Eman M. Khedr

Longlasting antalgic effects of daily sessions of repetitive transcranial magnetic stimulation in central and peripheral neuropathic pain

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, 10×10 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” × “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.

Therapeutic effect of repetitive transcranial magnetic stimulation on motor function in Parkinson's disease patients

Cortical excitability of the primary motor cortex is altered in patients with Parkinsons disease (PD). Therefore, modulation of cortical excitability by high frequency repetitive transcranial magnetic stimulation (rTMS) of the motor cortex might result in beneficial effects on motor functions in PD. The present study aims to evaluate the effect of rTMS of the motor cortex on motor functions in patients with PD.

Long-term effect of repetitive transcranial magnetic stimulation on motor function recovery after acute ischemic stroke.

Objective –  Although there is evidence for short term benefits of rTMS in stroke, longer term effects have not been reported. The aim of the study was to evaluate the effect of two different frequencies of rTMS on motor recovery and on cortical excitability up to 1 year post‐treatment.

Role of 1 and 3 Hz repetitive transcranial magnetic stimulation on motor function recovery after acute ischaemic stroke

Background and purpose:  The purpose of this study was to compare the long‐term effect of five daily sessions of 1 vs. 3 Hz repetitive transcranial magnetic stimulation (rTMS) on motor recovery in acute stroke.

Effect of daily repetitive transcranial magnetic stimulation on motor performance in Parkinson's disease

Previous studies in patients with Parkinsons disease have reported that a single session of repetitive transcranial magnetic stimulation (rTMS) can improve some or all of the motor symptoms for 30 to 60 minutes. A recent study suggested that repeated sessions of rTMS lead to effects that can last for at least 1 month. Here we report data that both confirm and extend this work. Fifty‐five unmedicated PD patients were classified into four groups: two groups (early and late PD) received 25 Hz rTMS bilaterally on the motor arm and leg areas; other groups acted as control for frequency (10 Hz) and for site of stimulation (occipital stimulation). All patients received six consecutive daily sessions (3,000 pulses for each session). The first two groups then received a further three booster sessions (3 consecutive days of rTMS) after 1, 2, and 3 months, while the third group had only one additional session after the first month. Unified Parkinsons Disease Rating Scale (UPDRS), walking time, key‐tapping speed, and self‐assessment scale were measured for each patient before and after each rTMS session and before and after the monthly sessions. Compared to occipital stimulation, 25 Hz rTMS over motor areas improved all measures in both early and late groups; the group that received 10 Hz rTMS improved more than the occipital group but less than the 25 Hz groups. The effect built up gradually during the sessions and was maintained for 1 month after, with a slight reduction in efficacy. Interestingly, the effect was restored and maintained for the next month by the booster sessions. We conclude that 25 Hz rTMS can lead to cumulative and long‐lasting effects on motor performance.

Effect of daily repetitive transcranial magnetic stimulation for treatment of tinnitus: comparison of different stimulus frequencies

We compared the effect of different frequencies of repetitive transcranial magnetic stimulation (rTMS) (1 Hz, 10 Hz, 25 Hz and sham (occipital, 1 Hz)), given daily over the left temporoparietal cortex for 2 weeks, on 66 patients with chronic tinnitus randomly divided into four treatment groups. Patients were assessed using the Tinnitus Handicap Inventory, self-ratings of symptoms and audiometric measures of residual inhibition before, immediately after 2 weeks’ treatment and monthly thereafter for 4 consecutive months. Results: There were no significant differences in basal measures between the four groups of patients. A two-factor ANOVA revealed a significant “rTMS” × “time” interaction for all measures. This was because real rTMS produced greater improvement than sham. However, there was no significant difference between the responses to different frequencies of rTMS. The response to rTMS depended on the duration of tinnitus: patients who had tinnitus for the longest period of time were the least likely to respond to treatment. Conclusion: Daily sessions of rTMS over the temporoparietal cortex may be a useful potential treatment for tinnitus.

rTMS for Suppressing Neuropathic Pain: A Meta-Analysis

UNLABELLED This pooled individual data (PID)-based meta-analysis collectively assessed the analgesic effect of repetitive transcranial magnetic stimulation (rTMS) on various neuropathic pain states based on their neuroanatomical hierarchy. Available randomized controlled trials (RCTs) were screened. PID was coded for age, gender, pain neuroanatomical origins, pain duration, and treatment parameters analyses. Coded pain neuroanatomical origins consist of peripheral nerve (PN); nerve root (NR); spinal cord (SC); trigeminal nerve or ganglion (TGN); and post-stroke supraspinal related pain (PSP). Raw data of 149 patients were extracted from 5 (1 parallel, 4 cross-over) selected (from 235 articles) RCTs. A significant (P < .001) overall analgesic effect (mean percent difference in pain visual analog scale (VAS) score reduction with 95% confidence interval) was detected with greater reduction in VAS with rTMS in comparison to sham. Including the parallel study (Khedr et al), the TGN subgroup was found to have the greatest analgesic effect (28.8%), followed by PSP (16.7%), SC (14.7%), NR (10.0%), and PN (1.5%). The results were similar when we excluded the parallel study with the greatest analgesic effect observed in TGN (33.0%), followed by SC (14.7%), PSP (10.5%), NR (10.0%), and PN (1.5%). In addition, multiple (vs single, P = .003) sessions and lower (>1 and < or =10 Hz) treatment frequency range (vs >10 Hz) appears to generate better analgesic outcome. In short, rTMS appears to be more effective in suppressing centrally than peripherally originated neuropathic pain states. PERSPECTIVE This is the first PID-based meta-analysis to assess the differential analgesic effect of rTMS on neuropathic pain based on the neuroanatomical origins of the pain pathophysiology and treatment parameters. The derived information serves as a useful resource in regards to treatment parameters and patient population selection for future rTMS-pain studies.

The use of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) to relieve pain

Chronic pain resulting from injury of the peripheral or central nervous system may be associated with a significant dysfunction of extensive neural networks. Noninvasive stimulation techniques, such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) may be suitable to treat chronic pain as they can act on these networks by modulating neural activities not only in the stimulated area, but also in remote regions that are interconnected to the site of stimulation. Motor cortex was the first cortical target that was proved to be efficacious in chronic pain treatment. At present, significant analgesic effects were also shown to occur after the stimulation of other cortical targets (including prefrontal and parietal areas) in acute provoked pain, chronic neuropathic pain, fibromyalgia, or visceral pain. Therapeutic applications of rTMS in pain syndromes are limited by the short duration of the induced effects, but prolonged pain relief can be obtained by repeating rTMS sessions every day for several weeks. Recent tDCS studies also showed some effects on various types of chronic pain. We review the evidence to date of these two techniques of noninvasive brain stimulation for the treatment of pain.

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.

Effect of Surgical Menopause on Cognitive Functions

To investigate the effect of estrogen deficiency on cognitive function in surgically menopausal women, a prospective study was conducted at the University Hospital in Assiut, Egypt, during the period of July 1997 to August 1999. The study included 35 women subjected to total abdominal hysterectomy and bilateral salpingo-oophorectomy for nonmalignant causes. They were subjected to cognitive assessment by Mini-Mental State Examination (MMSE), Wechsler Memory Scale (WMS) subtests, and measurement of auditory Event-Related Potentials (ERPs) and serial serum estradiol levels determination. Eighteen age- and education-, body-weight- and parity-matched control women were recruited for comparison. A significant decline in MMSE, WMS subtests (digit span, visual memory, logical memory and mental control) and prolongation of P300 of ERP latency was observed in the patient group at 3 and 6 months postoperatively. These changes were not observed in the control group. A significant correlation was found between serum estradiol level and mental control subtest score and P300 latency in patients preoperatively. Patients who had a drop of estrogen level >50% had more cognitive function decline. Rapid decline in estrogen level following surgical menopause was associated with a deleterious effect on cognitive function. Such observations may contribute to more understanding of the age-related cognitive decline in females.