Altered somatosensory neurovascular coupling in patients with becker muscular dystrophy

WCN 2013 No: 2405 Topic: 7 Neuromuscular disorders Low and high frequency repetitive nerve stimulation in the diagnosis of myasthenia gravis N. Kvirkvelia, N.Mikava, R. Nikolaishvili, M. Jibladze, T. Akhvlediani, R. Shakarishvili. Department of Neurology and Neurosurgery, Ivane Javakhishvili Tbilisi State University, Tbilisi, Georgia; Sarajishvili Institute of Clinical Neurology and Neurosurgery, Tbilisi, Georgia; Neurology Department, Khechinashvili University Clinic, Georgia; Ivane Javakhishvili Tbilisi State University, Tbilisi, Georgia Background: Diagnosis of myasthenia gravis (MG) typically is made based on patient's history and clinical findings. However, the diagnosis must be verified by the electrophysiological investigation of neuro-muscular transmission. The repetitive nerve stimulation (RNS) is an electrodiagnostic technique used to assess the efficacy of neuromuscular transmission. Objective: The objective of this study was to evaluate combined muscle action potential (CMAP) changes in response to high and low frequency rates of RNS in patients with MG. Patients and methods: The correlation of muscle strength and CMAP changes were investigated in 104 myasthenic patients. The muscle strength was graded on a scale from 0 to 5. Two stimulating parameters were used throughout the experiments — the low frequency stimulation (LFS) and high frequency stimulation (HFS). Results: It was found that in 15% of muscles with clinically detectable weakness the CMAP amplitudewas decreased, by 21% in area, and by8% in duration of the negative phase. The positive correlation was observed between the negative phase of CMAP and the muscle strength and negative correlation was observed between the negative phase duration and the muscle strength. Conclusion:We used RNS in a large cohort of patients as an additional tool for the confirmation of the MG diagnosis. We registered higher decrement in larger muscle groups which are more commonly affected clinically. However, smaller muscles, such as the abductor digiti quinti muscle are often preferable to investigate, because they create less discomfort for the patient and have fewer artifacts. doi:10.1016/j.jns.2013.07.1636 Abstract WCN 2013 No: 2277 Topic: 7 Neuromuscular disorders Altered somatosensory neurovascular coupling in patients with becker muscular dystrophy WCN 2013 No: 2277 Topic: 7 Neuromuscular disorders Altered somatosensory neurovascular coupling in patients with becker muscular dystrophy U. Lindberg, C. Kruuse, S. Joergensen, J. Vissing, N. Witting, E. Rostrup, H.B. Larsson. Functional Imaging Unit, Diagnostic Department, Glostrup Hospital, University of Copenhagen, Denmark; Lundbeck Foundation Center for Neurovascular Signalling, Glostrup, Denmark; Neurology, Herlev Hospital, University of Copenhagen, Herlev, Denmark; Department Neurology, Rigshospitalet, University of Copenhagen, Kbh O, Denmark Background: In patients suffering from Becker muscular dystrophy (BMD) variable degrees of cognitive impairment have been reported in addition to the well-known muscular and cardiac symptoms. BMD is caused by mutations in the dystrophin gene, changing the cellular dystrophin complex and subsequent muscular blood flow. Few studies have addressed the mechanisms of cognitive impairment. Lack of dystrophin, however, causes secondary loss of vasoactive molecules such as nitric oxide, which is as an important player in brain vascular control. We hypothesised that dystrophin can be involved in neurovascular coupling and cerebral reactivity measured by functional MRI and EEG. Objective: To study the baseline electrophysiological and fMRI BOLDresponse to external somatosensory stimulation in BMD patients compared to age and sex-matched healthy controls. Patients and methods: 17 men (mean age 38.5, range 25–63) with BMD and 8 healthy sex matched controls were included. Functional MRI (fMRI, BOLD) (3T, Phillips) and EEG with evoked potentials were performed during a somatosensoric stimulation paradigm on the dominant median nerve. Results: BMD patients showed a significantly (p b 0.02) decreased electrophysiological adaptation together with a decreased (p b 0.01) BOLD-response in the primary somatosensory cortex when compared to healthy controls. Conclusion: The preliminary results suggest that patients with BMD have a fundamentally altered cerebral neurovascular coupling, which could impact cognitive function in BMD patients. doi:10.1016/j.jns.2013.07.1637 Abstract — WCN 2013 No: 2379 Topic: 7 — Neuromuscular disorders Two cases of POEMS syndrome: Initially misdiagnosed as CIDP WCN 2013 No: 2379 Topic: 7 — Neuromuscular disorders Two cases of POEMS syndrome: Initially misdiagnosed as CIDP O. Watanabe, K. Arimura, T. Nakamura, Y. Arimura, Y. Inamori, Y. Takata, K. Michizono, E. Matsuura, H. Takashima. Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan POEMS syndrome (also known as Crow-Fukase syndrome) is a serious systemic disease characterized by polyneuropathy, anasarca, skin lesions and associated with osteoclastic bone lesions and with M-proteinemia. The diagnosis of POEMS syndrome is made robust by finding increased serum vascular endothelial growth factor (VEGF) in addition to the combination of the mentioned characteristic manifestations. The diagnosis of advanced POEMS syndrome is not difficult when the combinations of characteristic manifestations are fulfilled. However, in the initial stages, only half of POEMS patients start with neuropathy. Neuropathy in POEMS syndrome is characterized by a subacute, progressive sensorimotor type of polyneuropathy with mixed features of demyelination and axonal degeneration. However, nerve conduction study (NCS) results of POEMS syndrome occasionally fulfill the electrophysiological criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), thus leading to the caveat of an often initial misdiagnosis of CIDP. We herein present two female patients with POEMS syndrome. Case 1: A 67-year-old woman was admitted to one university hospital with a 1.5-year history of progressive weakness and paraesthesia. Her weakness and paraesthesia initially affected his lower limbs, progressing within 2 months to her upper limbs. Case 2: A 24-year-old woman was admitted to another university hospital with a 2-month history of progressive paraesthesia and muscle weakness affecting her lower limbs. Both cases were electrophysiologically diagnosed as CIDP, then treated with intravenous Abstracts / Journal of the Neurological Sciences 333 (2013) e422–e480 e459