• Annals of Clinical Neurophysiology
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• v.1 no.2
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• pp.112-117
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• 1999

Background : Posterior tibial nerve somatosensory evoked potentials (PTSEP) have cortical potentials on primary sensory area of foot around 40 msec. The direct cortical recordings of the cortical potentials shows high voltage positive wave on medial hemisphere, especially on paracentral lobule (PCL). However, it is so difficult to record the potential directly on PCL that the cortical potential of PTSEP is not well understood. We investigated the cortical potential of PTSEP on subdural electrodes. Methods : We recorded cortical potentials to posterior tibial nerve stimulation on subdural electrodes which were on medial hemisphere near PCL in 15 intractable neocortical epilepsy patients. The numbers of subdural electrodes were 8 in 10 subjects ($1{\times}8array$) and 16 in 5 subjects ($2{\times}8arrays$). Seven subjects had three-dimensional imaging fusion (3D-fusion) of MRI and the electrodes using Analyze program. We investigated the amplitude, latency, polarity, and phase of the waves regarding location. Results : The waves had maximal amplitude on PCL in 4 subjects, precuneus in 1, cingulate gyrus nearest to PCL in 2 among 7 subjects with 3D-fusion. Also the electrodes were located on posterior area of PCL (2 out of 2 subjects with more than two electrodes put on PCL in 3D-fusion) and superior area of it (5 out of 5 subjects with $2{\times}8arrays $). All the high (more than 20 uV) amplitude around 40msec had positive polarity in 7 subjects. The phase reversals were detected between the electrodes with the highest amplitude and the just posterior (2 subjects) or anterior (6 subjects) located electrodes. The just posterior located electrodes had sharper phase reversal than the anterior one. Conclusion : PTSEP might have maximal amplitude of cortical potentials on the more superior and posterior area of PCL. The highest amplitude potential has positivity. The wave with maximal amplitude could have phase reversal of cortical potentials with surrounding electrodes, especially shaper with posterior part than with anterior one.

• Clinical and Experimental Pediatrics
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• v.51 no.10
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• pp.1047-1051
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• 2008

Purpose : This study aims to evaluate the efficacy and safety of sedatives for pediatric patients using noninvasive procedures. Methods : We performed a prospective study in 446 (aged 1 month-21 y) consecutive pediatric patients undergoing sedation to study noninvasive sedation techniques from February to August 2007. We reviewed demographic data, sedative drugs, dosage, complications, and successful rates of sedation according to the underlying diseases. Results : The overall successful rate of sedation was 435/446 (97.5%). The overall rate of successful sedation using chloral hydrate was 99.1% (420/424), and was 70.6% (12/17) and 60.0% (3/5) with ketamine and midazolam, respectively. Of the neurologic patients (n=172, aged 1 month to 21 years), 136 patients were sedated for EEGs, 5 patients for renal scans, and 31 patients for neuroimaging studies such as brain CT or MRI. All non-neurological patients (n=274, aged 1 month to 5 years) were diagnosed with urinary tract infection and sedated for renal scan. The overall success rate of sedation for this group was 99.6% (273/274). A total of 14 adverse events were observed (3.1%). Most adverse reactions were mild in severity and clinically insignificant. Conclusion : Using chloral hydrate alone has enough effect to sedate non-neurologic patients. However, neurologic patients in the severe course group, especially those suffering from intractable epilepsy, autism, or severe cerebral palsy, must be medicated with chloral hydrate 2 times at most; instead, injections of ketamine or midazolam in the early stage may result in a more promising outcome.