Introduction Andersen‐Tawil syndrome (ATS) is characterized by a triad of periodic paralysis, ventricular arrhythmias, and dysmorphism. However, patients often lack one or more of these features. Methods Clinical and neurophysiological features were reviewed of five members in two families with heterozygous mutations in KCNJ2 (R218Q and R67W). Results Only one patient had all features of the triad of ATS. One patient had low‐set ears, and the others had minor anomalies. Bidirectional ventricular tachycardias were seen in two patients. Two patients (R67W) never had episodes of paralysis. The long exercise test was abnormal in three patients with episodes of paralysis, but normal in two without paralytic episodes. Discussion ATS patients without skeletal muscle symptoms can have normal neurophysiological examinations. They can show variability in phenotype or the severity of arrhythmias. Such variability among patients who share the same gene mutations may result in underdiagnosis of ATS.

The detection of thiol functionality and intramolecular disulfide bond formation of peptides using the α-Keggin type polyoxometalate molybdenum−oxygen cluster (H 3 PMo 12 O 40 •nH 2 O) is described. Our method entails the addition of this polyoxometalate to solutions of thiol, whereupon the color of the solution changes from colorless to deep blue. Reduction of the polyoxometalate from Mo(VI) to Mo(V) occurs with concomitant oxidation of the thiol functionality, to form disulfide bonds. To exemplify the utility this phenomenon, we accomplished the oxidation of glutathione, reduced linear oxytocin, bactenecin, and α-conotoxin SI; all of which proceeded smoothly and in good conversion in 24 h to less and were accomplished by a change in the color of the reaction solutions.

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Background: On needle electromyography (EMG), abnormal spontaneous activity is considered a feature of active myositis. However, the correlation between needle EMG and muscle pathology is not always clear. Moreover, the changes in EMG findings after corticosteroid therapy are not fully understood. Aim:To investigate the correlations among muscle pathology, needle EMG and muscle MRI findings in patients with idiopathic inflammatory myopathies (IIMs). Methods:The clinical features, laboratory results, needle EMG, muscle MRI findings and pathological features of 50 consecutive patients with IIMs who underwent muscle biopsies were reviewed. We also describe the changes in these findings between before and after corticosteroid treatments. Results:The most common IIM was dermatomyositis (40%). On needle EMG, fibrillation/positive sharp waves (Fib/PSWs) were observed in 72% of the patients. MRI abnormalities were observed in 86% of the patients. In the pathology study, 88% of patients had inflammatory markers. The incidence of Fib/PSWs did not differ between pretreatment patients (79%) and steroid-treated patients (62%). In the pathology study, perimysium/perivascular cell infiltration also did not differ between before and after treatment. However, endomysium cell infiltration was significantly less frequent in steroid-treated patients (0%) than in pretreatment patients (29%) (P < .05). Conclusions:Our study confirmed that Fib/PSWs on needle EMG and muscle MRI were sensitive guides for diagnosing IIMs, and Fib/PSWs might be correlated with muscle fiber injuries or segmental necrosis rather than inflammatory cell infiltration in the affected muscles. Before treatment and within at least 1 month after starting corticosteroid treatment, Fib/PSWs could be detected by needle EMG.

Bilateral hippocampal hyperintensities on diffusion-weighted images in transient global amnesiaA 60-year-old woman with hypertension was referred to Dokkyo Medical University Hospital, Tochigi, Japan, for a sudden onset of amnesia and repeating the same questions every few minutes after a quarrel with her mother. Her blood pressure was 138/108 mmHg. Neurological findings were unremarkable, except for anterograde amnesia and impaired orientation. Her symptoms disappeared 6 h after the symptom onset. Diffusion-weighted brain magnetic resonance images obtained 24 h after the symptom onset showed dot-like hyperintense lesions in the bilateral hippocampus (Fig. 1a,b), with the corresponding low signal intensity on the apparent diffusion coefficient maps (Fig. 1c,d). Based on these findings, a diagnosis of transient global amnesia (TGA) was made.Transient global amnesia is characterized by abrupt onset of anterograde amnesia and repetitive questioning, lasting less than 24 h.1-3 Diffusion-weighted brain magnetic resonance imaging abnormalities in the hippocampus in the acute phase are rarely detected, but can be observed in up to 80% of patients after 24 -48 h of onset.1,2 Bilateral hippocampal abnormalities on diffusion-weighted images are also reported in approximately one-sixth to one-third of TGA patients. 2,3Brain diffusion-weighted brain magnetic resonance images of the present patient clearly detected characteristic imaging findings of TGA involving the bilateral hippocampus. AcknowledgmentThe authors declare no conflict of interest. References