Publications by authors named "Gary Hotton"

Background And Objectives: Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a subtype of CAA with distinct clinical and radiologic features. Existing diagnostic criteria require the presence of characteristic asymmetrical white matter hyperintensity (WMH), together with classical hemorrhagic neuroimaging markers of CAA. There are limited data for other diagnostic neuroimaging markers of CAA-ri.

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Integrated care systems join up health and care services, so that people have the support they need, in the right place, at the right time. The aims include improving outcomes in healthcare, tackling inequalities in access and enhancing productivity and value for money. This is needed for neuroscience care as the traditional delivery of neuroscience care is inefficient, outdated and expensive, and can involve complex referral pathways and long waiting times.

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Background: Despite an initially indolent course, all WHO grade II, LGGs inevitably transform to malignant, WHO grades III and IV, without current curative options. Malignant transformation (MT) remains unpredictable with limited prognostic markers to steer timing of interventions. The aim of this study was to review and assign predictive value to specific clinical, molecular, and radiological markers impacting MT, thereby justifying timely therapeutic interventions.

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Article Synopsis
  • * In a study of 43 patients, most were confirmed or probable COVID-19 cases, revealing five main categories of neurological disorders: encephalopathies, inflammatory central nervous system syndromes, ischemic strokes, peripheral neurological disorders, and other central disorders.
  • * Treatment outcomes varied, with many patients showing full or partial recovery, particularly those with encephalopathy and inflammatory CNS syndromes, while some experienced severe conditions like stroke or Guillain-Barré syndrome.
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Primary familial brain calcification (PFBC) is a rare neurodegenerative disorder characterized by a combination of neurological, psychiatric, and cognitive decline associated with calcium deposition on brain imaging. To date, mutations in five genes have been linked to PFBC. However, more than 50% of individuals affected by PFBC have no molecular diagnosis.

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Psychotic symptoms have previously been reported following right hemisphere brain injury. We sought to identify the specific neuroanatomical basis of delusions following stroke by studying a series of patients with post-stroke psychosis. Lesion overlap analysis was conducted on three individuals with delusions following right hemisphere stroke.

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We previously reported clinical improvement, increase in putamen [(18)F]-dopa uptake on PET imaging, and neuropathologic evidence of sprouting of dopaminergic fibers following chronic intraputaminal delivery of glial cell line-derived neurotrophic factor (GDNF) in idiopathic Parkinson disease (PD).(1-3) We now provide clinical and PET evidence of persistent efficacy lasting for at least 3 years following cessation of GDNF infusion in a patient with PD. This is a single-case observational study, providing Class IV evidence.

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Levodopa-induced dyskinesias are a common complication of long-term therapy in Parkinson's disease. Although both pre- and post-synaptic mechanisms seem to be implicated in their development, the precise physiopathology of these disabling involuntary movements remains to be fully elucidated. Abnormalities in glutamate transmission (over expression and phosphorylation of N-methyl-D-aspartate receptors) have been associated with the development of levodopa-induced dyskinesias in animal models of Parkinsonism.

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PET studies in parkin-linked parkinsonism have generally been performed to assess striatal dopaminergic dysfunction and very little is known about the involvement of other monoaminergic structures in these patients. Measurements of (18)F-dopa uptake into serotonergic and noradrenergic structures provide an indication of the functional integrity of these nerve terminals. We used (18)F-dopa PET to assess changes in brain monoaminergic function associated with parkin mutations.

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Idiopathic Parkinson's disease (PD) is often accompanied by a pattern of executive deficits similar to those found in patients with frontal lobe lesions. We investigated whether such cognitive deficits are attributable to frontal lobe dysfunction as a direct consequence of impaired mesocortical dopaminergic transmission or an indirect consequence of impaired nigrostriatal dopaminergic function. For this purpose, changes in synaptic dopamine levels during task performance were monitored using a marker of dopamine D2-receptor availability (11)C-raclopride (RAC) PET.

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[(11)C]diprenorphine (DPN) is a non-subtype selective opioid receptor PET ligand with slow kinetics and no region devoid of specific binding. Parametric maps are desirable but have to overcome high noise at the voxel level. We obtained parameter values, parametric map image quality, test-retest reproducibility and reliability (using intraclass correlation coefficients (ICCs)) for conventional spectral analysis and a derived method (rank shaping), compared them with values obtained through sampling of volumes of interest (VOIs) on the dynamic data sets and tested whether smaller amounts of radioactivity injected maintained reliability.

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Background: Carotid body (CB) glomus cells are highly dopaminergic and express the glial cell line derived neurotrophic factor. The intrastriatal grafting of CB cell aggregates exerts neurotrophic actions on nigrostriatal neurons in animal models of Parkinson disease (PD).

Objective: We conducted a phase I-II clinical study to assess the feasibility, long term safety, clinical and neurochemical effects of intrastriatal CB autotransplantation in patients with PD.

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To investigate the effects of bilateral subthalamic nucleus (STN) stimulation on patterns of brain activation during random number generation (RNG), a task that requires suppression of habitual counting and response selection under competition. We used H(2)(15)O positron emission tomography to investigate the changes of regional cerebral blood flow (rCBF) induced by bilateral STN stimulation during a RNG task, in six patients with Parkinson's disease. Paced RNG at 1 Hz was compared with a control counting task.

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Objective: Glial cell line-derived neurotrophic factor (GDNF) exerts potent trophic influence on midbrain dopaminergic neurons. This randomized controlled clinical trial was designed to confirm initial clinical benefits observed in a small, open-label trial using intraputamenal (Ipu) infusion of recombinant human GDNF (liatermin).

Methods: Thirty-four PD patients were randomized 1 to 1 to receive bilateral continuous Ipu infusion of liatermin 15 microg/putamen/day or placebo.

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Idiopathic Parkinson's disease (PD) is a neurodegenerative disorder associated with akinesia, tremor and rigidity. While the characteristic Lewy body pathology targets pigmented and other brainstem nuclei at post-mortem, activated microglia are found in both subcortical and cortical areas. [11C](R)-PK11195 is a positron emission tomography (PET) marker of peripheral benzodiazepine sites (PBBS), which are selectively expressed by activated microglia.

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The role of changes in inter-regional cortical synchronization in the pathophysiology of Parkinson's disease and the mechanism of action of dopaminergic therapy and high frequency subthalamic nucleus (STN) stimulation is unclear. We hypothesized that synchronization between distributed cortical areas would correlate with parkinsonism and that changes in synchronization with treatment would correlate with improvements in parkinsonism. To this end, we recorded scalp EEG in parkinsonian patients off treatment (16 patients, 31 sides) and then separately during high frequency stimulation (HFS) of the STN (16 patients, 31 sides) and following drug treatment (12 patients, 24 sides).

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Averaging techniques have demonstrated that movement preparatory cues and movement itself are associated with marked reductions in the oscillatory synchrony of local neuronal populations in the area of the human parkinsonian subthalamic nucleus (STN), as indexed by 8-30 Hz local field potential (LFP) activity. In order to examine the detailed nature and strength of the relationship between reductions in oscillatory activity and movement we examined single-trial LFP activity recorded from the STN area of parkinsonian subjects engaged in a choice reaction task. In this task an initial warning cue was either fully predictive or non-predictive of the hand required to make a later motor response.

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Magnetic resonance imaging (MRI) after implantation of electrodes in the subthalamic nuclei is currently performed at a number of sites, but a recent adverse incident and changes in MRI technology may heighten safety concerns. In this report, it is demonstrated that given whole-head image data, registration of postimplantation computed tomography to preimplantation MRI can enable verification of the position of electrodes to an accuracy of 2 mm. This registration technique can remove the need for potentially risky postoperative MRI.

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The speed with which one reacts to an imperative signal depends on the extent to which preceding cues predict that command. When reliable warning cues are available, the processing of the imperative stimulus can be favoured and responses partially pre-prepared, leading to shorter reaction times. Here we seek evidence for involvement of the human basal ganglia in the exploitation of behaviourally relevant predictive cues.

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Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor with restorative effects in a wide variety of rodent and primate models of Parkinson disease, but penetration into brain tissue from either the blood or the cerebro-spinal fluid is limited. Here we delivered GDNF directly into the putamen of five Parkinson patients in a phase 1 safety trial. One catheter needed to be repositioned and there were changes in the magnetic resonance images that disappeared after lowering the concentration of GDNF.

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