Non-motor symptoms following transient ischaemic attack (TIA) may reflect disruption of cortical GABA-dependent functional connectivity. In this case series, we quantified global cortical dynamics using the perturbational complexity index based on state transitions (PCIst) and intertrial coherence (ITC) derived from transcranial magnetic stimulation-electroencephalography (TMS-EEG). Seven patients who presented with sensory, visual, or motor symptoms during TIA underwent TMS-EEG stimulation of the left primary motor cortex. Individual PCIst and ITC values were classified relative to a normative dataset of 164 healthy participants. Six of seven patients exhibited abnormal PCIst and/or ITC values, with alterations most frequently observed in the beta and alpha frequency bands. Four patients reported persistent post-TIA symptoms, including fatigue, memory difficulties, or impaired concentration. These findings suggest that TIA may be associated with measurable alterations in cortical synchronization, and large-scale brain dynamics. Importantly, it is currently unknown whether the observed alterations preceded the TIA, emerged as its consequence, or were influenced by unmeasured mediators such as premorbid factors such as cognitive or affective symptoms. These preliminary findings support further investigation of TMS-EEG-derived measures as candidate neurophysiological biomarkers of cortical network vulnerability or susceptibility to persistent neuropsychiatric symptoms after TIA.
Context The hypersomnolence disorder diagnostic criteria of the DSM-5-TR rely on the report of a ‘hypersomnolence’ syndrome, without defining the term or proposing any measuring tool to assess this. Among the vast diversity of tools to measure hypersomnolence, the Hypersomnia Severity Index (HSI) has been specifically designed to account for the multidimensionality of hypersomnolence. Showing good psychometric validity in two previous validation studies, the HSI has never been validated against the gold-standard Multiple Sleep Latency Test (MSLT). Objective This preliminary study aims to validate the French version of the HSI and to provide a first exploration of the link between HSI and the MSLT in a group of French subjects clinically diagnosed with hypersomnolence disorders. In addition, we propose an original visualization of the dimensions of the HSI. Method This study is a secondary analysis of a cohort of 34 patients diagnosed with hypersomnolence disorders without comorbidity. They underwent a MSLT and filled out the French version HSI as well as classical sleep medicine questionnaires. The HSI has undergone a rigorous translation and psychometric validation, which we compare with two previous psychometric validation studies. Results We obtained the same level of psychometric validity as previous studies, validating our French version on a population of patients with hypersomnolence disorder. However, we did not find any correlation between the HSI and the MSLT. Nevertheless, the dimensional approach offered by the HSI combined with our data visualization provide a valuable tool for sleep medicine clinical practice and research.
Objective Breach rhythm (BR) is an EEG phenomenon typically associated with skull defects. While its continuous form is well recognized, the significance of intermittent BR has not been systematically studied. Methods This cross-sectional, multicenter observational study included 90 patients with BR on routine EEGs. Patients were categorized based on BR continuity (continuous BR, CBR vs. intermittent BR, IBR). Structural imaging parameters, including residual lesion volume (RLV) and skull defect measurements, were also analyzed. Results Of 90 patients, 55 (61.1%) had CBR and 35 (38.9%) had IBR. There were no significant differences in demographic or seizure characteristics between groups. Residual lesion volumes were significantly larger in the CBR group, while skull defect size and surface area did not differ between groups. Interictal epileptiform discharges within BR regions were common in both groups (52.7% vs. 65.7%, p= 0.224). However, non-epileptiform interictal abnormalities outside BR regions were significantly more frequent in the IBR group (37.1% vs. 5.5%, p< 0.01). Right-sided BR was more often (70.2%) continuous than left-sided BR (48.8%) (p= 0.040). Conclusions Breach rhythm on EEG can present as a continuous or intermittent pattern. Continuous BR appears associated with greater residual lesion burden and focal neurological findings, whereas intermittent BR is linked to smaller residual lesions but more widespread cortical abnormalities beyond the breach region. These findings suggest that BR reflects not only skull defects but also the functional state of underlying cortex. Significance This study is the first to systematically differentiate intermittent from continuous BR, demonstrating that intermittent BR is common and BR may serve as a marker of distributed or dynamic cortical dysfunction in addition to structural cranial abnormalities.
Intracerebral electrical stimulation during stereoelectroencephalography (SEEG) is a key technique for functional mapping in the presurgical evaluation of patients with drug-resistant epilepsy. This article presents a concise anatomical overview and outlines standardized methodologies for SEEG-guided stimulation in motor, premotor, somatosensory, and operculo-insular regions. In these areas, functional stimulations are generally feasible under optimal conditions, yielding clear and reproducible clinical responses. We detail stimulation protocols, patient task paradigms, and the range of motor, sensory, and speech effects elicited, providing practical guidance for accurate and safe functional mapping in this eloquent cortex
OBJECTIVE:Severe scoliosis, defined by a Cobb angle exceeding 80°, requires surgical correction and is associated with a high risk of postoperative neurological complications. These complications may be reduced by halo gravity traction (HGT) and neuromonitoring. This study evaluated the outcomes of preoperative and intraoperative multimodal neuromonitoring by somatosensory evoked potential (SSEP) and motor evoked potential (MEP) in patients undergoing HGT before and during spinal surgery for severe idiopathic scoliosis. The secondary objective was to investigate any changes in SSEP associated with traction. METHODS:A single-center retrospective review was conducted including all patients who underwent surgery for severe idiopathic scoliosis following HGT. Demographic data were collected. Pre-traction, post-traction, and postoperative Cobb angle corrections were reported. Complications, preoperative and intraoperative neuromonitoring data were recorded. RESULTS:70 patients with an average age at surgery of 14.4 years were included. The mean postoperative correction rate was 68.79%±7.57. Postoperatively, five deficits were observed, with one being permanent. There were 19 neuromonitoring alerts during surgery (27.14%). One false negative occurred, while 15 alerts did not result in postoperative deficits. Abnormal SSEP before traction or at the beginning of the intervention was associated with an intraoperative alert. SSEP latencies increased, and amplitude decreased between the period before traction was applied and the beginning of the surgery. CONCLUSIONS:Multimodal neuromonitoring by MEP and SSEP presents a high number of alerts with low postoperative deficit. Traction appeared to increase SSEP latencies and decrease amplitudes. However, multimodal monitoring remains a valuable tool for reducing the risk of neurological deficits in severe scoliosis undergoing preoperative HGT.
BACKGROUND AND OBJECTIVE:In patients with functional neurological disorder (FND), transcranial magnetic stimulation (TMS) can be used for either diagnostic or therapeutic purpose. This study aimed to determine patients' expectations and tolerance of TMS techniques. METHODS:Data were collected prospectively using a standardized questionnaire before, immediately after, and 14 days after a session combining TMS for diagnosis and treatment (based on repeated single-pulse TMS). RESULTS:32 patients with FND were included. Most patients (79%) had received little or no information about TMS methods before the session. However, the majority of patients felt neither anxiety (78%) nor fear (69%) regarding this technique. With TMS, patients hoped more for a diagnosis (91%) than for even partial improvement of their symptoms (59%). Most patients (69%) rated the TMS experience as positive, although adverse events were frequent after the session (75%), but generally very mild. The occurrence of adverse events was associated with greater prior knowledge of TMS techniques and higher patients' expectations of treatment efficacy. Finally, an improvement in at least one of the initial symptoms was reported by 45% of patients during an interview conducted 14 days after the TMS session. CONCLUSION:This work fills a significant clinical gap in our understanding of the expectations of patients with FND regarding the applications of TMS, and their relationship to tolerance and short-term outcomes. Patients' initial knowledge of TMS did not alter their expectations, which were higher regarding its diagnostic than therapeutic value. An important finding of this study is that it demonstrates, for the first time, that the therapeutic efficacy of TMS is not related to patients' expectations or their initial level of information distinguishing this technique from a placebo.
OBJECTIVES:This exploratory observational study characterized high-frequency electromyographic (EMG) components embedded in scalp electroencephalography (EEG) recordings during episodes of focal-to-bilateral tonic-clonic seizures (FBTCS) and evaluated their potential for FBTCS detection and lateralization. METHODS:We retrospectively analyzed 21 FBTCS episodes with head version in 16 patients who underwent long-term video-EEG monitoring and simultaneous bilateral deltoid EMG. High-frequency components (64-256 Hz) were extracted from EEG and EMG signals. The mean integrated root mean square (iRMS) was calculated to identify EEG electrode pairs showing the highest sensitivity to EMG activity embedded in scalp EEG. Power spectral density (PSD) and cross-correlation analyses were used to assess signal similarity. Mean iRMS amplitude and RMS rise slope were compared between ipsiversive and contraversive (head-version side) electrode pairs during head version. RESULTS:High-frequency EMG components were most prominent at T3/T4 electrodes under Cz and average references, and they showed strong correlations with deltoid EMG activity (median Pearson's r > 0.90, p < 0.05) as revealed by PSD and cross-correlation analyses. During head version, mean iRMS was significantly higher at contraversive electrodes relative to the Cz, average and Laplacian references, while RMS rise slope was significantly higher relative to Cz and average references. CONCLUSION:High-frequency EMG components embedded in the scalp EEG, particularly at T3/T4, showed strong similarity to deltoid EMG signals under Cz and average referencing and reflected greater contraversive EMG-related activity during ictal head version. These findings suggest that EEG-embedded EMG activity may provide supplementary electrophysiological markers relevant to the detection and lateralization of FBTCS.
INTRODUCTION:Recent findings suggest that key areas in the brain, particularly the medial prefrontal cortex (mPFC), are important for regulating bladder function. This research explores the potential of transcranial direct current stimulation (tDCS) on the mPFC as an emerging approach to alleviate overactive bladder (OAB) symptoms, in comparison to transcutaneous tibial nerve stimulation (TTNS). METHODS:This single-blind, two-arm, parallel, randomized controlled clinical trial with a 1:1 allocation ratio was conducted at Firoozgar Hospital. A total of forty-four women diagnosed with overactive bladder (OAB) were randomly divided into two groups: one group received tDCS (transcranial Direct Current Stimulation) combined with PFMT (Pelvic Floor Muscle Training), and the other received TTNS(Trancutaneous Tibial Nerve Stimulation) combined with PFMT. The primary outcome measure was the quality of life through the International Consultation on Incontinence Questionnaire Lower Urinary Tract Symptoms Quality of Life Module (ICIQ-LUTSqol). Secondary outcome measures included the International Consultation on Incontinence Questionnaire Overactive Bladder Module (ICIQ-OAB), a three-day bladder diary, and assessment of pelvic floor muscle strength using a perineometer. RESULTS:Both groups exhibited improvements in OAB symptoms; however, the tDCS group appeared to show greater reductions in ICIQ-OAB scores and symptom bother (p < 0.05). As measured by the ICIQ-LUTSqol questionnaire, quality of life improved in both groups, with indications of comparatively greater improvements in the tDCS group after treatment and at the one-month follow-up (p = 0.05 and p < 0.05 respectively). Moreover, the number of urinary incontinence episodes tended to decline more markedly in the tDCS group, and this improvement was sustained during the follow-up period (p < 0.05). CONCLUSION:This study's findings suggest that while both TTNS and tDCS may effectively improve the quality of life in women with overactive bladder (OAB), the improvements observed in the tDCS group appear to be greater. However, further sham-controlled studies are needed to confirm these potential benefits. TRIAL REGISTRATION:Iranian Registry of Clinical Trials (IRCT) ID: IRCT20090301001722N26, date of registration: 17 May 2023. https://en.irct.ir/.
Cortical electrical stimulation (CES) provides a unique window into the neural architecture supporting human emotion by perturbing local circuits while revealing distributed network dynamics. Yet despite decades of clinical use in stereo-EEG and subdural mapping, the emotional phenomena elicited by CES remain conceptually heterogeneous and methodologically inconsistent, reflecting the absence of a unified interpretative framework. Here, by outlining the conceptual foundations of emotion and examining the scattered evidence from CES, we show how definitional and methodological divergences undermine cumulative insight. We first situate CES findings relative to competing models of emotion, highlighting how assumptions about discreteness, appraisal, and construction shape the interpretation of evoked responses. We then assess how theoretical stance, emotion features, stimulation parameters, anatomical constraints, and task conditions are reported across studies, revealing major inconsistencies in methodological transparency than may account for systematic biases in affective outcomes. Finally, we propose the eMAP operational framework-a minimal reporting structure organised around four pillars: Emotion, Modulation, Architecture, and Phenomenology. This framework aims to guide future research by allowing perturbational evidence to be interpreted in a cumulative and comparable manner, while improving the clinical utility of CES for probing the functional architecture of emotion and refining surgical risk assessment.
AIM:To assess the value of quantitative EEG (qEEG) as a diagnostic and prognostic biomarker in infants with abusive head trauma (AHT). Despite its central role in monitoring encephalopathy, EEG remains underused in multimodal evaluations, and its quantitative analysis may provide objective, real-time insights into cerebral dysfunction and long-term outcome. METHODS:This retrospective monocentric case-control study included infants under two years with confirmed AHT and age- and sex-matched controls. Clinical and early EEG data were collected. Patients' outcome was stratified by Pediatric Overall Performance Category score (POPC1-3 vs. 4-6). Quantitative EEG features were analyzed, and two neural networks were trained using five-fold cross-validation for diagnosis and outcome prediction. RESULTS:84 EEGs from 75 participants were analyzed (46 EEGs from 40 AHT; 38 EEGs from 35 controls). Compared with controls, AHT EEGs showed significantly reduced entropy and Hurst exponent values and increased low-frequency power, reflecting diffuse cortical dysfunction. Within the AHT group, reduced signal complexity and loss of interhemispheric asymmetry correlated with unfavorable outcomes (POPC4-6, p< 0.01). Machine learning perfectly classified AHT cases versus controls and classified patients into POPC1-3 or POPC4-6 groups with 73±14 % accuracy. Combined models distinguished control, POPC1-3, and POPC4-6 groups with 90±5 % accuracy. DISCUSSION:Early qEEG provides functional information that complements imaging and clinical findings. qEEG-derived biomarkers may enable early risk stratification, guide neuroprotective strategies, and improve prognostic counseling in infants with AHT. Larger multicenter prospective studies are warranted to validate these exploratory findings and define their clinical applicability.
OBJECTIVE:To characterize sweating issues in people with multiple sclerosis (pwMS) using the Quantitative Sudomotor Axon Reflex Test (QSART) and SUDOSCAN. METHODS:In 75 pwMS, sweating symptoms were evaluated using the Composite Autonomic Symptom Score (COMPASS-31). Sweating function was assessed with QSART and SUDOSCAN. RESULTS:Symptomatic sweating problems were observed in 22 (29.3 %) pwMS. Pathological results of the QSART (sudomotor index (SI) >0) were identified in 13 (17.3 %) pwMS, while SUDOSCAN results showed pathology in 8 (10.7 %) pwMS. We found a positive correlation between the QSART volume of the foot and the SUDOSCAN electrochemical skin conductance (ESC) results for the corresponding leg (r = 0.282, p = 0.015). pwMS with cervical spinal cord lesions had higher ESC values for the hand mean, left, and right (69.88±12.84 vs 76.15±9.29, p = 0.022; 69.88±12.82 vs 76.22±9.36, p = 0.021; and 70.33±13.00 vs 76.52±9.27, p = 0.024; respectively). CONCLUSIONS:People with MS frequently experience sweating problems. Using various methods to identify sweating issues in pwMS reveals differences in the causes of these problems in pwMS.
Stereo-EEG is a fundamental part of the diagnostic process for a significant number of selected patients with focal epilepsy. The complexity inherent in planning a SEEG study means that this method can only reasonably be put into practice in treatment centers with multidisciplinary teams dedicated to epilepsy surgery and where teaching and specific training are considered essential for the proper development of a SEEG program. In our short communication, we present the development of the SEEG program at our hospital, which is one of the most important tertiary pediatric centers in Europe.
This observational open-label study evaluates the clinical and neurophysiological effects of multiple sessions of contralesional motor cortex low-frequency repetitive transcranial magnetic stimulation (LF-rTMS) on seventeen patients with chronic post-stroke hand spasticity. Results: LF-rTMS improved spasticity (Modified Ashworth Scale, p < 0.001), strength (tip pinch, p = 0.002; grip force, p < 0.001), flexibility (finger tapping test, p = 0.014; tapping test, p = 0.008), motor threshold difference (p < 0.001), and motor evoked potential latency (p = 0.004), with no adverse events reported. Improvement in spasticity persisted after 3 months. Conclusion: LF-rTMS is a safe and effective therapy for chronic post-stroke hand spasticity.
OBJECTIVES:Increased beta-oscillations (13-35 Hz) in the basal ganglia have been linked to Parkinsonian motor symptoms. Deep brain stimulation (DBS) approaches have been proposed to mitigate pathological beta-activity, with some leading to a global suppression of this activity and others selectively trimming beta-bursts leading to a redistribution of beta-bursts towards shorter, more physiological, durations. Recently, DBS electrode-guided neurofeedback has been explored as an alternative, endogenous technique enabling patients to acquire mental strategies to modulate ongoing subthalamic beta-activity. Here, we investigated the effect of DBS-neurofeedback on beta-burst prevalence, amplitude, and duration. METHODS:We characterised the local field potential (LFP) in the subthalamic nucleus (STN) in terms of beta-burst prevalence, amplitude and length during DBS electrode-guided neurofeedback-modulation of ongoing subthalamic beta-activity. RESULTS:We previously showed that a cohort of eight Parkinson's disease (PD) patients with externalised DBS electrodes was able to volitionally control ongoing beta-oscillatory activity by visual neurofeedback within minutes of training, which was also accompanied by an improvement in motor performance. Here, we additionally demonstrate a decrease in beta-burst (> 0.1 s) durations, amplitude and prevalence when transitioning from rest to downregulation after neurofeedback-learning. In addition, downregulation vs. upregulation also resulted in shorter and lower amplitude beta-bursts (>0.1 s) after neurofeedback. DISCUSSION:DBS electrode-guided neurofeedback enabled patients with PD to exert control over subthalamic beta-oscillations, with downregulation in particular leading to a redistribution of beta-burst characteristics towards more physiological states. This technique may represent a complementary approach to existing DBS strategies by providing patients with an endogenous means of modulating pathological beta-activity.
INTRODUCTION:The House-Brackmann grading system exhibits inherent subjectivity despite widespread clinical adoption. Although electrophysiological assessments provide objective neurophysiological data, their correlation with initial clinical severity remains inadequately characterized in large-scale cohorts with standardized methodologies. This study aimed to evaluate the diagnostic utility of electrodiagnostic parameters in determining initial severity among Bell's palsy patients. METHODS:This retrospective study analyzed 3219 patients with unilateral Bell's palsy who underwent electrodiagnostic testing within 14 days of symptom onset. Patients were stratified using House-Brackmann (H-B) grades into mild (2-3) and moderate-to-severe (4-6) groups. Five electrophysiological parameters were evaluated: electroneurography degeneration index (ENoG DI), motor unit action potential (MUAP) interference patterns, compound muscle action potential latency, blink reflex, and abnormal spontaneous activity. Associations were analyzed using logistic regression and ROC analyses. RESULTS:ENoG DI and MUAP interference patterns in orbicularis oculi showed strongest association with initial H-B grade (area under curve = 0.75). Patients with moderate-to-severe paralysis (H-B grades 4-6) had significantly higher prevalence of severe axonal degeneration (ENoG DI ≥ 90 %) compared to mild paralysis (34.9 % vs. 8.3 %, p < 0.0001). MUAP interference grades ≤3 were strongly associated with increased severity. CONCLUSION:ENoG DI and MUAP interference patterns serve as reliable early electrophysiological indicators of facial paralysis severity, providing objective markers for patient stratification. These findings establish standardized electrodiagnostic criteria for severity assessment, enabling evidence-based early rehabilitation decisions in Bell's palsy management.
Sleep disturbances in anti-NMDAR encephalitis evolve dynamically across disease phases. We monitored a patient longitudinally from the acute phase through remission, relapse, and recovery, using video-EEG and polysomnography. No sleep complaints were reported during the prodromal phase, whereas coma was characterized by rhythmic theta-delta activity devoid of sleep patterns. Sleep stages gradually emerged after teratoma removal and immunotherapy, paralleling clinical improvement. A second teratoma caused relapse with severe sleep disruption and agrypnia excitata, then residual status dissociatus persisted before normalization. Sleep changes mirrored disease progression, suggesting that sleep patterns may serve as biomarkers and potential therapeutic targets in anti-NMDAR encephalitis.
AIMS:Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder characterized by progressive motor neuron degeneration, leading to symmetrical proximal weakness, bulbar dysfunction, and respiratory involvement. Although extraocular muscles (EOMs) are typically spared, there are conflicting reports regarding oculomotor abnormalities in SMA. This study aimed comprehensively to assess eye movement function in patients with SMA types II and III using videonystagmography (VNG). METHODS:We included 18 SMA patients and 21 healthy subjects of similar ages and sexes. All participants underwent an otoscopic/audiological examination before the VNG recording. In VNG testing, we analyzed and compared optokinetic nystagmus (OKN), saccade parameters, and smooth pursuit movement (SPM) gain. RESULTS:There were no statistical differences between the OKN gain and saccade velocity between groups. There was a lower percentage of saccade accuracy in the SMA group than in the control group (p = 0.017). SPM gain was lower in the SMA group than in the control group (p < 0.0001). The correlation analyses revealed a positive correlation between age and saccade latency (r = 0.613, p < 0.0001) and a negative correlation between age and SPM gain (r = -0.487, p = 0.003). DISCUSSION:In this study, we performed a comprehensive evaluation of eye movement function with VNG in patients with SMA. Our findings indicate that while extraocular muscles remain unaffected in SMA, subtle central oculomotor control abnormalities-likely involving supranuclear and/or cerebellar pathways-may accompany the disease and can be quantitatively detected using VNG.
OBJECTIVE:To assess the diagnostic utility of distal sural (DSUR) sensory responses and amplitude ratios compared with conventional proximal sural (PSUR) studies in diabetic polyneuropathy (DPN). METHODS:Fifty-eight patients with diabetes and clinical evidence of polyneuropathy (neuropathic symptoms and/or signs, median Neuropathy Impairment Score of the Lower Limbs (NIS-LL) score 6 [IQR 2-8]) and 44 healthy controls underwent bilateral nerve conduction studies of the PSUR and DSUR, and the right radial nerve. Amplitudes, conduction velocities (CV), and amplitude ratios [sural-to-radial amplitude ratio (SRAR), distal sural-to-radial amplitude ratio (DSRAR), and proximal-to-distal sural amplitude ratio (PDSR)] were analysed. RESULTS:PSUR and DSUR amplitudes were significantly lower and conduction velocities slower in patients compared with controls (p < 0.001). DSUR amplitude achieved diagnostic accuracy comparable to PSUR amplitude (AUC 0.762 vs. 0.775), with higher sensitivity (58.5% vs. 41.5 %) and preserved specificity (91 % vs. 93%). SRAR and DSRAR were reduced in patients, but their diagnostic performance was modest (AUC < 0.65). PDSR did not differ significantly between groups (p > 0.05) and was therefore not included in ROC analysis. Amplitude ratios showed weak correlations with diabetes duration, vibration threshold, and NIS-LL. CONCLUSION:DSUR amplitude is a feasible and reliable parameter that increases sensitivity in the electrophysiological detection of DPN while maintaining high specificity. In contrast, PDSR did not provide significant diagnostic value, suggesting that absolute amplitude measures are more informative than ratio-based indices in routine clinical practice.
OBJECTIVES:Cognitive impairment constitutes one of the most prevalent sequelae associated with obstructive sleep apnea (OSA). Given the established correlation between chronic hypoxia in patients with OSA and the deterioration of cortical functions, this study hypothesize that levels of cortical excitability diminish in direct relation to the severity of hypoxic episodes. METHODS:A cohort of 102 individuals diagnosed with OSA participated. Patients exhibiting a T90 value of ≥30 % were categorized into the desaturated cohort, whereas those with a T90 value of <30 % were designated as the non-desaturated cohort. To evaluate alterations in cortical excitability, Transcranial Magnetic Stimulation (TMS) was employed to quantify various parameters including resting muscle motor evoked potential (MEP) latency and amplitude, resting motor threshold, active muscle MEP latency andamplitude, and active motor threshold in both the dominant and non-dominant abductor pollicis brevis (APB) muscles. RESULTS:The findings indicated that resting dominant APB muscle MEP latency (t=-2.659; p = 0.009), active dominant APB muscle MEP latency (Z=-2.322; p = 0.020), resting non-dominant APB muscle MEP latency (Z=-2.666; p = 0.008), and active motor threshold for dominant APB (Z=-2.410; p = 0.016) were significantly elevated in the desaturated cohort compared to the non-desaturated cohort. CONCLUSION:This study showed that chronic hypoxia in patients with OSA is associated with modifications in cortical excitability as assessed through TMS. A marked decrease in cortical excitability was identified in the desaturated cohort. It is hypothesized that a disturbance in gamma-aminobutyric acid (GABA) and glutamate transmission could be crucial to understanding OSA and cortical excitability.
OBJECTIVES:To identify baseline predictors of clinical response to the primary motor cortex high-frequency repetitive transcranial magnetic stimulation (M1 HF-rTMS) in patients with fibromyalgia. MATERIALS AND METHODS:We performed a secondary analysis of 32 women with fibromyalgia from a randomized, double-blind, sham-controlled international multicenter trial registered at clinicaltrials.gov (NCT03658694). Enrolled participants received active or HF-rTMS-over the primary motor cortex (M1). Baseline demographic data, psychological assessments (Hospital Anxiety and Depression Scale, Brief Pain Inventory, Fibromyalgia Impact Questionnaire, Toronto Alexithymia Scale, and Interoception Questionnaire), psychophysical measures (Conditioned Pain Modulation), and structural brain MRI variables were collected and analyzed. Responders were defined as patients who achieved a ≥ 50 % reduction in pain on a numerical rating scale eight weeks after treatment. Associations between baseline variables and response were analyzed using Wilcoxon Rank Sum tests, chi-square tests, and logistic regression where appropriate. RESULTS:At the end of the treatment period, 15 out of 32 participants (47 %) in the active M1 HF-rTMS group and 7 out of 30 (23 %) in the sham group achieved ≥50 % reduction in pain. None of the baseline demographic, clinical, psychological, psychophysical, or neuroimaging variables evaluated were significantly associated with clinical response to M1 HF-rTMS. Although M1 HF-rTMS induced significant antinociceptive effects measured by psychophysical assessments (heat pain threshold), these effects did not predict clinical outcomes. CONCLUSIONS:No clear baseline predictors of response to M1 HF-rTMS were identified in patients with fibromyalgia, emphasizing the heterogeneity and complexity of the disorder. Further research incorporating larger samples and additional biomarkers is necessary to establish individualized prediction strategies for M1 HF-rTMS therapy in fibromyalgia.
