Introduction: several cases of Guillain-Barre Syndrome (GBS) associated with SARS-CoV-2 infection have been described. This study illustrated the demographic, clinical, and neurophysiological characteristics of patients with GBS and COVID-19, as well as associated factors with disability at discharge. Methods: A retrospective analytical observational study was conducted. It included patients diagnosed with GBS admitted in a national reference center in Peru between 2019 and 2021. Epidemiological, clinical, neurophysiological and cerebrospinal fluid data were analyzed. A multivariate analysis, using the generalized linear model, was performed, considering the presence of disability at discharge as the dependent variable. Results: 81 subjects diagnosed with GBS were included. The mean age was 46.8 years (SD: 15.2), with a predominance of males (61.73%). The most frequent clinical presentation was the classic sensory-motor form in 74 cases (91.36%) with AIDP (82.35%) as the most frequent neurophysiological pattern in the group with COVID-19,while AMAN pattern predominated (59.26%) in those without COVID-19 (p=<0.000). The disability prevalence ratio at discharge between subjects with COVID-19 and those without COVID-19 was 1.89 (CI 1.06 - 3.34), p=0.030, adjusted for age, sex, and neurophysiological subtype. Conclusions: The neurophysiologic subtype AIDP, and a higher disability were associated with the presence of COVID-19.

Introduction Guillain-Barré syndrome is a polyradiculoneuropathy of autoimmune origin, considered the most frequent cause of acute flaccid paralysis. Various associations of Guillain-Barré syndrome with other non-neurological autoimmune diseases have been reported, some of them extremely rare, such as that which occurs with primary biliary cholangitis, a chronic disease of autoimmune etiology whose diagnosis is also supported by the clinical picture. , in the alteration of liver enzymes and the presence of anti-mitochondrial antibodies. Clinical case A 38-year-old male patient, with no history of previous comorbidities, who, after presenting with diarrheal disease two weeks prior, developed subacute onset ascending weakness associated with paresthesias in four extremities that progressed to quadriplegia and respiratory distress. Cerebrospinal fluid cytochemistry was performed, which showed albuminocytological dissociation and electromyography, which showed findings compatible with acute motor axonal neuropathy, for which he received treatment with intravenous immunoglobulin at 0.4g/kg/day, achieving improvement in the neurological condition. Since admission and during hospitalization, he presented persistent changes in liver enzymes which followed a cholestatic pattern, in addition to mild abdominal pain and generalized itching, for which he was evaluated by gastroenterology, who requested anti-mitochondrial antibodies that were positive. Concluding in the diagnosis of primary biliary cholangitis. Conclusion The present case shows an extremely rare association of two autoimmune diseases Guillain-Barré syndrome and primary biliary cholangitis, so much so that it represents the first case reported, not linked to SARS-CoV-2.

Chronic inflammatory demyelinating polyradiculoneuropathy is a clinically heterogeneous group of immune- mediated peripheral neuropathies that share neurophysiological manifesta-tions of demyelination and albuminocytologic dissociation. There are typical and atypical variants of this disease, some associated with antibodies against proteins of the node of Ranvier, such as neurofascin- 155. We present the case of a 38- year- old male who presented with an eight- month history of par-esthesia and progressive weakness of four limbs associated with diplopia and dysphagia. The patient was conscious, with symmetric flaccid quadriparesis of distal predominance, hyp-otrophy in the dorsum and palm of both hands, generalized areflexia, postural low frequency, and high amplitude tremor in upper limbs of left predominance, appendicular dysmetria, dys-diadochokinesia, ophthalmoparesis to dextroversion in the right eye, absent gag reflex, ataxic gait with an increased base of support and positive Romberg's sign. Cerebrospinal fluid showed albuminocytologic dissociation, and electromyography was com-patible with primarily demyelinating sensory- motor polyneuropathy. Due to clinical suspicion, we requested anti- neurofascin- 155 antibodies, which tested positive. The patient was treated with methylprednisolone at a dose of one gram per day for five days, followed by one milligram per kilogram for three months of prednisone, with progressive de-crease, which improved diplopia and dysphagia, with no effect on limb strength and even worsening of function. For this reason, treatment with rituximab was started in doses of two grams, presenting a substantial improvement in distal muscle strength, tremor, gait stability, coordination, and functionality measured with the modified Rankin scale.