Somatosensory information is propagated from the periphery to the cerebral cortex by two parallel pathways through the ventral posterolateral (VPL) and ventral posteromedial (VPM) thalamus. VPL and VPM neurons receive somatosensory signals from the body and head, respectively. VPL and VPM neurons may also receive cell type-specific GABAergic input from the reticular nucleus of the thalamus. Although VPL and VPM neurons have distinct connectivity and physiological roles, differences in their functional properties remain unclear as they are often studied as one ventrobasal thalamus neuron population. Here, we directly compared synaptic and intrinsic properties of VPL and VPM neurons in C57Bl/6J mice of both sexes aged P25-P32. VPL neurons showed greater depolarization-induced spike firing and spike frequency adaptation than VPM neurons. VPL and VPM neurons fired similar numbers of spikes during hyperpolarization rebound bursts, but VPM neurons exhibited shorter burst latency compared with VPL neurons, which correlated with larger sag potential. VPM neurons had larger membrane capacitance and more complex dendritic arbors. Recordings of spontaneous and evoked synaptic transmission suggested that VPL neurons receive stronger excitatory synaptic input, whereas inhibitory synapse strength was stronger in VPM neurons. This work indicates that VPL and VPM thalamocortical neurons have distinct intrinsic and synaptic properties. The observed functional differences could have important implications for their specific physiological and pathophysiological roles within the somatosensory thalamocortical network.NEW & NOTEWORTHY This study revealed that somatosensory thalamocortical neurons in the VPL and VPM have substantial differences in excitatory synaptic input and intrinsic firing properties. The distinct properties suggest that VPL and VPM neurons could process somatosensory information differently and have selective vulnerability to disease. This work improves our understanding of nucleus-specific neuron function in the thalamus and demonstrates the critical importance of studying these parallel somatosensory pathways separately.

• MeSH
• mozková kůra MeSH
• myši MeSH
• nervový přenos fyziologie   MeSH
• neurony * fyziologie   MeSH
• somatosenzorické korové centrum fyziologie   MeSH
• synapse fyziologie   MeSH
• thalamus * fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

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

Ablační procedury, které jsou součástí funkční neurochirurgie, prodělávají v posledních letech renesanci. Mezi tyto procedury se řadí i mediální talamotomie jako analgetický výkon u širokého spektra bolestivých stavů. Jednou z možných indikací k mediální talamotomii je refrakterní neural gie trigeminu. Management pacientů s refrakterní neuralgií trigeminu je svízelný a mediální talamotomie pomocí Leksellova gama nože těmto pacientům může pomoci. Následující článek má za cíl stručně a přehledně představit mediální talamotomii pomocí Leksellova gama nože jako bezpečnou a efektivní metodu v léčbě chronické bolesti a naše zkušenosti s touto metodou u pacientů s neuralgií trigeminu, u kterých farmako logická i chirurgická léčba selhala.

Ablative procedures, as an important part of functional neurosurgery, have experienced a renaissance in recent years. These procedures include medial thalamotomy as an analgesic procedure for a wide range of pain syndromes. Refractory trigeminal neuralgia is one of the indications for medial thalamotomy. Management of patients with refractory trigeminal neuralgia is challenging, and medial thalamotomy using the Leksell gamma knife may help these patients. This article aims to briefly and clearly present medial thalamotomy using the Leksell gamma knife as a safe and effective method in the treatment of chronic pain and our experience with this procedure in patients with trigeminal neuralgia in whom pharmacological and surgical treatment has failed.

• Klíčová slova
• radiochirurgická talamotomie,
• MeSH
• lidé MeSH
• neuralgie trigeminu * chirurgie   radioterapie   MeSH
• radiochirurgie metody   MeSH
• thalamus chirurgie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

BACKGROUND: As a step towards clinical use of AAV-mediated gene therapy, brains of large animals are used to settle delivery parameters as most brain connections, and relative sizes in large animals and primates, are reasonably common. Prior to application in the clinic, approaches that have shown to be successful in rodent models are tested in larger animal species, such as dogs, non-human primates, and in this case, minipigs. NEW METHOD: We evaluated alternate delivery routes to target the basal ganglia by injections into the more superficial corona radiata, and, deeper into the brain, the thalamus. Anatomically known connections can be used to predict the expression of the transgene following infusion of AAV5. For optimal control over delivery of the vector with regards to anatomical location in the brain and spread in the tissue, we have used magnetic resonance image-guided convection-enhanced diffusion delivery. RESULTS: While the transduction of the cortex was observed, only partial transduction of the basal ganglia was achieved via the corona radiata. Thalamic administration, on the other hand, resulted in widespread transduction from the midbrain to the frontal cortex COMPARISON WITH EXISTING METHODS: Compared to other methods, such as delivery directly to the striatum, thalamic injection may provide an alternative when for instance, injection into the basal ganglia directly is not feasible. CONCLUSIONS: The study results suggest that thalamic administration of AAV5 has significant potential for indications where the transduction of specific areas of the brain is required.

• MeSH
• Dependovirus genetika   MeSH
• genetická terapie metody   MeSH
• genetické vektory MeSH
• konvekce * MeSH
• magnetická rezonanční tomografie MeSH
• miniaturní prasata genetika   MeSH
• prasata MeSH
• psi MeSH
• thalamus * diagnostické zobrazování   MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články 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

Paramediálne obojstranné ischemické poškodenie talamu sa častokrát spája s rozmanitým klinickým obrazom, ktorého diferenciálna diagnostika zahŕňa viacero možných príčin. V klinickom obraze dominuje porucha vedomia, hypersomnia, okohybné a neuropsychiatrické poruchy. Okrem klinického nálezu sa pri určovaní diagnózy môžeme oprieť o typický rádiologický nález. Jednou z príčin môže byť trombóza tzv. Percheronovej artérie, ktorá má spoločný kmeň zásobujúci obojstranné paramediálne talamické jadrá. Uvedenou kazuistikou prezentujeme prípad pacienta s klinickým, ako aj rádiologickým nálezom potvrdzujúcim ischemické poškodenie talamu a mezencefalu na podklade infarktu v povodí Percheronovej artérie v koincidencii s ďalším typom anatomickej variácie odstupu arteria cerebri posterior.

Paramedian bilateral thalamic ischemia often leads to different clinical presentation, the differential diagnosis of which includes several possible causes. The major features are unconsciousness, hypersomnia, ocular and neuropsychiatric disorders. In addition to the clinical manifestations, neuroradiological findings can also lead to diagnosis. Thrombosis of so-called Percheron artery is presumed cause. In this case report we would like to present a patient with clinical and radiological diagnosis of bilateral paramedian thalamic stroke due to thrombosis of Percheron artery in coincidence with an anatomical vascular anomaly of the posterior cerebral artery origin.

• MeSH
• arteria cerebri posterior patologie   MeSH
• ischemická cévní mozková příhoda * diagnóza   etiologie   patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• thalamus krevní zásobení   patologie   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• kazuistiky 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

BACKGROUND: Childhood thalamopeduncular gliomas arise at the interface of the thalamus and cerebral peduncle. The optimal treatment is total resection but not at the cost of neurological function. We present long-term clinical and oncological outcomes of maximal safe resection. METHODS: Retrospective review of prospectively collected data: demography, symptomatology, imaging, extent of resection, surgical complications, histology, functional and oncological outcome. RESULTS: During 16-year period (2005-2020), 21 patients were treated at our institution. These were 13 girls and 8 boys (mean age 7.6 years). Presentation included progressive hemiparesis in 9 patients, raised intracranial pressure in 9 patients and cerebellar symptomatology in 3 patients. The tumour was confined to the thalamus in 6 cases. Extent of resection was judged on postoperative imaging as total (6), near-total (6) and less extensive (9). Surgical complications included progression of baseline neurological status in 6 patients, and 5 of these gradually improved to preoperative status. All tumours were classified as low-grade gliomas. Disease progression was observed in 9 patients (median progression-free survival 7.3 years). At last follow-up (median 6.1 years), all patients were alive, median Lansky score of 90. Seven patients were without evidence of disease, 6 had stable disease, 7 stable following progression and 1 had progressive disease managed expectantly. CONCLUSION: Paediatric patients with low-grade thalamopeduncular gliomas have excellent long-term functional and oncological outcomes when gross total resection is not achievable. Surgery should aim at total resection; however, neurological function should not be endangered due to excellent chance for long-term survival.

• MeSH
• dítě MeSH
• gliom * komplikace   diagnostické zobrazování   chirurgie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• nádory mozku * komplikace   diagnostické zobrazování   chirurgie   MeSH
• neurochirurgické výkony metody   MeSH
• retrospektivní studie MeSH
• thalamus diagnostické zobrazování   patologie   chirurgie   MeSH
• výsledek terapie MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Chronic brain recordings suggest that seizure risk is not uniform, but rather varies systematically relative to daily (circadian) and multiday (multidien) cycles. Here, one human and seven dogs with naturally occurring epilepsy had continuous intracranial EEG (median 298 days) using novel implantable sensing and stimulation devices. Two pet dogs and the human subject received concurrent thalamic deep brain stimulation (DBS) over multiple months. All subjects had circadian and multiday cycles in the rate of interictal epileptiform spikes (IES). There was seizure phase locking to circadian and multiday IES cycles in five and seven out of eight subjects, respectively. Thalamic DBS modified circadian (all 3 subjects) and multiday (analysis limited to the human participant) IES cycles. DBS modified seizure clustering and circadian phase locking in the human subject. Multiscale cycles in brain excitability and seizure risk are features of human and canine epilepsy and are modifiable by thalamic DBS.

• MeSH
• cirkadiánní rytmus MeSH
• elektroencefalografie MeSH
• epilepsie prevence a kontrola   MeSH
• hluboká mozková stimulace metody   MeSH
• lidé MeSH
• psi MeSH
• riziko MeSH
• thalamus fyziologie   MeSH
• záchvaty prevence a kontrola   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH