno T, Kon T, Kurihara AI, et al. : Unilateral oculomotor nerve palsy following campylobacter infection: A mild form of miller fisher syndrome without ataxia. Intern Med. 2017;56(21):2929–2932. 10.2169/internalmedicine.8824-17 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20. Sahin U, Muik A, Derhovanessian E, et al. : COVID-19 vaccine BNT162b1 elicits human antibody and T H1 T cell responses. Nature. 2020;586(7830):594–599. 10.1038/s41586-020-2814-7 [DOI] [PubMed] [Google Scholar]
- 21. Hartge MM, Unger T, Kintscher U: The endothelium and vascular inflammation in diabetes. Diab Vasc Dis Res. 2007;4(2):84–88. 10.3132/dvdr.2007.025 [DOI] [PubMed] [Google Scholar]
- 22. Peric S, Bozovic I, Bjelica B, et al. : Diabetes mellitus may affect short-term outcome of Guillain-Barré syndrome. J Peripher Nerv Syst. 2017;22(2):127–130. 10.1111/jns.12206 [DOI] [PubMed] [Google Scholar]
- 23. Zhang Y, Zhao Y, Wang Y: Prognostic factors of Guillain-Barré syndrome: a 111-case retrospective review. Chin Neurosurg J. 2018;4:14. 10.1186/s41016-018-0122-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24. Bae JS, Kim YJ, Kim JK: Diabetes mellitus exacerbates the clinical and electrophysiological features of Guillain-Barré syndrome. Eur J Neurol. 2016;23(3):439–446. 10.1111/ene.12885 [DOI] [PubMed] [Google Scholar]
