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OBJECTIVES: Hereditary transthyretin (TTR) amyloidosis (ATTRv) is frequently complicated by polyneuropathy (ATTRv-PN) and cardiomyopathy (ATTRv-CM). The long-term efficacy of diflunisal on both polyneuropathy and cardiomyopathy in ATTRv patients, especially those with non-V30M genotypes, has not been fully investigated and compared with that of tafamidis. METHODS: We compared the structural and biochemical characteristics of A97S-TTR complexed with tafamidis with those of diflunisal, and prospectively followed up and compared the progression of polyneuropathy and cardiomyopathy between ATTRv-PN patients taking diflunisal and those taking tafamidis. RESULTS: Both diflunisal and tafamidis effectively bind to the two thyroxine-binding sites at the A97S-TTR dimer-dimer interface and equally and almost sufficiently reduce amyloid fibril formation. Thirty-five ATTRv-PN patients receiving diflunisal and 22 patients receiving tafamidis were enrolled. Compared with no treatment, diflunisal treatment significantly delayed the transition of FAP Stage 1 to 2 and Stage 2 to 3 and decreased the deterioration in parameters of the ulnar nerve conduction study (NCS). The progression of FAP stage or NCS parameters did not differ between patients treated with diflunisal and those treated with tafamidis. Both diflunisal and tafamidis treatments significantly decreased radiotracer uptake on 99mTc-PYP SPECT and stabilized cardiac wall thickness and blood pro-B-type natriuretic peptide levels. No significant adverse events occurred during diflunisal or tafamidis treatment. INTERPRETATIONS: The binding patterns of both tafamidis and diflunisal to A97S-TTR closely resembled those observed in the wild type. Diflunisal can effectively delay the progression of polyneuropathy and cardiomyopathy with similar efficacy to tafamidis and may become a cost-effective alternative treatment for late-onset ATTRv-PN.
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Numerous evidence suggests coronavirus disease 2019 (COVID-19) potentially triggers demyelinating diseases, inclusive of multiple sclerosis (MS), and acute disseminated encephalomyelitis (ADEM), and various mechanisms have been proposed. We report a 42-year-old male presented with bilateral optic neuritis and encephalopathy, 2 weeks following COVID-19 infection. He denied any history or family history of neurological and ocular diseases. Severe bilateral visual impairment (only light perception) and pain with eye movement were reported. Fundoscopy revealed bilateral optic disc swelling. Magnetic resonance imaging showed tortuous bilateral optic nerves with optic nerve and nerve sheath enhancement. Multiple hyperintense nodules in bilateral cerebral white matter were noted on fluid-attenuated inversion recovery T2-weighted imaging without diffusion restriction or gadolinium contrast enhancement. Hypointense nodules in cerebral white matter were also noted on T1-weighted imaging, which implied some old lesions. Dissemination in space and time and cerebrospinal fluid-specific oligoclonal bands confirmed the diagnosis of MS. Both serum aquaporin-4 and myelin oligodendrocyte glycoprotein antibodies were negative. He received pulse steroid therapy for 5 days, followed by slowly tapering oral prednisolone. His vision, ocular motion pain, and encephalopathy improved gradually. However, the visual outcome was still poor (bilateral 20/400), and optic atrophy was noticed during 1-year follow-up. To our knowledge, this is the first case of MS following severe acute respiratory syndrome coronavirus 2 infection presented with bilateral optic neuritis and encephalopathy. Since these manifestations are exceedingly rare in MS, we suspect acute immune reactions induced by COVID-19 could bring about the atypical ADEM-like presentations of MS.
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INTRODUCTION: Multifocal acquired demyelinating sensory and motor neuropathy (MADSAM) is an asymmetric immune-related neuropathy with conduction block. We report 2 MADSAM cases with detailed clinical, electrophysiological, and sonography profiles. PATIENT CONCERNS AND DIAGNOSIS: Two cases presented with patchy sensorimotor impairment in both clinical and electrophysiological findings. Notably, nerve ultrasound demonstrated multifocal nerve enlargement not only at sites of conduction blockade but also at the unaffected contralateral sites. Interestingly, in our first case, focal radial nerve enlargement was observed prior to the clinical manifestations, suggesting nerve dynamic pathogenesis with variable clinical significance. INTERVENTIONS AND OUTCOMES: The first patient was initially treated with prednisolone, however, 3âmonths after steroid therapy, her symptoms progressed. After treatment with intravenous immunoglobulin for 3 months, the symptoms stabilized. The second patient showed improvement after 2 months of prednisolone treatment. CONCLUSION: These observations suggest a more widespread pathomechanism underlying MADSAM, and ultrasound may detect nerve lesions earlier than clinical electrophysiology studies, and is warranted for early detection and thorough documentation of nerve pathology.