Abstract BACKGROUND AND OBJECTIVE: A single session of repetitive transcranial magnetic stimulation (rTMS) over motor cortex had been reported to produce short term relief of some types of chronic pain. The present study investigated whether five consecutive days of rTMS would lead to longer lasting pain relief in unilateral chronic intractable neuropathic pain. PATIENTS AND METHODS: Forty eight patients with therapy resistant chronic unilateral pain syndromes (24 each with trigeminal neuralgia (TGN) and post-stroke pain syndrome (PSP)) participated. Fourteen from each group received 10 minutes real rTMS over the hand area of motor cortex (20 Hz, 10x10 s trains, intensity 80% of motor threshold) every day for five consecutive days. The remaining patients received sham stimulation. Pain was assessed using a visual analogue scale (VAS) and the Leeds assessment of neuropathic symptoms and signs (LANSS) scale, before, after the first, fourth, and fifth sessions, and two weeks after the last session. RESULTS: No significant differences were found in basal pain ratings between patients receiving real- and sham-rTMS. However, a two factor ANOVA revealed a significant "+/- TMS" x "time" interaction indicating that real and sham rTMS had different effects on the VAS and LANSS scales. Post hoc testing showed that in both groups of patients, real-rTMS led to a greater improvement in scales than sham-rTMS, evident even two weeks after the end of the treatment. No patient experienced adverse effects. CONCLUSION: These results confirm that five daily sessions of rTMS over motor cortex can produce longlasting pain relief in patients with TGN or PSP.

Abstract The occurrence of dysarthria is not infrequent in stroke but little is known about its pathophysiology. The aims of the present study were to assess the central motor innervation of the tongue in normal adults using transcranial magnetic stimulation (TMS) and to compare this with that seen in stroke patients with or without dysarthria. The study included 46 patients with acute monohemispheric stroke due to occlusion of the territory of the middle cerebral artery as documented by CT brain scan (26 patients with dysarthria and 20 patients without dysarthria). Forty-five (age and sex matched) normal volunteers served as controls. Corticolingual pathways were assessed for each subject after TMS of each hemisphere. TMS over the motor cortex of healthy subjects elicited consistent ipsilateral and contralateral lingual responses. The ipsilateral response was usually smaller and approximately 73% of the amplitude of the contralateral response. The cross talk between the two halves of the tongue as estimated after unilateral electrical stimulation of hypoglossal nerve gave a contra/ipsi ratio of 36%, which was significantly smaller than the ratio seen after cortical stimulation (CL). For the patients, with or without dysarthria, motor evoked potential (MEP) latencies (ipsilateral and contralateral) were significantly prolonged after stimulation of affected hemisphere compared with the non-affected hemisphere or the control group (P 0.001). MEP amplitudes were significantly smaller in hemiplegic patients with dysarthria compared to patients without dysarthria. In patients without dysarthria stimulation of the unaffected hemisphere tended to evoke responses that were of similar size on both sides. There were no significant associations between neurophysiological parameters and side of infarction. We conclude that interruption of the corticolingual pathways is frequent in stroke patients with or without dysarthria. The ability of unaffected hemisphere to evoke responses in the side contralateral to the lesion may relate to the absence or presence of dysarthria.

Abstract Repetitive transcranial magnetic stimulation (rTMS) or sham stimulation was given over the motor cortex daily for 10 days to two randomly assigned groups of 26 patients with acute ischemic stroke. Patients otherwise continued their normal treatment. Disability scales measured before rTMS, at the end of the last rTMS session, and 10 days later showed that real rTMS improved patients' scores more than sham.

Abstract Repetitive transcranial magnetic stimulation (rTMS) or sham stimulation was given over the motor cortex daily for 10 days to two randomly assigned groups of 26 patients with acute ischemic stroke. Patients otherwise continued their normal treatment. Disability scales measured before rTMS, at the end of the last rTMS session, and 10 days later showed that real rTMS improved patients' scores more than sham.

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 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 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.