Abstract Few comprehensive epidemiological studies of the prevalence of muscle diseases have been undertaken, and none has been carried out in our locality. The present cross-sectional study was conducted in Assiut Governorate (Upper Egypt) to estimate the prevalence of different types of primary muscular disorder in 1997. The study involved 52,203 subjects, 15,617 (30%) from the rural community and 36,586 (70%) from the urban community. Patients were identified from a door-to-door survey, and all were subjected to a full clinical examination, with confirmation of the diagnosis through electrophysiological, and biochemical investigations. Histopathological studies were performed for the classification of muscular dystrophies. Forty patients with muscular disorders were identified, with a point prevalence of 76.6 per 100,000 in the total community with no significant differences between the rural and urban communities. The creatine kinase level was abnormally high (>225 IU/l) in 80% of the cases, increased in all patients with muscular dystrophy or myositis, in 88.8% of patients with systemic myopathy and 66.6% of patients with myotonia. None of the cases of myasthenia showed an increase in the creatine kinase level. The lifetime prevalence per 100,000 was 26.8 for muscular dystrophy, 11.49 for myotonia, 11.49 for myositis, 17.24 for systemic myopathy and 9.57 for myasthenia.

Abstract BACKGROUND AND PURPOSE OF STUDY: Controversy surrounds measures of visual and motor cortical excitability in migraineurs: some authors report that interictal excitability is increased, others decreased. The aim of this work was to provide further evidence about motor and visual cortical excitability in migraineurs between attacks. PATIENTS AND METHODS: Twenty-eight migraineurs patients, 18 with aura and 10 patients without aura and 20 healthy right-handed, age and sex matched volunteers were included in the study. Each subject underwent transcranial magnetic stimulation and was submitted to the following: determination of resting motor threshold (rMT), silent period (SP), MEP input-output curves, phosphene threshold (PT). RESULTS: Patients had lower rMT, shorter SP, and increased MEP recruitment compared with control group. There was an increased prevalence of phosphene (85%) as well as lower PT (63% of the stimulator output) in migraineurs compared with control group (75%, and 72%, respectively). There was a significant negative correlation between duration of attacks and PT (P = 0.02). No significant differences between patients with aura and without aura in different parameters of cortical excitability. CONCLUSION: Our findings confirm that the motor and visual cortexes are hyperexcitable and this appears partly to be consequent upon a failure of inhibitory circuits.

Abstract BACKGROUND AND PURPOSE OF STUDY: Controversy surrounds measures of visual and motor cortical excitability in migraineurs: some authors report that interictal excitability is increased, others decreased. The aim of this work was to provide further evidence about motor and visual cortical excitability in migraineurs between attacks. PATIENTS AND METHODS: Twenty-eight migraineurs patients, 18 with aura and 10 patients without aura and 20 healthy right-handed, age and sex matched volunteers were included in the study. Each subject underwent transcranial magnetic stimulation and was submitted to the following: determination of resting motor threshold (rMT), silent period (SP), MEP input-output curves, phosphene threshold (PT). RESULTS: Patients had lower rMT, shorter SP, and increased MEP recruitment compared with control group. There was an increased prevalence of phosphene (85%) as well as lower PT (63% of the stimulator output) in migraineurs compared with control group (75%, and 72%, respectively). There was a significant negative correlation between duration of attacks and PT (P = 0.02). No significant differences between patients with aura and without aura in different parameters of cortical excitability. CONCLUSION: Our findings confirm that the motor and visual cortexes are hyperexcitable and this appears partly to be consequent upon a failure of inhibitory circuits.

Abstract OBJECTIVE: To investigate the effect of high frequency rTMS (25 Hz at 90-100% of resting motor threshold) on the excitability of the motor cortex of healthy human subjects. METHODS: Resting and active motor threshold, MEP recruitment curve (I/O curve), short interval intracortical inhibition (SICI) and facilitation (ICF), and the duration of the silent period (SP) were tested in the right first dorsal interosseous muscle (FDI) before and twice after the end of 1500 pulses in 16 normal young adult male volunteers. RESULTS: Twenty-five Hertz rTMS decreased motor thresholds, reduced the duration of the silent period and had a tendency to increase the slope of the I/O curve. Most of these effects lasted for the duration of the two post-testing sessions (at least 30 min) and had returned to normal by 2h. There were no significant effects on SICI/ICF. CONCLUSION: Twenty-five Hertz rTMS can produce a long lasting increase in cortical excitability in healthy subjects. SIGNIFICANCE: This method may prove useful for the study of normal human physiology and for therapeutic manipulation of brain plasticity.

Abstract OBJECTIVE: To investigate the effect of high frequency rTMS (25 Hz at 90-100% of resting motor threshold) on the excitability of the motor cortex of healthy human subjects. METHODS: Resting and active motor threshold, MEP recruitment curve (I/O curve), short interval intracortical inhibition (SICI) and facilitation (ICF), and the duration of the silent period (SP) were tested in the right first dorsal interosseous muscle (FDI) before and twice after the end of 1500 pulses in 16 normal young adult male volunteers. RESULTS: Twenty-five Hertz rTMS decreased motor thresholds, reduced the duration of the silent period and had a tendency to increase the slope of the I/O curve. Most of these effects lasted for the duration of the two post-testing sessions (at least 30 min) and had returned to normal by 2h. There were no significant effects on SICI/ICF. CONCLUSION: Twenty-five Hertz rTMS can produce a long lasting increase in cortical excitability in healthy subjects. SIGNIFICANCE: This method may prove useful for the study of normal human physiology and for therapeutic manipulation of brain plasticity.

Abstract OBJECTIVE: To investigate the effect of high frequency rTMS (25 Hz at 90-100% of resting motor threshold) on the excitability of the motor cortex of healthy human subjects. METHODS: Resting and active motor threshold, MEP recruitment curve (I/O curve), short interval intracortical inhibition (SICI) and facilitation (ICF), and the duration of the silent period (SP) were tested in the right first dorsal interosseous muscle (FDI) before and twice after the end of 1500 pulses in 16 normal young adult male volunteers. RESULTS: Twenty-five Hertz rTMS decreased motor thresholds, reduced the duration of the silent period and had a tendency to increase the slope of the I/O curve. Most of these effects lasted for the duration of the two post-testing sessions (at least 30 min) and had returned to normal by 2h. There were no significant effects on SICI/ICF. CONCLUSION: Twenty-five Hertz rTMS can produce a long lasting increase in cortical excitability in healthy subjects. SIGNIFICANCE: This method may prove useful for the study of normal human physiology and for therapeutic manipulation of brain plasticity.

Abstract Previous studies in patients with Parkinson's disease have reported that a single session of repetitive transcranial magnetic stimulation (rTMS) can improve some or all of the motor symptoms for 30 to 60 minutes. A recent study suggested that repeated sessions of rTMS lead to effects that can last for at least 1 month. Here we report data that both confirm and extend this work. Fifty-five unmedicated PD patients were classified into four groups: two groups (early and late PD) received 25 Hz rTMS bilaterally on the motor arm and leg areas; other groups acted as control for frequency (10 Hz) and for site of stimulation (occipital stimulation). All patients received six consecutive daily sessions (3,000 pulses for each session). The first two groups then received a further three booster sessions (3 consecutive days of rTMS) after 1, 2, and 3 months, while the third group had only one additional session after the first month. Unified Parkinson's Disease Rating Scale (UPDRS), walking time, key-tapping speed, and self-assessment scale were measured for each patient before and after each rTMS session and before and after the monthly sessions. Compared to occipital stimulation, 25 Hz rTMS over motor areas improved all measures in both early and late groups; the group that received 10 Hz rTMS improved more than the occipital group but less than the 25 Hz groups. The effect built up gradually during the sessions and was maintained for 1 month after, with a slight reduction in efficacy. Interestingly, the effect was restored and maintained for the next month by the booster sessions. We conclude that 25 Hz rTMS can lead to cumulative and long-lasting effects on motor performance. Copyright 2006 Movement Disorder Society

Abstract Previous studies in patients with Parkinson's disease have reported that a single session of repetitive transcranial magnetic stimulation (rTMS) can improve some or all of the motor symptoms for 30 to 60 minutes. A recent study suggested that repeated sessions of rTMS lead to effects that can last for at least 1 month. Here we report data that both confirm and extend this work. Fifty-five unmedicated PD patients were classified into four groups: two groups (early and late PD) received 25 Hz rTMS bilaterally on the motor arm and leg areas; other groups acted as control for frequency (10 Hz) and for site of stimulation (occipital stimulation). All patients received six consecutive daily sessions (3,000 pulses for each session). The first two groups then received a further three booster sessions (3 consecutive days of rTMS) after 1, 2, and 3 months, while the third group had only one additional session after the first month. Unified Parkinson's Disease Rating Scale (UPDRS), walking time, key-tapping speed, and self-assessment scale were measured for each patient before and after each rTMS session and before and after the monthly sessions. Compared to occipital stimulation, 25 Hz rTMS over motor areas improved all measures in both early and late groups; the group that received 10 Hz rTMS improved more than the occipital group but less than the 25 Hz groups. The effect built up gradually during the sessions and was maintained for 1 month after, with a slight reduction in efficacy. Interestingly, the effect was restored and maintained for the next month by the booster sessions. We conclude that 25 Hz rTMS can lead to cumulative and long-lasting effects on motor performance. Copyright 2006 Movement Disorder Society

Abstract Previous studies in patients with Parkinson's disease have reported that a single session of repetitive transcranial magnetic stimulation (rTMS) can improve some or all of the motor symptoms for 30 to 60 minutes. A recent study suggested that repeated sessions of rTMS lead to effects that can last for at least 1 month. Here we report data that both confirm and extend this work. Fifty-five unmedicated PD patients were classified into four groups: two groups (early and late PD) received 25 Hz rTMS bilaterally on the motor arm and leg areas; other groups acted as control for frequency (10 Hz) and for site of stimulation (occipital stimulation). All patients received six consecutive daily sessions (3,000 pulses for each session). The first two groups then received a further three booster sessions (3 consecutive days of rTMS) after 1, 2, and 3 months, while the third group had only one additional session after the first month. Unified Parkinson's Disease Rating Scale (UPDRS), walking time, key-tapping speed, and self-assessment scale were measured for each patient before and after each rTMS session and before and after the monthly sessions. Compared to occipital stimulation, 25 Hz rTMS over motor areas improved all measures in both early and late groups; the group that received 10 Hz rTMS improved more than the occipital group but less than the 25 Hz groups. The effect built up gradually during the sessions and was maintained for 1 month after, with a slight reduction in efficacy. Interestingly, the effect was restored and maintained for the next month by the booster sessions. We conclude that 25 Hz rTMS can lead to cumulative and long-lasting effects on motor performance. Copyright 2006 Movement Disorder Society

Abstract Previous studies in patients with Parkinson's disease have reported that a single session of repetitive transcranial magnetic stimulation (rTMS) can improve some or all of the motor symptoms for 30 to 60 minutes. A recent study suggested that repeated sessions of rTMS lead to effects that can last for at least 1 month. Here we report data that both confirm and extend this work. Fifty-five unmedicated PD patients were classified into four groups: two groups (early and late PD) received 25 Hz rTMS bilaterally on the motor arm and leg areas; other groups acted as control for frequency (10 Hz) and for site of stimulation (occipital stimulation). All patients received six consecutive daily sessions (3,000 pulses for each session). The first two groups then received a further three booster sessions (3 consecutive days of rTMS) after 1, 2, and 3 months, while the third group had only one additional session after the first month. Unified Parkinson's Disease Rating Scale (UPDRS), walking time, key-tapping speed, and self-assessment scale were measured for each patient before and after each rTMS session and before and after the monthly sessions. Compared to occipital stimulation, 25 Hz rTMS over motor areas improved all measures in both early and late groups; the group that received 10 Hz rTMS improved more than the occipital group but less than the 25 Hz groups. The effect built up gradually during the sessions and was maintained for 1 month after, with a slight reduction in efficacy. Interestingly, the effect was restored and maintained for the next month by the booster sessions. We conclude that 25 Hz rTMS can lead to cumulative and long-lasting effects on motor performance. Copyright 2006 Movement Disorder Society