scholarly journals TAP: Targeting and analysis pipeline for optimization and verification of TMS coil placement

2021 ◽  
Author(s):  
Moritz Dannhauer ◽  
Ziping Huang ◽  
Lysianne Beynel ◽  
Eleanor Wood ◽  
Noreen Bukhari-Parlakturk ◽  
...  
Keyword(s):  
Graphical User Interface ◽  
Magnetic Stimulation ◽  
Regions Of Interest ◽  
Analysis Pipeline ◽  
Modulate Function ◽  
Placement Optimization ◽  
Neuronavigation System ◽  
Brain Target ◽  
The Brain ◽  
Targeting Accuracy

Transcranial magnetic stimulation (TMS) offers possibilities to modulate function in regions of interest (ROI) in the brain via an induced electric field (E-field). The ROI E-field can be maximized using individualized computational head modeling to find an optimal scalp coil placement. We present a TMS targeting and analysis pipeline (TAP) software that uses an MRI/fMRI-derived brain target to optimize a coil placement considering experimental requirements such as subjects hair thickness and coil placement restriction. The coil placement optimization is implemented in SimNIBS 3.2 for which an additional graphical user interface (TargetingNavigator) is provided to visualize and adjust procedural parameters. The optimized coil placement information is prepared for neuronavigation software (Brainsight) which supports the targeting during the TMS experiment. The neuronavigation system can record the coil placement during the experiment and these data can be processed in TAP to evaluate retrospectively and visualize the TMS targeting accuracy.

scholarly journals TREATMENT-RESISTANT OBSESSIVE COMPULSIVE DISORDER: AN EVALUATION STUDY OF THE AUGMENTATION EFFECT OF LOW-FREQUENCY REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION

2020 ◽  
Vol 8 (10) ◽  
pp. 1286-1296
Author(s):  
Hend Mohammed Naguib Aref (MSCh) ◽  
◽  
Hossam El Din Fathallah El Sawy (MD) ◽  
Mai Abd El Raouf Essea (MD) ◽  
Ehab Sayed Ramadan (MD) ◽  
...  
Keyword(s):  
Magnetic Stimulation ◽  
Sham Group ◽  
Rating Scale ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Low Frequency ◽  
Treatment Resistant ◽  
Obsessive Compulsive ◽  
Hamilton Anxiety Rating Scale ◽  
Brain Target ◽  
The Brain

Background: Thelifetime prevalence of obsessive-compulsive disorders (OCD) is estimated to be around 3% in the general population. Selective serotonin reuptake inhibitors (SSRIs) are considered to be the primary treatment strategy of OCD in addition to psychotherapy. Unfortunately, current medications, augmentation strategies, and behavioral therapies fail to provide adequate benefits in many cases. A large percentage of patients (40-60%) do not show satisfactory response to the standard treatments, some of them experiencing a chronically deteriorating course, leading to marked interpersonal and occupational impairments. In recent years, non-invasive neuromodulatory techniques such as repetitive transcranial magnetic stimulation have been increasingly studied as potential adjunct or alternative therapies for a wide range of neurological and psychiatric conditions including pain disorder, depression, and stroke rehabilitation and OCD. Aims: the aim of this work to evaluate rTMS as an augmentation strategy in treatment-resistant OCD, to test the potential value oflow frequency rTMS to SMA,orbitofrontal cortex and right DLPFC in the treatment of resistant OCD and to compare between the therapeutic values of applying the TMS coil to those different areas of the cortex. Patients and Methods: This study was carried out in Psychiatry, Neurology and Neurosurgery Center, Tanta University from September 2017 to November 2019. Eighty patients (52 females and 28 males) aging between 18 and 65 years underwent complete psychiatric evaluation, including full medical history, psychiatric and physical examination and diagnosed as having OCD accordingto DSM-5 with failure of at least two adequate therapeutic trials of SRIs. Results: Before rTMS sessions there was no statistical significant difference between the three active groups and the sham group regarding the scores onYale-Brown obsessive compulsive scale,Hamilton anxiety rating scale, Hamilton depression rating scale and Clinical global impression scale. Results after rTMS sessions revealed the following: Active rTMS on the SMA, the left OFC and right DLPFC was associated with marked improvement in YBOCS, Hamilton anxiety rating scale, Hamilton Depression rating scale and clinical global impression scale. The most significant improvement in Yale Brown Obsessive Compulsive scale was obtained when the brain target was the SMA. The most significant improvement in anxiety rating scale and depression ratingscale was obtained when the brain target was the left OFC. Sham group didnt have significant improvement through the study. Conclusions: We can thus conclude that low frequency rTMS is significantly effective as an adjunctive treatment for resistant OCD and that the SMA is the most effective brain target.

Vorläufige Ergebnisse von 99mTc-HMPAO-SPECT-Untersuchungen bei endogenen Psychosen

1989 ◽  
Vol 28 (03) ◽  
pp. 88-91
Author(s):  
J. Schröder ◽  
H. Henningsen ◽  
H. Sauer ◽  
P. Georgi ◽  
K.-R. Wilhelm
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Regions Of Interest ◽  
Post Mortem ◽  
Regional Cerebral Blood ◽  
Hmpao Spect ◽  
Endogenous Psychoses ◽  
The Brain ◽  
99Mtc Hmpao

18 psychopharmacologically treated patients (7 schizophrenics, 5 schizoaffectives, 6 depressives) were studied using 99mTc-HMPAO-SPECT of the brain. The regional cerebral blood flow was measured in three transversal sections (infra-/supraventricular, ventricular) within 6 regions of interest (ROI) respectively (one frontal, one parietal and one occipital in each hemisphere). Corresponding ROIs of the same section in each hemisphere were compared. In the schizophrenics there was a significantly reduced perfusion in the left frontal region of the infraventricular and ventricular section (p < 0.02) compared with the data of the depressives. The schizoaffectives took an intermediate place. Since the patients were treated with psychopharmaca, the result must be interpreted cautiously. However, our findings seem to be in accordance with post-mortem-, CT- and PET-studies presented in the literature. Our results suggest that 99mTc-HMPAO-SPECT may be helpful in finding cerebral abnormalities in endogenous psychoses.

scholarly journals A Simple Method to Avoid Brain Shift during Neuronavigation: Technical Note

2020 ◽  
Author(s):  
Jair Leopoldo Raso
Keyword(s):  
Dura Mater ◽  
Brain Area ◽  
Conventional Technique ◽  
Technical Note ◽  
Cortical Surface ◽  
Brain Shift ◽  
Simple Method ◽  
Cortex Area ◽  
Neuronavigation System ◽  
The Brain

Abstract Introduction The precise identification of anatomical structures and lesions in the brain is the main objective of neuronavigation systems. Brain shift, displacement of the brain after opening the cisterns and draining cerebrospinal fluid, is one of the limitations of such systems. Objective To describe a simple method to avoid brain shift in craniotomies for subcortical lesions. Method We used the surgical technique hereby described in five patients with subcortical neoplasms. We performed the neuronavigation-guided craniotomies with the conventional technique. After opening the dura and exposing the cortical surface, we placed two or three arachnoid anchoring sutures to the dura mater, close to the edges of the exposed cortical surface. We placed these anchoring sutures under microscopy, using a 6–0 mononylon wire. With this technique, the cortex surface was kept close to the dura mater, minimizing its displacement during the approach to the subcortical lesion. In these five cases we operated, the cortical surface remained close to the dura, anchored by the arachnoid sutures. All the lesions were located with a good correlation between the handpiece tip inserted in the desired brain area and the display on the navigation system. Conclusion Arachnoid anchoring sutures to the dura mater on the edges of the cortex area exposed by craniotomy constitute a simple method to minimize brain displacement (brain-shift) in craniotomies for subcortical injuries, optimizing the use of the neuronavigation system.

An accurate 3-D model for magnetic stimulation of the brain cortex

1995 ◽  
Vol 19 (1) ◽  
pp. 7-16 ◽  
Author(s):  
G. Cerri ◽  
R. De Leo ◽  
F. Moglie ◽  
A. Schiavoni
Keyword(s):  
Magnetic Stimulation ◽  
Brain Cortex ◽  
D Model ◽  
The Brain ◽  
Stimulation Of

Stereotactic Brain Biopsy in Eloquent Areas Assisted by Navigated Transcranial Magnetic Stimulation: a Technical Case Report

2018 ◽  
Vol 17 (3) ◽  
pp. E124-E129 ◽  
Author(s):  
Jiri Bartek ◽  
Gerald Cooray ◽  
Mominul Islam ◽  
Margret Jensdottir
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Stereotactic Biopsy ◽  
Brain Biopsy ◽  
Awake Surgery ◽  
Histopathological Diagnosis ◽  
Navigated Transcranial Magnetic Stimulation ◽  
Stereotactic Brain Biopsy ◽  
Eloquent Areas ◽  
The Brain

Abstract BACKGROUND AND IMPORTANCE Stereotactic brain biopsy (SB) is an important part of the neurosurgical armamentarium, with the possibility of achieving histopathological diagnosis in otherwise inaccessible lesions of the brain. Nevertheless, the procedure is not without the risk of morbidity, which is especially true for lesions in eloquent parts of the brain, where even a minor adverse event can result in significant deficits. Navigated transcranial magnetic stimulation (nTMS) is widely used to chart lesions in eloquent areas, successfully guiding maximal safe resection, while its potential role in aiding with the planning of a stereotactic biopsy is so far unexplored. CLINICAL PRESENTATION Magnetic resonance imaging of a 67-yr-old woman presenting with dysphasia revealed a noncontrast enhancing left-sided lesion in the frontal and parietal pars opercularis. Due to the location of the lesion, nTMS was used to chart both primary motor and language cortex, utilizing this information to plan a safe SB trajectory and sampling area according to the initial work-up recommendations from the multidisciplinary neuro-oncology board. The SB was uneventful, with histology revealing a ganglioglioma, WHO I. The patient was discharged the following day, having declined to proceed with tumor resection (awake surgery) due to the non-negligible risk of morbidity. Upon 1- and 3-mo follow-up, she showed no signs of any procedure-related deficits. CONCLUSION nTMS can be implemented to aid with the planning of a stereotactic biopsy procedure in eloquent areas of the brain, and should be considered part of the neurosurgical armamentarium.

Direct Causal Networks for the Study of Transcranial Magnetic Stimulation Effects on Focal Epileptiform Discharges

2015 ◽  
Vol 25 (05) ◽  
pp. 1550006 ◽  
Author(s):  
Dimitris Kugiumtzis ◽  
Vasilios K. Kimiskidis
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Network Structure ◽  
Magnetic Stimulation ◽  
Brain Connectivity ◽  
Effective Connectivity ◽  
Epileptic Focus ◽  
Sham Stimulation ◽  
Focal Seizures ◽  
Epileptiform Discharges ◽  
The Brain

Background: Transcranial magnetic stimulation (TMS) can have inhibitory effects on epileptiform discharges (EDs) of patients with focal seizures. However, the brain connectivity before, during and after EDs, with or without the administration of TMS, has not been extensively explored. Objective: To investigate the brain network of effective connectivity during ED with and without TMS in patients with focal seizures. Methods: For the effective connectivity a direct causality measure is applied termed partial mutual information from mixed embedding (PMIME). TMS-EEG data from two patients with focal seizures were analyzed. Each EEG record contained a number of EDs in the majority of which TMS was administered over the epileptic focus. As a control condition, sham stimulation over the epileptogenic zone or real TMS at a distance from the epileptic focus was also performed. The change in brain connectivity structure was investigated from the causal networks formed at each sliding window. Conclusion: The PMIME could detect distinct changes in the network structure before, within, and after ED. The administration of real TMS over the epileptic focus, in contrast to sham stimulation, terminated the ED prematurely in a node-specific manner and regained the network structure as if it would have terminated spontaneously.

scholarly journals Fourier SPoC: A customised machine-learning analysis pipeline for auditory beat-based entrainment in the MEG

2021 ◽  
Author(s):  
Stephanie Brandl ◽  
Niels Trusbak Haumann ◽  
Simjon Radloff ◽  
Sven Dähne ◽  
Leonardo Bonetti ◽  
...  
Keyword(s):  
Machine Learning ◽  
Frequency Band ◽  
Target Function ◽  
Tone Sequence ◽  
Data Driven ◽  
Beta Band ◽  
Analysis Pipeline ◽  
Source Power ◽  
The Brain ◽  
Permutation Analysis

AbstractWe propose here (the informed use) of a customised, data-driven machine-learning pipeline to analyse magnetoencephalography (MEG) in a theoretical source space, with respect to the processing of a regular beat. This hypothesis- and data-driven analysis pipeline allows us to extract the maximally relevant components in MEG source-space, with respect to the oscillatory power in the frequency band of interest and, most importantly, the beat-related modulation of that power. Our pipeline combines Spatio-Spectral Decomposition as a first step to seek activity in the frequency band of interest (SSD, [1]) with a Source Power Co-modulation analysis (SPoC; [2]), which extracts those components that maximally entrain their activity with the given target function, that is here with the periodicity of the beat in the frequency domain (hence, f-SPoC). MEG data (102 magnetometers) from 28 participants passively listening to a 5-min long regular tone sequence with a 400 ms beat period (the “target function” for SPoC) were segmented into epochs of two beat periods each to guarantee a sufficiently long time window. As a comparison pipeline to SSD and f-SpoC, we carried out a state-of-the-art cluster-based permutation analysis (CBPA, [3]). The time-frequency analysis (TFA) of the extracted activity showed clear regular patterns of periodically occurring peaks and troughs across the alpha and beta band (8-20 Hz) in the f-SPoC but not in the CBPA results, and both the depth and the specificity of modulation to the beat frequency yielded a significant advantage. Future applications of this pipeline will address target the relevance to behaviour and inform analogous analyses in the EEG, in order to finally work toward addressing dysfunctions in beat-based timing and their consequences.Author summaryWhen listening to a regular beat, oscillations in the brain have been shown to synchronise with the frequency of that given beat. This phenomenon is called entrainment and has in previous brain-imaging studies been shown in the form of one peak and trough per beat cycle in a range of frequency bands within 15-25 Hz (beta band). Using machine-learning techniques, we designed an analysis pipeline based on Source-Power Co-Modulation (SPoC) that enables us to extract spatial components in MEG recordings that show these synchronisation effects very clearly especially across 8-20 Hz. This approach requires no anatomical knowledge of the individual or even the average brain, it is purely data driven and can be applied in a hypothesis-driven fashion with respect to the “function” that we expect the brain to entrain with and the frequency band within which we expect to see this entrainment. We here apply our customised pipeline using “f-SPoC” to MEG recordings from 28 participants passively listening to a 5-min long tone sequence with a regular 2.5 Hz beat. In comparison to a cluster-based permutation analysis (CBPA) which finds sensors that show statistically significant power modulations across participants, our individually extracted f-SPoC components find a much stronger and clearer pattern of peaks and troughs within one beat cycle. In future work, this pipeline can be implemented to tackle more complex “target functions” like speech and music, and might pave the way toward rhythm-based rehabilitation strategies.

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