Neuromuscular junction dysfunction in Miller Fisher syndrome

Case Report: A Patient Diagnosed With Miller Fisher Syndrome and Myasthenia Gravis at the Same Time

In this case report, we describe a patient who was first diagnosed with Miller Fisher syndrome (MFS) combined with myasthenia gravis (MG). A 58-year-old male patient presented with acute dysarthria with dizziness, ophthalmoplegia, absence of deep tendon reflexes in the extremities, and ataxia. Lumbar puncture 1 week after onset showed albuminocytologic dissociation and serum antibodies against GQ1b and GT1a turned out to be positive. Ultimately, the patient was diagnosed with MFS, which is a rare variant of Guillain-Barre syndrome. Because the clinical manifestations of the patient could not exclude MG, electromyography, and serum muscle weakness antibody profile were performed. The results showed positive for axillary nerve repetitive electrical stimulation and antibodies against acetylcholine receptor (AChR) and titin were detected, so the patient was diagnosed with MG at the same time. Even though only five cases of overlapping MFS and MG so far have been described, two different autoimmune diseases may coexist. When one disease presents with uncommon symptoms, careful identification of the presence or absence of other comorbid diseases should be required.

Pediatric Miller Fisher Syndrome and Ocular Myasthenia Gravis (A Reminder of Clinical Mimicry): A Case Report

Miller Fisher syndrome (MFS) is a rare immune-mediated neuropathy that often presents with diplopia and bilateral external ophthalmoplegia. Other neurological deficits may occur such as ataxia and areflexia but not in all cases. Although MFS is a clinical diagnosis, serological confirmation is possible by identifying the anti-GQ1b antibody found in the majority of patients. Myasthenia gravis is an autoimmune disorder of the availability of acetylcholine receptors in the neuromuscular junction. Ocular myasthenia gravis is a disease subtype characterized by variable patterns of weakness of extraocular muscles, eyelid elevator, and orbicular muscle in which the initial sign in most adults and children is ptosis. We report a child with MFS who presented with clinical signs suggestive of ocular myasthenia gravis, but in whom the correct diagnosis was made on the basis of serological testing for the anti-GQ1b antibody. We aim to highlight the similarity between the two rare conditions and address the importance of early liaison with neurologists and ophthalmologists in reaching to the proper diagnosis.

Guillain-Barré syndrome associated with myasthenia gravis: Three cases report and a literature review

RATIONALE

Myasthenia gravis (MG) and Guillain-Barré syndrome (GBS) are 2 common neurologic autoimmune diseases. Although both the diseases can present with acute or subacute onset of muscular weakness involving the limbs and bulb, the coexistence in the same patient is unusual and rarely described in the literature.

PATIENT CONCERNS

Three cases of combined MG and GBS at the department of Neurology were described. All the 3 patients developed GBS, who had had MG for 30 years, 6 years, and 6 months, respectively.

DIAGNOSES

The newly developed GBS was clinically confirmed by the clinical features, electromyographic (EMG) studies, typical albumino-cytologic dissociation in cerebrospinal fluid (CSF), and positive anti-ganglioside antibodies in serum.

INTERVENTIONS

The 3 patients had been treated with intravenous immunoglobulin (IVIG), or plasma-exchange (PE), or IVIG combined with PE in the acute stage of severe muscle weakness. In light of the MG symptoms, they have received glucocorticoids, oral pyridostigmine, and immunosuppressive agents.

OUTCOMES

The patient 1 was able to walk longer than 5 m with assistance (Hughes 3). The patient 2 had significantly improved, and completely recovered at the 1-year follow-up (Hughes 0). But unfortunately, the patient 3 was severely disabled and chair-bound at the last interview (Hughes 4).

LESSONS

The combination of MG and GBS is quite rare. Limbs and oculo-bulbar weakness are the cardinal manifestations of both the diseases. Although their characteristics are quite different, there are still some difficulties in diagnosing them when they occur in the same patient. Early diagnosis and proper treatment will yield satisfactory prognosis. Further researches are needed to elucidate the pathogenesis of the coexistence.

Ophthalmoplegia Due to Miller Fisher Syndrome in a Patient With Myasthenia Gravis

Here, we describe a 79-year-old man, admitted to our unit for worsening diplopia and fatigue, started a few weeks after an episode of bronchitis and flu vaccination. Past medical history includes myasthenia gravis (MG), well-controlled by Pyridostigmine, Azathioprine, and Prednisone. During the first days, the patient developed progressive ocular movement abnormalities up to complete external ophthalmoplegia, severe limb and gait ataxia, and mild dysarthria. Deep tendon reflexes were absent in lower limbs. Since not all the symptoms were explainable with the previous diagnosis of myasthenia gravis, other etiologies were investigated. Brain MRI and cerebrospinal fluid analysis were normal. Electromyography showed a pattern of predominantly sensory multiple radiculoneuritis. Suspecting Miller Fisher syndrome (MFS), the patient was treated with plasmapheresis with subsequent clinical improvement. Antibodies against GQ1b turned out to be positive. MFS is an immune-mediated neuropathy presenting with ophthalmoplegia, ataxia, and areflexia. Even if only a few cases of MFS overlapping with MG have been described so far, the coexistence of two different autoimmune disorders can occur. It is always important to evaluate possible differential diagnosis even in case of known compatible diseases, especially when some clinical features seem atypical.

[A case of Miller Fisher syndrome with a false-positive edrophonium test]

A 69-year-old woman presented with acute bilateral ptosis, ophthalmoplegia, ataxia, and hyporeflexia in the extremities following an antecedent upper respiratory infection. We suspected that she had Miller Fisher syndrome (MFS) and performed an edrophonium test (ET) to rule out myasthenia gravis (MG). Edrophonium chloride improved the patient's bilateral ptosis, but not her ophthalmoplegia. Given the absence of the waning phenomenon on electrophysiological examination, the anti-acetylcholine receptor antibody, and a diurnal variation of symptoms, we concluded that the ET result was a false-positive. A diagnosis of MFS was confirmed by the presence of a positive anti-GQ1b antibody. To our knowledge, this is the first case report of MFS with a false-positive ET.

The clinical features of patients concurrent with Guillain-Barre syndrome and myasthenia gravis

OBJECTIVE

To evaluate all the coincidence cases of Guillain-Barre syndrome (GBS) and myasthenia gravis (MG).

METHODS

We performed web-based research of the overlapping incidence of GBS and MG in studies occurring from 1982 to 2016 and restricted to the English language.

RESULTS

Among 15 cases, an elevated CSF protein level without pleocytosis was found in 10 cases (66.7%); reduced nerve conduction was found in 13 cases (86.6%); a positive repetitive nerve stimulation test occurred in 11 cases (73.3%); anti-AChR antibodies were found in 13 cases (86.6%); anti-GQ1b antibodies were found in 6 cases (40%); a positive edrophonium chloride test was present in 10 cases (66.7%); and a co-occurring thymoma or thymectomy occurred in 4 cases (26.6%). The MG co-occurred with acute inflammatory demyelinating polyneuropathy (AIDP) in 8 cases and with Miller Fisher Syndrome in 5 cases. Treatment in the assessed cases included pyridostigmine (10 cases), prednisolone (7 cases), intravenous immunoglobulin (9 cases), plasmapheresis (3 cases), combined intravenous immunoglobulin and plasmapheresis in one case, and immunosuppressive drugs in 2 cases (azathioprine). Functional outcome was mentioned in 13 patients. The prognosis was favorable in 8 of the 15 recorded patients (Hughes 0-1), and 2 cases resulted in death.

CONCLUSION

Although comorbidity of GBS and MG is extremely rare, early recognition of this combination of inflammation of peripheral nerves and the neuromuscular junction is of great importance for both initial treatment and a better prognosis.

Overlap of Myasthenia Gravis and Miller Fisher Syndrome

In this case report, we describe a patient with myasthenia gravis (MG) and Miller Fisher syndrome (MFS) overlap. A 69-year-old woman presented with acute bilateral ptosis, ophthalmoplegia, ataxic gait, and areflexia. The MFS diagnosis was confirmed with by a positive anti-GQ1b IgG antibody test result. MG was diagnosed from electrophysiological, edrophonium, and serological test results. Although intravenous immunoglobulin therapy is effective for both diseases, two courses of the therapy did not improve the patient's symptoms. However, steroid therapy was effective. Although the overlap of MG and MFS is very rare, it should be considered in the differential diagnosis of neuro-ophthalmic diseases.

Combined Guillain-Barré syndrome and myasthenia gravis

BACKGROUND

Guillain-Barré syndrome and myasthenia gravis both lead to muscle weakness but the two combined is uncommon. Detection of these entities can help identify forms of autoimmune neuromuscular diseases that may respond to immunotherapy. This report sought to characterize the clinical features of these two entities when combined.

METHODS

This report is of a case of combined Guillain-Barré syndrome and myasthenia gravis. The clinical features were analyzed and correlated to those published in English literature from 1960 to 2012. Ten reports and 12 cases, including the present case, were reviewed.

RESULTS

There were 12 patients (4 women and 8 men), aged 17 to 84 years, with combined Guillain-Barré syndrome and myasthenia gravis. Four had post-infectious Guillain-Barré syndrome followed by the development of myasthenia gravis concurrently or concomitantly within one month. All cases had symptoms of ptosis and areflexia. The other common presentations were limb weakness, oculobulbar weakness, and respiratory involvement. Functional outcome was mentioned in 10 patients and seven had good outcome (Hughes scale ≤ 2).

CONCLUSION

Detection of ptosis with or without ophthalmoplegia, distribution of limb weakness, and reflex can help in recognizing combined Guillain-Barré syndrome and myasthenia gravis. The early recognition of this combination of peripheral nervous and neuro-muscular junction inflammation is important for initial treatment and prognosis.

Myasthenia gravis and Guillain-Barré cooccurrence syndrome

OBJECTIVE

The objective of this study was to review all cases in literature in which the clinical manifestations of myasthenia gravis (MG) and Guillain-Barré syndrome (GBS) were presented in the same patient including a new case of our own and identify the clinical characteristics and possible mechanisms of this syndrome.

METHODS

We reviewed 12 reports in which 13 cases were diagnosed as MG and GBS. The clinical manifestations of the 13 cases and our new case were analyzed in detail to show the characteristics of this kind of syndrome.

RESULTS

Of all the cases, 5 females and 9 males, 6 of them were Chinese; 3 were Americans; 3 were Israelis; 1 was white and one was a Frenchman. The age of seven patients was no more than 45 years old. They all had the symptoms of extrocular muscle weakness. Nerve conduction and RNS abnormal were seen in all tested cases. Acetylcholine receptor antibody was positive in all tested patients. Prognosis was good in 8 of the 11 recorded patients.

CONCLUSIONS

Although extremely rare, MG and GBS may present in the same patient with variant characteristics. The typical clinical characteristics of GBS and MG may be helpful for the diagnosis of future possible cases.

Miller Fisher syndrome mimicking ocular myasthenia gravis

PURPOSE.: Miller Fisher syndrome (MFS) is a rare immune-mediated neuropathy that commonly presents with diplopia after the acute onset of complete bilateral external ophthalmoplegia. Ophthalmoplegia is often accompanied by other neurological deficits such as ataxia and areflexia that characterize MFS. Although MFS is a clinical diagnosis, serological confirmation is possible by identifying the anti-GQ1b antibody found in most of the affected patients. We report a patient with MFS who presented with clinical signs suggestive of ocular myasthenia gravis but in whom the correct diagnosis was made on the basis of serological testing for the anti-GQ1b antibody. CASE REPORT.: An 81-year-old white man presented with an acute onset of diplopia after a mild gastrointestinal illness. Clinical examination revealed complete bilateral external ophthalmoplegia and left-sided ptosis. He developed more marked bilateral ptosis, left greater than right, with prolonged attempted upgaze. He was also noted to have a Cogan lid twitch. Same day evaluation by a neuro-ophthalmologist revealed mild left-sided facial and bilateral orbicularis oculi weakness. He had no limb ataxia but exhibited a slightly wide-based gait with difficulty walking heel-to-toe. A provisional diagnosis of ocular myasthenia gravis was made, and anticholinesterase inhibitor therapy was initiated. However, his symptoms did not improve, and serological testing was positive for the anti-GQ1b immunoglobulin G antibody, supporting a diagnosis of MFS. CONCLUSIONS.: Although the predominant ophthalmic feature of MFS is complete bilateral external ophthalmoplegia, it should be recognized that MFS has variable associations with lid and pupillary dysfunction. Such confounding neuro-ophthalmic features require a thorough history, neurological examination, neuroimaging, and serological testing for the anti-GQ1b antibody to arrive at a diagnosis of MFS.

Pathophysiological actions of neuropathy-related anti-ganglioside antibodies at the neuromuscular junction

The outer leaflet of neuronal membranes is highly enriched in gangliosides. Therefore, specific neuronal roles have been attributed to this family of sialylated glycosphingolipids, e.g. in modulation of ion channels and transporters, neuronal interaction and recognition, temperature adaptation, Ca(2+) homeostasis, axonal growth, (para)node of Ranvier stability and synaptic transmission. Recent developmental, ageing and injury studies on transgenic mice lacking subsets of gangliosides indicate that gangliosides are involved in maintenance rather than development of the nervous system and that ganglioside family members are able to act in a mutually compensatory manner. Besides having physiological functions, gangliosides are the likely antigenic targets of autoantibodies present in Guillain-Barré syndrome (GBS), a group of neuropathies with clinical symptoms of motor- and/or sensory peripheral nerve dysfunction. Antibody binding to peripheral nerves is thought to either interfere with ganglioside function or activate complement, causing axonal damage and thereby disturbed action potential conduction. The presynaptic motor nerve terminal at the neuromuscular junction (NMJ) may be a prominent target because it is highly enriched in gangliosides and lies outside the blood-nerve barrier, allowing antibody access. The ensuing neuromuscular synaptopathy might contribute to the muscle weakness in GBS patients. Several groups, including our own, have studied the effects of anti-ganglioside antibodies in ex vivo and in vivo experimental settings at mouse NMJs. Here, after providing a background overview on ganglioside synthesis, localization and physiology, we will review those studies, which clearly show that anti-ganglioside antibodies are capable of binding to NMJs and thereby can exert a variety of pathophysiological effects. Furthermore, we will discuss the human clinical electrophysiological and histological evidence produced so far of the existence of a neuromuscular synaptopathy contributing to muscle weakness in GBS patients.