Faculty Profiles - HASHIZUME Atsushi

Brugada syndrome in spinal and bulbar muscular atrophy. Reviewed International journal

Amane Araki, Masahisa Katsuno, Keisuke Suzuki, Haruhiko Banno, Noriaki Suga, Atsushi Hashizume, Tomoo Mano, Yasuhiro Hijikata, Hideaki Nakatsuji, Hirohisa Watanabe, Masahiko Yamamoto, Takeru Makiyama, Seiko Ohno, Megumi Fukuyama, Shin-Ichiro Morimoto, Minoru Horie, Gen Sobue

Neurology Vol. 82 ( 20 ) page： 1813 - 21 2014.5

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: The aim of this study was to clarify myocardial involvement and its clinical implications in subjects with spinal and bulbar muscular atrophy (SBMA), a neuromuscular disease affecting both neuronal and nonneuronal tissues. METHODS: Two independent cardiologists evaluated ECGs from a total of 144 consecutive subjects with SBMA. We performed immunohistochemical, immunoblot, and quantitative real-time PCR analyses of autopsied myocardium. RESULTS: Abnormal ECGs were detected in 70 (48.6%) of 144 subjects. The most frequent findings were ST-segment abnormalities in V1-3 (19.4%), followed by ST-segment abnormalities in V5-6 (18.1%). We detected Brugada-type ECGs in 17 of 28 subjects with ST-segment abnormalities in V1-3. Of those, one subject presented with syncope that required an implantable cardioverter defibrillator and led to eventual sudden death, and another subject also died suddenly. No subjects with Brugada-type ECGs had mutations in SCN5A, CACNA1C, or CACNB2 genes. In autopsied cases, we detected nuclear accumulation of the mutant androgen receptor protein and decreased expression levels of SCN5A in the myocardium. CONCLUSIONS: Subjects with SBMA often show Brugada-type ECG. The accumulation of the pathogenic androgen receptor may have a role in the myocardial involvement in SBMA.

DOI： 10.1212/WNL.0000000000000434

Distinct acoustic features in spinal and bulbar muscular atrophy patients with laryngospasm. Reviewed International journal Open Access

Seiya Tanaka, Haruhiko Banno, Masahisa Katsuno, Keisuke Suzuki, Noriaki Suga, Atsushi Hashizume, Tomoo Mano, Amane Araki, Hirohisa Watanabe, Hiroaki Adachi, Hiroshi Tatsumi, Masahiko Yamamoto, Gen Sobue

Journal of the neurological sciences Vol. 337 ( 1-2 ) page： 193 - 200 2014.2

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: Laryngospasm is a sudden onset of transient respiratory difficulty that is perceived as life-threatening by patients with spinal and bulbar muscular atrophy (SBMA). The purpose of the study was to analyze the voice characteristics of SBMA patients with laryngospasm using acoustic voice analysis. METHODS: Acoustic measurements were obtained from 39 consecutive Japanese patients with genetically confirmed SBMA. A comparison was made between the acoustic voice profiles of 16 patients with laryngospasm and 23 patients without laryngospasm within 6 months before the evaluation. Computerized acoustic analysis was performed for a prolonged vowel (/a:/) using the Multi-Dimensional Voice Program (MDVP). RESULTS: SBMA patients with laryngospasm had smaller fluctuations of vocal fold vibration and the turbulent noise component, indicating stronger vocal fold closure than in those without laryngospasm. Receiver operating characteristic curve analysis showed that the noise-to-harmonic ratio, which globally measures the noise components of voice, is the most useful acoustic parameter to distinguish laryngospasm (area under the curve = 0.767, p = 0.007). CONCLUSIONS: The smaller noise component in patients with laryngospasm suggests that the vocal folds of these patients are more adducted during phonation than those of the patients without laryngospasm, even in the absence of laryngospasm. Quantitative laryngeal analysis using the MDVP helps to detect laryngeal dysfunction and provides physiological insight into the pathophysiology of laryngospasm in SBMA.

DOI： 10.1016/j.jns.2013.12.010

Tongue pressure as a novel biomarker of spinal and bulbar muscular atrophy. Reviewed International journal

Tomoo Mano, Masahisa Katsuno, Haruhiko Banno, Keisuke Suzuki, Noriaki Suga, Atsushi Hashizume, Amane Araki, Hirohisa Watanabe, Seiya Tanaka, Masahiko Yamamoto, Gen Sobue

Neurology Vol. 82 ( 3 ) page： 255 - 62 2014.1

Language：English Publishing type：Research paper (scientific journal)

OBJECTIVE: This study aimed to explore the reliability and validity of tongue pressure measurement as a quantitative evaluation of swallowing function in patients with spinal and bulbar muscular atrophy (SBMA). METHODS: This study enrolled 47 genetically confirmed patients with SBMA and 38 age- and sex-matched healthy controls. In both groups we measured tongue pressure using an intraoral pressure probe and assessed questionnaires that evaluated swallowing functions. We then analyzed the relationship between tongue pressure, functional scales, and the muscle weakness of other regions. RESULTS: Levels of tongue pressure were decreased in patients with SBMA within 3 years from the onset of the disease compared to healthy controls (SBMA 15.3 ± 6.4 kPa; healthy controls 37.3 ± 9.6 kPa; p < 0.001). Test-retest analysis showed a high reliability in patients with SBMA (intraclass correlation coefficient = 0.986). Tongue pressure showed a strong correlation with bulbar-related functional scales. Decrease of tongue pressure was detected in patients who reported no subjective dysphagia, and repetition of swallowing compensated for tongue weakness in such subjects. In patients with SBMA, tongue pressure more strongly correlates with the strength of pharyngeal, neck, and upper limb musculatures than with that of the lower limbs. CONCLUSION: Tongue pressure measurement is reliable and reflects swallowing function in patients with SBMA. The muscle strength of the tongue appears to decrease in SBMA before the awareness of subjective dysphagia, suggesting that tongue pressure measurement is a novel biomarker of SBMA and is applicable to early-stage detection.

DOI： 10.1212/WNL.0000000000000041