The novel coronavirus disease 2019 (COVID-19) has created a global health impact to millions of people. There have been studies of COVID-19 patients manifesting with neurologic symptoms. Although the number of adult COVID-19 infections diagnosed with Guillain-Barré Syndrome (GBS) is increasing, the occurrence of cases in pediatric population remains limited or perhaps underreported. We report a rare case of an asymptomatic COVID-19 infection manifesting as acute progressive ascending polyneuropathy and hyporeflexia in a 16-year-old teen. The diagnosis of COVID-19 infection was confirmed by reverse transcription polymerase chain reaction for SARS-CoV-2 of oropharyngeal and nasopharyngeal swab specimens. Magnetic resonance imaging of the spine revealed abnormal enhancement of the cauda equina, including the dorsal and ventral roots. Electromyography and nerve conduction studies were compatible with an acute inflammatory demyelinating polyneuropathy subtype of GBS. Although lumbar puncture was not done, the clinical findings and electrodiagnostic tests were both consistent with GBS. The patient had improvement of both motor and sensory functions after completing the treatment of intravenous immunoglobulins. Neurologic manifestations of systemic illness especially in children during this time of pandemic warrants scrutiny, as these may mask a potentially dangerous and infectious ongoing COVID infection.
COVID-19 ; Guillain-Barre Syndrome ; Polyneuropathies ; Pediatrics ; SARS-CoV-2

BACKGROUND: Multifocal motor neuropathy (MMN), Lewis-Sumner syndrome (LSS), and many chronic inflammatory demyelinating polyradiculoneuropathies (CIDPs) are representative of acquired multifocal polyneuropathy and are characterized by conduction block (CB). This retrospective study aimed to investigate the demyelinating distribution and the selective vulnerability of MMN, LSS, and CIDP with CB (CIDP-CB) in nerves. METHODS: Fifteen LSS subjects (107 nerves), 24 MMN subjects (176 nerves), and 17 CIDP-CB subjects (110 nerves) were included. Their clinical information was recorded, blood and cerebrospinal fluid tests were conducted, and nerve conductions of the median, ulnar, radial, peroneal, and tibial nerves were evaluated. CB, temporal dispersion, distal motor latency (DML), and F-wave latency were recorded, and nerve conduction velocity, terminal latency index, and modified F-wave ratio were calculated. RESULTS: CB was more likely to occur around the elbow in CIDP-CB than in MMN (78.6% vs. 6.8%, P < 0.01) but less likely to occur between the wrist and the elbow than in LSS (10.7% vs. 39.3%, P < 0.05). Tibial nerve CB was most frequently observed in MMN (47.4%, P < 0.05). CIDP-CB was characterized by a prolonged DML in all nerves, and slow motor nerve velocity of the upper limb was significant when CB nerves were excluded (P < 0.05). CONCLUSIONS We report the different distributions of segmental and diffuse demyelination of the ulnar and tibial nerves in LSS, MMN, and CIDP-CB. These distinct distributions could help in differentiating among these conditions.
Humans ; Neural Conduction ; Peripheral Nerves ; Polyneuropathies ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating ; Retrospective Studies

As far as we are aware of, we report the fi rst documented case of a 51-year-old Filipino female with multifocal motor neuropathy who presented with asymmetric weakness, unusually in the lower extremity, and confi rmed with anti-GM1 antibody. The treatment of intravenous immunoglobulin with a total dose of 2 g/kg was initiated and repeated every two months with noticeable improvement based on electromyography and nerve conduction studies. Apart from the unreported Filipino case of multifocal motor neuropathy substantiated by features in clinical, electrophysiologic, antibody testing and response to immunotherapy, the unique occurrence in a female and involving the lower extremity in this rare disorder deserve this present documentation. Multifocal motor neuropathy is seen more in males with a ratio of 2.7:1. It is described as a pure motor disease without sensory defi cits and predominantly affects the upper extremities. The diagnosis for the disorder is supported by determination of ganglioside GM1 antibodies.
Immune System Diseases ; Polyneuropathies

POEMS syndrome is a rare paraneoplastic syndrome, which includes polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes due to plasma cell (PC) neoplasm. Diagnosis of this disease is challenging because of its rarity and complex clinical manifestations. We attempted to identify the key clinical features and characteristic bone marrow (BM) findings of POEMS syndrome, by reviewing the medical records and BM analyses of 24 Korean patients. Frequent clinical manifestations included polyneuropathy (100%), monoclonal gammopathy (100%), organomegaly (92%), extravascular volume overload (79%), and endocrinopathy (63%). The BM analyses revealed mild PC hyperplasia (median PCs: 5.5%) and frequent megakaryocytic hyperplasia (88%), megakaryocyte clusters (88%), and hyperlobation (100%). Flow cytometry of BM aspirates using CD138/CD38/CD45/CD19/CD56 showed normal (67%, 4/6) or neoplastic PC immunophenotypes (33%, 2/6). A diagnosis of POEMS syndrome must be considered when a patient suspected of having PC dyscrasia shows the above clinical presentation and BM findings.
Bone Marrow ; Diagnosis ; Flow Cytometry ; Humans ; Hyperplasia ; Medical Records ; Megakaryocytes ; Paraneoplastic Syndromes ; Paraproteinemias ; Plasma Cells ; POEMS Syndrome ; Polyneuropathies ; Skin

We report two cases of subacute combined degeneration (SCD) caused by nitrous oxide (N₂O) gas intoxication, which is rarely reported in Korea. Two patients recreationally inhaled N₂O gas daily for several months. They presented with paresthesia of limbs, voiding difficulty, and gait disturbance. The initial vitamin B₁₂ levels were normal or decreased, but homocysteine levels of the two patients were increased. Magnetic resonance imaging of the cervical spine showed T2-weighted hyperintensity in the bilateral dorsal columns of the cervical spinal cord. Electromyography and somatosensory evoked potential tests for both patients suggested posterior column lesion of the spinal cord combined with sensorimotor polyneuropathy. According to these findings, we concluded that the two patients had SCD. The patient’s symptoms partially improved after cessation of N₂O gas inhalation and the receiving of vitamin B₁₂ supplementation therapy. As the incidence of recreational N₂O gas inhalation is increasing in Korea, physicians must be alert to the N₂O induced SCD in patients presenting with progressive myelopathy.
Cervical Cord ; Electromyography ; Evoked Potentials, Somatosensory ; Extremities ; Gait ; Homocysteine ; Humans ; Incidence ; Inhalation ; Korea ; Magnetic Resonance Imaging ; Nitrous Oxide ; Paresthesia ; Polyneuropathies ; Recreation ; Spinal Cord ; Spinal Cord Diseases ; Spine ; Subacute Combined Degeneration ; Vitamin B 12 ; Vitamins

Electrodiagnostic tests (EDX) is essential for the diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP). EDX could provide information about demyelinating pathology in the peripheral nerves. According to phenotypes, CIDP could be classified several phenotypes, which has different clinical manifestations, EDX could present a different distribution pattern of demyelinating lesions. In addition, EDX could be useful markers for predicting treatment response of prognosis of CIDP.
Classification ; Diagnosis ; Electrodiagnosis ; Neural Conduction ; Pathology ; Peripheral Nerves ; Phenotype ; Polyneuropathies ; Polyradiculoneuropathy, Chronic Inflammatory Demyelinating ; Prognosis

The most prevalent microvascular complication of diabetes mellitus is neuropathy, which encompasses distal symmetric polyneuropathy, mononeuropathy, radiculoplexopathy, and autonomic neuropathy. Intensive glucose control prevents and effectively halts the progression of diabetic neuropathy in patients with type 1 diabetes mellitus. However, the effect of strict glucose control itself is at modest in those with type 2 diabetes. Although we have better understanding of the mechanism of diabetic neuropathy, many pharmacologic trials for the targeting underlying nerve damage have reported unsuccessful results. In this review, the effects and limitations of the current therapeutic options will be discussed.
Diabetes Mellitus ; Diabetes Mellitus, Type 1 ; Diabetic Neuropathies ; Glucose ; Humans ; Life Style ; Mononeuropathies ; Polyneuropathies

This article provides an overview for understanding the classification and pathogenesis of diabetic neuropathy. Diabetic neuropathies are prevalent disorder. The most common manifestation is distal symmetric polyneuropathy, but various patterns of neuropathy can occur. New information for the pathogenesis of diabetic neuropathy continues to emerge, which will lead to identifying new drug targets.
Classification ; Diabetic Neuropathies ; Polyneuropathies

BACKGROUND AND PURPOSE: Tafamidis functions to delay the loss of function in transthyretin familial amyloid polyneuropathy (TTR-FAP), which is a rare inherited amyloidosis with progressive sensorimotor and autonomic polyneuropathy. This systematic literature review and meta-analysis evaluated the efficacy and safety of tafamidis in TTR-FAP patients, with the aim of improving the evidence-based medical evidence of this treatment option for TTP-FAP. METHODS: A systematic search of the English-language literature in five databases was performed through to May 31, 2018 by two reviewers who independently extracted data and assessed the risk of bias. We extracted efficacy and safety outcomes and performed a meta-analysis. Statistical tests were performed to check for heterogeneity and publication bias. RESULTS: The meta-analysis identified six relevant studies. The tafamidis group showed smaller changes from baseline in the Neuropathy Impairment Score–Lower Limbs [mean difference (MD)=−3.01, 95% confidence interval (CI)=−3.26 to −2.75, p < 0.001] and the Norfolk Quality of Life-Diabetic Neuropathy total quality of life score (MD=−6.67, 95% CI=−9.70 to −3.64, p < 0.001), and a higher modified body mass index (MD=72.45, 95% CI=69.41 to 75.49, p < 0.001), with no significant difference in total adverse events [odds ratio (OR)=0.69, 95% CI=0.35 to 1.35, p=0.27]. The incidence of adverse events did not differ between tafamidis and placebo treatment except for fatigue (OR=0.13, 95% CI=0.02 to 0.72, p=0.02) and hypesthesia (OR=0.16, 95% CI=0.03 to 0.92, p=0.04). CONCLUSIONS: This systematic review and meta-analysis has demonstrated that tafamidis delays neurologic progression and preserves a better nutritional status and the quality of life. The rates of adverse events did not differ between the patients in the tafamidis and placebo groups. Tafamidis might be a safer noninvasive option for patients with TTR-FAP.
Amyloid Neuropathies ; Amyloid Neuropathies, Familial* ; Amyloidosis ; Bias (Epidemiology) ; Body Mass Index ; Extremities ; Fatigue ; Humans ; Hypesthesia ; Incidence ; Nutritional Status ; Polyneuropathies ; Population Characteristics ; Prealbumin* ; Publication Bias ; Quality of Life

Swallowing can be affected by a variety of systemic diseases. The etiology of dysphagia in the geriatric population is usually overlooked due mainly to a presumed diagnosis of presbyphagia or difficulty in revealing the direct cause. On the other hand, dysphagia can be a meaningful clinical sign of premalignant systemic disease. A 78-year-old man, without any prior medical or family history, was admitted with the chief complaint of dysphagia with recent aspiration pneumonia. Instrumental swallowing tests revealed a severe degree of dysphagia due to decreased laryngopharyngeal sensation and weakness of the pharyngeal constrictor muscles. Extensive workup, including electromyography and laboratory tests, revealed severe sensorimotor peripheral polyneuropathy related to monoclonal gammopathy. Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant precursor of multiple myeloma, which is characterized by the proliferation of monoclonal proteins. These conditions are often associated with peripheral polyneuropathy, ataxia, and sometimes even muscle weakness. Although dysphagia can occur in other systemic disorders, such as vasculitis or paraneoplastic syndrome-related malignancies, there are few reports of dysphagia related to MGUS. The patient was followed up for three years. The MGUS showed no further progression, but the patient showed no improvement, indicating a protracted clinical course and poor prognosis when dysphagia is related to MGUS.
Aged ; Ataxia ; Deglutition ; Deglutition Disorders ; Diagnosis ; Electromyography ; Hand ; Humans ; Monoclonal Gammopathy of Undetermined Significance ; Multiple Myeloma ; Muscle Weakness ; Muscles ; Paraproteinemias ; Pneumonia, Aspiration ; Polyneuropathies ; Prognosis ; Sensation ; Vasculitis