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Objective: A general lack of longitudinal studies on interhemispheric interactions following stroke led us to use transcranial magnetic stimulation (TMS) to examine changes in corticospinal/intracortical excitability and transcallosal inhibition over a 1-year period following subcortical stroke., Methods: We measured TMS parameters such as motor threshold (MT), short-interval intracortical inhibition (SICI), and ipsilateral silent period (iSP) and evaluated clinical scores at three time-points (T1, T2, and T3) in 24 patients and 25 age-matched healthy subjects., Results: At T1, we observed reduced MTs and SICIs with prolonged iSPs in the unaffected hemisphere (UH). In contrast, increased MTs and reduced SICIs were observed in the affected hemisphere (AH). These abnormalities gradually reduced and no MEP response to TMS at T1 predicted a worse prognosis. The prolonged iSP at T1 was associated with more severe impairments, but it did not necessarily predict a worse prognosis after 1year., Conclusions: UH excitability was increased at the post-acute time-period, which may have resulted in enhanced transcallosal inhibition to the AH. However, it is unclear whether there was a causal relationship between the enhanced transcallosal inhibition and the extent of clinical recovery., Significance: This is the first study to demonstrate changes in transcallosal inhibition over a longitudinal period following stroke., (Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Objective: To investigate electroencephalographic (EEG) features of benign adult familial myoclonic epilepsy (BAFME)., Methods: We reviewed interictal EEG features in patients with BAFME treated between April 2005 and November 2012 at a tertiary referral center. The diagnostic criteria for BAFME were the presence of infrequent generalized tonic-clonic seizures, myoclonus or myoclonic seizures, and autosomal dominant inheritance. Interictal EEG findings of epilepsy with generalized tonic-clonic seizure only (EGTCS) were reviewed for comparison. We randomly selected 10 generalized spike/polyspike and wave complexes (GSW) for each BAFME patient and measured the duration of them. Photic stimulation and hyperventilation were performed in all., Results: Nineteen (eight men, 11 women) patients with BAFME were included in this study. The mean frequency of GSW was 4.3±1.0Hz (mean±SD, n=14) in BAFME and 3.2±0.8Hz (n=10) in EGTCS. There was a statistically significant difference (p=0.008) between the two. Photoparoxysmal responses (PPR) were noted in 18 (95%) patients with BAFME but 1 (10%) with EGTCS., Conclusion: Faster frequency of GSW, compared with that in EGTCS, accompanied by PPR may be characteristic EEG features of BAFME., Significance: These findings may lead the diagnosis of BAFME., (Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Purpose: Epidemiologic studies have shown that the incidence of epilepsy is the highest in the elderly population. Because the elderly constitutes the most rapidly growing population, epilepsy in this group is an important health issue worldwide. To identify the characteristics of epilepsy in the elderly, we reviewed our experience at a tertiary referral center in Japan., Methods: We searched all electronic medical records of the past 6 years at the epilepsy clinic of the hospital affiliated to our University-affiliated hospital. We defined an elderly person as an individual aged 65 years and above. All patients underwent history and physical examinations, 3T magnetic resonance imaging and/or computer tomography, and electroencephalogram (EEG). The diagnosis of epilepsy, age of onset, etiology, and antiepileptic medication were recorded., Results: We identified 70 patients who developed epilepsy after the age of 65 years. The mean age of seizure onset was 73.1 years and 52.9% patients were males. Complex partial seizures (CPS) without secondarily generalization (n=33, 47.1%) were most frequent. The most frequent diagnosis was temporal lobe epilepsy (n=50, 71.4%). Etiological diagnosis was possible in nearly 50% patients, including those with cerebrovascular disease. A clear cause of epilepsy was not found (i.e., non-lesional epilepsy) in 52.8% patients. Interictal EEG revealed focal epileptiform discharges in 72.9% (n=51) patients. Of the 54 patients who were followed more than 1 year, 42 patients (77.8%) were on antiepileptic monotherapy and 52 patients (96.3%) had been seizure-free for more than 1 year., Conclusion: The most frequent diagnosis in our cohort of elderly persons with new-onset epilepsy was temporal lobe epilepsy. Non-lesional temporal lobe epilepsy was not uncommon. Epileptogenecity was relatively low in elderly patients and they responded well to antiepileptic medication., (Copyright © 2013 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

A double-blind sham-controlled study demonstrated that high-frequency repetitive transcranial magnetic stimulation (rTMS) over the supplementary motor area (SMA) provided relief of motor symptoms in patients with Parkinson's disease (PD). However, it remains to be determined which parkinsonian symptoms were improved by this treatment. Subanalysis of Unified Parkinson Disease Rating Scale revealed that rTMS over SMA significantly improved bradykinesia in PD. Results support the hypothesis that neuronal activity of SMA was profoundly associated with hypokinetic symptoms in PD.

We report a family with 16q-ADCA(16q 22.1 linked autosomal dominant cerebellar ataxia) coexisting with SCA8 repeat expansion. The brothers in this family presented with pyramidal signs, tremor, myoclonus and mental retardation in addition to cerebellar symptom in childhood. They showed both C-to-T substitution puratrophin-1 gene and an expanded allele of the SCA8 gene in the brothers and their father. These siblings presented with atypical symptoms and early onset age as16q-ADCA. Although it remains controversial whether the expanded SCA8 allele is associated with cerebellar symptoms, the coexistence of SCA8 repeat expansion with SCA6 was reported previously. Pure or predominant cerebellar symptoms were found in patients with SCA8, SCA6 and 16q-ADCA. In addition, common findings in neuropathology of SCA8, SCA6 and 16q-ADCA have been reported. We suppose that coexistence of SCA8 repeat expansion with 16q-ADCA may be involved in the pathogenesis and severe symptoms in this family.

Objective: To study the after-effect of theta burst stimulation (TBS) over the left sensorimotor cortex on the size of somatosensory as well as motor evoked potentials evoked from both hemispheres in healthy human subjects., Methods: We used a continuous TBS paradigm for 40 s (600 pulses) in which a burst of 3 transcranial magnetic stimuli at 50 Hz is repeated at 5 Hz [Huang YZ, Edwards MJ, Rounis E, Bhatia KP, Rothwell JC. Theta burst stimulation of the human motor cortex. Neuron 2005;45:201-6]. Somatosensory evoked potentials (SEPs) following electrical stimulation of right or left median nerve and motor evoked potentials (MEPs) in the right or left first dorsal interosseous (FDI) muscles were recorded before and after TBS over the left motor cortex (M1) or a point 2 cm posterior to left M1., Results: Amplitudes of P25/N33 (parietal components) following right median nerve stimulation were significantly increased for at least 53 min after TBS over the left M1, whereas this component was suppressed for 13 min after TBS over a point 2 cm posterior. MEPs in right as well as left FDI muscles were suppressed with a similar time course after TBS over the left M1., Conclusions: A single-session of TBS over the sensorimotor cortex can induce a short-lasting change in the size of ipsilateral cortical components of SEPs as well as MEPs evoked from both hemispheres., Significance: TBS is an interventional tool that can induce rapid reorganization within cortical somatosensory as well as motor networks in humans.

Objective: To evaluate the electrophysiological findings of clinically unaffected cranial nerves (facial, accessory and hypoglossal nerves) in hereditary motor and sensory neuropathy (HMSN)., Methods: The conduction times of the facial, accessory, and hypoglossal nerves in 10 patients with HMSN type I (HMSN I), 2 patients with HMSN Type II (HMSN II), and 20 normal controls were determined. The extra- and intracranial segments of the cranial nerves were stimulated electrically and magnetically, respectively. The relationships between the conduction parameters of the cranial nerves and limb nerves were analyzed., Results: In patients with HMSN I, the conduction times of the distal and proximal segments were significantly prolonged in all 3 cranial nerves. A positive correlation was found between the conduction parameters of the cranial nerves and the limb nerves., Conclusions: Electrophysiological involvement of the whole segment of the facial, accessory and hypoglossal nerves is common in patients with HMSN I without clinical signs of alterations. The degree of conduction slowing of the facial, accessory, and hypoglossal nerves paralleled that of limb nerves.

Objective: To study the after-effect of transcranial direct current stimulation (tDCS) over the sensorimotor cortex on the size of somatosensory evoked potentials (SEPs) in humans., Methods: SEPs were elicited by electrical stimulation of right or left median nerve at the wrist before and after anodal or cathodal tDCS in 8 healthy subjects. tDCS was applied for 10 min to the left motor cortex at a current strength of 1 mA., Results: Amplitudes of P25/N33, N33/P40 (parietal components) and P22/N30 (frontal component) following right median nerve stimulation were significantly increased for at least 60 min after the end of anodal tDCS, whereas P14/N20, N20/P25 (parietal components) and N18/P22 (frontal component) were unaffected. There was no effect on SEPs evoked by left median nerve stimulation. Cathodal tDCS had no effect on SEPs evoked from stimulation of either arm., Conclusions: Anodal tDCS over the sensorimotor cortex can induce a long-lasting increase in the size of ipsilateral cortical components of SEPs., Significance: tDCS can modulate cortical somatosensory processing in humans and might be a useful tool to induce plasticity in cortical sensory processing.

Objectives: To evaluate the focal nature of the early and late inhibition of corticospinal neurons demonstrated by a paired-pulse stimulation paradigm., Methods: We performed paired-electric pulse stimulation studies using subdural electrodes implanted in 4 patients with intractable partial epilepsy., Results: Inhibition of motor evoked potentials in the first dorsal interosseous muscle was obtained by paired-pulse stimulation of the hand motor cortex (M1) with a subthreshold conditioning stimulus at conditioning-test intervals between 1 and 6ms. This early inhibition was abolished when the conditioning stimulus was moved to the sensory cortex (S1) or the arm M1. The inhibition was also produced by paired-pulse stimulation of the hand M1 with a suprathreshold conditioning stimulus between 50 and 300ms in all 3 patients. This late inhibition was still recognized when moving the conditioning stimulus to the hand S1 only in one of 3 patients., Conclusions: The early inhibition arises from very small areas in the M1 and is little mediated by neuronal circuits in the S1. On the other hand, the focal nature of the late inhibition is complicated and it arises mainly from the M1 but the S1 may be related to the generation of the late inhibition in some cases.