Publications by authors named "Harmsen I"

Objective: There has been rapid advancement in the development of deep brain stimulation (DBS) as a treatment option for adults for neurological and neuropsychiatric conditions. Here, we present a scoping review of completed and ongoing clinical trials focused on DBS in pediatric populations, highlighting key knowledge gaps.

Methods: Three databases (PubMed, OVID, and Embase) and the clinicaltrials.

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Background And Aims: Pseudoxanthoma elasticum (PXE) patients have more arterial calcification due to lower levels of inorganic pyrophosphate, caused by mutations in the ABCC6 gene, but the relation with vascular complications is poorly understood. Because of the slow progressing nature of arterial disease in PXE patients, there is a need for a valid and reliable intermediate endpoint to be used in future clinical trials. Arterial calcification measured on computed tomography (CT) is a promising candidate, if associated with future cardiovascular events.

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  • Freezing of gait (FOG) is a debilitating symptom of Parkinson's Disease and Progressive Supranuclear Palsy, leading to significant quality of life impairment, and its underlying mechanisms remain poorly understood.
  • A study involving three patients with Progressive Supranuclear Palsy-progressive gait freezing (PSP-PGF) showed no deterioration in gait and balance after spinal cord stimulation (SCS) over 13 months, alongside notable changes in brain activity patterns.
  • The findings indicate improved communication between brain and spinal circuits during SCS, suggesting potential advancements in treatments utilizing brain-spine interfaces for FOG patients.
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  • Large language models like ChatGPT show promise in medical fields, especially clinical neuroscience, with significant developments from OpenAI's GPT-3.5 and GPT-4.
  • The paper explores how ChatGPT can assist in neurosurgery education, including passing medical licensing exams and creating personalized study materials.
  • Caution is advised when using AI tools due to risks like hallucinations and the potential for user overreliance, highlighting the need for careful integration into neurosurgical training.
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  • Pseudoxanthoma elasticum (PXE) is a rare genetic disorder that leads to calcification in tissues like arteries due to mutations that lower levels of a natural calcification inhibitor called pyrophosphate.
  • A study showed that using cyclical etidronate, a pyrophosphate analog, significantly decreased arterial calcification over a year when compared to a placebo.
  • Following 73 patients for an average of 3.6 years without etidronate and 2.8 years with it, results indicated a significant reduction in the progression of calcification rates with etidronate treatment, with no serious side effects reported.
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Restoring motor function after stroke necessitates involvement of numerous cognitive systems. However, the impact of damage to motor and cognitive network organization on recovery is not well understood. To discover correlates of successful recovery, we explored imaging characteristics in chronic stroke subjects by combining noninvasive brain stimulation and fMRI.

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Alzheimer's disease (AD) is a prevalent and debilitating neurodegenerative disease that leads to substantial loss of quality of life. Therapies currently available for AD do not modify the disease course and have limited efficacy in symptom control. As such, novel and precise therapies tailored to individual patients' neurophysiologic profiles are needed.

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Major depressive disorder (MDD) is a prevalent and debilitating psychiatric disease that leads to substantial loss of quality of life. There has been little progress in developing new MDD therapeutics due to a poor understanding of disease heterogeneity and individuals' responses to treatments. Electroencephalography (EEG) is poised to improve this, owing to the ease of large-scale data collection and the advancement of computational methods to address artifacts.

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Background And Aims: - Pseudoxanthoma elasticum (PXE) is a rare genetic disease caused by pathogenic mutations in the ABCC6 gene, resulting in low values of inorganic pyrophosphate (PPi). While low PPi is thought to contribute to arterial calcification, it remains unclear whether this fully explains premature calcification in PXE. It has been hypothesized that the ABCC6 gene could be related to dyslipidemia, which could contribute to vascular calcification seen in PXE.

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Identifying functional biomarkers related to treatment success can aid in expediting therapy optimization, as well as contribute to a better understanding of the neural mechanisms of the treatment-resistant depression (TRD) and subcallosal cingulate deep brain stimulation (SCC-DBS). Magnetoencephalography data were obtained from 16 individuals with SCC-DBS for TRD and 25 healthy subjects. The first objective of the study was to identify region-specific oscillatory modulations that both (i) discriminate individuals with TRD (with SCC-DBS OFF) from healthy controls, and (ii) discriminate TRD treatment responders from non-responders (with SCC-DBS ON).

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Objective: This proof-of-concept study aimed to examine the overlap between structural and functional activity (coupling) related to surgical response.

Methods: We studied intracranial rest and ictal stereoelectroencephalography (sEEG) recordings from 77 seizures in thirteen participants with temporal lobe epilepsy (TLE) who subsequently underwent resective/laser ablation surgery. We used the stereotactic coordinates of electrodes to construct functional (sEEG electrodes) and structural connectomes (diffusion tensor imaging).

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Background: Pseudoxanthoma elasticum (PXE) is an autosomal recessive disease characterized by diminished inorganic plasma pyrophosphate (PPi), a strong calcification inhibitor. In addition to more typical calcification of skin, retina and arterial wall a diminished plasma PPi could lead to other ectopic calcification, such as formation of kidney stones.

Objective: To compare the prevalence of kidney stones between PXE patients and hospital controls on computed tomography (CT).

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Objective: Low-intensity transcranial focused ultrasound (TUS) is a novel method for neuromodulation. We aimed to study the feasibility of stimulating the bilateral primary motor cortices (M1) with accelerated theta-burst TUS (a-tbTUS) on neurophysiologic and clinical outcomes in Parkinson's disease (PD).

Methods: Patients were randomly assigned to receive active or sham a-tbTUS for the first visit and the alternate condition on the second visit, at least 10 days apart.

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Background: In patients with glioma, clinical manifestations of neural network disruption include behavioral changes, cognitive decline, and seizures. However, the extent of network recovery following surgery remains unclear. The aim of this study was to characterize the neurophysiologic and functional connectivity changes following glioma surgery using magnetoencephalography (MEG).

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Background: To design a comprehensive approach to promote children's sleep health in Amsterdam, the Netherlands, we combined Intervention Mapping (IM) with the Health in All Policies (HiAP) perspective. We aimed to create an approach that fits local infrastructures and policy domains across sectors.

Methods: First, a needs assessment was conducted, including a systematic review, two concept mapping studies, and one cross-sectional sleep diary study (IM step 1).

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Duplication of the internal maxillary artery (IMAX) results from a failed regression of either the embryological superficial or deep ring and is reported to be exceedingly rare. We present a patient with this rare anatomical variant who was treated by endovascular technique in the clinical context of an acute oropharyngeal hemorrhage.

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Deep brain stimulation (DBS) and non-invasive neuromodulation are currently being investigated for treating network dysfunction in Alzheimer's Disease (AD). However, due to heterogeneity in techniques and targets, the cognitive outcome and brain network connectivity remain unknown. We performed a systematic review, meta-analysis, and normative functional connectivity to determine the cognitive outcome and brain networks of DBS and non-invasive neuromodulation in AD.

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Introduction: There is currently a gap in accessibility to neuromodulation tools that can approximate the efficacy and spatial resolution of invasive methods. Low intensity transcranial focused ultrasound stimulation (TUS) is an emerging technology for non-invasive brain stimulation (NIBS) that can penetrate cortical and deep brain structures with more focal stimulation compared to existing NIBS modalities. Theta burst TUS (tbTUS, TUS delivered in a theta burst pattern) is a novel repetitive TUS protocol that can induce durable changes in motor cortex excitability, thereby holding promise as a novel neuromodulation tool with durable effects.

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Background: We investigated prospectively among community-dwelling older adults aged 65 years and older whether a larger kyphosis angle is associated with poorer physical performance (balance, muscle strength, or both), and whether this association is unidirectional.

Methods: Male and female participants performed a multicomponent physical performance test with subscores for gait, muscle strength, and balance at baseline and after 2 years. Hand grip strength was also measured at baseline and at follow-up.

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Objective: Pain is the most common nonmotor symptom of Parkinson's disease (PD) and is often undertreated. Deep brain stimulation (DBS) effectively mitigates the motor symptoms of this multisystem neurodegenerative disease; however, its therapeutic effect on nonmotor symptoms, especially pain, remains inconclusive. While there is a critical need to help this large PD patient population, guidelines for managing this significant disease burden are absent.

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Psychiatry remains the only medical specialty where diagnoses are still based on clinical syndromes rather than measurable biological abnormalities. As imaging technology and analytical methods evolve, it is becoming clear that subtle but measurable radiological characteristics exist and can be used to experimentally classify psychiatric disorders, predict response to treatment and, hopefully, develop new, more effective therapies. This review highlights advances in neuroimaging modalities that are now allowing assessment of brain structure, connectivity and neural network function, describes technical aspects of the most promising methods, and summarizes observations made in some frequent psychiatric disorders.

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Background: Deep brain stimulation (DBS) is a neuromodulatory technique that delivers adjustable electrical stimuli to brain targets to relieve symptoms associated with dysregulated neural circuitry. Over the last several decades, DBS has been applied to a number of conditions, including motor, pain, mood, and cognitive disorders. An assessment of the body of work in this field is warranted to determine where we have been, define the current state of the field, and chart a path toward the future.

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The evaluation and manipulation of structural and functional networks, which has been integral to advancing functional neurosurgery, is beginning to transcend classical subspecialty boundaries. Notably, its application in neuro-oncologic surgery has stimulated an exciting paradigm shift from the traditional localizationist approach, which is lacking in nuance and optimization. This manuscript reviews the existing literature and explores how structural and functional connectivity analyses have been leveraged to revolutionize and individualize pre-operative tumor evaluation and surgical planning.

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