Long-Term Safety and Efficacy of Tacrolimus in Myasthenia Gravis.

PURPOSE: Myasthenia gravis (MG) is a lifelong autoimmune disorder that affects neuromuscular transmission. The long-term treatment plan should include immunotherapy. We investigated the long-term safety and efficacy of tacrolimus for the treatment of MG in real-world clinical practice. MATERIALS AND METHODS: We retrospectively reviewed 160 MG patients treated with tacrolimus from 2005 to 2015. Myasthenia Gravis Foundation of America (MGFA) clinical classification, MGFA post-intervention status, myasthenic functional score, and dose of oral prednisolone were investigated. RESULTS: Adverse events occurred in 68 patients (42.5%), most of which were minor and well-managed. Clinical severity scales improved after administration of tacrolimus, compared to the baseline. Compared to 6 months before administration of tacrolimus, prednisolone dose significantly decreased at 12 months after treatment (2.85±0.92 mg/day, p=0.002), 18 months after treatment (3.36±0.99 mg/day, p=0.001), and 24 months after treatment (3.71±0.93 mg/day, p<0.001). CONCLUSION: Tacrolimus may be effective in reducing the severity of MG and may permit a reduction in the steroid dose prescribed to the patients. Adverse events due to tacrolimus treatment were not serious.

Using the Region of Interest from Time-of-Flight Magnetic Resonance Angiography to Differentiate Between Intracranial Arterial Dissection and True Atherosclerotic Stenosis.

BACKGROUND: Noncontrast three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA) is commonly used to examine intracranial arterial stenosis, although it can be difficult to identify the etiology of the stenosis. Our aim was to determine the effectiveness of 3D TOF MRA in differentiating an intracranial arterial dissection from atherosclerosis. METHODS: During 2015-2017, 356 patients had confirmed intracranial arterial stenosis based on high resolution-magnetic resonance imaging. This study ultimately included 51 patients with severe focal stenosis that was caused by dissection and atherosclerosis. We compared the dissection group with the atherosclerotic narrowing group by measuring the region-of-interest (ROI) values 3 mm proximal and 3 mm distal from sites of severe focal stenosis. RESULTS: A significant difference was observed between the median ROI difference values in the dissection group (n = 18) and the atherosclerosis group (n = 33; 35.6 [20.9-78.4] vs. 165.5 [99.8-328.5]; p < 0.001). A receiver operating characteristic curve was prepared to distinguish between dissection and atherosclerosis using the ROI difference values. The area under the curve was 0.919 (sensitivity 75.8%, specificity 94.4%). The optimal cutoff value for using ROI to distinguish between dissection and atherosclerosis was found to be 99.0 based on the Youden's index. CONCLUSION: The ROI difference value from 3D TOF MRA could help distinguish between dissection and atherosclerosis. If the ROI difference value from 3D TOF MRA is small (< 99.0), detailed testing should be performed to identify dissection.

Quantitative evaluation of hand motor function using a gyrosensor in mild and moderate carpal tunnel syndrome.

INTRODUCTION: The objective of this study was to determine whether patients with carpal tunnel syndrome (CTS) manifest changes in early-stage motor function and to investigate the utility of a gyrosensor for quantitative evaluation of motor function. METHODS: Angular velocity signal was measured during finger tapping in 52 patients with mild-to-moderate CTS and 45 controls. Four finger-tapping performance (FTP) values-root-mean-squared (RMS) velocity, RMS angle, peak power, and total power-were derived from the signal. RESULTS: All FTP values were significantly lower in patients with CTS than in controls (P = 0.001 or P < 0.001). There were no significant differences between the mild and moderate CTS subgroups. DISCUSSION: FTP measurement with a gyrosensor represents a valuable tool for the evaluation of median nerve motor function in patients with CTS. It facilitates the detection of subclinical motor dysfunction in patients with early stage CTS. Muscle Nerve 59:465-469, 2019.

Clinical Significance of Repetitive Compound Muscle Action Potentials in Patients with Myasthenia Gravis: A Predictor for Cholinergic Side Effects of Acetylcholinesterase Inhibitors.

BACKGROUND AND PURPOSE: Acetylcholinesterase inhibitors (AChEIs) are widely used to treat myasthenia gravis (MG). Although AChEIs are usually tolerated well, some MG patients suffer from side effects. Furthermore, a small proportion of MG patients show cholinergic hypersensitivity and cannot tolerate AChEIs. Because repetitive compound muscle action potentials (R-CMAPs) are an electrophysiologic feature of cholinergic neuromuscular hyperactivity, we investigated the clinical characteristics of MG patients with R-CMAPs to identify their clinical usefulness in therapeutic decision-making. METHODS: We retrospectively reviewed the clinical records and electrodiagnostic findings of MG patients who underwent electrodiagnostic studies and diagnostic neostigmine testing (NT). RESULTS: Among 71 MG patients, 9 could not tolerate oral pyridostigmine bromide (PB) and 17 experienced side effects of PB. R-CMAPs developed in 24 patients after NT. The highest daily dose of PB was lower in the patients with R-CMAPs (240 mg/day vs. 480 mg/day, p<0.001). The frequencies of PB intolerance and side effects were higher in the patients with R-CMAPs than in those without R-CMAPs [37.5% vs. 0% (p<0.001) and 45.8% vs. 12.8% (p=0.002), respectively]. The MG Foundation of America postintervention status did not differ significantly between MG patients with and without R-CMAPs, and the response to immunotherapy was also good in both groups. CONCLUSIONS: Side effects of and intolerance to AChEIs are more common in MG patients with R-CMAPs than in those without R-CMAPs. AChEIs should be used carefully in MG patients with R-CMAPs. The presence of R-CMAPs after NT may be a good indicator of the risks of PB side effects and intolerance.

Utility of the Midbrain Tegmentum Diameter in the Differential Diagnosis of Progressive Supranuclear Palsy from Idiopathic Parkinson's Disease.

BACKGROUND AND PURPOSE: Various magnetic resonance (MR) measurements have been proposed to aid in differentiating between progressive supranuclear palsy (PSP) and idiopathic Parkinson's disease (IPD); however, these methods have not been compared directly. The aim of this study was to determine which measurement method exhibits the highest power to differentiate between PSP and IPD. METHODS: Brain MR images from 82 IPD and 29 PSP patients were analyzed retrospectively. T1-weighted 3D volumetric axial images, or sagittal images reconstructed from those axial images were examined. MR measurements included the length from the interpeduncular fossa to the center of the cerebral aqueduct at the mid-mammillary-body level, adjusted according to the anterior commissure-posterior commissure length (MB(Tegm)), the ratio of the midbrain area to the pons area (M/P ratio) as measured by both Oba's method (Oba M/P) and Cosottini's method (Cosottini M/P), and a modified MR parkinsonism index (mMRPI). RESULTS: Receiver operating characteristic (ROC) analysis indicated that the areas under the ROC curves (AUCs) exceeded 0.70, with a high intrarater reliability for all MR measurement methods. ROC analyses of four MR measurements yielded AUCs of 0.69-0.76. At the cutoff value with the highest Youden index, mMRPI had the highest sensitivity, while Oba M/P offered the highest specificity. A comparison of the ROC analyses revealed that MB(Tegm) was superior to mMRPI in differentiating PSP from IPD (p=0.049). There was no difference in discriminating power among Oba M/P, Cosottini M/P, and MB(Tegm). CONCLUSIONS: Simple measurements of MB(Tegm) on axial MR images at the mid-mammillary-body level are comparable to measurements of the M/P ratio with regard to their ability to discriminate PSP from IPD.

Miller Fisher syndrome related to Orientia tsutsugamushi infection.

Miller Fisher syndrome is typically associated with a preceding infection, especially with Campylobacter jejuni. We describe a patient with Miller Fisher syndrome following Orientia tsutsugamushi infection, which to our knowledge has not been previously reported.