109 research outputs found
Involvement of electrophysiological localization of the subthalamic nucleus in deep brain stimulation for Parkinsonâs disease
We studied the involvement of the electrophysiological localization of the subthalamic nucleus (NST) using a multi-unit recording technique by means of semi-microelectrode in a set of thirty Parkinsonâs patients who benefited from a bilateral stimulation of the NST and who were operated on under local or general anesthesia. The multi-unit recording
technique by means of semi-microelectrodes appeared efficient,capable of improving the localization of the NST and leading to improvement in clinical results. We believe that the use of our technique will allow for time savings while providing good results, and that the choice of the angle of the trajectory will allow for improved localization
of the NST and thus improved clinical results
Effects of Transcranial Direct Current Stimulation on Information Processing Speed, Working Memory, Attention, and Social Cognition in Multiple Sclerosis
Multiple Sclerosis (MS) is a chronic inflammatory disease of the central nervous system. Cognitive impairment occurs in 40â65% of patients and could drastically affect their quality of life. Deficits could involve general cognition (e.g., attention and working memory) as well as social cognition. Transcranial direct current stimulation (tDCS), is a novel brain stimulation technique that has been assessed in the context of several neuropsychiatric symptoms, including those described in the context of MS. However, very rare trials have assessed tDCS effects on general cognition in MS, and none has tackled social cognition. The aim of this work was to assess tDCS effects on general and social cognition in MS. Eleven right-handed patients with MS received two blocks (bifrontal tDCS and sham, 2 mA, 20 min, anode/cathode over left/right prefrontal cortex) of 5 daily stimulations separated by a 3-week washout interval. Working memory and attention were, respectively, measured using N-Back Test (0-Back, 1-Back, and 2-Back) and Symbol Digit Modalities Test (SDMT) at the first and fifth day of each block and 1 week later. Social cognition was evaluated using Faux Pas Test and Eyes Test at baseline and 1 week after each block. Interestingly, accuracy of 1-Back test improved following sham but not active bifrontal tDCS. Therefore, active bifrontal tDCS could have impaired working memory via cathodal stimulation of the right prefrontal cortex. No significant tDCS effects were observed on social cognitive measures and SDMT. Admitting the small sample size and the learning (practice) effect that might arise from the repetitive administration of each task, the current results should be considered as preliminary and further investigations in larger patient samples are needed to gain a closer understanding of tDCS effects on cognition in MS
Neurourology and Urodynamics Diagnostic Criteria for Pudendal Neuralgia by Pudendal Nerve Entrapment (Nantes Criteria)
Aims: The diagnosis of pudendal neuralgia by pudendal nerve entrapment syndrome is essentially clinical. There are no pathognomonic criteria, but various clinical features can be suggestive of the diagnosis. We defined criteria that can help to the diagnosis. Materials and Methods: A working party has validated a set of simple diagnostic criteria (Nantes criteria). Results: The five essentials diagnostic criteria are: (1) Pain in the anatomical territory of the pudendal nerve
Validation of the Body ScanÂź, a new device to detect small fiber neuropathy by assessment of the sudomotor function: agreement with the SudoscanÂź
BackgroundSudomotor dysfunction is one of the earliest manifestations of small fiber neuropathy (SFN), reflecting the alteration of sympathetic C fiber innervation of the sweat glands. Among other techniques, such innervation can be assessed by measuring electrochemical skin conductance (ESC) in microsiemens (ÎŒS). In this study, ESC was measured at the feet to detect distal SFN. For this objective, the performance of a new device, the Body ScanÂź (Withings, France), intended for home use, was compared with that of a reference device, the SudoscanÂź (Impeto Medical, France), which requires a hospital setting.MethodsIn patients with diabetes with or without neuropathy or non-diabetic patients with lower-limb neuropathy, the diagnostic performance of the Body ScanÂź measurement was assessed by calculating its sensitivity (Se) and specificity (Sp) to detect at least moderate SFN (Se70 and Sp70), defined by a value of feet ESCââ€â70âÎŒS andâ>â50âÎŒS on the SudoscanÂź measure, or severe SFN (Se50 and Sp50), defined by a value of feet ESCââ€â50âÎŒS on the SudoscanÂź measure. The agreement between the two devices was assessed with the analysis of BlandâAltman plots, mean absolute error (MAE), and root mean squared error (RMSE) calculations. The repeatability of the measurements was also compared between the two devices.ResultsA total of 147 patients (52% men, mean age 59âyears old, 76% diabetic) were included in the analysis. The sensitivity and specificity to detect at least moderate or severe SFN were: Se70â=â0.91 ([0.83, 0.96]), Sp70â=â0.97 ([0.88, 0.99]), Se50â=â0.91 ([0.80, 0.98]), and Sp50â=â0.99 ([0.94, 1]), respectively. The bias and 95% limits of agreement were 1.5 [â5.4, 8.4]. The MAE was 2.9 and the RMSE 3.8. The intra-sample variability was 2.0 for the Body ScanÂź and 2.3 for the SudoscanÂź.ConclusionThe ESC measurements provided by the Body ScanÂź were in almost perfect agreement with those provided by the reference device, the SudoscanÂź, which validates the accuracy of the Body ScanÂź for the detection of SFN. By enabling simple, rapid, and autonomous use by the patient at home, this new technique will facilitate screening and monitoring of SFN in daily practice.Clinical trial registrationClinicalTrials.gov, identifier NCT05178459
Non-Invasive Brain Stimulation in Conversion (Functional) Weakness and Paralysis: A Systematic Review and Future Perspectives
Conversion (functional) limb weakness or paralysis (FW) can be a debilitating condition, and often causes significant distress or impairment in social, occupational, or other important areas of functioning. Most treatment concepts are multi-disciplinary, containing a behavioral approach combined with a motor learning program. Non-invasive brain stimulation (NIBS) methods, such as electroconvulsive therapy (ECT), and transcranial magnetic stimulation (TMS) have been used in the past few decades to treat FW. In order to identify all published studies that used NIBS methods such as ECT, TMS and transcranial direct current stimulation (tDCS) for treating FW patients a systematic review of the literature was conducted in PubMed and Web of Science. In a second step, narratives were used to retrospectively determine nominal CGI-I (Clinical Global Impression scaleâImprovement) scores to describe approximate changes of FW symptoms. We identified two articles (case reports) with ECT used for treatment of FW, five with TMS with a total of 86 patients, and none with tDCS. In 75 out of 86 patients treated with repetitive (r)TMS a nominal CGI-I score could be estimated, showing a satisfactory short-term improvement. Fifty-four out of seventy-five identified patients (72%) had a CGI-I score of 1 (very much improved), 13 (17%) a score of 2 (much improved), 5 (7%) a score of 3 (minimally improved), and 3 (5%) remained unchanged (CGI-I = 4). In no case did patients worsen after rTMS treatment, and no severe adverse effects were reported. At follow-up, symptom improvement was not quantifiable in terms of CGI-I for the majority of the cases. Patients treated with ECT showed a satisfactory short-term response (CGI-I = 2), but deterioration of FW symptoms at follow-up. Despite the predominantly positive results presented in the identified studies and satisfactory levels of efficacy measured with retrospectively calculated nominal CGI-I scores, any assumption of a beneficial effect of NIBS in FW has to be seen with caution, as only few articles could be retrieved and their quality was mostly poor. This article elucidates how NIBS might help in FW and gives recommendations for future study designs using NIBS in this condition
Long-Term Relief of Painful Bladder Syndrome by High-Intensity, Low-Frequency Repetitive Transcranial Magnetic Stimulation of the Right and Left Dorsolateral Prefrontal Cortices
Aim: To show the value of low-frequency repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) to treat bladder pain syndrome (BPS), characterized by suprapubic pain, urgency and increased micturition frequency.Methods: A 68-year-old woman with BPS underwent 16 sessions of high-intensity, low-frequency (1 Hz) rTMS of the DLPFC, first on the right hemisphere (one daily session for 5 days, followed by one weekly session for 5 weeks), and then on the left hemisphere (one monthly session for 6 months).Results: At the end of the rTMS protocol, suprapubic pain completely vanished, micturition frequency dramatically decreased (by 60â80%), while fatigue and sleep quality improved (by 57â60%). The patient reported an overall satisfaction rate of 80% and her activities of daily living tending to normalize.Conclusion: This is the first report showing that high-intensity, low-frequency rTMS delivered on the DLPFC region of both hemispheres can relieve most symptoms of BPS (pain, urinary symptoms, and interference with physical functioning) in clinical practice
The Value of High-Frequency Repetitive Transcranial Magnetic Stimulation of the Motor Cortex to Treat Central Pain Sensitization Associated With Knee Osteoarthritis
AimChronic pain associated with knee osteoarthritis may develop in connection with a maladaptive process of pain sensitization in the central nervous system. Repetitive transcranial magnetic stimulation (rTMS) has been proposed to treat various pain syndromes related to central sensitization phenomenon, but was never applied in the context of knee osteoarthritis.MethodsA 71-year-old woman presenting clinical evidence of central sensitization of pain associated with left knee osteoarthritis underwent monthly sessions of rTMS delivered at 10 Hz over the right motor cortex.ResultsFrom the week following the third session, she began to improve on various clinical aspects, including pain. After 10 sessions (i.e., almost one year of follow-up), pain was reduced by 67%, especially regarding neuropathic components, while sleep disorders and fatigue also improved by 57â67%. The central sensitization inventory (CSI) score was reduced by 70%.ConclusionThis observation suggests that high-frequency motor cortex rTMS could be a therapeutic option to treat neuropathic pain and psychological symptoms associated with central sensitization developing in the context of chronic osteoarthritis of the knee joint
Prefrontal tDCS Decreases Pain in Patients with Multiple Sclerosis
Background: In the last few years, transcranial direct current stimulation (tDCS) has emerged as an appealing therapeutic option to improve brain functions. Promising data support the role of prefrontal tDCS in augmenting cognitive performance and ameliorating several neuropsychiatric symptoms, namely pain, fatigue, mood disturbances, and attentional impairment. Such symptoms are commonly encountered in patients with multiple sclerosis (MS). Objective: The main objective of the current work was to evaluate the tDCS effects over the left dorsolateral prefrontal cortex (DLPFC) on pain in MS patients.Our secondary outcomes were to study its influence on attention, fatigue, and mood. Materials and Methods: Sixteen MS patients with chronic neuropathic pain were enrolled in a randomized, sham-controlled, and cross over study Patients randomly received two anodal tDCS blocks (active or sham), each consisting of three consecutive daily tDCS sessions, and held apart by 3 weeks. Evaluations took place before and after each block. To evaluate pain, we used the Brief Pain Inventory (BPI) and the Visual Analog Scale (VAS). Attention was assessed using neurophysiological parameters and the Attention Network Test (ANT). Changes in mood and fatigue were measured using various scales. Results: Compared to sham, active tDCS yielded significant analgesic effects according to VAS and BPI global scales.There were no effects of any block on mood, fatigue, or attention. Conclusion: Based on our results, anodal tDCS over the left DLPFC appears to act in a selective manner and would ameliorate specific symptoms, particularly neuropathic pain. Analgesia might have occurred through the modulation of the emotional pain network. Attention, mood, and fatigue were not improved in this work. This could be partly attributed to the short protocol duration, the small sample size, and the heterogeneity of our MS cohort. Future large-scale studies can benefit from comparing the tDCS effects over different cortical sites, changing the stimulation montage, prolonging the duration of protocol, and coupling tDCS with neuroimaging techniques for a better understanding of its possible mechanism of action
Left Shifting of Language Related Activity Induced by Bihemispheric tDCS in Postacute Aphasia Following Stroke
Both anodal transcranial direct current stimulation (tDCS) of the left IFG and cathodal stimulation of the right IFG were shown to improve rehabilitation of stroke patients with Brocaâs aphasia. The study aimed at assessing the impact of a bihemispheric IFG stimulation compared to sham on postacute non-fluent aphasia. Twelve patients with non-fluent aphasia were included at least 4 weeks following cerebral stroke. Ten daily sessions of 2 mA bihemispheric verum or sham tDCS (anode on left IFG and cathode on right IFG) were performed concomitantly with individual language therapy in a double-blinded randomized controlled study with parallel group design. Language functions [i.e., communication (ANELT), picture naming and the Aachen aphasia test (AAT)] were assessed up to 1 month following tDCS. The picture naming task significantly improved (increased number of nouns) at the end of the tDCS procedure in the verum but not sham group. Improvements in the picture naming task and the communication task of the AAT at 4 weeks after tDCS procedure were only seen in the verum group. In patients with postacute cerebral stroke, repeated sessions of tDCS applied on both IFG concomitantly with language therapy were able to induce immediate effects on picture naming presumably due to an early left shift of language-associated function that maintained for 4 weeks. Effects on clinically relevant communicative abilities are likely
Clinical diagnostic utility of transcranial magnetic stimulation in neurological disorders. Updated report of an IFCN committee
The review provides a comprehensive update (previous report: Chen R, Cros D, Curra A, Di Lazzaro V,
Lefaucheur JP, Magistris MR, et al. The clinical diagnostic utility of transcranial magnetic stimulation:
report of an IFCN committee. Clin Neurophysiol 2008;119(3):504â32) on clinical diagnostic utility of
transcranial magnetic stimulation (TMS) in neurological diseases. Most TMS measures rely on stimulation
of motor cortex and recording of motor evoked potentials. Paired-pulse TMS techniques, incorporating
conventional amplitude-based and threshold tracking, have established clinical utility in neurodegenerative,
movement, episodic (epilepsy, migraines), chronic pain and functional diseases. Cortical hyperexcitability
has emerged as a diagnostic aid in amyotrophic lateral sclerosis. Single-pulse TMS measures are
of utility in stroke, and myelopathy even in the absence of radiological changes. Short-latency afferent
inhibition, related to central cholinergic transmission, is reduced in Alzheimerâs disease. The triple stimulation
technique (TST) may enhance diagnostic utility of conventional TMS measures to detect upper
motor neuron involvement. The recording of motor evoked potentials can be used to perform functional
mapping of the motor cortex or in preoperative assessment of eloquent brain regions before surgical
resection of brain tumors. TMS exhibits utility in assessing lumbosacral/cervical nerve root function,
especially in demyelinating neuropathies, and may be of utility in localizing the site of facial nerve palsies.
TMS measures also have high sensitivity in detecting subclinical corticospinal lesions in multiple
sclerosis. Abnormalities in central motor conduction time or TST correlate with motor impairment and
disability in MS. Cerebellar stimulation may detect lesions in the cerebellum or cerebello-dentatothalamo-
motor cortical pathways. Combining TMS with electroencephalography, provides a novel
method to measure parameters altered in neurological disorders, including cortical excitability, effective
connectivity, and response complexity
- âŠ