The spectrum of anti-GQ1B antibody syndrome: beyond Miller Fisher syndrome and Bickerstaff brainstem encephalitis.

INTRODUCTION: Since the initial identification of Miller Fisher syndrome (MFS) and Bickerstaff brainstem encephalitis (BBE),significant milestones have been achieved in understanding these diseases.Discoveries of common serum antibodies (IgG anti-GQ1b), antecedent infections, neurophysiological data, andneuroimaging suggested a shared autoimmune pathogenetic mechanism rather than distinct pathogenesis, leadingto the hypothesis that both diseases are part of a unified syndrome, termed "Fisher-Bickerstaff syndrome". The subsequent identification of atypical anti-GQ1b-positive forms expanded the classification to a broader condition known as "Anti-GQ1b-Antibody syndrome". METHODS: An exhaustive literature review was conducted, analyzing a substantial body of research spanning from the initialdescriptions of the syndrome's components to recent developments in diagnostic classification and researchperspectives. RESULTS: Anti-GQ1b syndrome encompasses a continuous spectrum of conditions defined by a common serological profilewith varying degrees of peripheral (PNS) and central nervous system (CNS) involvement. MFS and BBE represent theopposite ends of this spectrum, with MFS primarily affecting the PNS and BBE predominantly involving the CNS.Recently identified atypical forms, such as acute ophthalmoparesis, acute ataxic neuropathy withoutophthalmoparesis, Guillain-Barré syndrome (GBS) with ophthalmoparesis, MFS-GBS and BBE-GBS overlap syndromes,have broadened this spectrum. CONCLUSION: This work aims to provide an extensive, detailed, and updated overview of all aspects of the anti-GQ1b syndromewith the intention of serving as a stepping stone for further shaping thereof. Special attention was given to therecently identified atypical forms, underscoring their significance in redefining the boundaries of the syndrome.

Navigating the complexity of Guillain-Barré syndrome and Miller-Fisher syndrome overlap syndrome: a pediatric case report.

Guillain-Barré syndrome/Miller-Fisher syndrome (GBS/MFS) overlap syndrome is an extremely rare variant of Guillain-Barré syndrome (GBS) in which Miller-Fisher syndrome (MFS) coexists with other characteristics of GBS, such as limb weakness, paresthesia, and facial paralysis. We report the clinical case of a 12-year-old patient, with no pathological history, who acutely presents with ophthalmoplegia, areflexia, facial diplegia, and swallowing and phonation disorders, followed by progressive, descending, and symmetrical paresis affecting first the upper limbs and then the lower limbs. An albuminocytological dissociation was found in the cerebrospinal fluid study. Magnetic resonance imaging of the spinal cord showed enhancement and thickening of the cauda equina roots. The patient was treated with immunoglobulins with a favorable clinical outcome.

Clinical, paraclinical and outcome features of 166 patients with acute anti-GQ1b antibody syndrome.

BACKGROUND & PURPOSE: In this retrospective study, we aimed at defining the clinical, paraclinical and outcome features of acute neurological syndromes associated with anti-GQ1b antibodies. RESULTS: We identified 166 patients with neurological symptoms appearing in less than 1 month and anti-GQ1b antibodies in serum between 2012 and 2022. Half were female (51%), mean age was 50 years (4-90), and the most frequent clinical features were areflexia (80% of patients), distal upper and lower limbs sensory symptoms (78%), ophthalmoplegia (68%), sensory ataxia (67%), limb muscle weakness (45%) and bulbar weakness (45%). Fifty-three patients (32%) presented with complete (21%) and incomplete (11%) Miller Fisher syndrome (MFS), thirty-six (22%) with Guillain-Barre syndrome (GBS), one (0.6%) with Bickerstaff encephalitis (BE), and seventy-three (44%) with mixed MFS, GBS & BE clinical features. Nerve conduction studies were normal in 46% of cases, showed demyelination in 28%, and axonal loss in 23%. Anti-GT1a antibodies were found in 56% of cases, increased cerebrospinal fluid protein content in 24%, and Campylobacter jejuni infection in 7%. Most patients (83%) were treated with intravenous immunoglobulins, and neurological recovery was complete in 69% of cases at 1 year follow-up. One patient died, and 15% of patients relapsed. Age > 70 years, initial Intensive Care Unit (ICU) admission, and absent anti-GQ1b IgG antibodies were predictors of incomplete recovery at 12 months. No predictors of relapse were identified. CONCLUSION: This study from Western Europe shows acute anti-GQ1b antibody syndrome presents with a large clinical phenotype, a good outcome in 2/3 of cases, and frequent relapses.

Effect of the Task Approach, Airway Clearance, Kinesthetic Exercise (TASKS) Paediatric Rehabilitation Protocol on Miller-Fisher Syndrome Variant of Guillain-Barré Syndrome: A Case Report.

Miller-Fisher syndrome (MFS) is a rare variant of Guillain-Barré syndrome (GBS) with varying incidence rates geographically. MFS is primarily diagnosed based on clinical features, such as ataxia and areflexia, although other neurological symptoms may also present. A case of MFS has been presented, characterized by complaints of ataxia, areflexia, bilateral foot and hand pain and difficulty in swallowing. In this regard, a paediatric rehabilitation approach has been adopted, utilizing outcome measures, such as the Erasmus Guillain-Barre Syndrome Respiratory Insufficiency Score-Kids, WeeFIM and paediatric balance scale, in addition to clinical evaluation. It is worth noting that the presented case demonstrates the importance of accurately diagnosing and treating this rare neurological condition MFS. Through the implementation of appropriate rehabilitation strategies, it is possible to enhance patients' quality of life.

Anti-sulfatide antibody-related Guillain-Barré syndrome presenting with overlapping syndromes or severe pyramidal tract damage: a case report and literature review.

Introduction: Anti-sulfatide antibodies are key biomarkers for the diagnosis of Guillain-Barré syndrome (GBS). However, case reports on anti-sulfatide antibody-related GBS are rare, particularly for atypical cases. Case description case 1: A 63 years-old man presented with limb numbness and diplopia persisting for 2 weeks, with marked deterioration over the previous 4 days. His medical history included cerebral infarction, diabetes, and coronary atherosclerotic cardiomyopathy. Physical examination revealed limited movement in his left eye and diminished sensation in his extremities. Initial treatments included antiplatelet agents, cholesterol-lowering drugs, hypoglycemic agents, and medications to improve cerebral circulation. Despite this, his condition worsened, resulting in bilateral facial paralysis, delirium, ataxia, and decreased lower limb muscle strength. Treatment with intravenous high-dose immunoglobulin and dexamethasone resulted in gradual improvement. A 1 month follow-up revealed significant neurological sequelae. Case description case 2: A 53 years-old woman was admitted for adenomyosis and subsequently experienced sudden limb weakness, numbness, and pain that progressively worsened, presenting with diminished sensation and muscle strength in all limbs. High-dose intravenous immunoglobulin, vitamin B1, and mecobalamin were administered. At the 1 month follow-up, the patient still experienced limb numbness and difficulty walking. In both patients, albuminocytologic dissociation was found on cerebrospinal fluid (CSF) analysis, positive anti-sulfatide antibodies were detected in the CSF, and electromyography indicated peripheral nerve damage. Conclusion: Anti-sulfatide antibody-related GBS can present with Miller-Fisher syndrome, brainstem encephalitis, or a combination of the two, along with severe pyramidal tract damage and residual neurological sequelae, thereby expanding the clinical profile of this GBS subtype. Anti-sulfatide antibodies are a crucial diagnostic biomarker. Further exploration of the pathophysiological mechanisms is necessary for precise treatment and improved prognosis.

Effectiveness of Symptomatic Physiotherapy in Enhancing the Psychological Parameters of a Patient With Guillain-Barré Syndrome: A Case Report.

Guillain-Barré syndrome is a polyneuropathy that can be caused by an autoimmune condition or a bacterial infection. In typical GBS cases, there is hypo- or areflexia, symmetrical limb weakness that worsens within four weeks of the symptoms. The facial nerve is involved in this situation, which results in weak facial muscles, which, in turn, affect facial emotions and movements. In this case study, a 21-year-old athlete who suffered from unexpected weakness that resulted in quadriplegia had goal-oriented physical therapy treatment designed for the patient, who recovered quickly. This case study aims to emphasize how goal-oriented physical therapy treatment can help patients recover quickly.

Rehabilitation of a 51-Year-Old Patient With Miller Fisher Syndrome: A Case Report.

Miller Fisher syndrome is a rare and atypical variation of Guillain-Barré syndrome, which includes the clinical triad of areflexia, ataxia, and ophthalmoplegia. Miller Fisher syndrome is commonly associated with the involvement of the lower cranial and facial nerves. Miller Fisher syndrome is one of the types of Guillain-Barré syndrome. Guillain-Barré syndrome has been defined to be the foremost incapacitating form of neurological disease following the disease polio. Guillain-Barré syndrome is a broad category that encompasses several types of acute immune-mediated polyneuropathies, the most common of which is acute inflammatory demyelinating polyradiculoneuropathy. Here, we describe a case report of a 51-year-old patient who displayed the characteristic symptoms of Miller Fisher syndrome. We also describe the patient's clinical course, diagnostic method, and therapy. This case demonstrates the value of early detection, quick action in treating Miller Fisher syndrome, and the possibility of full recovery with adequate therapy. Techniques utilized in physical therapy emphasize performing everyday tasks along with strengthening muscles.

Miller-Fisher Syndrome Following Influenza A Infection.

Miller-Fisher syndrome (MFS), characterized by ophthalmoplegia, ataxia, and areflexia, is a Guillain-Barré syndrome (GBS) variant. It is well-known that the causative antibody for MFS is anti-GQ1b antibody. This report describes a rare case of MFS with not only anti-GQ1b antibodies but also anti-GT1a antibodies following Influenza A infection. The patient, a 47-year-old woman, contracted Influenza A three weeks before admission. She complained of double vision followed by areflexia, ataxia in the four extremities, and complete gaze palsy. She was treated with intravenous methylprednisolone pulse and intravenous immunoglobulin therapies. Her neurological symptoms were recovered after these immunotherapies.

Bickerstaff's Brainstem Encephalitis and Miller Fisher Syndrome: A Rare Overlap.

A rare illness known as "Bickerstaff's brainstem encephalitis" (BBE) is characterized by an abrupt brainstem dysfunction and includes the triad of diminished consciousness, ataxia, and ophthalmoplegia. It differs from the Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS) by involving the central nervous system (CNS) and frequently manifesting as reduced consciousness. Here, we describe a rare instance of Bickerstaff's encephalitis coexisting with MFS, where the patient had rapidly progressing quadriplegia, VII cranial nerve palsy, and episodes of unconsciousness.

Evaluating yield and utilization of ganglioside antibody testing in clinical practice.

BACKGROUND AND OBJECTIVES: Ganglioside antibodies can help diagnose distinct acute and chronic inflammatory neuropathies including axonal variants of Guillain-Barre syndrome, Miller-Fisher syndrome (MFS), multifocal motor neuropathy, and chronic sensory ataxic neuropathies. Because ganglioside antibody testing may be routinely ordered in patients with suspected inflammatory neuropathy, we sought to evaluate its yield and utilization in clinical practice. METHODS: We performed a retrospective chart review of all patients at London Health Sciences Centre who underwent ganglioside antibody testing between April 2019 and August 2023. The disease phenotype was determined for each patient, and the proportion of all tests that yielded a true-positive result was calculated. Ganglioside antibody positivity was classified as a true-positive result if the disease phenotype was robustly associated with the detected ganglioside antibody and there was no other more likely diagnosis. RESULTS: We identified 92 patients who underwent ganglioside antibody testing. One patient (1%) was classified as having a true-positive result; this patient had GQ1b-IgG positivity with MFS. Among 92 patients tested, 20 patients (22%) had a disease phenotype that was considered to be robustly associated with ganglioside antibody positivity. CONCLUSIONS: The yield of ganglioside antibody testing in clinical practice is low. We found that this testing is frequently ordered in patients with disease phenotypes that are not robustly associated with ganglioside antibody positivity, indicating that suboptimal test utilization is a primary contributor to its low yield. Restricting ganglioside antibody testing to patients with characteristic disease phenotypes would be valuable to improving yield and utilization of this testing.

Only anti-GM4 antibody positivity in a Chinese girl with overlapping MFS/GBS: a case report.

BACKGROUND: Guillain-Barré syndrome (GBS), as the most common cause of acute flaccid paralysis worldwide, is considered a part of a clinical spectrum in which discrete, complete, or incomplete forms of GBS and overlapping syndromes lie on the basis of their clinical features. The term overlapping Miller Fisher syndrome (MFS)/GBS is used when patients with MFS also suffer from progressive motor weakness of the limbs. Anti-ganglioside GQ1b has been specifically associated with MFS and ophthalmoplegia. CASE DESCRIPTION: Here, we report a Chinese girl who was diagnosed with overlapping MFS/GBS showing acute flaccid paralysis of all four limbs, sensory symptoms, cranial nerve dysfunction, autonomic involvement, ophthalmoplegia, and ataxia. She had high serum and cerebrospinal fluid titres of monospecific anti-GM4 IgG antibody instead of anti-GQ1b antibody in the acute phase. CONCLUSION: Anti-GM4 antibodies usually coexist with other antiganglioside antibodies, leading to missed diagnoses. The findings of the present study show that antibodies to ganglioside GM4 may in overlapping MFS/GBS as the lone immunological factors.

Retrospective analysis of COVID-19 patients with Guillain-Barre, Miller-Fisher, and opsoclonus-myoclonus-ataxia syndromes-a case series.

BACKGROUND: In accordance with the rising number of SARS-CoV­2 infections, reports of neurological complications have also increased. They include cerebrovascular diseases but also immunological diseases such as Guillain-Barre syndrome (GBS), Miller-Fisher syndrome (MFS), and opsoclonus-myoclonus-ataxia syndrome (OMAS). While GBS and MFS are typical postinfectious complications, OMAS has only recently been described in the context of COVID-19. GBS, MFS, and OMAS can occur as para- and postinfectious, with different underlying pathomechanisms depending on the time of neurological symptom onset. The study aimed to describe clinical features, time between infection and onset of neurological symptoms, and outcome for these diseases. METHODS: All COVID-19 patients treated in the neurological ward between January 2020 and December 2022 were screened for GBS, MFS, and OMAS. The clinical features of all patients, with a particular focus on the time of onset of neurological symptoms, were analyzed. RESULTS: This case series included 12 patients (7 GBS, 2 MFS, 3 OMAS). All GBS and one MFS patient received immunomodulatory treatment. Three patients (2 GBS, 1 OMAS) had a severe COVID-19 infection and received mechanical ventilation. In patients with OMAS, only one patient received treatment with intravenous immunoglobulin and cortisone. The remaining two patients, both with disease onset concurrent with SARS-COV­2 infection, recovered swiftly without treatment. In all subgroups, patients with concurrent onset of neurological symptoms and COVID-19 infection showed a trend toward shorter disease duration. CONCLUSION: All patient groups displayed a shorter disease duration if the onset of neurological symptoms occurred shortly after the COVID-19 diagnosis. In particular, both the OMAS patients with symptom onset concurrent with COVID-19 showed only abortive symptoms followed by a swift recovery. This observation would suggest different pathomechanisms for immune-mediated diseases depending on the time of onset after an infection.

Relation between Guillain-Barré syndrome and Covid-19: Case-Series.

Approximately two-thirds of the Guillain-Barré syndrome (GBS) cases are preceded by upper respiratory tract infection or enteritis. There has been previous documentation of a clear association between Covid-19 and GBS. Covid-19 can affect the nervous tissue either through direct damage or through triggering a host immune response with subsequent development of autoimmune diseases such as GBS. Covid-19 can affect the host`s immune system through the activation and interaction of the T-and B-lymphocytes with subsequent production of antibodies that cross-react with the gangliosides. Depending on the nature of the neuronal autoimmune destruction, the affected individual may have either a demyelinating or axonal subtype of GBS. These subtypes differ not only in symptoms but also in the likelihood of recovery. This report presents two cases of GBS that developed after the respiratory symptoms of Covid-19. Their neurological features indicated demyelination, axonal damage, irritation of spinal nerve roots, and impaired sensory and motor transmission with additional facial nerve palsy in the second-studied case. This case report highlights the relationship between GBS and Covid-19 infection.

Miller-Fisher Syndrome Unveiled in the Presence of Cholangiocarcinoma.

Miller-Fisher syndrome (MFS) is a rare variant of Guillain-Barré syndrome, characterized by ataxia, areflexia, ophthalmoplegia, and possible facial, swallowing and limb weakness alongside respiratory failure. Variations within MFS may include respiratory and limb weakness and Bickerstaff brainstem encephalitis (BBE), marked by altered consciousness, ataxia, ophthalmoparesis, and paradoxical hyperreflexia. MFS can emerge in both children and adults, often following bacterial or viral illness. While autoimmune-driven nerve damage occurs, most MFS patients recover within six months without specific treatment, with a low risk of lasting neurological deficits or relapses. Rarely fatal, MFS's co-occurrence with cholangiocarcinoma (CCA) presents unique management challenges. CCA, primarily affecting bile ducts, has a bleak prognosis; surgical resection offers limited cure potential due to late-stage detection and high recurrence rates. Advances in CCA's molecular understanding have led to novel diagnostic and therapeutic approaches, requiring a comprehensive interdisciplinary care approach for optimal MFS and CCA management outcomes. Herein, we present a 50-year-old male with a complex medical history who was admitted to the hospital due to abdominal discomfort, nausea, vomiting, and ascites. Imaging revealed pneumonia and secondary bacterial peritonitis. Later, he developed neurological symptoms, including weakness, gait abnormalities, and brainstem symptoms, leading to the diagnosis of MFS. Despite treatment efforts, his condition deteriorated, leading to acute liver failure and unexplained anasarca. N-acetyl cysteine was initiated for liver issues. Neurologically, he showed quadriparesis and areflexia. Intravenous immunoglobulin (IVIG) treatment improved his neurological symptoms but worsened gastrointestinal issues, including ileus and elevated CA19-9 levels, suggesting a potential carcinoma. A liver biopsy was performed. After IVIG treatment, he experienced widespread discomfort, emotional unresponsiveness, swallowing difficulties, and aspiration risk, ultimately leading to his demise.

Miller-Fisher Syndrome With Initial Manifestation of Rhinolalia Aperta: A Case Report and Literature Review.

Rhinolalia aperta (hypernasal speech) is rarely reported in patients with Miller-Fisher syndrome (MFS). Here, we report a patient with MFS who presented with rhinolalia aperta. A 35-year-old man with a history of alcohol abuse and hepatic cirrhosis presented with a three-day acute hypernasal voice change and numbness of both hands/thighs. After admission, the exam also revealed palatal hypomobility, decreased bilateral hand/thigh sensation, ataxic gait, dysmetria, areflexia, and bilateral abducens palsy. Serum immunoglobulin G (IgG) anti-GQ1b antibody titer was elevated (1:6400). A five-day intravenous IgG was administered with a robust clinical response. Oropharyngeal involvement in MFS can initially manifest with isolated hypernasal speech.

Emerging biomarkers to predict clinical outcomes in Guillain-Barré syndrome.

INTRODUCTION: Guillain-Barré syndrome (GBS) is an immune-mediated poly(radiculo)neuropathy with a variable clinical outcome. Identifying patients who are at risk of suffering from long-term disabilities is a great challenge. Biomarkers are useful to confirm diagnosis, monitor disease progression, and predict outcome. AREAS COVERED: The authors provide an overview of the diagnostic and prognostic biomarkers for GBS, which are useful for establishing early treatment strategies and follow-up care plans. EXPERT OPINION: Detecting patients at risk of developing a severe outcome may improve management of disease progression and limit potential complications. Several clinical factors are associated with poor prognosis: higher age, presence of diarrhea within 4 weeks of symptom onset, rapid and severe weakness progression, dysautonomia, decreased vital capacity and facial, bulbar, and neck weakness. Biological, neurophysiological and imaging measures of unfavorable outcome include multiple anti-ganglioside antibodies elevation, increased serum and CSF neurofilaments light (NfL) and heavy chain, decreased NfL CSF/serum ratio, hypoalbuminemia, nerve conduction study with early signs of demyelination or axonal loss and enlargement of nerve cross-sectional area on ultrasound. Depicting prognostic biomarkers aims at predicting short-term mortality and need for cardio-pulmonary support, long-term patient functional outcome, guiding treatment decisions and monitoring therapeutic responses in future clinical trials.

Clinical characteristics and prognosis of temporary miller fisher syndrome following COVID-19 vaccination: a systematic review of case studies.

BACKGROUND: Miller Fisher syndrome (MFS) is a subtype of Guillain-Barré syndrome (GBS) which is characterized by the three components of ophthalmoplegia, ataxia, and areflexia. Some studies reported MFS as an adverse effect of the COVID-19 vaccination. We aimed to have a detailed evaluation on demographic, clinical, and para-clinical characteristics of subjects with MFS after receiving COVID-19 vaccines. MATERIALS AND METHODS: A thorough search strategy was designed, and PubMed, Web of Science, and Embase were searched to find relevant articles. Each screening step was done by twice, and in case of disagreement, another author was consulted. Data on different characteristics of the patients and types of the vaccines were extracted. The risk of bias of the studies was assessed using Joanna Briggs Institute (JBI) tools. RESULTS: In this study, 15 patients were identified from 15 case studies. The median age of the patients was 64, ranging from 24 to 84 years. Ten patients (66.6%) were men and Pfizer made up 46.7% of the injected vaccines. The median time from vaccination to symptoms onset was 14 days and varied from 7 to 35 days. Furthermore,14 patients had ocular signs, and 78.3% (11/14) of ocular manifestations were bilateral. Among neurological conditions, other than MFS triad, facial weakness or facial nerve palsy was the most frequently reported side effect that was in seven (46.7%) subjects. Intravenous immunoglobulin (IVIg) was the most frequently used treatment (13/15, 86.7%). Six patients received 0.4 g/kg and the four had 2 g/kg. Patients stayed at the hospital from five to 51 days. No fatal outcomes were reported. Finally, 40.0% (4/15) of patients completely recovered, and the rest experienced improvement. CONCLUSION: MFS after COVID-19 immunization has favorable outcomes and good prognosis. However, long interval from disease presentation to treatment in some studies indicates that more attention should be paid to MFS as the adverse effect of the vaccination. Due to the challenging diagnosis, MFS must be considered in list of the differential diagnosis in patients with a history of recent COVID-19 vaccination and any of the ocular complaints, ataxia, or loss of reflexes, specially for male patients in their 60s and 70s.

Miller Fisher Syndrome Associated With COVID-19: A History of Molecular Mimicry and an Up-to-Date Review of the Literature.

Miller Fisher syndrome (MFS) was first recognized by Collier in 1932 as a clinical triad of ataxia, areflexia, and ophthalmoplegia. In 1956, three cases with this triad were published by Miller Fisher as a limited variant of Guillian-Barré syndrome (GBS), and the disease started to be called by his name. Since the beginning of the SARS-CoV-2 pandemic, there have been many reports of peripheral and central nervous system involvement. Until December 2022, a total of 24 cases, including four children associated with MFS, had been reported. This current review aimed to present the basic clinical and laboratory characteristics of patients with MFS and coronavirus disease-2019 (COVID-19). Since 2020, cases with different age and gender characteristics have been reported from eight different countries. Most cases were reported from Europe. SARS-CoV-2 infection was confirmed in seven of the cases. The youngest case reported was a 6-year-old boy from Turkey, while the oldest case was a 70-year-old female from Spain. All these reported cases and our past medical knowledge of MFS suggest that molecular mimicry is the main immunological mechanism. Despite all these data, more case reports, cohorts, and case-control studies will be needed to clarify the relationship between MFS and COVID-19.

Miller Fisher syndrome: an updated narrative review.

Introduction: Miller Fisher syndrome (MFS) is considered a rare variant of Guillain-Barré syndrome (GBS), a group of acute-onset immune-mediated neuropathies characterized by the classic triad of ataxia, areflexia, and ophthalmoparesis. The present review aimed to provide a detailed and updated profile of all aspects of the syndrome through a collection of published articles on the subject, ranging from the initial description to recent developments related to COVID-19. Methods: We searched PubMed, Scopus, EMBASE, and Web of Science databases and gray literature, including references from the identified studies, review studies, and conference abstracts on this topic. We used all MeSH terms pertaining to "Miller Fisher syndrome," "Miller Fisher," "Fisher syndrome," and "anti-GQ1b antibody." Results: An extensive bibliography was researched and summarized in the review from an initial profile of MFS since its description to the recent accounts of diagnosis in COVID-19 patients. MFS is an immune-mediated disease with onset most frequently following infection. Anti-ganglioside GQ1b antibodies, detected in ~85% of patients, play a role in the pathogenesis of the syndrome. There are usually no abnormalities in MFS through routine neuroimaging. In rare cases, neuroimaging shows nerve root enhancement and signs of the involvement of the central nervous system. The most consistent electrophysiological findings in MFS are reduced sensory nerve action potentials and absent H reflexes. Although MFS is generally self-limited and has excellent prognosis, rare recurrent forms have been documented. Conclusion: This article gives an updated narrative review of MFS with special emphasis on clinical characteristics, neurophysiology, treatment, and prognosis of MFS patients.