Cíl: U nemocných s farmakorezistentní epilepsií bez možnosti jiné operační terapie lze zvážit stimulaci předního talamického jádra (anterior thalamic nucleus; ATN). ATN prominuje do postranní komory jako tuberculum thalami, jehož ohraničení a koridor pro implantaci elektrody tvoří v. thalamostriata laterálně a choroidální plexus s v. chorioidea superior mediálně. Cílem práce bylo studium šířky tohoto vaskulárního koridoru z hlediska bezpečnosti implantace a redukce záchvatů (nejlepší při stimulaci přední části jádra). Soubor a metodika: Po disekci obou hemisfér preparátů s nástřikem intrakraniálních cév bylo identifikováno tuberculum thalami (ATN) s cévním ohraničením. Měření šířky koridoru byla prováděna 2, 4 a 6 mm od překrytí v. thalamostriata a plexus chorioideus nebo od junkce zmíněných žil. Výsledky: Měření byla provedena celkem na šesti preparátech. Medián šířky koridoru byl 2 mm od žilní junkce 2,5–3 mm a ve vzdálenosti 4 a 6 mm 4–4,5 mm. V dorzální části tuberculum thalami byla pozorována malá nekonstantní žilní struktura. Po odečtení 1,3 mm (průměr elektrody) od šířky koridoru je rezervní prostor ve vzdálenosti 2 mm 1,2–1,8 mm a ve vzdálenosti 4 i 6 mm od junkce 2,7–3,2 mm. Závěr: Úzký vaskulární koridor (především v přední části ATN) klade vysoké nároky na předoperační plánování a přesnost implantace, aby se maximalizoval účinek stimulační léčby a zároveň se zabránilo riziku vaskulárního konfliktu.
Aim: Stimulation of the anterior thalamic nucleus (ATN) is considered for patients with refractory epilepsy if there is no other surgical option. The target structure, the ATN, protrudes to the lateral brain ventricle as a thalamic tubercle, bordered by the thalamostriate vein laterally and the choroid plexus with the superior choroidal vein medially. The study aim was to analyze this vascular corridor for electrode implantation considering both surgical safety and possible association with stimulation outcomes. The best results are achieved when the anterior part of the ATN is stimulated. Materials and methods: The thalamic tubercle and its vascular borders were identified in dissection of both brain hemispheres of cadaveric specimens with intracranial vessel injections. The width of the vascular corridor was measured at distances of 2, 4, and 6 mm from the covering spot of the thalamostriate vein and choroid plexus or from the junction of these veins. Results: Six cadaveric specimens were measured. The median widths of the vascular corridor were 2.5–3 mm at the 2 mm, and 4–4.5 mm at the 4 mm, and 6 mm measures from the junction points, respectively. A small inconstant venous structure was observed in the dorsal part of the thalamic tubercle. After subtracting 1.3 mm (the diameter of a stimulation electrode) from the corridor width, the reserve space was 1.2–1.8 mm at the distance of 2 mm, and 2.7–3.2 mm at distances of 4 mm, and 6 mm from the junction, respectively. Conclusions: The narrow vascular corridor for electrode implantation (particularly in the anterior part of the thalamic tubercle) requires meticulous presurgical planning and precise implantation to maximize the effect of stimulation treatment while avoiding the risk of vascular conflict.
- MeSH
- epilepsie * chirurgie MeSH
- hluboká mozková stimulace metody MeSH
- klinická studie jako téma MeSH
- lidé MeSH
- mozkové žíly chirurgie MeSH
- nuclei anteriores thalami chirurgie MeSH
- refrakterní epilepsie * chirurgie MeSH
- stereotaktické techniky MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
BACKGROUND: Symmetric biphasic pulses have been shown to acutely increase the therapeutic window of ventralis intermedius deep brain stimulation (Vim-DBS) for essential tremor (ET) compared to cathodic pulses. Acute supratherapeutic stimulation can induce ataxic side effects in Vim-DBS. OBJECTIVE: To investigate the effect on tremor, ataxia and dysarthria of 3 h of biphasic stimulation in patients with DBS for ET. METHODS: A randomized, doubled-blind, cross-over design was used to compare standard cathodic pulses with symmetric biphasic pulses (anode-first) during a 3-h period per pulse shape. During each 3-h period, all stimulation parameters were identical, except for the pulse shape. Tremor (Fahn-Tolosa-Marin Tremor Rating Scale), ataxia (International Cooperative Ataxia Rating Scale) and speech (acoustic and perceptual measures) were assessed hourly during the 3-h periods. RESULTS: Twelve ET patients were included. During the 3-h stimulation period, tremor control was equivalent between the two pulse shapes. Biphasic pulses elicited significantly less ataxia than cathodic pulses (p = 0.006). Diadochokinesis rate of speech was better for the biphasic pulse (p = 0.048), but other measures for dysarthria were not significantly different between the pulses. CONCLUSION: Symmetric biphasic pulses induce less ataxia than conventional pulses after 3 h of stimulation DBS in ET patients.
- MeSH
- ataxie etiologie MeSH
- dysartrie etiologie MeSH
- elektrody MeSH
- esenciální tremor * terapie etiologie MeSH
- hluboká mozková stimulace * škodlivé účinky MeSH
- lidé MeSH
- nuclei ventrales thalami chirurgie MeSH
- tremor etiologie MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- randomizované kontrolované studie MeSH
OBJECTIVE: To review the therapeutic effects of deep brain stimulation of the anterior nuclei of the thalamus (ANT-DBS) and the predictors of its effectiveness, safety, and adverse effects. METHODS: A comprehensive search of the medical literature (PubMed) was conducted to identify relevant articles investigating ANT-DBS therapy for epilepsy. Out of 332 references, 77 focused on focal epilepsies were reviewed. RESULTS: The DBS effect is probably due to decreased synchronization of epileptic activity in the cortex. The potential mechanisms from cellular to brain network levels are presented. The ANT might participate actively in the network elaborating focal seizures. The effects of ANT-DBS differed in various studies; ANT-DBS was linked with a 41% seizure frequency reduction at 1 year, 69% at 5 years, and 75% at 7 years. The most frequently reported adverse effects, depression and memory impairment, were considered non-serious in the long-term follow-up view. ANT-DBS also has been used in a few cases to treat status epilepticus. CONCLUSIONS: We reviewed the clinical literature and identified several factors that may predict seizure outcome following DBS therapy. More large-scale trials are required since there is a need to explore stimulation settings, apply patient-tailored therapy, and identify the presurgical predictors of patient response. SIGNIFICANCE: A critical review of the published literature on ANT-DBS in focal epilepsy is presented. ANT-DBS mechanisms are not fully understood; possible explanations are provided. Biomarkers of ANT-DBS effectiveness may lead to patient-tailored therapy.
- MeSH
- epilepsie parciální * terapie MeSH
- epilepsie * terapie MeSH
- hluboká mozková stimulace * MeSH
- lidé MeSH
- nuclei anteriores thalami * MeSH
- záchvaty terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Objective.Electrical deep brain stimulation (DBS) is an established treatment for patients with drug-resistant epilepsy. Sleep disorders are common in people with epilepsy, and DBS may actually further disturb normal sleep patterns and sleep quality. Novel implantable devices capable of DBS and streaming of continuous intracranial electroencephalography (iEEG) signals enable detailed assessments of therapy efficacy and tracking of sleep related comorbidities. Here, we investigate the feasibility of automated sleep classification using continuous iEEG data recorded from Papez's circuit in four patients with drug resistant mesial temporal lobe epilepsy using an investigational implantable sensing and stimulation device with electrodes implanted in bilateral hippocampus (HPC) and anterior nucleus of thalamus (ANT).Approach.The iEEG recorded from HPC is used to classify sleep during concurrent DBS targeting ANT. Simultaneous polysomnography (PSG) and sensing from HPC were used to train, validate and test an automated classifier for a range of ANT DBS frequencies: no stimulation, 2 Hz, 7 Hz, and high frequency (>100 Hz).Main results.We show that it is possible to build a patient specific automated sleep staging classifier using power in band features extracted from one HPC iEEG sensing channel. The patient specific classifiers performed well under all thalamic DBS frequencies with an average F1-score 0.894, and provided viable classification into awake and major sleep categories, rapid eye movement (REM) and non-REM. We retrospectively analyzed classification performance with gold-standard PSG annotations, and then prospectively deployed the classifier on chronic continuous iEEG data spanning multiple months to characterize sleep patterns in ambulatory patients living in their home environment.Significance.The ability to continuously track behavioral state and fully characterize sleep should prove useful for optimizing DBS for epilepsy and associated sleep, cognitive and mood comorbidities.
- MeSH
- epilepsie komplikace MeSH
- hipokampus MeSH
- hluboká mozková stimulace * metody MeSH
- lidé MeSH
- mozek MeSH
- nuclei anteriores thalami * MeSH
- poruchy spánku a bdění * komplikace diagnóza terapie MeSH
- retrospektivní studie MeSH
- thalamus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Functional MRI (fMRI) has become an important tool for probing network-level effects of deep brain stimulation (DBS). Previous DBS-fMRI studies have shown that electrical stimulation of the ventrolateral (VL) thalamus can modulate sensorimotor cortices in a frequency and amplitude dependent manner. Here, we investigated, using a swine animal model, how the direction and orientation of the electric field, induced by VL-thalamus DBS, affects activity in the sensorimotor cortex. Adult swine underwent implantation of a novel 16-electrode (4 rows x 4 columns) directional DBS lead in the VL thalamus. A within-subject design was used to compare fMRI responses for (1) directional stimulation consisting of monopolar stimulation in four radial directions around the DBS lead, and (2) orientation-selective stimulation where an electric field dipole was rotated 0°-360° around a quadrangle of electrodes. Functional responses were quantified in the premotor, primary motor, and somatosensory cortices. High frequency electrical stimulation through leads implanted in the VL thalamus induced directional tuning in cortical response patterns to varying degrees depending on DBS lead position. Orientation-selective stimulation showed maximal functional response when the electric field was oriented approximately parallel to the DBS lead, which is consistent with known axonal orientations of the cortico-thalamocortical pathway. These results demonstrate that directional and orientation-selective stimulation paradigms in the VL thalamus can tune network-level modulation patterns in the sensorimotor cortex, which may have translational utility in improving functional outcomes of DBS therapy.
- MeSH
- elektrická stimulace metody MeSH
- hluboká mozková stimulace * metody MeSH
- magnetická rezonanční tomografie metody MeSH
- motorické korové centrum fyziologie MeSH
- nervové dráhy fyziologie MeSH
- nuclei ventrales thalami fyziologie MeSH
- nucleus subthalamicus fyziologie MeSH
- prasata MeSH
- thalamus fyziologie MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
There is a paucity of data to guide anterior nucleus of the thalamus (ANT) deep brain stimulation (DBS) with brain sensing. The clinical Medtronic Percept DBS device provides constrained brain sensing power within a frequency band (power-in-band [PIB]), recorded in 10-min averaged increments. Here, four patients with temporal lobe epilepsy were implanted with an investigational device providing full bandwidth chronic intracranial electroencephalogram (cEEG) from bilateral ANT and hippocampus (Hc). ANT PIB-based seizure detection was assessed. Detection parameters were cEEG PIB center frequency, bandwidth, and epoch duration. Performance was evaluated against epileptologist-confirmed Hc seizures, and assessed by area under the precision-recall curve (PR-AUC). Data included 99 days of cEEG, and 20, 278, 3, and 18 Hc seizures for Subjects 1-4. The best detector had 7-Hz center frequency, 5-Hz band width, and 10-s epoch duration (group PR-AUC = .90), with 75% sensitivity and .38 false alarms per day for Subject 1, and 100% and .0 for Subjects 3 and 4. Hc seizures in Subject 2 did not propagate to ANT. The relative change of ANT PIB was maximal ipsilateral to seizure onset for all detected seizures. Chronic ANT and Hc recordings provide direct guidance for ANT DBS with brain sensing.
- MeSH
- epilepsie * terapie MeSH
- hipokampus diagnostické zobrazování MeSH
- hluboká mozková stimulace * MeSH
- lidé MeSH
- nuclei anteriores thalami * fyziologie MeSH
- thalamus MeSH
- záchvaty diagnóza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
We hypothesized that local/regional properties of stimulated structure/circuitry contribute to the effect of deep brain stimulation (DBS). We analyzed intracerebral electroencephalographic (EEG) recordings from externalized DBS electrodes targeted bilaterally in the anterior nuclei of the thalamus (ANT) in 12 patients (six responders, six nonresponders) with more than 1 year of follow-up care. In the bipolar local field potentials of the EEG, spectral power (PW) and power spectral entropy (PSE) were calculated in the passbands 1-4, 4-8, 8-12, 12-20, 20-45, 65-80, 80-200 and 200-500 Hz. The most significant differences between responders and nonresponders were observed in the BRIDGE area (bipolar recordings with one contact within the ANT and the second contact in adjacent tissue). In responders, PW was significantly decreased in the frequency bands of 65-80, 80-200, and 200-500 Hz (p < .05); PSE was significantly increased in all frequency bands (p < .05) except for 200-500 Hz (p = .06). The local EEG characteristics of ANT recorded after implantation may play a significant role in DBS response prediction.
OBJECTIVE: The extreme lateral supracerebellar infratentorial (ELSI) approach has the potential to access several distinct anatomical regions that are otherwise difficult to reach. We have illustrated the surgical anatomy through cadaveric dissections and provided an extensive review of the literature to highlight the versatility of this approach, its limits, and comparisons with alternative approaches. METHODS: The surgical anatomy of the ELSI has been described using 1 adult-injected cadaveric head. Formalized noninjected brain specimens were also dissected to describe the brain parenchymal anatomy of the region. An extensive review of the literature was performed according to each targeted anatomical region. Illustrative cases are also presented. RESULTS: The ELSI approach allows for wide exposure of the middle and posterolateral incisural spaces with direct access to centrally located intra-axial structures such as the splenium, pulvinar, brainstem, and mesial temporal lobe. In addition, for skull base extra-axial tumors such as petroclival meningiomas, the ELSI approach represents a rapid and adequate method of access without the use of extensive skull base approaches. CONCLUSIONS: The ELSI approach represents one of the most versatile approaches with respect to its ability to address several anatomical regions centered at the posterior and middle incisural spaces. For intra-axial pathologies, the approach allows for access to the central core of the brain with several advantages compared with alternate approaches that frequently involve significant brain retraction and cortical incisions. In specific cases of skull base lesions, the ELSI approach is an elegant alternative to traditionally used skull base approaches, thereby avoiding approach-related morbidity.
- MeSH
- disekce MeSH
- dura mater anatomie a histologie MeSH
- hluboké zádové svaly anatomie a histologie chirurgie MeSH
- lidé MeSH
- mozeček anatomie a histologie MeSH
- mozkový kmen anatomie a histologie chirurgie MeSH
- mrtvola MeSH
- neurochirurgické výkony metody MeSH
- pulvinar anatomie a histologie chirurgie MeSH
- skalní kost anatomie a histologie chirurgie MeSH
- spánkový lalok anatomie a histologie chirurgie MeSH
- thalamus anatomie a histologie chirurgie MeSH
- zadní jáma lební anatomie a histologie chirurgie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
PURPOSE: Despite documented clinical effectiveness, deep brain stimulation (DBS) therapy for drug-resistant epilepsy rarely yields long-term seizure free outcomes. METHODS: This pilot study in five patients investigated circuit of Papez evoked potentials (EPs) using hippocampal sensing during anterior nucleus of the thalamus (ANT) electrical stimulation. We hypothesize that hippocampal EP is a potential biomarker that could be useful for ANT electrode targeting and improving seizure reduction. We obtained bilateral circuit of Papez EPs in five patients with bilateral temporal lobe epilepsy (TLE). The circuit of Papez EPs were measured and assessed by signal amplitude. Volumetric analysis of relevant mesial temporal structures and ANT stimulation analysis was performed on immediate post-implantation images. RESULTS: The patient with the most favorable seizure outcome, which meant long-term seizure reduction greater than 50 % compared to baseline, had strong bilateral EPs and normal hippocampal structure. Conversely, those without clinical benefit with ANT DBS had absent or weak bilateral EPs as well as MRI findings consistent with mesial temporal sclerosis (MTS). CONCLUSION: The data support the hypothesis that hippocampal EPs with ANT stimulation may be used to as a surrogate marker to probe circuit of Papez and predict ANT DBS efficacy.
- MeSH
- dospělí MeSH
- elektrická stimulace MeSH
- epilepsie temporálního laloku patofyziologie MeSH
- evokované potenciály fyziologie MeSH
- hipokampus patofyziologie MeSH
- lidé MeSH
- nervové dráhy patofyziologie MeSH
- nuclei anteriores thalami patofyziologie MeSH
- pilotní projekty MeSH
- záchvaty patofyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
The structure of neurons in the central auditory system is vulnerable to various kinds of acoustic exposures during the critical postnatal developmental period. Here we explored long-term effects of exposure to an acoustically enriched environment (AEE) during the third and fourth weeks of the postnatal period in rat pups. AEE consisted of a spectrally and temporally modulated sound of moderate intensity, reinforced by a behavioral paradigm. At the age of 3-6 months, a Golgi-Cox staining was used to evaluate the morphology of neurons in the inferior colliculus (IC), the medial geniculate body (MGB), and the auditory cortex (AC). Compared to controls, rats exposed to AEE showed an increased mean dendritic length and volume and the soma surface in the external cortex and the central nucleus of the IC. The spine density increased in both the ventral and dorsal divisions of the MGB. In the AC, the total length and volume of the basal dendritic segments of pyramidal neurons and the number and density of spines on these dendrites increased significantly. No differences were found on apical dendrites. We also found an elevated number of spines and spine density in non-pyramidal neurons. These results show that exposure to AEE during the critical developmental period can induce permanent changes in the structure of neurons in the central auditory system. These changes represent morphological correlates of the functional plasticity, such as an improvement in frequency tuning and synchronization with temporal parameters of acoustical stimuli.
- MeSH
- akustická stimulace MeSH
- colliculus inferior cytologie fyziologie MeSH
- dendritické trny fyziologie MeSH
- dendrity fyziologie MeSH
- krysa rodu rattus MeSH
- metathalamus cytologie fyziologie MeSH
- neurony cytologie fyziologie MeSH
- neuroplasticita fyziologie MeSH
- novorozená zvířata MeSH
- potkani Long-Evans MeSH
- sluchová dráha cytologie fyziologie MeSH
- sluchové korové centrum cytologie fyziologie MeSH
- tvar buňky fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
