-
Frontiers in Behavioral Neuroscience 2022The midline and intralaminar nuclei of the thalamus form a major part of the "limbic thalamus;" that is, thalamic structures anatomically and functionally linked with...
The midline and intralaminar nuclei of the thalamus form a major part of the "limbic thalamus;" that is, thalamic structures anatomically and functionally linked with the limbic forebrain. The midline nuclei consist of the paraventricular (PV) and paratenial nuclei, dorsally and the rhomboid and nucleus reuniens (RE), ventrally. The rostral intralaminar nuclei (ILt) consist of the central medial (CM), paracentral (PC) and central lateral (CL) nuclei. We presently concentrate on RE, PV, CM and CL nuclei of the thalamus. The nucleus reuniens receives a diverse array of input from limbic-related sites, and predominantly projects to the hippocampus and to "limbic" cortices. The RE participates in various cognitive functions including spatial working memory, executive functions (attention, behavioral flexibility) and affect/fear behavior. The PV receives significant limbic-related afferents, particularly the hypothalamus, and mainly distributes to "affective" structures of the forebrain including the bed nucleus of stria terminalis, nucleus accumbens and the amygdala. Accordingly, PV serves a critical role in "motivated behaviors" such as arousal, feeding/consummatory behavior and drug addiction. The rostral ILt receives both limbic and sensorimotor-related input and distributes widely over limbic and motor regions of the frontal cortex-and throughout the dorsal striatum. The intralaminar thalamus is critical for maintaining consciousness and directly participates in various sensorimotor functions (visuospatial or reaction time tasks) and cognitive tasks involving striatal-cortical interactions. As discussed herein, while each of the midline and intralaminar nuclei are anatomically and functionally distinct, they collectively serve a vital role in several affective, cognitive and executive behaviors - as major components of a brainstem-diencephalic-thalamocortical circuitry.
PubMed: 36082310
DOI: 10.3389/fnbeh.2022.964644 -
Frontiers in Human Neuroscience 2022Responsive neurostimulation is an evolving therapeutic option for patients with treatment-refractory epilepsy. Open-loop, continuous stimulation of the anterior thalamic... (Review)
Review
INTRODUCTION
Responsive neurostimulation is an evolving therapeutic option for patients with treatment-refractory epilepsy. Open-loop, continuous stimulation of the anterior thalamic nuclei is the only approved modality, yet chronic stimulation rarely induces complete seizure remission and is associated with neuropsychiatric adverse effects. Accounts of off-label responsive stimulation in thalamic nuclei describe significant improvements in patients who have failed multiple drug regimens, vagal nerve stimulation, and other invasive measures. This systematic review surveys the currently available data supporting the use of responsive thalamic neurostimulation in primary and secondary generalized, treatment-refractory epilepsy.
MATERIALS AND METHODS
A systematic review was performed using the following combination of keywords and controlled vocabulary: ("Seizures"[Mesh] AND "Thalamus"[Mesh] AND "Deep Brain Stimulation"[Mesh]) OR (responsive neurostim* AND (thalamus[MeSH])) OR [responsive neurostimulation AND thalamus AND (epilepsy OR seizures)]. In addition, a search of the publications listed under the PubMed "cited by" tab was performed for all publications that passed title/abstract screening in addition to manually searching their reference lists.
RESULTS
Ten publications were identified describing a total of 29 subjects with a broad range of epilepsy disorders treated with closed-loop thalamic neurostimulation. The median age of subjects was 31 years old (range 10-65 years). Of the 29 subjects, 15 were stimulated in the anterior, 11 in the centromedian, and 3 in the pulvinar nuclei. Excluding 5 subjects who were treated for 1 month or less, median time on stimulation was 19 months (range 2.4-54 months). Of these subjects, 17/24 experienced greater than or equal to 50%, 11/24 least 75%, and 9/24 at least 90% reduction in seizures. Although a minority of patients did not exhibit significant clinical improvement by follow-up, there was a general trend of increasing treatment efficacy with longer periods on closed-loop thalamic stimulation.
CONCLUSION
The data supporting off-label closed-loop thalamic stimulation for refractory epilepsy is limited to 29 adult and pediatric patients, many of whom experienced significant improvement in seizure duration and frequency. This encouraging progress must be verified in larger studies.
PubMed: 35865353
DOI: 10.3389/fnhum.2022.910345 -
The Cochrane Database of Systematic... Jul 2017Despite optimal medical treatment, including epilepsy surgery, many epilepsy patients have uncontrolled seizures. Since the 1970s interest has grown in invasive... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Despite optimal medical treatment, including epilepsy surgery, many epilepsy patients have uncontrolled seizures. Since the 1970s interest has grown in invasive intracranial neurostimulation as a treatment for these patients. Intracranial stimulation includes both deep brain stimulation (DBS) (stimulation through depth electrodes) and cortical stimulation (subdural electrodes). This is an updated version of a previous Cochrane review published in 2014.
OBJECTIVES
To assess the efficacy, safety and tolerability of DBS and cortical stimulation for refractory epilepsy based on randomized controlled trials (RCTs).
SEARCH METHODS
We searched the Cochrane Epilepsy Group Specialized Register on 29 September 2015, but it was not necessary to update this search, because records in the Specialized Register are included in CENTRAL. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2016, Issue 11, 5 November 2016), PubMed (5 November 2016), ClinicalTrials.gov (5 November 2016), the WHO International Clinical Trials Registry Platform ICTRP (5 November 2016) and reference lists of retrieved articles. We also contacted device manufacturers and other researchers in the field. No language restrictions were imposed.
SELECTION CRITERIA
RCTs comparing deep brain or cortical stimulation versus sham stimulation, resective surgery, further treatment with antiepileptic drugs or other neurostimulation treatments (including vagus nerve stimulation).
DATA COLLECTION AND ANALYSIS
Four review authors independently selected trials for inclusion. Two review authors independently extracted the relevant data and assessed trial quality and overall quality of evidence. The outcomes investigated were seizure freedom, responder rate, percentage seizure frequency reduction, adverse events, neuropsychological outcome and quality of life. If additional data were needed, the study investigators were contacted. Results were analysed and reported separately for different intracranial targets for reasons of clinical heterogeneity.
MAIN RESULTS
Twelve RCTs were identified, eleven of these compared one to three months of intracranial neurostimulation with sham stimulation. One trial was on anterior thalamic DBS (n = 109; 109 treatment periods); two trials on centromedian thalamic DBS (n = 20; 40 treatment periods), but only one of the trials (n = 7; 14 treatment periods) reported sufficient information for inclusion in the quantitative meta-analysis; three trials on cerebellar stimulation (n = 22; 39 treatment periods); three trials on hippocampal DBS (n = 15; 21 treatment periods); one trial on nucleus accumbens DBS (n = 4; 8 treatment periods); and one trial on responsive ictal onset zone stimulation (n = 191; 191 treatment periods). In addition, one small RCT (n = 6) compared six months of hippocampal DBS versus sham stimulation. Evidence of selective reporting was present in four trials and the possibility of a carryover effect complicating interpretation of the results could not be excluded in five cross-over trials without any or a sufficient washout period. Moderate-quality evidence could not demonstrate statistically or clinically significant changes in the proportion of patients who were seizure-free or experienced a 50% or greater reduction in seizure frequency (primary outcome measures) after one to three months of anterior thalamic DBS in (multi)focal epilepsy, responsive ictal onset zone stimulation in (multi)focal epilepsy patients and hippocampal DBS in (medial) temporal lobe epilepsy. However, a statistically significant reduction in seizure frequency was found for anterior thalamic DBS (mean difference (MD), -17.4% compared to sham stimulation; 95% confidence interval (CI) -31.2 to -1.0; high-quality evidence), responsive ictal onset zone stimulation (MD -24.9%; 95% CI -40.1 to -6.0; high-quality evidence) and hippocampal DBS (MD -28.1%; 95% CI -34.1 to -22.2; moderate-quality evidence). Both anterior thalamic DBS and responsive ictal onset zone stimulation do not have a clinically meaningful impact on quality life after three months of stimulation (high-quality evidence). Electrode implantation resulted in postoperative asymptomatic intracranial haemorrhage in 1.6% to 3.7% of the patients included in the two largest trials and 2.0% to 4.5% had postoperative soft tissue infections (9.4% to 12.7% after five years); no patient reported permanent symptomatic sequelae. Anterior thalamic DBS was associated with fewer epilepsy-associated injuries (7.4 versus 25.5%; P = 0.01) but higher rates of self-reported depression (14.8 versus 1.8%; P = 0.02) and subjective memory impairment (13.8 versus 1.8%; P = 0.03); there were no significant differences in formal neuropsychological testing results between the groups. Responsive ictal-onset zone stimulation seemed to be well-tolerated with few side effects.The limited number of patients preclude firm statements on safety and tolerability of hippocampal DBS. With regards to centromedian thalamic DBS, nucleus accumbens DBS and cerebellar stimulation, no statistically significant effects could be demonstrated but evidence is of only low to very low quality.
AUTHORS' CONCLUSIONS
Except for one very small RCT, only short-term RCTs on intracranial neurostimulation for epilepsy are available. Compared to sham stimulation, one to three months of anterior thalamic DBS ((multi)focal epilepsy), responsive ictal onset zone stimulation ((multi)focal epilepsy) and hippocampal DBS (temporal lobe epilepsy) moderately reduce seizure frequency in refractory epilepsy patients. Anterior thalamic DBS is associated with higher rates of self-reported depression and subjective memory impairment. There is insufficient evidence to make firm conclusive statements on the efficacy and safety of hippocampal DBS, centromedian thalamic DBS, nucleus accumbens DBS and cerebellar stimulation. There is a need for more, large and well-designed RCTs to validate and optimize the efficacy and safety of invasive intracranial neurostimulation treatments.
Topics: Anterior Thalamic Nuclei; Cerebral Cortex; Deep Brain Stimulation; Electrodes, Implanted; Epilepsy; Hippocampus; Humans; Mediodorsal Thalamic Nucleus; Nucleus Accumbens; Outcome Assessment, Health Care; Randomized Controlled Trials as Topic
PubMed: 28718878
DOI: 10.1002/14651858.CD008497.pub3 -
European Neurology 2018After a stroke, movement disorders are rare manifestations mainly affecting the deep structures of the brain like the basal ganglia (44%) and thalamus (37%), although...
BACKGROUND
After a stroke, movement disorders are rare manifestations mainly affecting the deep structures of the brain like the basal ganglia (44%) and thalamus (37%), although there have been case studies of movement disorders in strokes affecting the cerebral cortex also.
SUMMARY
This review aims to delineate the various movement disorders seen in association with thalamic strokes and tries to identify the location of the nuclei affected in each of the described movement disorders. Cases were identified through a search of PubMed database using different search terms related to post-thalamic stroke movement disorders and a secondary search of references of identified articles. We reviewed 2,520 research articles and only 86 papers met the inclusion criteria. Cases were included if they met criteria for post-thalamic stroke movement disorders. Case-cohort studies were also reviewed and will be discussed further. Key Messages: The most common post-stroke abnormal movement disorder reported in our review was dystonia followed by hemiataxia. There was a higher association between ischaemic stroke and movement disorder. Acute onset movement disorders were more common than delayed. The posterolateral thalamus was most commonly involved in post-thalamic stroke movement disorders.
Topics: Female; Humans; Movement Disorders; Stroke; Thalamus
PubMed: 29870983
DOI: 10.1159/000490070 -
PloS One 2020Iron is involved in many processes in the brain including, myelin generation, mitochondrial function, synthesis of ATP and DNA and the cycling of neurotransmitters....
Iron is involved in many processes in the brain including, myelin generation, mitochondrial function, synthesis of ATP and DNA and the cycling of neurotransmitters. Disruption of normal iron homeostasis can result in iron accumulation in the brain, which in turn can partake in interactions which amplify oxidative damage. The development of MRI techniques for quantifying brain iron has allowed for the characterisation of the impact that brain iron has on cognition and neurodegeneration. This review uses a systematic approach to collate and evaluate the current literature which explores the relationship between brain iron and cognition. The following databases were searched in keeping with a predetermined inclusion criterion: Embase Ovid, PubMed and PsychInfo (from inception to 31st March 2020). The included studies were assessed for study characteristics and quality and their results were extracted and summarised. This review identified 41 human studies of varying design, which statistically assessed the relationship between brain iron and cognition. The most consistently reported interactions were in the Caudate nuclei, where increasing iron correlated poorer memory and general cognitive performance in adulthood. There were also consistent reports of a correlation between increased Hippocampal and Thalamic iron and poorer memory performance, as well as, between iron in the Putamen and Globus Pallidus and general cognition. We conclude that there is consistent evidence that brain iron is detrimental to cognitive health, however, more longitudinal studies will be required to fully understand this relationship and to determine whether iron occurs as a primary cause or secondary effect of cognitive decline.
Topics: Adult; Aged; Aged, 80 and over; Brain; Child; Cognition; Female; Humans; Iron; Male; Middle Aged
PubMed: 33057378
DOI: 10.1371/journal.pone.0240697 -
Stereotactic and Functional Neurosurgery 2020Direct targeting methods for stereotactic neurosurgery in the treatment of essential tremor have been the subject of active research over the past decade but have not... (Meta-Analysis)
Meta-Analysis
Direct targeting methods for stereotactic neurosurgery in the treatment of essential tremor have been the subject of active research over the past decade but have not yet been systematically reviewed. We present a clinically oriented topic review based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses Group guidelines. Our focus is studies using advanced magnetic resonance imaging (MRI) techniques (ultrahigh-field structural MRI, diffusion-weighted imaging, diffusion-tensor tractography, and functional MRI) for patient specific, in vivo identification of the ventral intermediate nucleus and the dentato-rubro-thalamic tract.
Topics: Cerebellar Nuclei; Deep Brain Stimulation; Diffusion Tensor Imaging; Essential Tremor; Female; Humans; Magnetic Resonance Imaging; Male; Neural Pathways; Red Nucleus; Stereotaxic Techniques; Thalamus
PubMed: 32403112
DOI: 10.1159/000507030 -
Frontiers in Psychiatry Dec 2013Deep brain stimulation (DBS) is an established, in selected cases therapeutically effective, non-lesional treatment method delivering current rectangular pulses into... (Review)
Review
Deep brain stimulation (DBS) is an established, in selected cases therapeutically effective, non-lesional treatment method delivering current rectangular pulses into dysfunctional brain structures via chronically implanted stimulation electrodes. DBS is a recognized method applied in movement disorders and is increasingly evaluated as a possible therapeutic option for psychiatric diseases such as refractory obsessive-compulsive disorders, Gilles de la Tourette syndrome, major depression, and substance-related addiction. Latest research indicates that DBS may be a method for improving cognitive functions in Alzheimer's dementia (AD). Translational data in healthy and AD animals appear to support this notion. Nevertheless, many aspects remain unclear, particularly with regard to the optimal target structure. The objective of this review is to present a systematic overview regarding published research on DBS and cognitive functioning in animal and human studies as well as to provide a systematic overview of the feasibility and efficacy of the treatment. We describe three studies investigating the effects of DBS in patients with dementia, using either the fornix or the nucleus basalis of Meynert (NBM) as a target. In total, we identified 25 animal studies with 10 brain structures being targeted: fornix, NBM, anterior caudate nucleus, dorsal striatum, anterior thalamic nucleus, midline thalamic nuclei, central thalamus, lateral hypothalamus, hippocampus (entorhinal cortex, perforant path), and amygdala. Considering the wide and diverse spectrum of targets, we add to this review a supposition about possible underlying mechanisms of operation and recommendations for further research.
PubMed: 24363647
DOI: 10.3389/fpsyt.2013.00159 -
Asian Journal of Surgery Sep 2023Chronic pain has been a major problem in personal quality of life and social economy, causing psychological disorders in people and a larger amount of money loss in... (Review)
Review
Chronic pain has been a major problem in personal quality of life and social economy, causing psychological disorders in people and a larger amount of money loss in society. Some targets were adopted for chronic pain, but the efficacy of the CM nucleus for pain was still unclear. A systematic review was performed to summarize GK surgery and DBS of the CM nucleus for chronic pain. PubMed, Embase and Medline were searched to review all studies discussing GK surgery and DBS on the CM nucleus for chronic pain. Studies that were review, meet, conference, not English or not the therapy of pain were excluded. Demographic characteristics, surgery parameters and outcomes of pain relief were selected. In total, 101 patients across 12 studies were included. The median age of most patients ranged from 44.3 to 80 years when the duration of pain ranged from 5 months to 8 years. This review showed varied results of 30%-100% pain reduction across studies. The difference in the effect between GK surgery and DBS cannot be judged. Moreover, three retrospective articles related to GK surgery of the CM nucleus for trigeminal neuralgia presented an average pain relief rate of 34.6-82.5%. Four studies reported adverse effects in a small number of patients. GK surgery and DBS of the CM nucleus might be promising therapeutic approaches for chronic refractory pain. More rigorous studies and larger samples with longer follow-up periods are needed to support the effectiveness and safety.
Topics: Humans; Child, Preschool; Child; Intralaminar Thalamic Nuclei; Chronic Pain; Deep Brain Stimulation; Quality of Life; Retrospective Studies
PubMed: 37422388
DOI: 10.1016/j.asjsur.2023.06.026 -
Neurosciences (Riyadh, Saudi Arabia) Oct 2022To review the current literature regarding the efficacy and safety of deep brain stimulation (DBS) in Lennox-Gastaut syndrome (LGS).
OBJECTIVES
To review the current literature regarding the efficacy and safety of deep brain stimulation (DBS) in Lennox-Gastaut syndrome (LGS).
METHODS
The authors conducted a systematic review of PubMed databases using keywords relevant to the objective of this research. Titles and abstracts were reviewed, after which studies that met the inclusion criteria were selected. Findings were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.
RESULTS
Thirteen studies were identified, and only 3 studies that reported 50 patients (age range from 3 to 65 years) met the inclusion criteria of DBS for LGS. Radiological imaging findings and neurophysiological findings were described in all studies. The thalamus nuclei, particularly the centromedian thalamic nucleus (CMN), were found to be highly active in LGS. By targeting this brain region, patients showed favorable outcomes. Overall, the mean seizure reduction was more than 50% in all patients (among whom 2 were seizure free) at a mean follow-up of 15 (12-18) months.
CONCLUSION
According to this systemic review, DBS for LGS showed satisfactory outcomes, indicating that DBS should be considered a valid treatment option. However, more studies are needed to ensure the role of DBS in LGS by establishing accurate targeting of the CMN using proper lead positioning and radiological imaging, a standard DBS intervention, and long-term outcomes.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Deep Brain Stimulation; Humans; Intralaminar Thalamic Nuclei; Lennox Gastaut Syndrome; Middle Aged; Seizures; Young Adult
PubMed: 36252974
DOI: 10.17712/nsj.2022.4.20220043