Repetitive transcranial magnetic stimulation for protection against delayed neuronal death induced by transient ischemia

2003 ◽  
Vol 99 (6) ◽  
pp. 1063-1069 ◽  
Author(s):  
Minoru Fujiki ◽  
Hidenori Kobayashi ◽  
Tatsuya Abe ◽  
Tohru Kamida
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Neuronal Death ◽  
Magnetic Stimulation ◽  
Neuronal Damage ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Ischemic Tolerance ◽  
Delayed Neuronal Death ◽  
Similar Degree ◽  
Content Type ◽  
Fine Print

Object. Data in the present study demonstrate that repetitive transcranial magnetic stimulation (rTMS) induces ischemic tolerance against delayed neuronal death (DND) of hippocampal neurons following an otherwise lethal ischemic insult. Methods. Various regimens of rTMS were delivered to adult gerbils at various times prior to an episode of ischemia induced by transient (5-minute) bilateral common carotid artery (CCA) occlusion. The extent of DND in the CA1 region of the hippocampus was assessed quantitatively 7 days after the transient ischemic episode. When rTMS was delivered 2 to 5 days prior to bilateral CCA occlusion, DND was substantially attenuated; delivery of rTMS 12 to 24 hours prior to occlusion induced partial tolerance. In the group of animals that had received stimulation 2 days prior to occlusion, neuron density in the CA1 sector was significantly higher (three gerbils, 210.33, 86.01% of normal) than in the group that experienced ischemia only (three gerbils, 10.66, 4.36% of normal). A similar degree of neuron sparing occurred when stimulation was delivered 3, 4, or 5 days prior to occlusion. Note that rTMS was effective when it was delivered at frequencies of 25 and 50 Hz. Stimulation at 25 Hz for 128 seconds (3200 pulses) was more effective than stimulation at 50 Hz for 64 seconds (3200 pulses) or 128 seconds (6400 pulses), however. Conclusions. Noninvasive rTMS represents an important tool for exploring the mechanisms of ischemic tolerance and preventing ischemic neuronal damage.

Platelet-activating factor and progressive brain damage following focal brain injury

1990 ◽  
Vol 73 (2) ◽  
pp. 223-233 ◽  
Author(s):  
Kai U. Frerichs ◽  
Perttu J. Lindsberg ◽  
John M. Hallenbeck ◽  
Giora Z. Feuerstein
Keyword(s):  
Brain Injury ◽  
Brain Damage ◽  
Neuronal Death ◽  
Hippocampal Neurons ◽  
Neuronal Damage ◽  
Platelet Activating Factor ◽  
Secondary Brain Damage ◽  
Content Type ◽  
Focal Brain Injury ◽  
Fine Print

✓ The effects of a platelet-activating factor (PAF) antagonist on brain edema, cortical microcirculation, blood-brain barrier (BBB) disruption, and neuronal death following focal brain injury are reported. A neodymium:yttrium-aluminum-garnet (Nd:YAG) laser was used to induce highly reproducible focal cortical lesions in anesthetized rats. Secondary brain damage in this model was characterized by progressive cortical hypoperfusion, edema, and BBB disruption in the vicinity of the hemispheroid lesion occurring acutely after injury. The histopathological evolution was followed for up to 4 days. Neuronal damage in the cortex and the hippocampus (CA-1) was assessed quantitatively, revealing secondary and progressive loss of neuronal tissue within the first 24 hours following injury. Pretreatment with the PAF antagonist BN 50739 ameliorated the severe hypoperfusion in 12 rats (increasing local cerebral blood flow from a mean ± standard error of the mean of 40.5% ± 8.3% to 80.2% ± 7.8%, p < 0.01) and reduced edema by 70% in 10 rats (p < 0.05) acutely after injury. The PAF antagonist also reduced the progression of neuronal damage in the cortex and the CA-1 hippocampal neurons (decrease of neuronal death from 88.0% ± 3.9% to 49.8% ± 4.2% at 24 hours in the cortex and from 40.2 ± 5.0% to 13.2% ± 2.1% in the hippocampus in 30 rats; p < 0.05). This study provides evidence to support progressive brain damage following focal brain injury, associated with secondary loss of neuronal cells. In this latter process, PAF antagonists may provide significant therapeutic protection in arresting secondary brain damage following cerebral ischemia and neurological trauma.

Magnetic and electrical stimulation of the auditory cortex for intractable tinnitus

2004 ◽  
Vol 100 (3) ◽  
pp. 560-564 ◽  
Author(s):  
Dirk De Ridder ◽  
Gert De Mulder ◽  
Vincent Walsh ◽  
Neil Muggleton ◽  
Stefan Sunaert ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Transcranial Magnetic Stimulation ◽  
Auditory Cortex ◽  
Magnetic Stimulation ◽  
Cortical Plasticity ◽  
Cortical Reorganization ◽  
Complete Suppression ◽  
Content Type ◽  
Fine Print ◽  
Stimulation Of

✓ Tinnitus is a distressing symptom that affects up to 15% of the population for whom no satisfactory treatment exists. The authors present a novel surgical approach for the treatment of intractable tinnitus, based on cortical stimulation of the auditory cortex. Tinnitus can be considered an auditory phantom phenomenon similar to deafferentation pain, which is observed in the somatosensory system. Tinnitus is accompanied by a change in the tonotopic map of the auditory cortex. Furthermore, there is a highly positive association between the subjective intensity of the tinnitus and the amount of shift in tinnitus frequency in the auditory cortex, that is, the amount of cortical reorganization. This cortical reorganization can be demonstrated by functional magnetic resonance (fMR) imaging. Transcranial magnetic stimulation (TMS) is a noninvasive method of activating or deactivating focal areas of the human brain. Linked to a navigation system that is guided by fMR images of the auditory system, TMS can suppress areas of cortical plasticity. If it is successful in suppressing a patient's tinnitus, this focal and temporary effect can be perpetualized by implanting a cortical electrode. A neuronavigation-based auditory fMR imaging-guided TMS session was performed in a patient who suffered from tinnitus due to a cochlear nerve lesion. Complete suppression of the tinnitus was obtained. At a later time an extradural electrode was implanted with the guidance of auditory fMR imaging navigation. Postoperatively, the patient's tinnitus disappeared and remains absent 10 months later. Focal extradural electrical stimulation of the primary auditory cortex at the area of cortical plasticity is capable of suppressing contralateral tinnitus completely. Transcranial magnetic stimulation may be an ideal method for noninvasive studies of surgical candidates in whom stimulating electrodes might be implanted for tinnitus suppression.

scholarly journals The use of repetitive transcranial magnetic stimulation for treatment of obsessive-compulsive disorder: a scoping review

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Medard Kofi Adu ◽  
Ejemai Eboreime ◽  
Adegboyega Oyekunbi Sapara ◽  
Andrew James Greenshaw ◽  
Pierre Chue ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Obsessive Compulsive Disorder ◽  
Scoping Review ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Therapeutic Effects ◽  
Obsessive Compulsive ◽  
Content Type ◽  
Compulsive Disorder ◽  
Data Search

Purpose This paper aims to explore the relevant literature available regarding the use of repetitive transcranial magnetic stimulation (rTMS) as a mode of treatment for obsessive-compulsive disorder (OCD); to evaluate the evidence to support the use of rTMS as a treatment option for OCD. Design/methodology/approach The authors electronically conducted data search in five research databases (MEDLINE, CINAHL, Psych INFO, SCOPUS and EMBASE) using all identified keywords and index terms across all the databases to identify empirical studies and randomized controlled trials. The authors included articles published with randomized control designs, which aimed at the treatment of OCD with rTMS. Only full-text published articles written in English were reviewed. Review articles on treatment for conditions other than OCD were excluded. The Covidence software was used to manage and streamline the review. Findings Despite the inconsistencies in the published literature, the application of rTMS over the supplementary motor area and the orbitofrontal cortex has proven to be promising in efficacy and tolerability compared with other target regions such as the prefrontal cortex for the treatment of OCD. Despite the diversity in terms of the outcomes and clinical variability of the studies under review, rTMS appears to be a promising treatment intervention for OCD. Research limitations/implications The authors of this scoping review acknowledge several limitations. First, the search strategy considered only studies published in English and the results are up to date as the last day of the electronic data search of December 10, 2020. Though every effort was made to identify all relevant studies for the purposes of this review per the eligibility criteria, the authors still may have missed some relevant studies, especially those published in other languages. Originality/value This review brought to bare the varying literature on the application of rTMS and what is considered gaps in the knowledge in this area in an attempt to evaluate and provide information on the potential therapeutic effects of rTMS for OCD.

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