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JAMA Neurology Jun 2024Unilateral magnetic resonance imaging (MRI)-guided focused ultrasound subthalamotomy (FUS-STN) improves cardinal motor features among patients with asymmetrical...
IMPORTANCE
Unilateral magnetic resonance imaging (MRI)-guided focused ultrasound subthalamotomy (FUS-STN) improves cardinal motor features among patients with asymmetrical Parkinson disease (PD). The feasibility of bilateral FUS-STN is as yet unexplored.
OBJECTIVE
To assess the safety and effectiveness of staged bilateral FUS-STN to treat PD.
DESIGN, SETTING, AND PARTICIPANTS
This prospective, open-label, case series study was conducted between June 18, 2019, and November 7, 2023, at HM-CINAC, Puerta del Sur University Hospital, Madrid, Spain, and included 6 patients with PD who had been treated with unilateral FUS-STN contralateral to their most affected body side and whose parkinsonism on the untreated side had progressed and was not optimally controlled with medication.
INTERVENTION
Staged bilateral FUS-STN.
MAIN OUTCOMES AND MEASURES
Primary outcomes were assessed 6 months after the second treatment and included safety (incidence and severity of adverse events after second treatment) and effectiveness in terms of motor change (measured with the Movement Disorders Society Unified Parkinson's Disease Rating Scale part III [MDS-UPDRS III]) in the off-medication state (ie, after at least 12 hours of antiparkinsonian drug withdrawal) compared with baseline (ie, prior to the first side ablation). Secondary outcomes included motor change in patients in the on-medication state (ie, after usual antiparkinsonian medication intake), motor complications (measured with the MDS-UPDRS IV), daily living activities (measured with the MDS-UPDRS I-II), quality of life (measured with the 39-item Parkinson's Disease Questionnaire), change in dopaminergic treatment, patient's global impression of change (measured with the Global Impression of Change [PGI-C] scale), and long-term (24-month) follow-up.
RESULTS
Of 45 patients previously treated with unilateral FUS-STN, 7 were lost to follow-up, and 4 were excluded due to adverse events. Of the remaining 34 patients, 6 (median age at first FUS-STN, 52.6 years [IQR, 49.0-57.3 years]; 3 women [50%]) experienced progression of parkinsonism on the untreated body side and were included. At the time of the first FUS-STN, patients' median duration of disease was 5.7 years (IQR, 4.7-7.3 years). The median time between procedures was 3.2 years (IQR, 1.9-3.5 years). After the second FUS-STN, 4 patients presented with contralateral choreic dyskinesia, which resolved by 3 months. Four patients developed speech disturbances, which gradually improved but remained in a mild form for 2 patients at 6 months; 1 patient experienced mild imbalance and dysphagia during the first week after treatment, which subsided by 3 months. No behavioral or cognitive disturbances were found on neuropsychological testing. For patients in the off-medication state, MDS-UPDRS III scores improved by 52.6% between baseline and 6 months after the second FUS-STN (from 37.5 [IQR, 34.2-40.0] to 20.5 [IQR, 8.7-24.0]; median difference, 23.0 [95% CI, 7.0-33.7]; P = .03). The second treated side improved by 64.3% (MDS-UPDRS III score, 17.0 [IQR, 16.0-19.5] prior to the second treatment vs 5.5 [IQR, 3.0-10.2]; median difference, 9.5 [95% CI, 3.2-17.7]; P = .02). After the second procedure, all self-reported PGI-C scores were positive.
CONCLUSIONS
Findings of this pilot study suggest that staged bilateral FUS-STN was safe and effective for the treatment of PD, although mild but persistent speech-related adverse events were observed among a small number of patients.
Topics: Humans; Parkinson Disease; Female; Male; Middle Aged; Aged; Prospective Studies; Subthalamic Nucleus; Magnetic Resonance Imaging; Treatment Outcome
PubMed: 38739377
DOI: 10.1001/jamaneurol.2024.1220 -
The Journal of Comparative Neurology May 2024We used diverse methods to characterize the role of avian lateral spiriform nucleus (SpL) in basal ganglia motor function. Connectivity analysis showed that SpL receives...
We used diverse methods to characterize the role of avian lateral spiriform nucleus (SpL) in basal ganglia motor function. Connectivity analysis showed that SpL receives input from globus pallidus (GP), and the intrapeduncular nucleus (INP) located ventromedial to GP, whose neurons express numerous striatal markers. SpL-projecting GP neurons were large and aspiny, while SpL-projecting INP neurons were medium sized and spiny. Connectivity analysis further showed that SpL receives inputs from subthalamic nucleus (STN) and substantia nigra pars reticulata (SNr), and that the SNr also receives inputs from GP, INP, and STN. Neurochemical analysis showed that SpL neurons express ENK, GAD, and a variety of pallidal neuron markers, and receive GABAergic terminals, some of which also contain DARPP32, consistent with GP pallidal and INP striatal inputs. Connectivity and neurochemical analysis showed that the SpL input to tectum prominently ends on GABAA receptor-enriched tectobulbar neurons. Behavioral studies showed that lesions of SpL impair visuomotor behaviors involving tracking and pecking moving targets. Our results suggest that SpL modulates brainstem-projecting tectobulbar neurons in a manner comparable to the demonstrated influence of GP internus on motor thalamus and of SNr on tectobulbar neurons in mammals. Given published data in amphibians and reptiles, it seems likely the SpL circuit represents a major direct pathway-type circuit by which the basal ganglia exerts its motor influence in nonmammalian tetrapods. The present studies also show that avian striatum is divided into three spatially segregated territories with differing connectivity, a medial striato-nigral territory, a dorsolateral striato-GP territory, and the ventrolateral INP motor territory.
Topics: Animals; Basal Ganglia; Neural Pathways; Male; Neurons; Globus Pallidus
PubMed: 38733146
DOI: 10.1002/cne.25620 -
Cerebral Cortex (New York, N.Y. : 1991) May 2024Information flow in brain networks is reflected in local field potentials that have both periodic and aperiodic components. The 1/fχ aperiodic component of the power...
UNLABELLED
Information flow in brain networks is reflected in local field potentials that have both periodic and aperiodic components. The 1/fχ aperiodic component of the power spectra tracks arousal and correlates with other physiological and pathophysiological states. Here we explored the aperiodic activity in the human thalamus and basal ganglia in relation to simultaneously recorded cortical activity. We elaborated on the parameterization of the aperiodic component implemented by specparam (formerly known as FOOOF) to avoid parameter unidentifiability and to obtain independent and more easily interpretable parameters. This allowed us to seamlessly fit spectra with and without an aperiodic knee, a parameter that captures a change in the slope of the aperiodic component. We found that the cortical aperiodic exponent χ, which reflects the decay of the aperiodic component with frequency, is correlated with Parkinson's disease symptom severity. Interestingly, no aperiodic knee was detected from the thalamus, the pallidum, or the subthalamic nucleus, which exhibited an aperiodic exponent significantly lower than in cortex. These differences were replicated in epilepsy patients undergoing intracranial monitoring that included thalamic recordings. The consistently lower aperiodic exponent and lack of an aperiodic knee from all subcortical recordings may reflect cytoarchitectonic and/or functional differences.
SIGNIFICANCE STATEMENT
The aperiodic component of local field potentials can be modeled to produce useful and reproducible indices of neural activity. Here we refined a widely used phenomenological model for extracting aperiodic parameters (namely the exponent, offset and knee), with which we fit cortical, basal ganglia, and thalamic intracranial local field potentials, recorded from unique cohorts of movement disorders and epilepsy patients. We found that the aperiodic exponent in motor cortex is higher in Parkinson's disease patients with more severe motor symptoms, suggesting that aperiodic features may have potential as electrophysiological biomarkers for movement disorders symptoms. Remarkably, we found conspicuous differences in the aperiodic parameters of basal ganglia and thalamic signals compared to those from neocortex.
Topics: Humans; Male; Female; Thalamus; Cerebral Cortex; Basal Ganglia; Parkinson Disease; Middle Aged; Adult; Epilepsy; Aged; Electroencephalography
PubMed: 38725290
DOI: 10.1093/cercor/bhae186 -
Journal of Neurology, Neurosurgery, and... May 2024Sleep fragmentation is a persistent problem throughout the course of Parkinson's disease (PD). However, the related neurophysiological patterns and the underlying...
BACKGROUND
Sleep fragmentation is a persistent problem throughout the course of Parkinson's disease (PD). However, the related neurophysiological patterns and the underlying mechanisms remained unclear.
METHOD
We recorded subthalamic nucleus (STN) local field potentials (LFPs) using deep brain stimulation (DBS) with real-time wireless recording capacity from 13 patients with PD undergoing a one-night polysomnography recording, 1 month after DBS surgery before initial programming and when the patients were off-medication. The STN LFP features that characterised different sleep stages, correlated with arousal and sleep fragmentation index, and preceded stage transitions during N2 and REM sleep were analysed.
RESULTS
Both beta and low gamma oscillations in non-rapid eye movement (NREM) sleep increased with the severity of sleep disturbance (arousal index (ArI)-beta: r=0.9, p=0.0001, sleep fragmentation index (SFI)-beta: r=0.6, p=0.0301; SFI-gamma: r=0.6, p=0.0324). We next examined the low-to-high power ratio (LHPR), which was the power ratio of theta oscillations to beta and low gamma oscillations, and found it to be an indicator of sleep fragmentation (ArI-LHPR: r=-0.8, p=0.0053; ArI-LHPR: r=-0.6, p=0.0373; SFI-LHPR: r=-0.7, p=0.0204; SFI-LHPR: r=-0.6, p=0.0428). In addition, long beta bursts (>0.25 s) during NREM stage 2 were found preceding the completion of transition to stages with more cortical activities (towards Wake/N1/REM compared with towards N3 (p<0.01)) and negatively correlated with STN spindles, which were detected in STN LFPs with peak frequency distinguishable from long beta bursts (STN spindle: 11.5 Hz, STN long beta bursts: 23.8 Hz), in occupation during NREM sleep (β=-0.24, p<0.001).
CONCLUSION
Features of STN LFPs help explain neurophysiological mechanisms underlying sleep fragmentations in PD, which can inform new intervention for sleep dysfunction.
TRIAL REGISTRATION NUMBER
NCT02937727.
PubMed: 38724231
DOI: 10.1136/jnnp-2023-331979 -
Annals of Neurology May 2024Bradykinesia and rigidity are considered closely related motor signs in Parkinson disease (PD), but recent neurophysiological findings suggest distinct...
OBJECTIVE
Bradykinesia and rigidity are considered closely related motor signs in Parkinson disease (PD), but recent neurophysiological findings suggest distinct pathophysiological mechanisms. This study aims to examine and compare longitudinal changes in bradykinesia and rigidity in PD patients treated with bilateral subthalamic nucleus deep brain stimulation (STN-DBS).
METHODS
In this retrospective cohort study, the clinical progression of appendicular and axial bradykinesia and rigidity was assessed up to 15 years after STN-DBS in the best treatment conditions (ON medication and ON stimulation). The severity of bradykinesia and rigidity was examined using ad hoc composite scores from specific subitems of the Unified Parkinson's Disease Rating Scale motor part (UPDRS-III). Short- and long-term predictors of bradykinesia and rigidity were analyzed through linear regression analysis, considering various preoperative demographic and clinical data, including disease duration and severity, phenotype, motor and cognitive scores (eg, frontal score), and medication.
RESULTS
A total of 301 patients were examined before and 1 year after surgery. Among them, 101 and 56 individuals were also evaluated at 10-year and 15-year follow-ups, respectively. Bradykinesia significantly worsened after surgery, especially in appendicular segments (p < 0.001). Conversely, rigidity showed sustained benefit, with unchanged clinical scores compared to preoperative assessment (p > 0.05). Preoperative motor disability (eg, composite scores from the UPDRS-III) predicted short- and long-term outcomes for both bradykinesia and rigidity (p < 0.01). Executive dysfunction was specifically linked to bradykinesia but not to rigidity (p < 0.05).
INTERPRETATION
Bradykinesia and rigidity show long-term divergent progression in PD following STN-DBS and are associated with independent clinical factors, supporting the hypothesis of partially distinct pathophysiology. ANN NEUROL 2024.
PubMed: 38721781
DOI: 10.1002/ana.26961 -
Movement Disorders Clinical Practice May 2024Subthalamic deep brain stimulation (STN-DBS) reduces antiparkinsonian medications in Parkinson's disease (PD) compared with the preoperative state. Longitudinal and...
BACKGROUND
Subthalamic deep brain stimulation (STN-DBS) reduces antiparkinsonian medications in Parkinson's disease (PD) compared with the preoperative state. Longitudinal and comparative studies on this effect are lacking.
OBJECTIVE
To compare longitudinal trajectories of antiparkinsonian medication in STN-DBS treated patients to non-surgically treated control patients.
METHODS
We collected retrospective information on antiparkinsonian medication from PD patients that underwent subthalamic DBS between 1999 and 2010 and control PD patients similar in age at onset and baseline, sex-distribution, and comorbidities.
RESULTS
In 74 DBS patients levodopa-equivalent daily dose (LEDD) were reduced by 33.9-56.0% in relation to the preoperative baseline over the 14-year observational period. In 61 control patients LEDDs increased over approximately 10 years, causing a significant divergence between groups. The largest difference amongst single drug-classes was observed for dopamine agonists.
CONCLUSION
In PD patients, chronic STN-DBS was associated with a lower LEDD compared with control patients over 14 years.
PubMed: 38715209
DOI: 10.1002/mdc3.14065 -
Journal of Neuroscience Methods Jul 2024DBS entails the insertion of an electrode into the patient brain, enabling Subthalamic nucleus (STN) stimulation. Accurate delineation of STN borders is a critical but...
BACKGROUND
DBS entails the insertion of an electrode into the patient brain, enabling Subthalamic nucleus (STN) stimulation. Accurate delineation of STN borders is a critical but time-consuming task, traditionally reliant on the neurosurgeon experience in deciphering the intricacies of microelectrode recording (MER). While clinical outcomes of MER have been satisfactory, they involve certain risks to patient safety. Recently, there has been a growing interest in exploring the potential of local field potentials (LFP) due to their correlation with the STN motor territory.
METHOD
A novel STN detection system, integrating LFP and wavelet packet transform (WPT) with stacking ensemble learning, is developed. Initial steps involve the inclusion of soft thresholding to increase robustness to LFP variability. Subsequently, non-linear WPT features are extracted. Finally, a unique ensemble model, comprising a dual-layer structure, is developed for STN localization. We harnessed the capabilities of support vector machine, Decision tree and k-Nearest Neighbor in conjunction with long short-term memory (LSTM) network. LSTM is pivotal for assigning adequate weights to every base model.
RESULTS
Results reveal that the proposed model achieved a remarkable accuracy and F1-score of 89.49% and 91.63%.
COMPARISON WITH EXISTING METHODS
Ensemble model demonstrated superior performance when compared to standalone base models and existing meta techniques.
CONCLUSION
This framework is envisioned to enhance the efficiency of DBS surgery and reduce the reliance on clinician experience for precise STN detection. This achievement is strategically significant to serve as an invaluable tool for refining the electrode trajectory, potentially replacing the current methodology based on MER.
Topics: Subthalamic Nucleus; Humans; Wavelet Analysis; Deep Brain Stimulation; Support Vector Machine; Machine Learning; Signal Processing, Computer-Assisted; Microelectrodes
PubMed: 38703796
DOI: 10.1016/j.jneumeth.2024.110156 -
Journal of Neural Engineering May 2024Deep brain stimulation (DBS) is a therapy for Parkinson's disease (PD) and essential tremor (ET). The mechanism of action of DBS is still incompletely understood....
Deep brain stimulation (DBS) is a therapy for Parkinson's disease (PD) and essential tremor (ET). The mechanism of action of DBS is still incompletely understood. Retrospective group analysis of intra-operative data recorded from ET patients implanted in the ventral intermediate nucleus of the thalamus (Vim) is rare. Intra-operative stimulation tests generate rich data and their use in group analysis has not yet been explored.To implement, evaluate, and apply a group analysis workflow to generate probabilistic stimulation maps (PSMs) using intra-operative stimulation data from ET patients implanted in Vim.A group-specific anatomical template was constructed based on the magnetic resonance imaging scans of 6 ET patients and 13 PD patients. Intra-operative test data (total:= 1821) from the 6 ET patients was analyzed: patient-specific electric field simulations together with tremor assessments obtained by a wrist-based acceleration sensor were transferred to this template. Occurrence and weighted mean maps were generated. Voxels associated with symptomatic response were identified through a linear mixed model approach to form a PSM. Improvements predicted by the PSM were compared to those clinically assessed. Finally, the PSM clusters were compared to those obtained in a multicenter study using data from chronic stimulation effects in ET.Regions responsible for improvement identified on the PSM were in the posterior sub-thalamic area (PSA) and at the border between the Vim and ventro-oral nucleus of the thalamus (VO). The comparison with literature revealed a center-to-center distance of less than 5 mm and an overlap score (Dice) of 0.4 between the significant clusters. Our workflow and intra-operative test data from 6 ET-Vim patients identified effective stimulation areas in PSA and around Vim and VO, affirming existing medical literature.This study supports the potential of probabilistic analysis of intra-operative stimulation test data to reveal DBS's action mechanisms and to assist surgical planning.
Topics: Humans; Essential Tremor; Deep Brain Stimulation; Female; Male; Aged; Middle Aged; Thalamus; Brain Mapping; Retrospective Studies; Magnetic Resonance Imaging; Ventral Thalamic Nuclei; Parkinson Disease; Intraoperative Neurophysiological Monitoring
PubMed: 38701768
DOI: 10.1088/1741-2552/ad4742 -
Movement Disorders Clinical Practice Jun 2024Blood pressure control in Parkinson's disease (PD) under subthalamic deep brain stimulation (STN-DBS) is influenced by several intertwined aspects, including autonomic...
BACKGROUND
Blood pressure control in Parkinson's disease (PD) under subthalamic deep brain stimulation (STN-DBS) is influenced by several intertwined aspects, including autonomic failure and levodopa treatment.
OBJECTIVE
To evaluate the effect of chronic STN-DBS, levodopa, and their combination on cardiovascular autonomic functions in PD.
METHODS
We performed cardiovascular reflex tests (CRTs) before and 6-months after STN-DBS surgery in 20 PD patients (pre-DBS vs. post-DBS). CRTs were executed without and with medication (med-OFF vs. med-ON).
RESULTS
CRT results and occurrence of neurogenic orthostatic hypotension (OH) did not differ between pre- and post-DBS studies in med-OFF condition. After levodopa intake, the BP decrease during HUTT was significantly greater compared to med-OFF, both at pre-DBS and post-DBS evaluation. Levodopa-induced OH was documented in 25% and 5% of patients in pre-DBS/med-ON and post-DBS/med-ON study.
CONCLUSION
Chronic stimulation did not influence cardiovascular responses, while levodopa exerts a relevant hypotensive effect. The proportion of patients presenting levodopa-induced OH decreases after STN-DBS surgery.
Topics: Humans; Parkinson Disease; Deep Brain Stimulation; Male; Female; Middle Aged; Aged; Levodopa; Autonomic Nervous System; Antiparkinson Agents; Blood Pressure; Subthalamic Nucleus; Hypotension, Orthostatic
PubMed: 38698586
DOI: 10.1002/mdc3.14060 -
Physiological Reports May 2024Local field potential (LFP) oscillations in the beta band (13-30 Hz) in the subthalamic nucleus (STN) of Parkinson's disease patients have been implicated in disease...
Local field potential (LFP) oscillations in the beta band (13-30 Hz) in the subthalamic nucleus (STN) of Parkinson's disease patients have been implicated in disease severity and treatment response. The relationship between single-neuron activity in the STN and regional beta power changes remains unclear. We used spike-triggered average (STA) to assess beta synchronization in STN. Beta power and STA magnitude at the beta frequency range were compared in three conditions: STN versus other subcortical structures, dorsal versus ventral STN, and high versus low beta power STN recordings. Magnitude of STA-LFP was greater within the STN compared to extra-STN structures along the trajectory path, despite no difference in percentage of the total power. Within the STN, there was a higher percent beta power in dorsal compared to ventral STN but no difference in STA-LFP magnitude. Further refining the comparison to high versus low beta peak power recordings inside the STN to evaluate if single-unit activity synchronized more strongly with beta band activity in areas of high beta power resulted in a significantly higher STA magnitude for areas of high beta power. Overall, these results suggest that STN single units strongly synchronize to beta activity, particularly units in areas of high beta power.
Topics: Subthalamic Nucleus; Parkinson Disease; Humans; Male; Beta Rhythm; Middle Aged; Female; Aged; Action Potentials; Neurons; Deep Brain Stimulation
PubMed: 38697943
DOI: 10.14814/phy2.16001