[Fisher Syndrome].

Fisher syndrome is recognized as a variant of Guillain-Barré syndrome, encompassing acute onset immune-mediated neuropathies marked by the classical triad of ataxia, areflexia, and ophthalmoplegia. Generally, Fisher syndrome follows a self-limited course with a good prognosis. Ophthalmoplegia, typically bilateral, progresses to complete external ophthalmoplegia within 1-2 weeks. Ataxia, often very severe, may cause an inability to walk without support despite normal strength. Fisher syndrome is also frequently concomitant with additional clinical features, including ptosis, internal ophthalmoplegia, facial nerve palsy, sensory deficits, and bulbar palsy. The confirmation of an antecedent infection is often established. Among the ganglioside antibodies, anti-GQ1b antibodies exhibit positivity in over 80% of patients. The syndrome manifests in three distinct types: a partial subtype exhibiting only a subset of the triad symptoms, Bickerstaff's brainstem encephalitis marked by impaired consciousness and pyramidal tract signs, and an overlapping subtype with Guillain-Barré syndrome, characterized by weakness in the extremities.

A case report of thrombocytopenic COVID-19 and Miller-Fisher syndrome on a concurrent chronic immune neuropathy.

RATIONALE: Miller-Fisher syndrome (MFS) is a rare subtype of Guillain-Barre syndrome with classic features of ataxia, areflexia, and ophthalmoplegia that can be caused by a preceding infection including COVID-19. We present a current, asymptomatic thrombocytopenic COVID-19 infection as a cause of MFS in a 60-year-old male with a concurrent chronic immune neuropathy. PATIENT CONCERNS: A 60-year-old male presenting with acute symptoms of MFS including ataxia, areflexia, and ophthalmoplegia on a chronic immune neuropathy for at least 1 year and concurrent asymptomatic COVID-19 positive infection. DIAGNOSIS: MFS suspected secondary to a current thrombocytopenic COVID-19 infection. INTERVENTIONS: Five days of intravenous immune globulin with continued monthly intravenous immune globulin as an outpatient, follow-up long-term in a neuromuscular clinic, electromyography as an outpatient, and continued physical therapy. OUTCOMES: The patient significantly improved after initial treatment. LESSONS: The full effect of COVID-19 on the various Guillain-Barre syndrome subtypes is unknown, although it clearly can be a cause of the various variants including being caused by a current, asymptomatic infection.

Antiganglioside antibody frequency in routine clinical care settings.

BACKGROUND AND PURPOSE: Antiganglioside antibodies (AGAs) might be involved in the etiopathogenesis of many neurological diseases, such as Miller-Fisher syndrome (MFS) and Guillain-Barré syndrome (GBS). Available comprehensive reference data regarding AGA positivity rates and cross-responsiveness among AGAs (where one line immunoblot is positive for ≥1 AGA) during routine clinical care are scant. METHODS: In this 10-year monocentric retrospective study, 3560 immunoglobulin (Ig) G and IgM line blots (GA Generic Assays' Anti-Ganglioside Dot kit) obtained using cerebrospinal fluid (CSF) and serum samples from 1342 patients were analyzed for AGA positivity in terms of 14 diagnosis categories and AGA cross-responsiveness. RESULTS: Of all 3560 line blots 158 (4.4%) and of all CSF samples 0.4% (4/924) CSF line blots were AGA positive. For serum IgG, blots with positivity rates higher than the standard deviation of 15.6% were associated with MFS (GD3, GD1a, GT1a and GQ1b) and acute motor axonal neuropathy (AMAN) (GM1, GD1a and GT1a). For serum IgM, blots with positivity rates higher than the standard deviation of 8.1% were associated with AMAN (GM2, GT1a and GQ1b), MFS (GM1, GT1a and GQ1b), multifocal motor neuropathy (MMN) (GM1, GM2 and GQ1b) and chronic inflammatory demyelinating polyneuropathy (CIDP) (GM1). Cross-responsiveness was observed in 39.6% of all positive serum AGA. CONCLUSIONS: Testing for AGAs during routine clinical care rarely led to positive findings, both in serum and even less in CSF, except for the diagnoses AMAN, MFS, MMN and CIDP. Nonspecific findings found as cross-responsiveness between different AGA samples occur frequently, impacting the positivity of most AGA subtypes.

A study on the role of serum uric acid in differentiating acute inflammatory demyelinating polyneuropathy from acute-onset chronic inflammatory demyelinating polyneuropathy.

BACKGROUND AND PURPOSE: Clinical symptoms and laboratory indices for acute inflammatory demyelinating polyneuropathy (AIDP), a variant of Guillain-Barré syndrome, and acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) were analyzed to identify factors that could contribute to early differential diagnosis. METHODS: A retrospective chart review was performed on 44 AIDP and 44 A-CIDP patients looking for any demographic characteristics, clinical manifestations or laboratory parameters that might differentiate AIDP from acutely presenting CIDP. RESULTS: In Guillain-Barré syndrome patients (N = 63), 69.84% (N = 44) were classified as having AIDP, 19.05% (N = 12) were found to have acute motor axonal neuropathy, 6.35% (N = 4) were found to have acute motor and sensory axonal neuropathy, and 4.76% (N = 3) were found to have Miller Fisher syndrome. Serum uric acid (UA) was higher in A-CIDP patients (329.55 ± 72.23 µmol/L) than in AIDP patients (221.08 ± 71.32 µmol/L) (p = 0.000). Receiver operating characteristic analyses indicated that the optimal UA cutoff was 283.50 µmol/L. Above this level, patients were more likely to present A-CIDP than AIDP (specificity 81.80%, sensitivity 81.80%). During the follow-up process, serum samples were effectively collected from 19 AIDP patients during the rehabilitation phase and 28 A-CIDP patients during the remission stage, and it was found that UA levels were significantly increased in A-CIDP (remission) (298.9 ± 90.39 µmol/L) compared with AIDP (rehabilitation) (220.1 ± 108.2 µmol/L, p = 0.009). CONCLUSION: These results suggest that serum UA level can help to differentiate AIDP from A-CIDP with high specificity and sensitivity, which is helpful for early diagnosis and guidance of treatment.

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.

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.

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.

Delayed onset Bickerstaff brainstem encephalitis overlapping Miller-Fisher Syndrome during SARS-CoV-2 infection.

Bickerstaff brainstem encephalitis (BBE) is a neuroimmunologic disease characterized by the acute onset of external ophthalmoplegia, ataxia, and consciousness disturbance, mostly subsequent to an infection. BBE is considered to be a variant of Miller-Fisher syndrome (MFS), which also exhibits external ophthalmoplegia and ataxia but not presenting consciousness alterations. Therefore, these two medical conditions are included in the clinical spectrum of the "Fisher-Bickerstaff syndrome" ( Shahrizaila and Yuki in J Neurol Neurosurg Psychiatry 84(5):576-583) [1]. With regard to the etiopathogenesis, increasing evidence worldwide suggests that SARS-CoV-2 infection-enhanced immune response is involved in a wide range of neurological complications such as Guillain-Barré syndrome (GBS), MFS, acute necrotizing encephalitis (ANE), myelitis, acute disseminated encephalomyelitis (ADEM), and, although very rarely, BBE either (Hosseini et al. in Rev Neurosci 32:671-691) [2]. We report a case of a patient affected by delayed onset BBE overlapping MFS during a mild SARS-CoV-2 infection. To the best of our knowledge, similar cases have never been reported.

Miller-Fisher syndrome with positive anti-GD1b and anti-GM1 antibodies combined with multiple autoimmune antibodies: A case report.

RATIONALE: Anti-ganglioside antibodies (AGA) play an essential role in the development of Miller-Fisher syndrome (MFS). The positive rate of ganglioside antibodies was exceptionally high in MFS, especially anti-GQ1b antibodies. However, the presence of other ganglioside antibodies does not exclude MFS. PATIENT CONCERNS: We present a 48-year-old male patient who suddenly developed dizziness, visual rotation, nausea, and vomiting accompanied by unsteady gait and diplopia for 3 days before presentation to our clinic. DIAGNOSES: On physical examination, the patient's right eye could not fully move to the right side and horizontal nystagmus was found. Coordination was also impaired in the upper and lower extremities with dysmetria and dysdiadochokinesia. The electromyography and cerebrospinal fluid examination results were normal. The serum anti-GQlb antibody test results were negative. However, serum anti-GD1b IgM and anti-GM1 IgM antibodies were positive. Meanwhile, the anti-thyroid peroxidase antibody was >600.00 IU/mL (0.00-34.00), and the anti-SS-A/Ro52 antibody was positive. He was diagnosed with MFS. INTERVENTIONS: The patient received IVIg treatment for 5 days (0.4 g/kg/day) from day 2 to day 6 of hospitalization. On the 7th day of admission, the patient was administered intravenous methylprednisolone (500 mg/day), which was gradually reduced. OUTCOMES: The patient's symptoms improved after treatment with immunoglobulins and hormones. LESSONS: We report a case of MFS with positive anti-GD1b and anti-GM1 antibodies combined with multiple autoimmune antibodies. Positive ganglioside antibodies may be used as supporting evidence for the diagnosis; however, the diagnosis of MFS is more dependent on clinical symptoms.

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.

[Guillain-Barré syndrome and its variants: Miller-Fisher syndrome. Description of a clinical case in pediatric age.] / La sindrome di Guillain-Barré e le sue varianti: la sindrome di Miller-Fisher. Descrizione di un caso clinico in età pediatrica.

Miller-Fisher syndrome is a rare acquired nerve disease related to Guillain-Barré syndrome. Clinical features include asthenia, ocular muscle weakness with ophthalmoplegia, impaired limb coordination with instability, and absence of tendon reflexes. Swallowing disorders and rarely respiratory failure may be associated. The article aims to summarize, starting from the presentation of a clinical case, the latest updates which, in clinical practice, can be useful for a correct diagnosis and treatment of this condition which concerns both adult and pediatric patients.

Miller Fischer syndrome after COVID-19 infection and vaccine: a systematic review.

BACKGROUND: COVID-19 (CoranaVirus disease 2019) is an ongoing infectious disease caused by the RNA SARS-CoV-2 virus (Severe Acute Respiratory Syndrome CoronaVirus-2). The virus mainly causes respiratory symptoms, but neurological symptoms have also been reported to be part of the clinical manifestations of the disease. The aim of this study was to systematically review Miller fisher syndrome (MFS) published cases, in the context of COVID-19 infection or vaccination. METHODS: A systematic literature review on Medline was performed. A total of 21 papers were included in the present review. RESULTS: Twenty-two MFS cases (77% males) were identified, 14 related to COVID-19 infection and 8 to vaccination against COVID-19. The median age of the adult patients was 50 years (interquartile range 36-63 years). Sixteen patients (73%) had the classic triad of MFS (ophthalmoplegia, ataxia, areflexia), four (18%) had acute ophthalmoplegia and one other characteristic symptom and two patients (9%) had only one other characteristic symptom, but they tested positive for GQ1b antibodies. Nine (41%) patients had positive GQ1b antibodies and were classified as "definite" MFS. Albuminocytologic dissociation was found in half of the cases. The outcome was favourable in the majority of cases (86%) whereas one patient, despite the initial improvement, died because of a cardiac arrest, after cardiac arrythmia. CONCLUSIONS: MFS after COVID-19 infection/vaccination was found to have the typical epidemiological characteristics of classic MFS; being rare, occurring more often after infection than vaccination, affecting mainly middle-aged males usually within 3 weeks after the event and having an excellent prognosis after treatment with IVIG or even with no treatment at all. We found no evidence that MFS after COVID-19 infection was different from MFS after COVID-19 vaccination, although the former tended to occur earlier.

Anti-GT1a and anti-GQ1b immunoglobulin G antibody positivity with overlapping Miller Fisher/Guillain-Barré syndromes and prominent headache: a case report.

Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS) are acute immune-mediated peripheral neuropathies. In addition to their classic presentations, a variety of other signs and symptoms have been reported; however, headache appears to be relatively uncommon. We describe a 53-year-old woman who presented with acute bulbar palsy as the first symptom of overlapping MFS/GBS accompanied by severe headache. The first important clinical impairment of the patient was acute bulbar palsy along with prominent headache, without limb weakness. Although her initial diagnosis was acute bulbar palsy plus, she subsequently developed lower limb diffuse weakness, and her final clinical diagnosis was overlapping MFS/GBS. Anti-ganglioside antibodies were positive for anti-GQ1b and anti-GT1a immunoglobulin G. The patient received intravenous immunoglobulin on day 2 of admission. Early identification of these overlapping syndromes is important for the management of patients, to avoid respiratory failure or severe weakness with axonal degeneration. We therefore remind clinicians of the importance of further examination in patients with headache and acute bulbar palsy of unknown origin.

Atypical anti-GQ1b antibody syndrome presenting with vomiting as the initial symptom: a case report and literature review.

BACKGROUND: Anti-GQ1b antibody syndrome is a rare autoimmune neuropathy, and atypical cases are even more rare, only a few cases have been reported. Anti-GQ1b antibody syndrome is difficult in early diagnosis and prone to misdiagnosis. Generally,in children with anti-GQ1b antibody syndrome,extraocular muscle paralysis is the initial symptom. However, anti-GQ1b antibody syndrome with vomiting as the initial symptom followed by abnormal gait has not been reported. CASE PRESENTATION: We reported a case of anti-GQ1b antibody syndrome with vomiting as the initial symptom, followed by abnormal gait. One day after vomiting, the child developed abnormal gait, which primarily manifested as a slight tilt of the upper body during walking as well as an opening and swaying of the legs at fast walking paces,then progressively aggravated, and finally he could not stand on his own.In the auxiliary examination, cerebrospinal fluid routine,biochemical and metagenomic Next-Generation Sequencing (DNA and RNA), brain + spinal cord contrast magnetic resonance imaging (MRI),magnetic Resonance angiography (MRA) and diffusion-weighted image (DWI), hip and knee joint ultrasound showed normal results. Anti-GQ1b antibody syndrome was not confirmed until the positive anti-GQ1b IgG antibody was detected in the serum. After treatment with intravenous immunoglobulin (IVIG) and glucocorticoid, the child recovered well, and a 3-month outpatient follow-up showed that the child was able to walk normally. CONCLUSIONS: There are no previous reports of anti-GQ1b antibody syndrome with vomiting as the initial symptom, followed by abnormal gait. Therefore, this valuable case contributes to expanding the database of clinical manifestation of anti-GQ1b antibody syndrome, so as to improve pediatricians' awareness about such rare diseases and reduce misdiagnosis.

CSF Findings in Relation to Clinical Characteristics, Subtype, and Disease Course in Patients With Guillain-Barré Syndrome.

BACKGROUND AND OBJECTIVES: To investigate CSF findings in relation to clinical and electrodiagnostic subtypes, severity, and outcome of Guillain-Barré syndrome (GBS) based on 1,500 patients in the International GBS Outcome Study. METHODS: Albuminocytologic dissociation (ACD) was defined as an increased protein level (>0.45 g/L) in the absence of elevated white cell count (<50 cells/µL). We excluded 124 (8%) patients because of other diagnoses, protocol violation, or insufficient data. The CSF was examined in 1,231 patients (89%). RESULTS: In 846 (70%) patients, CSF examination showed ACD, which increased with time from weakness onset: ≤4 days 57%, >4 days 84%. High CSF protein levels were associated with a demyelinating subtype, proximal or global muscle weakness, and a reduced likelihood of being able to run at week 2 (odds ratio [OR] 0.42, 95% CI 0.25-0.70; p = 0.001) and week 4 (OR 0.44, 95% CI 0.27-0.72; p = 0.001). Patients with the Miller Fisher syndrome, distal predominant weakness, and normal or equivocal nerve conduction studies were more likely to have lower CSF protein levels. CSF cell count was <5 cells/µL in 1,005 patients (83%), 5-49 cells/µL in 200 patients (16%), and ≥50 cells/µL in 13 patients (1%). DISCUSSION: ACD is a common finding in GBS, but normal protein levels do not exclude this diagnosis. High CSF protein level is associated with an early severe disease course and a demyelinating subtype. Elevated CSF cell count, rarely ≥50 cells/µL, is compatible with GBS after a thorough exclusion of alternative diagnoses. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that CSF ACD (defined by the Brighton Collaboration) is common in patients with GBS.

A Case with Anti-ganglioside Antibodies Showing Multiple Cranial Nerve Palsies Detected on Gadolinium-enhanced Magnetic Resonance Imaging.

The anti-GQ1b IgG antibody is often accompanied by other anti-ganglioside antibodies, which induces various neurological symptoms. We herein report a patient with anti-ganglioside antibodies, including anti-GQ1b IgG and anti-GT1a IgG antibodies, showing bilateral ophthalmoplegia, facial nerve palsies, dysarthria, dysphagia, dysesthesia in both hands, and enhancement of the bilateral oculomotor, abducens, and facial nerves on gadolinium (Gd)-enhanced T1-weighted brain magnetic resonance imaging (MRI). He was first treated with intravenous immunoglobulin, which improved ophthalmoplegia, bulbar palsies, and dysesthesia of hands, but the facial nerve palsies worsened, and Gd enhancement of the brain nerves persisted. High-dose methylprednisolone therapy subsequently improved the facial nerve palsies and Gd enhancement of the cranial nerves. This is the first case with anti-ganglioside antibodies presenting with multiple cranial nerve palsies that was followed to track the changes in the Gd enhancement of cranial nerves on MRI.

A Case of Miller Fisher Syndrome with Cerebellar Hypoperfusion.

We report a case of a 76-year-old man with Miller Fisher syndrome presenting with acute ophthalmoplegia and ataxia. Cerebrospinal fluid analysis showed normocytosis with an increased protein level. Serum anti-GQ1b IgG and anti-GT1a IgG antibodies were positive. Based on these results, the patient was diagnosed with Miller Fisher syndrome. He was treated with two courses of intravenous immunoglobulin, which improved his neurological symptoms. Brain perfusion single-photon emission computed tomography showed that cerebellar blood flow was decreased in the acute stage of the disease and improved after treatment. Although the prevailing view is that ataxia in Miller Fisher syndrome patients is of a peripheral origin, this case suggests that cerebellar hypoperfusion contributes to the development of ataxia in Miller Fisher syndrome.