Transcranial magnetic stimulation identifies cortical excitability changes in monosymptomatic nocturnal enuresis.

OBJECTIVES: A limited number of electroencephalography (EEG) studies in nocturnal enuresis (NE) have reported cortical dysmaturity. The aim of the present study was to test this notion by examining cortical excitability in subjects with nocturnal enuresis (NE) using transcranial magnetic stimulation (TMS). MATERIAL AND METHODS: We investigated 41 patients with NE meeting the DSM-IV diagnostic criteria for NE, and 18 age- and sex-matched controls. Each subject was assessed clinically regarding frequency, duration of enuresis and Health Survey Measurement. Neurophysiological measures included resting and active motor thresholds (RMT, AMT), motor evoked potentials (MEP) of upper and lower limbs, cortical silent period duration (CSP) and transcallosal inhibition (TCI), in the upper limbs. RESULTS: Patients had a significantly lower Health Survey Measurement score for both physical and mental health components compared to the control group. RMT and AMT of both upper and lower limbs as well as the duration of the CSP and TCI were significantly reduced compared with the control group. There was significant positive correlation between RMT, AMT and Health Survey Measurement scores, especially Social Functioning. CONCLUSION: Patients with nocturnal enuresis are characterized by pathologically increased excitability and reduced inhibitory processing in the motor cortex, which could contribute to the pathogenesis of nocturnal enuresis.

Contralateral versus ipsilateral rTMS of temporoparietal cortex for the treatment of chronic unilateral tinnitus: comparative study.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) applied over left temporoparietal cortex has been reported to have a long-term therapeutic effect on tinnitus. We compare the impact of 1 and 25 Hz rTMS delivered either contralateral or ipsilateral to symptoms in 62 patients with unilateral chronic tinnitus. MATERIAL AND METHODS: Patients were randomly assigned to one of four treatment groups: with stimulation at 1 or 25 Hz applied either ipsilateral or contralateral to symptoms. Two thousand pulses per session were given daily for 2 weeks. Changes in tinnitus handicap inventory (THI), self-rating scores of loudness, awareness, and annoyance were measured monthly for 10 months. Duration of residual inhibition (RI) and psychiatric morbidity were evaluated monthly for 3 months. RESULTS: There was a significant main effect of time (P < 0.0001) and a significant time x side interaction (P = 0.032) between groups. This was because of the fact that contralateral stimulation had a greater effect on THI than ipsilateral stimulation; it was also superior to left side stimulation (P = 0.027). Ratings of loudness improved more after contralateral rTMS (P = 0.037). Twenty patients had no remaining tinnitus after 3 months; the remainder had a significant increase in RI. Patients with the shortest history of tinnitus tended to respond better to rTMS. There was a significant correlation between changes in THI score and changes in Hamilton anxiety and depression scores. CONCLUSION: Ten daily treatments of 1 and 25 Hz rTMS contralateral to the side of tinnitus have a greater beneficial effect on symptoms than either ipsilateral or left side stimulation.

Treatment of post-stroke dysphagia with repetitive transcranial magnetic stimulation.

BACKGROUND: Up to one-third of patients experience swallowing problems in the period immediately after a stroke. OBJECTIVE: To investigate the therapeutic effect of repetitive transcranial magnetic stimulation (rTMS) on post-stroke dysphagia. MATERIALS AND METHODS: Twenty-six patients with post-stroke dysphagia due to monohemispheric stroke were randomly allocated to receive real (n = 14) or sham (n = 12) rTMS of the affected motor cortex. Each patient received a total of 300 rTMS pulses at an intensity of 120% hand motor threshold for five consecutive days. Clinical ratings of dysphagia and motor disability were assessed before and immediately after the last session and then again after 1 and 2 months. The amplitude of the motor-evoked potential (MEP) evoked by single-pulse TMS was also assessed before and at 1 month in 16 of the patients. RESULTS: There were no significant differences between patients who received real rTMS and the sham group in age, hand grip strength, Barthel Index or degree of dysphagia at the baseline assessment. Real rTMS led to a significantly greater improvement compared with sham in dysphagia and motor disability that was maintained over 2 months of follow-up. This was accompanied by a significant increase in the amplitude of the oesophageal MEP evoked from either the stroke or non-stroke hemisphere. CONCLUSION: rTMS may be a useful adjunct to conventional therapy for dysphagia after stroke.

Dysphagia and hemispheric stroke: a transcranial magnetic study.

INTRODUCTION: Dysphagia is a common and distressing consequence of hemispheric stroke. STUDY AIM: To verify the usefulness of transcranial magnetic stimulation (TMS) studies of swallowing in healthy subjects and in stroke patients. MATERIAL AND METHODS: TMS studies of the motor cortical projections to the upper esophageal sphincter were performed in 45 patients with acute mono-hemispheric stroke (26 patients with dysphagia) and 20 healthy adult volunteers. RESULTS: TMS of either hemisphere in normal volunteers evoked motor evoked potentials (MEP) in the esophagus. The average point of optimal excitability was slightly more anterior in the right hemisphere; otherwise, MEP amplitudes and latencies were similar from both hemispheres as were the areas of the cortical map. The cortical map area and amplitude of MEPs were significantly smaller and the latencies longer after stimulation of the affected hemisphere compared with the unaffected hemisphere and pooled control data. Twenty-four dysphagic patients (92.3%) had abnormalities of MEP of the affected hemisphere, while only five non-dysphagic patients (26%) had these abnormalities. Dysphagic patients were older and had more disability compared with non-dysphagic patients. MEPs of the affected hemisphere of patients with dysphagia were later and smaller in amplitude than MEPs of non-dysphagic patients. The cortical map area was also smaller. CONCLUSION: The esophagus is represented bilaterally in motor cortex, but the hot spot lies more anterior to Cz in right hemisphere compared to left hemisphere. Both the severity of stroke and neuroplasticity of the unaffected hemisphere have implications in the development of dysphagia.