Measurement of excitation-contraction coupling time in critical illness myopathy.

Objective: This study aimed to develop a simple and reliable technique to assess excitation-contraction (E-C) coupling for early diagnosis of critical illness myopathy (CIM).

Methods: We prospectively performed clinical and electrophysiological examinations on patients admitted to intensive care unit (ICU). In addition to full neurological examinations and routine nerve conduction study, motor related potential (MRP) was recorded using an accelerometer attached to the base of hallux after tibial nerve stimulation, and E-C coupling time (ECCT) was measured from the latency difference between soleus compound muscle action potential (CMAP) and MRP.

Oral corticosteroid dosing regimen and long-term prognosis in generalised myasthenia gravis: a multicentre cross-sectional study in Japan.

Objective: We examined the correlation between the dosing regimen of oral prednisolone (PSL) and the achievement of minimal manifestation status or better on PSL ≤5 mg/day lasting >6 months (the treatment target) in patients with generalised myasthenia gravis (MG).

Methods: We classified 590 patients with generalised MG into high-dose (n=237), intermediate-dose (n=187) and low-dose (n=166) groups based on the oral PSL dosing regimen, and compared the clinical characteristics, previous treatments other than PSL and prognosis between three groups. The effect of oral PSL dosing regimen on the achievement of the treatment target was followed for 3 years of treatment.

Effect of local cooling on excitation-contraction coupling in myasthenic muscle: Another mechanism of ice-pack test in myasthenia gravis.

Objective: The ice-pack test is a convenient diagnostic testing procedure for myasthenia gravis (MG). We investigated the underlying mechanism of the ice-pack test performed on bilateral masseters.

Methods: We performed trigeminal repetitive nerve stimulation (RNS), excitation-contraction (E-C) coupling assessment (Imai's method) and bite force measurement before and after cooling of the masseters in MG patients and normal controls.

Social disadvantages associated with myasthenia gravis and its treatment: a multicentre cross-sectional study.

Objectives: To clarify the social disadvantages associated with myasthenia gravis (MG) and examine associations with its disease and treatment.

Design: Cross-sectional study.

Setting And Participants: We evaluated 917 consecutive cases of established MG seen at 13 neurological centres in Japan over a short duration.

[Myopericarditis in a case of anti-signal recognition particle (anti-SRP) antibody-positive myopathy].

A 79 year-old female was admitted to our hospital because of high serum creatine kinase level together with proximal muscle weakness and pain on grasping. MRI revealed inflammatory changes in femoral muscles on both sides. Muscle biopsy showed size irregularity of muscle cells, and necrosis and regeneration of fibers.

Response to treatment of myasthenia gravis according to clinical subtype.

Background: We have previously reported using two-step cluster analysis to classify myasthenia gravis (MG) patients into the following five subtypes: ocular MG; thymoma-associated MG; MG with thymic hyperplasia; anti-acetylcholine receptor antibody (AChR-Ab)-negative MG; and AChR-Ab-positive MG without thymic abnormalities. The objectives of the present study were to examine the reproducibility of this five-subtype classification using a new data set of MG patients and to identify additional characteristics of these subtypes, particularly in regard to response to treatment.

Methods: A total of 923 consecutive MG patients underwent two-step cluster analysis for the classification of subtypes.

Early fast-acting treatment strategy against generalized myasthenia gravis.

Introduction: In this study we sought to clarify the effects of early fast-acting treatment (EFT) strategies on the time course for achieving the treatment target in generalized myasthenia gravis (MG).

Methods: This retrospective study of 923 consecutive MG patients analyzed 688 generalized MG patients who had received immunotherapy during the disease course. The time to first achieve minimal manifestations (MM) or better while receiving prednisolone at ≤5 mg/day for ≥6 months (MM-or-better-5mg) up to 120 months after starting immunotherapy was compared between EFT and non-EFT patients.

Impaired post-tetanic potentiation of muscle twitch in myasthenia gravis.

Objective: The aim of this study was to evaluate post-tetanic potentiation of muscle twitch in myasthenia gravis (MG).

Methods: Post-tetanic potentiation was evaluated by recording the compound muscle action potential (CMAP) of abductor pollicis brevis and movement-related potential (MRP) of the thumb using an accelerometer after tetanic stimulation of the median nerve at the wrist. After baseline recording, tetanic stimulation was delivered to the median nerve at a frequency of 10 Hz for 10s.

Association between Glucocorticoid-Induced Osteoporosis and Myasthenia Gravis: A Cross-Sectional Study.

Purpose: To investigate the association between glucocorticoid-induced osteoporosis and myasthenia gravis (MG) using a cross-sectional survey in Japan.

Methods: We studied 363 patients with MG (female 68%; mean age, 57 ± 16 years) who were followed at six Japanese centers between April and July 2012. We evaluated the clinical information of MG and fractures, bone markers, and radiological assessment.

[A case of atypical Tolosa-Hunt syndrome with a contrast enhanced lesion of the oculomotor and trigeminal nerves on MRI].

A 30-year-old woman was admitted to our hospital because of intractable orbital pain and ptosis on the left side. On admission, she had left oculomotor, ophthalmic and maxillary nerves palsy. MRI revealed a contrast enhanced lesion of the left oculomotor and trigeminal nerves through the covernous sinus and orbita.

Oral corticosteroid therapy and present disease status in myasthenia gravis.

Introduction: The aim of this study was to elucidate the effectiveness of oral prednisolone (PSL) according to dosing regimen in 472 patients with myasthenia gravis (MG).

Methods: We compared the clinical characteristics and PSL treatment between 226 patients who achieved minimal manifestations (MM) or better and 246 patients who remained improved (I) or worsened, according to the MG Foundation of America postintervention status.

Results: Achievement of MM or better at peak PSL dose (odds ratio 12.

Quality of life in purely ocular myasthenia in Japan.

Background: Since there has been no conclusive evidence regarding the treatment of ocular myasthenia, treatment guidelines were recently issued by the European Federation of Neurological Societies/European Neurological Society (EFNS/ENS). However, the therapeutic outcomes concerning the quality-of-life (QOL) of patients with ocular myasthenia are not yet fully understood.

Methods: We investigated the therapeutic outcomes of patients with purely ocular myasthenia in a multicenter cross-sectional survey in Japan.

Respiratory insufficiency with preserved diaphragmatic function in amyotrophic lateral sclerosis.

Objective: We performed a longitudinal study to elucidate the correlation between respiratory insufficiency and respiratory biomarkers, including diaphragmatic compound muscle action potential (DCMAP), at the initiation of noninvasive ventilation (NIV) in patients with amyotrophic lateral sclerosis (ALS).

Methods: The patients were assessed at least every six months. Additional assessments were performed at the start of respiratory therapy when the patients met the criteria for the initiation of NIV.

Health-related quality-of-life and treatment targets in myasthenia gravis.

Introduction: The aim of this study was to determine factors affecting health-related quality of life (HRQOL) and to propose appropriate treatment targets for patients with myasthenia gravis (MG).

Methods: We evaluated 640 consecutive patients with MG seen at 11 neurological centers. Two-year follow-up data were obtained for 282 patients.

Early effect of tacrolimus in improving excitation-contraction coupling in myasthenia gravis.

Objectives: Tacrolimus (FK506) is a macrolide T-cell immunomodulator used to treat myasthenia gravis (MG). Besides immunosuppression, tacrolimus has been reported to have the potential to increase muscle strength by enhancing ryanodine receptor (RyR) function. However, few attempts have been made to demonstrate the early effect of tacrolimus as an RyR enhancer in clinical investigation.

Contribution of anti-ryanodine receptor antibody to impairment of excitation-contraction coupling in myasthenia gravis.

Objective: The aim of this study was to elucidate the relationship between the impairment of excitation-contraction (E-C) coupling and anti-ryanodine receptor (RyR) antibody in patients with myasthenia gravis (MG).

Methods: Masseteric compound muscle action potential (CMAP) and mandibular movement-related potentials (MRPs) were recorded simultaneously after stimulating the trigeminal motor nerve with a needle electrode. The E-C coupling time (ECCT) was calculated as the latency difference between CMAP and MRP.

Reference values for voluntary and stimulated single-fibre EMG using concentric needle electrodes: a multicentre prospective study.

Objective: The aim of this study is to establish reference values for single-fibre electromyography (SFEMG) using concentric needles in a prospective, multicentre study.

Methods: Voluntary or stimulated SFEMG at the extensor digitorum communis (EDC) or frontalis (FRO) muscles was conducted in 56-63 of a total of 69 normal subjects below the age of 60years at six Japanese institutes. The cut-off values for mean consecutive difference (MCD) of individual potentials were calculated using +2.

Correlation of bite force with excitation-contraction coupling time of the masseter in myasthenia gravis.

Objective: The aim of this study was to elucidate the relationship between the impairment of excitation-contraction (E-C) coupling of masseter and the bite force in patients with myasthenia gravis (MG).

Methods: In 20 patients with MG, masseteric compound muscle action potential (CMAP) and mandibular movement-related potentials (MRP) were recorded simultaneously after stimulating the trigeminal motor nerve with a needle electrode. The E-C coupling time (ECCT) was calculated by the latency difference between CMAP and MRP.

Response of serum carboxylated and undercarboxylated osteocalcin to risedronate monotherapy and combined therapy with vitamin K(2) in corticosteroid-treated patients: a pilot study.

Objective: The aim of this study was to investigate the responses of serum osteocalcin (OC), undercarboxylated osteocalcin (ucOC) and N-terminal telopeptide of type I collagen (NTx) to corticosteroids, and to examine the effects of risedronate therapy with or without vitamin K(2) supplementation on bone metabolic markers in corticosteroid-treated patients.

Methods: Sixteen patients on corticosteroid therapy for neuromuscular disorders were assigned randomly to 2 groups (A: risedronate monotherapy, n=8; B: combined risedronate and vitamin K(2) therapy, n=8) and treated for 1 year. Another 6 patients who received intravenous steroid pulse therapy were assigned to group C for investigation of the effects of corticosteroids on OC and ucOC 1 month after pulse therapy.

Transient oculomotor palsy correlated with nerve enhancement on MRI in chronic inflammatory demyelinating polyneuropathy.

A 40-year-old woman was admitted to our hospital because of double vision combined with left ptosis. Although at 25 years of age she had already been diagnosed with limb weakness associated with chronic inflammatory demyelinating polyneuropathy (CIDP), she had never experienced double vision until her latest condition. Neurological examination revealed left oculomotor palsy without other cranial nerve involvement.