ABSTRACT
Objective: The last retrospective systematic review on Miller Fisher syndrome (MFS) took place in 1992. To understand the evolving nature of the disease and to update the clinical picture, diagnostic testing, treatment, and prognosis, a retrospective systematic review of 174 cases of MFS published in the last three decades was performed. Method(s): We screened 1034 articles on the PUBMED search engine. Out of these articles, 153 met the inclusion criteria of case reports/series published in English after 1992. Each case contained at least two signs of the triad, with the presence or absence of GQ1B antibodies. The Chi-square test or Fisher's exact test was used for data analysis. Assessing the Methodological Quality of Systematic Reviews (AMSTAR 2) was used to assess the quality of the systematic reviews. Finding(s): 174 cases were included, with five case series. Sinopulmonary infection (60%) and gastrointestinal infection (18%) were the most common preceding illnesses, while eight cases occurred after the onset of a COVID-19 infection, and seven had recent exposure to monoclonal antibodies. We found that misdiagnosis was seen in 13.8% of cases, stroke being the most common misnomer. Residual symptoms were reported in 30% of cases, death in three and recurrence in twelve. IVIG was the most frequently used treatment option (51.1%). Severity score was significantly associated with treatment (p=0.0195);however, it was not associated with age (p=0.4255), gender (p=0.7893), GQ1b antibody presence/level (p=0.3870/ p=0.6891), or non-GQ1B (p=0.5426) status. The outcome with residual symptoms was favorable for younger patients (Age 1-18: p=0.0223) and not associated with treatment. Mechanical ventilation (13.8%), feeding tube placement (9.8%), autonomic insufficiency (8.6%), and a patient requiring a cardiac pacemaker were the top three complications. Conclusion(s): Physicians should recognize the protean clinical manifestation of MFS and recognize the various recent preceding factors like COVID-19 and monoclonal antibodies. The benefit provided by the treatment is unclear. Therefore, further studies will be required to identify patients who should be treated and the appropriate treatment to maximize patient outcomes.