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Objectives: It has recently been suggested that drug-induced tardive syndromes (TS) might be due to maladaptive plasticity, which increases motor excitability in cerebral cortex and basal ganglia. In order to test this hypothesis, we performed the first measurements of cortical excitability in TS., Methods: Motor cortex excitability was examined using transcranial magnetic stimulation (TMS) in 22 TS patients and compared with that in 20 age and sex-matched healthy individuals. Resting and active motor threshold (RMT, AMT) and input-output curves (I/O curves) assessed corticospinal excitability. The duration of the contralateral silent period (cSP) at a range of stimulation intensities and ipsilateral silent period (iSP) were used as measures of inhibition., Results: There were no significant differences in RMT and AMT between patients and controls, although the input-output curves were significantly steeper in patients. The cSP (at different stimulus intensities) and iSP were both longer in the patients compared to the control group. However, most of this difference could be accounted for by increased recruitment of motor evoked potentials (MEPs) in patients., Conclusion: TS is characterized by hyperexcitability of corticospinal output that might contribute to the lack of selectivity in muscle recruitment and contribute to excess involuntary movement. The findings are opposite to those in naturally-occurring hyperkinesia such as Sydenham's and Huntington's chorea, suggesting a fundamental difference in the pathophysiology., (Crown Copyright © 2018. Published by Elsevier Masson SAS. All rights reserved.)

Objectives: The aim of the study was to estimate the crude prevalence rate (CPR) of compressive radiculopathies in Qena governorate/Egypt., Patients and Methods: 10 areas in Qena governorate were selected by random sampling, involving 9303 inhabitants with 57.3% urban residents and 42.7% rural residence. Patients were diagnosed using a screening questionnaire for the diagnosis of cervical and lumbosacral radiculopathies. All positive cases were referred to Qena University Hospital where they underwent full neurological examination, neuro-imaging, and neurophysiological investigations., Results: Out of 9303 inhabitants included in the study (1057 families), 49 cases were recruited positive on initial survey and 32 cases were confirmed after clinical examination, neuroimaging and neurophysiological examinations, giving a CPR of 10.1/1000 in those aged over 30 years. Compressive radiculopathy was more common in males than females (13 versus 6/1000) and in rural than urban populations (15 versus 7/1000). No cases were recruited below 30 years old. The highest age specific prevalence was at ≥60 years with a CPR of 26/1000. 11 cases had cervical radiculopathy while 21 cases had lumbosacral radiculopathy (CPR of 3.7 and 6.6/1000 respectively). The highest age specific CPR for males was earlier than females at 50-59 versus ≥60 years., Conclusion: The overall CPR of compressive radiculopathy in the general population in Qena governorate/Egypt is similar for cervical radiculopathy but higher for lumbosacral radiculopathy than a previous Egyptian study but mid-way compared to other countries., (Copyright © 2018 Elsevier B.V. All rights reserved.)