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P2.42 Clinical and imaging features of inclusion body myositis
Abstracts / Neuromuscular Disorders 20 (2010) 596–680
P2.40 Infantile onset anti-MUSK positive myasthenia gravis: report of two cases O. Duman 1, R. Koken 1, S. Haspolat 1, H. Topaloglu 2 1 Akdeniz University, Faculty of Medicine, Child Neurology, Antalya, Turkey, 2 Akdeniz University, Faculty of Medicine, Antalya, Turkey
Introduction: Antibodies against muscle-specific receptor tyrosine kinase (anti-MuSK) are rare in children with myasthenia gravis (MG). It is seen in 0–40% of cases with seronegative MG in adult patients. Here we reported two infancy onset anti-MUSK seropositive cases. As far as we know, our first case is the youngest reported patient. Case 1: A 14-months old boy patient presented with bilateral ptosis, mild drooling complaints and generalised weakness. On his physical examination there was axial and proximal weakness. He had no external ophthalmoparesis. He showed improvement after neostigmin test. He was put on pyridistogmin therapy. His symptoms partially improved. He was acetylcholine receptor antibody (AChR)-negative while anti-MUSK found to be positive. He was introduced IVIG treatment for his bulbar symptoms with partial benefit. Case 2: A 4.5-years old girl was diagnosed as MG at the age of 23-months. At that time she had ptosis and mild weakness. Her complaints were ceased with neostigmin test. Pyridostigmine treatment was initiated. She showed partial response to this therapy. She was seronegative for AChR. She was found to be anti-MUSK positive. Discussion: Anti-MUSK positive myasthenia gravis also evident in early infancy. Ptosis without ophthalmoparesis, proximal weakness were the characteristic findings in our patients. doi:10.1016/j.nmd.2010.07.112
INCLUSION BODY MYOSITIS; POSTER PRESENTATIONS P2.41 Prevalence of inclusion body myositis (IBM) in Japanese population N. Suzuki 1, M. Aoki 1, M. Tateyama 1, R. Izumi 1, H. Warita 1, Y. Itoyama 1, M. Mori 2, H. Kusaka 3, I. Higuchi 4, T. Kondo 5, M. Uchino 6, R. Kaji 7, I. Nishino 8 1
Tohoku University School of Medicine, Neurology, Sendai, Japan, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan, 3 Kansai Medical University, Osaka, Japan, 4 Kagoshima University, Kagoshima, Japan, 5 Wakayama Medical University, Wakayama, Japan, 6 Kumamoto University, Kumamoto, Japan, 7 Institute of Health Bioscience, Graduate School of Medicine, University of Tokushima, Tokushima, Japan, 8 National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Department of Neuromuscular Research, Kodaira, Japan 2
Background: The prevalence of inclusion body myositis (IBM) is variable in different populations and ethnic groups. Previous surveys revealed that the prevalence in Caucasians is 5–15 per million. The prevalence of IBM in Asian people including Japanese has not been elucidated. Method: We estimated the number of IBM by comparing the number of IBM with polymyositis (PM) diagnosed at the National Center of Neurology and Psychiatry (NCNP). The number of PM is calculated from national survey in Japan. This study is based on the hypothesis that the sampling rate of IBM and PM has been constant in these two decades. We also have performed a multi-center survey of Japanese patients with IBM. Only cases of definite and probable IBM fulfilling the clinical and biopsy criteria proposed by Needham and Mastaglia were included in the analysis. Result: The
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estimated prevalence of IBM in Japan was 11.8 per million in 2005. In 1995, the estimated prevalence of IBM was 2.5 per million suggesting increasing numbers of IBM in Japanese during the last decade. From the multi-center survey, a total of 146 IBM cases were identified between 2000 and 2009. Only 38% of patients were initially diagnosed as IBM. The mean time to diagnosis was 4.6 years. Discussion The prevalence of IBM may be increasing in Japan, although the aging population has a profound effect. A prospective nationwide survey is needed. The changing dietary habit to Western-style may have an influence on the increasing number of IBM in Japan. Diagnostic attention is required even among the Asian community. doi:10.1016/j.nmd.2010.07.113
P2.42 Clinical and imaging features of inclusion body myositis A. Hosaka, A. Ishii, Y. Tomidokoro, H. Tsuji, A. Oda, H. Takuma, K. Ishii, A. Tamaoka University of Tsukuba, Neurology, Tsukuba, Japan Objective: Sporadic inclusion body myositis (sIBM) is the most common myopathy presenting over the age of 50 years. The diagnosis of sIBM is frequently delayed being initial errors common, as a consequent of the variation of clinical phenotype at presentation and frequent false negative results of initial muscle biopsy because of lack of rimmed vacuoles. For better diagnosis, we evaluate the clinical and radiological characteristics of Japanese patients with sIBM. Patients and methods: Thirteen patients (11 male and 2 female, being mean age of onset and diagnosis 58 ± 8 years old and 65 ± 8 years old, respectively) with sIBM based on muscle biopsy in the Department of Neurology, the University of Tsukuba Hospital over a 33-year period from 1976 to 2009 were included in this study. The clinical features and muscle computed tomography (CT) findings were evaluated retrospectively. Results: Muscle weakness and atrophy were evident in the quadriceps femoris in the lower limbs as well as in the both distal and proximal muscles in the upper limbs. Their average serum creatine kinase (CK) level was 452 ± 213 IU/l. Muscle CT revealed selective involvement of the vastus lateralis, vastus medialis and vastus intermedius in the thighs, the medial gastrocnemius in the lower legs, and flexsor digitorum profundus in the forearm. In contrast, the rectus femoris, the lateral gastrocnemius and flexor digitorum profundus were spared. Twelve out of 13 patients were treated as follows; 7 IVIG, 3 IVIG and prednisolone, 1 IVIG and immunosuppressant and 1 prednisolone. Eleven patients responded to treatments revealing their increased muscular strength and/or their CK levels returned to normal range. Conclusion: CT scan is of good diagnostic value in the investigation of patients with suspected sIBM especially when patients present atypical clinical features or lack of rimmed vacuoles, since muscle CT scan is easier to be performed than muscle MRI imaging. doi:10.1016/j.nmd.2010.07.114
P2.43 A dysphagia study in patients with inclusion body myositis K. Murata 1, K. Kouda 2, H. Miwa 1, T. Kondo 1 1 Wakayama Medical University, Neurology, Wakayama, Japan, 2 Wakayama Medical University, Rehabilitation Medicine, Wakayama, Japan
Inclusion body myositis (IBM) is a chronic progressive inflammatory myopathy. Although approximately 40% of IBM patients
P2.40 Infantile onset anti-MUSK positive myasthenia gravis: report of two cases O. Duman 1, R. Koken 1, S. Haspolat 1, H. Topaloglu 2 1 Akdeniz University, Faculty of Medicine, Child Neurology, Antalya, Turkey, 2 Akdeniz University, Faculty of Medicine, Antalya, Turkey
Introduction: Antibodies against muscle-specific receptor tyrosine kinase (anti-MuSK) are rare in children with myasthenia gravis (MG). It is seen in 0–40% of cases with seronegative MG in adult patients. Here we reported two infancy onset anti-MUSK seropositive cases. As far as we know, our first case is the youngest reported patient. Case 1: A 14-months old boy patient presented with bilateral ptosis, mild drooling complaints and generalised weakness. On his physical examination there was axial and proximal weakness. He had no external ophthalmoparesis. He showed improvement after neostigmin test. He was put on pyridistogmin therapy. His symptoms partially improved. He was acetylcholine receptor antibody (AChR)-negative while anti-MUSK found to be positive. He was introduced IVIG treatment for his bulbar symptoms with partial benefit. Case 2: A 4.5-years old girl was diagnosed as MG at the age of 23-months. At that time she had ptosis and mild weakness. Her complaints were ceased with neostigmin test. Pyridostigmine treatment was initiated. She showed partial response to this therapy. She was seronegative for AChR. She was found to be anti-MUSK positive. Discussion: Anti-MUSK positive myasthenia gravis also evident in early infancy. Ptosis without ophthalmoparesis, proximal weakness were the characteristic findings in our patients. doi:10.1016/j.nmd.2010.07.112
INCLUSION BODY MYOSITIS; POSTER PRESENTATIONS P2.41 Prevalence of inclusion body myositis (IBM) in Japanese population N. Suzuki 1, M. Aoki 1, M. Tateyama 1, R. Izumi 1, H. Warita 1, Y. Itoyama 1, M. Mori 2, H. Kusaka 3, I. Higuchi 4, T. Kondo 5, M. Uchino 6, R. Kaji 7, I. Nishino 8 1
Tohoku University School of Medicine, Neurology, Sendai, Japan, National Center of Neurology and Psychiatry (NCNP), Kodaira, Japan, 3 Kansai Medical University, Osaka, Japan, 4 Kagoshima University, Kagoshima, Japan, 5 Wakayama Medical University, Wakayama, Japan, 6 Kumamoto University, Kumamoto, Japan, 7 Institute of Health Bioscience, Graduate School of Medicine, University of Tokushima, Tokushima, Japan, 8 National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Department of Neuromuscular Research, Kodaira, Japan 2
Background: The prevalence of inclusion body myositis (IBM) is variable in different populations and ethnic groups. Previous surveys revealed that the prevalence in Caucasians is 5–15 per million. The prevalence of IBM in Asian people including Japanese has not been elucidated. Method: We estimated the number of IBM by comparing the number of IBM with polymyositis (PM) diagnosed at the National Center of Neurology and Psychiatry (NCNP). The number of PM is calculated from national survey in Japan. This study is based on the hypothesis that the sampling rate of IBM and PM has been constant in these two decades. We also have performed a multi-center survey of Japanese patients with IBM. Only cases of definite and probable IBM fulfilling the clinical and biopsy criteria proposed by Needham and Mastaglia were included in the analysis. Result: The
631
estimated prevalence of IBM in Japan was 11.8 per million in 2005. In 1995, the estimated prevalence of IBM was 2.5 per million suggesting increasing numbers of IBM in Japanese during the last decade. From the multi-center survey, a total of 146 IBM cases were identified between 2000 and 2009. Only 38% of patients were initially diagnosed as IBM. The mean time to diagnosis was 4.6 years. Discussion The prevalence of IBM may be increasing in Japan, although the aging population has a profound effect. A prospective nationwide survey is needed. The changing dietary habit to Western-style may have an influence on the increasing number of IBM in Japan. Diagnostic attention is required even among the Asian community. doi:10.1016/j.nmd.2010.07.113
P2.42 Clinical and imaging features of inclusion body myositis A. Hosaka, A. Ishii, Y. Tomidokoro, H. Tsuji, A. Oda, H. Takuma, K. Ishii, A. Tamaoka University of Tsukuba, Neurology, Tsukuba, Japan Objective: Sporadic inclusion body myositis (sIBM) is the most common myopathy presenting over the age of 50 years. The diagnosis of sIBM is frequently delayed being initial errors common, as a consequent of the variation of clinical phenotype at presentation and frequent false negative results of initial muscle biopsy because of lack of rimmed vacuoles. For better diagnosis, we evaluate the clinical and radiological characteristics of Japanese patients with sIBM. Patients and methods: Thirteen patients (11 male and 2 female, being mean age of onset and diagnosis 58 ± 8 years old and 65 ± 8 years old, respectively) with sIBM based on muscle biopsy in the Department of Neurology, the University of Tsukuba Hospital over a 33-year period from 1976 to 2009 were included in this study. The clinical features and muscle computed tomography (CT) findings were evaluated retrospectively. Results: Muscle weakness and atrophy were evident in the quadriceps femoris in the lower limbs as well as in the both distal and proximal muscles in the upper limbs. Their average serum creatine kinase (CK) level was 452 ± 213 IU/l. Muscle CT revealed selective involvement of the vastus lateralis, vastus medialis and vastus intermedius in the thighs, the medial gastrocnemius in the lower legs, and flexsor digitorum profundus in the forearm. In contrast, the rectus femoris, the lateral gastrocnemius and flexor digitorum profundus were spared. Twelve out of 13 patients were treated as follows; 7 IVIG, 3 IVIG and prednisolone, 1 IVIG and immunosuppressant and 1 prednisolone. Eleven patients responded to treatments revealing their increased muscular strength and/or their CK levels returned to normal range. Conclusion: CT scan is of good diagnostic value in the investigation of patients with suspected sIBM especially when patients present atypical clinical features or lack of rimmed vacuoles, since muscle CT scan is easier to be performed than muscle MRI imaging. doi:10.1016/j.nmd.2010.07.114
P2.43 A dysphagia study in patients with inclusion body myositis K. Murata 1, K. Kouda 2, H. Miwa 1, T. Kondo 1 1 Wakayama Medical University, Neurology, Wakayama, Japan, 2 Wakayama Medical University, Rehabilitation Medicine, Wakayama, Japan
Inclusion body myositis (IBM) is a chronic progressive inflammatory myopathy. Although approximately 40% of IBM patients