Publications by authors named "Ajmal Zemmar"

The subthalamic nucleus is thought to play a crucial role in controlling impulsive actions. Networked among the basal ganglia and receiving input from several cortical areas, the subthalamic nucleus is well positioned to influence action selection when faced with competing and conflicting action outcomes. The purpose of this study was to test the dissociable roles of the dorsal and ventral aspects of the subthalamic nucleus during action conflict in patients with Parkinson's disease undergoing intraoperative neurophysiological recording and to explore a potential mechanism for this inhibitory control.

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Article Synopsis
  • 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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On June 3, 2023, the American Society of Transplant Surgeons convened a meeting in San Diego, California to (1) develop a consensus statement with supporting data on the ethical tenets of thoracoabdominal normothermic regional perfusion (NRP) and abdominal NRP; (2) provide guidelines for the standards of practice that should govern thoracoabdominal NRP and abdominal NRP; and (3) develop and implement a central database for the collection of NRP donor and recipient data in the United States. National and international leaders in the fields of neuroscience, transplantation, critical care, NRP, Organ Procurement Organizations, transplant centers, and donor families participated. The conference was designed to focus on the controversial issues of neurological flow and function in donation after circulatory death donors during NRP and propose technical standards necessary to ensure that this procedure is performed safely and effectively.

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Objective: Tumor fluid (TISF) refers to the fluid within surgical cavities of glioma. Several studies preliminarily proved the value of cell-free tumor DNA (cf-tDNA) from TISF in the dynamic characterization of the glioma genome. Here, we assessed the potential utility of TISF cf-tDNA in broad aspects of tumor evolution under therapeutic pressure.

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Background: We report a patient with bilateral HT treated with DBS.

Case Report: A 58-year-old man diagnosed with HIV/AIDS and progressive multifocal leukoencephalopathy (PML) presented with 20 years of bilateral arm tremor refractory to therapy. DBS was implanted on the left ventral intermediate nucleus and posterior subthalamic area (VIM/PSA).

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Background: Spinal cord stimulation (SCS) has been investigated as a potential therapeutic option for managing refractory symptoms in patients with Parkinson's disease (PD).

Objective: This systematic review and meta-analysis aimed to evaluate the safety and efficacy of SCS in PD.

Method: A comprehensive literature search was conducted on PubMed and Web of Science to identify SCS studies reporting Unified Parkinson Disease Rating Scale-III (UPDRS-III) or Visual Analogue Scale (VAS) score changes in PD cohorts with at least 3 patients and a follow-up period of at least 1 month.

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When do we die and what happens in the brain when we die? The mystery around these questions has engaged mankind for centuries. Despite the challenges to obtain recordings of the dying brain, recent studies have contributed to better understand the processes occurring during the last moments of life. In this review, we summarize the literature on neurophysiological changes around the time of death.

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Spinal cord stimulation (SCS) is an emerging technology to treat chronic pain from complex regional pain syndrome (CPRS) neuropathy and post-laminectomy syndrome. A rarely reported postoperative complication of SCS paddle implantation is abdominal pain that can result from thoracic radiculopathy. Ogilvie's syndrome (OS) is a disorder characterized by acute dilatation of the colon in the absence of an anatomic lesion that obstructs the flow of intestinal contents, which has seldom been observed after spine surgery.

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Introduction: Magnetic resonance-guided focused ultrasound (MRgFUS) is an emerging treatment for tremor and other movement disorders. An incisionless therapy, it is becoming increasingly common worldwide. However, given MRgFUS' relative novelty, there remain limited data on its benefits and adverse effects.

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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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Background: MR-guided focused ultrasound (MRgFUS) thalamotomy has been shown to be a safe and effective treatment for essential tremor (ET).

Objective: To investigate the effects of MRgFUS in patients with ET with an emphasis on ipsilateral-hand and axial tremor subscores.

Methods: Tremor scores and adverse effects of 100 patients treated between 2012 and 2018 were assessed at 1 week, 3, 12, and 24 months.

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A total of 15 individuals with cervical dystonia and good outcome after pallidal deep brain stimulation underwent resting-state functional magnetic resonance imaging under three conditions: stimulation using a priori clinically determined optimal settings (ON-Op), non-optimal settings (ON-NOp), and stimulation off (OFF). ON-Op > OFF and ON-Op > ON-NOp were both associated with significant deactivation within sensorimotor cortex (changes not seen with ON-NOp > OFF). Brain responses to stimulation were related to individual long-term clinical improvement (R = 0.

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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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Background: Deep brain stimulation (DBS) is an established treatment for certain movement disorders and has additionally shown promise for various psychiatric, cognitive, and seizure disorders. However, the mechanisms through which stimulation exerts therapeutic effects are incompletely understood. A technique that may help to address this knowledge gap is functional magnetic resonance imaging (fMRI).

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The neurophysiological footprint of brain activity after cardiac arrest and during near-death experience (NDE) is not well understood. Although a hypoactive state of brain activity has been assumed, experimental animal studies have shown increased activity after cardiac arrest, particularly in the gamma-band, resulting from hypercapnia prior to and cessation of cerebral blood flow after cardiac arrest. No study has yet investigated this matter in humans.

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Objective: Peripheral nerve field stimulation (PNFS) is a tool in the armamentarium of treatment options for trigeminal pain. The efficacy of this modality in mitigating trigeminal pain remains unclear. The aim of this study was to examine the existing literature on PNFS and elucidate pain score outcomes associated with its use in patients with trigeminal pain.

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Article Synopsis
  • Deep brain stimulation (DBS) is a treatment for drug-resistant epilepsy (DRE) that shows promising results, with average seizure reductions of around 60.8% to 73.4%, depending on the targeted brain area.
  • A systematic review analyzed 44 studies involving 527 patients, highlighting that anterior thalamic nucleus (ANT) stimulation has the strongest evidence but more research is needed for other targets like the centromedian thalamic nucleus (CMT) and hippocampus.
  • Future advancements in DBS technology, such as better targeting and responsive stimulation, along with identifying biomarkers for patient selection, could enhance therapy effectiveness and minimize risks for patients with epilepsy.
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Flow diverters (FD) have shown promising results in the treatment of intracranial aneurysms (IAs). However, there is still controversy whether pipeline flex embolization device (PED flex)-assisted coils can facilitate the curing of aneurysms. Our aim was to assess the safety and effectiveness of PED flex adjunctive with coils (PED flex + coil) in the treatment of IAs.

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Spinal cord stimulation (SCS) is an established treatment for refractory pain syndromes and has recently been applied to improve locomotion. Several technical challenges are faced by surgeons during SCS lead implantation, particularly in the confined dorsal epidural spaces in patients with spinal degenerative disease, scarring and while targeting challenging structures such as the dorsal root ganglion. Magnetic navigation systems (MNS) represent a novel technology that uses externally placed magnets to precisely steer tethered and untethered devices.

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