Ismael Huertas

Boston Scientific | BSCI · Neuromodulation

Parkinson’s disease (PD) is the neurological disorder showing the greatest rise in prevalence from 1990 to 2016. Despite clinical definition criteria and a tremendous effort to develop objective biomarkers, precise diagnosis of PD is still unavailable at early stage. In recent years, an increasing number of studies have used omic methods to unveil...

The striatum receives dense dopaminergic projections making it a key region of the dopaminergic system. Its dysfunction has been implicated in various conditions including Parkinson's disease (PD) and substance use disorder. However, the investigation of dopamine-specific functioning in humans is problematic as current MRI approaches are unable to...

A prodromal phase of Parkinson’s disease (PD) may precede motor manifestations by decades. PD patients’ siblings are at higher risk for PD, but the prevalence and distribution of prodromal symptoms are unknown. The study objectives were (1) to assess motor and non-motor features estimating prodromal PD probability in PD siblings recruited within th...

The striatum receives dense dopaminergic projections making it a key region of the dopaminergic system. Its dysfunction has been implicated in various conditions including Parkinson’s disease and substance use disorder. However, the investigation of dopamine-specific functioning in humans is problematic as the striatum is highly interconnected and...

Purpose: To determine whether the development of levodopa-induced dyskinesia (LID) in Parkinson disease (PD) specifically relates to dopaminergic depletion in sensorimotor-related subregions of the striatum. Methods: Our primary study sample consisted of 185 locally recruited PD patients, of which 73 (40%) developed LID. Retrospective 123I-FP-CI...

Purpose: Differences in site, device, and/or settings may cause large variations in the intensity profile of dopamine transporter (DAT) single-photon emission computed tomography (SPECT) images. However, the current standard to evaluate these images, the striatal binding ratio (SBR), does not efficiently account for this heterogeneity and the asse...

The dominant approach to neuroimaging data analysis employs the voxel as the unit of computation. While convenient, voxels lack biological meaning and their size is arbitrarily determined by the resolution of the image. Here, we propose a multivariate spatial model in which neuroimaging data is characterized as a linearly weighted combination of mu...

The dual syndrome hypothesis for cognitive impairment in Parkinson's disease (PD) establishes a dichotomy between a frontrostriatal dopamine-mediated syndrome, which leads to executive deficits, and a posterior cortical syndrome, which leads to dementia. Certain genes have been linked to these syndromes although the exact contribution is still cont...

List. (DOC)

Parkinson’s disease (PD) patients who present with tremor and maintain a predominance of tremor have a better prognosis. Similarly, PD patients with high levels of uric acid (UA), a natural neuroprotectant, have also a better disease course. Our aim was to investigate whether PD motor subtypes differ in their levels of UA, and if these differences...

Demographic values, motor information and the striatal subregional [123I]FP-CIT SBR. (DOCX)

Introduction Vascular parkinsonism is a syndrome that develops as a result of cerebrovascular disease. Although several studies on clinical features and neuroimaging have been published, little is known about its pathophysiology. Our aim was to study sensorimotor integration using transcranial magnetic stimulation in this condition and to correlate...

The presence of mutations in glucocerebrosidase (GBA) gene is a known factor increasing the risk of developing Parkinson’s disease (PD). Mutations carriers have earlier disease onset and are more likely to develop neuropsychiatric symptoms than other sporadic PD cases. These symptoms have primarily been observed in Parkinson’s patients carrying the...

List of GBA variants found in a southern Spanish population and in-silico assessment of its pathogenicity by bioinformatic tools. *Number of times in which a variation is present in each group. (DOC)

Cox regression analysis. Results of Cox regression analysis of GBA variant status, sex, age and years with L-DOPA (except for cognitive impairment and depression) as predictor variables for progression to motor fluctuations, dyskinesias, cognitive impairment, visual hallucinations and depression. (DOCX)

In PET/SPECT brain images there exist substantial inter-individual variability in intensity due to differences in metabolism and scanning protocol/machine. Current standards to intensity normalize these images work at the region level and do not deal efficiently with this variability. These suboptimal approaches may lead to bias, wrong estimates an...

Researching genetic factors involved in Parkinson's disease (PD) is crucial to increase our knowledge about the pathophysiology of the disorder. A missense mutation has recently been reported within CHCHD2, a gene newly associated with autosomal dominant PD. Subsequent studies in different ethnic populations have not reached any conclusive result a...

Objectives: Euthymic patients with bipolar disorder (BD) have deficits in cortical inhibition. However, whether cortical inhibitory deficits are trait- or state-dependent impairments is not yet known and their relationship with psychiatric symptoms is not yet understood. In the present study, we examined trait- and state-dependent cortical inhibit...

Introduction: Uric acid is a natural antioxidant, and it has been shown that low levels of uric acid could be a risk factor for the development of PD. Our aim was to investigate whether uric acid plays a role in PSP. Methods: We carried out a cross-sectional study to compare serum uric acid levels between PSP patients, PD patients, and healthy c...

Tourette syndrome is a disorder characterized by persistent motor and vocal tics, and frequently accompanied by the comorbidities attention deficit hyperactivity disorder and obsessive-compulsive disorder. Impaired synaptic neurotransmission has been implicated in its pathogenesis. Our aim was to investigate the association of 28 candidate genes, i...

Background Recent studies have shown altered cortical plasticity in adult patients with Tourette syndrome. However, the clinical significance of this finding remains elusive.Methods Motor cortical plasticity was evaluated in 15 adult patients with severe Tourette syndrome and 16 healthy controls using the paired associative stimulation protocol by...

Background: A recent genome-wide association study (GWAS) has identified a putative association, not statistically confirmed, of cervical dystonia within several regions in a British population. Hence, the authors proposed dysfunction of the ion channel NALCN (for sodium leak channel, nonselective) as a plausible cause of cervical dystonia. The ob...

Drooling is a common symptom in parkinsonian disorders. Our aim was to assess the safety and effect of botulinum toxin when applied to parotid glands without ultrasound guidance for sialorrhea in parkinsonian disorders in a retrospective study with a long-term follow-up. We evaluated 53 patients (64.2 % male and 35.8 % female) with a mean age of 70...

Background Dystonia is considered as a motor network disorder involving the dysfunction of the posterior parietal cortex, a region involved in preparing and executing reaching movements. Objective /Hypothesis. We used transcranial magnetic stimulation to test the hypothesis that cervical dystonic patients may have a disrupted parieto-motor connect...

Purpose: The study's objective was to develop diagnostic predictive models using data from two commonly used [(123)I]FP-CIT SPECT assessment methods: region-of-interest (ROI) analysis and whole-brain voxel-based analysis. Methods: We included retrospectively 80 patients with vascular parkinsonism (VP) and 164 patients with Parkinson's disease (P...

Background: The clinical profile in vascular parkinsonism (VP) patients is well described in the literature, but little is known about the neuropsychological features of this disease. The aim of our study was to evaluate the clinical characteristics and the profile of cognitive impairment in patients with VP. Methods: We prospectively evaluated...

Background: A polymorphism in brain-derived neurotrophic factor (BDNF) (Val66Met) has been reported as a risk factor in primary dystonia. However, overall the results have been inconclusive. Our aim was to clarify the association of Val66Met with primary dystonia, and with the most prevalent clinical subtypes, cervical dystonia and blepharospasm....

The short-term benefits of levodopa/carbidopa intestinal gel (LCIG) in patients with advanced Parkinson's disease (PD) are well documented, but the long-term benefits are still uncertain. The aim of this study was to investigate the motor and cognitive outcome of LCIG treatment in advanced PD after a follow-up period of at least 24 months. We asses...

Mutations in FBXO7 (PARK15) have been associated with a syndrome characterized by early-onset progressive parkinsonism with and without pyramidal tract signs. Therefore, our aim was to analyze this gene in a population from southern Spain (338 Parkinson's disease [PD] patients and 330 unrelated control subjects) to elucidate the potential involveme...

Parkinson’s disease (PD) is a neurodegenerative disease caused by both genetic and environmental factors. Sirtuins are highly-conserved, NAD-dependent class III deacetylases that regulate a variety of cellular functions. Most of the known sirtuins have been involved in animal models of neurodegenerative disorders, such as PD. Although seven sirtuin...

Objectives: To analyse the differences in the clinical features and characteristics of (123)I-labelled 2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane ((123)I-FP-CIT) single photon emission CT (SPECT) imaging among patients with vascular parkinsonism (VP) and Parkinson's disease (PD). Methods: We performed a case-control study to...