Guillain-Barré and Miller Fisher Overlap Syndrome Mimicking Alimentary Botulism

To be, or not to be… Guillain-Barré Syndrome

Guillain-Barré Syndrome (GBS) is currently the most frequent cause of acute flaccid paralysis on a global scale, being an autoimmune disorder wherein demyelination of the peripheral nerves occurs. Its main clinical features are a symmetrical ascending muscle weakness with reduced osteotendinous reflexes and variable sensory involvement. GBS most commonly occurs after an infection, especially viral (including COVID-19), but may also transpire after immunization with certain vaccines or in the development of specific malignancies. Immunoglobulins, plasmapheresis, and glucocorticoids represent the principal treatment modalities, however patients with severe disease progression may require supportive therapy in an intensive care unit. Due to its symptomology, which overlaps with numerous neurological and infectious illnesses, the diagnosis of GBS may often be misattributed to pathologies that are essentially different from this syndrome. Moreover, many of these require specific treatment methods distinct to those recommended for GBS, in lack of which the prognosis of the patient is drastically affected. Such diseases include exposure to toxins either environmental or foodborne, central nervous system infections, metabolic or serum ion alterations, demyelinating pathologies, or even conditions amenable to neurosurgical intervention. This extensive narrative review aims to systematically and comprehensively tackle the most notable and challenging differential diagnoses of GBS, emphasizing on the clinical discrepancies between the diseases, the appropriate paraclinical investigations, and suitable management indications.

A unique case of Miller Fisher-Guillain-Barré overlap syndrome in a liver transplant recipient

Guillain-Barré syndrome (GBS) is an ascending demyelinating polyneuropathy often associated with recent infection. Miller Fisher syndrome represents a variant with predominant facial and cranial nerve involvement, although Miller Fisher and Guillain-Barré overlap syndromes can occur. Guillain-Barré spectrum syndromes have been thought to be rare among solid organ transplant recipients. We describe an immunocompromised patient with a liver transplant who presented with ophthalmoplegia and bulbar deficits. His symptoms rapidly progressed to a state of descending paralysis involving the diaphragm; he then developed acute respiratory failure and eventually developed quadriparesis. Electromyography and a nerve conduction study demonstrated a severe sensorimotor axonal polyneuropathy consistent with Miller Fisher variant Guillain-Barré syndrome. Despite several negative nasopharyngeal swabs for COVID-19 polymerase chain reaction, a serology for SARS-CoV-2 IgG was positive. He was diagnosed with Miller Fisher-Guillain-Barré overlap syndrome with rapid recovery following treatment with plasma exchange. Although Guillain-Barré is a rare complication in solid organ transplant recipients, this case highlights the importance of rapid diagnosis and treatment of neurologic complications in transplant patients. Furthermore, it demonstrates a possible case of neurological complications from COVID-19 infection.

Toxemia in Human Naturally Acquired Botulism

Human botulism is a severe disease characterized by flaccid paralysis and inhibition of certain gland secretions, notably salivary secretions, caused by inhibition of neurotransmitter release. Naturally acquired botulism occurs in three main forms: food-borne botulism by ingestion of preformed botulinum neurotoxin (BoNT) in food, botulism by intestinal colonization (infant botulism and intestinal toxemia botulism in infants above one year and adults), and wound botulism. A rapid laboratory confirmation of botulism is required for the appropriate management of patients. Detection of BoNT in the patient's sera is the most direct way to address the diagnosis of botulism. Based on previous published reports, botulinum toxemia was identified in about 70% of food-borne and wound botulism cases, and only in about 28% of infant botulism cases, in which the diagnosis is mainly confirmed from stool sample investigation. The presence of BoNT in serum depends on the BoNT amount ingested with contaminated food or produced locally in the intestine or wound, and the timeframe between serum sampling and disease onset. BoNT levels in patient's sera are most frequently low, requiring a highly sensitive method of detection. Mouse bioassay is still the most used method of botulism identification from serum samples. However, in vitro methods based on BoNT endopeptidase activity with detection by mass spectrometry or immunoassay have been developed and depending on BoNT type, are more sensitive than the mouse bioassay. These new assays show high specificity for individual BoNT types and allow more accurate differentiation between positive toxin sera from botulism and autoimmune neuropathy patients.

Acute ophthalmoplegia in a patient with anti-GQ1b antibody and chronic facial diplegia

A 56-year-old man with a remote history of bilateral recurrent facial palsies presented with a week of ophthalmoplegia with intact deep tendon reflexes and lack of ataxia, cerebrospinal fluid with albuminocytologic dissociation and elevated serum anti-ganglioside Q1b (GQ1b) IgG antibody. We diagnosed the patient with acute ophthalmoplegia without ataxia, a condition under the spectrum of anti-GQ1b antibody syndromes which also includes Miller Fisher syndrome. Given the rarity of recurrent facial palsies and anti-GQ1b antibody syndromes as well as reports associating facial palsies and this syndrome, we suggest that our case may be an unusual presentation of an anti-GQ1b antibody syndrome beginning with recurrent facial palsies several years prior to ophthalmoplegia. Prior studies of human nerves provide insight into the pathophysiology, including ganglioside distribution and cross-reactivities underlying the heterogeneity of anti-GQ1b antibody syndromes. This report may expand the differential diagnosis in patients with recurrent facial palsies and broaden the phenotype of anti-GQ1b syndromes.