Jose Leon-Rojas

Prof. Dr. Jose Leon-Rojas

Escuela de Medicina, Universidad de Las Américas, Quito, Pichincha, Ecuador
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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 September 2020 in Frontiers in Neurology
Verified
Journal Article
Open access
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AGArash Ghaffari-Rafi
Arash Ghaffari-Rafi
RMRana Mehdizadeh
Rana Mehdizadeh
AKAndrew Wai Kei Ko
Andrew Wai Kei Ko
SGShadeh Ghaffari-Rafi
Shadeh Ghaffari-Rafi
Jose Leon-RojasJose Leon-Rojas
Jose Leon-Rojas
Background: Obesity's risk increases for low-income, female, young, and Black patients. By extrapolation, idiopathic intracranial hypertension (IIH)—a disease associated with body mass index—would potentially display socioeconomic and demographic disparities. Methods: IIH incidence (per 100,000) was investigated with respect to sex, age, income, residence, and race/ethnicity, by querying the largest United States (US) healthcare administrative dataset (1997–2016), the National (Nationwide) Inpatient Sample. Results: Annual national incidence (with 25th and 75th quartiles) for IIH was 1.15 (0.91, 1.44). Females had an incidence of 1.97 (1.48, 2.48), larger (p = 0.0000038) than males at 0.36 (0.26, 0.38). Regarding age, largest incidence was among those 18–44 years old at 2.47 (1.84, 2.73). Low-income patients had an incidence of 1.56 (1.47, 1.82), larger (p = 0.00024) than the 1.21 (1.01, 1.36) of the middle/high. No differences (χ2 = 4.67, p = 0.097) were appreciated between urban (1.44; 1.40, 1.61), suburban (1.30; 1.09, 1.40), or rural (1.46; 1.40, 1.48) communities. For race/ethnicity (χ2 = 57, p = 2.57 × 10−12), incidence was largest for Blacks (2.05; 1.76, 2.74), followed by Whites (1.04; 0.79, 1.41), Hispanics (0.67; 0.57, 0.94), and Asian/Pacific Islanders (0.16; 0.11, 0.19). Year-to-year, incidence rose for all strata subsets except Asian/Pacific Islanders (τ = −0.84, p = 0.00000068). Conclusion: IIH demonstrates several sociodemographic disparities. Specifically, incidences are larger for those low-income, Black, 18–44 years old, or female, while annually increasing for all subsets, except Asian/Pacific Islanders. Hence, IIH differentially afflicts the US population, yielding in healthcare inequalities.

26 October 2021 in Journal of Clinical Medicine
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Journal Article
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AGArash Ghaffari-Rafi
Arash Ghaffari-Rafi
CPCatherine Peterson
Catherine Peterson
Jose Leon-RojasJose Leon-Rojas
Jose Leon-Rojas
NTNobuaki Tadokoro
Nobuaki Tadokoro
SLStefan F. Lange
Stefan F. Lange
AMAllan R. Martin
Allan R. Martin
The clinical indications and added value of obtaining MRI in the acute phase of spinal cord injury (SCI) remain controversial. This review aims to critically evaluate evidence regarding the role of MRI to influence decision-making and outcomes in acute SCI. A systematic review and meta-analysis were performed according to PRISMA methodology to identify studies that address six key questions (KQs) regarding diagnostic accuracy, frequency of abnormal findings, frequency of altered decision-making, optimal timing, and differences in outcomes related to obtaining an MRI in acute SCI. A total of 32 studies were identified that addressed one or more KQs. MRI showed no adverse events in 156 patients (five studies) and frequently identified cord compression (70%, 12 studies), disc herniation (43%, 16 studies), ligamentous injury (39%, 13 studies), and epidural hematoma (10%, two studies), with good diagnostic accuracy (seven comparative studies) except for fracture detection. MRI findings often altered management, including timing of surgery (78%, three studies), decision to operate (36%, 15 studies), and surgical approach (29%, nine studies). MRI may also be useful to determine the need for instrumentation (100%, one study), which levels to decompress (100%, one study), and if reoperation is needed (34%, two studies). The available literature consistently concluded that MRI was useful prior to surgical treatment (13 studies) and after surgery to assess decompression (two studies), but utility before/after closed reduction of cervical dislocations was unclear (three studies). One study showed improved outcomes with an MRI-based protocol but had a high risk of bias. Heterogeneity was high for most findings (I2 > 0.75). MRI is safe and frequently identifies findings alter clinical management in acute SCI, although direct evidence of its impact on outcomes is lacking. MRI should be performed before and after surgery, when feasible, to facilitate improved clinical decision-making. However, further research is needed to determine its optimal timing, effect on outcomes, cost-effectiveness, and utility before and after closed reduction.

1 May 2020 in Clinical Neurology and Neurosurgery
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Journal Article
Closed access
AGArash Ghaffari-Rafi
Arash Ghaffari-Rafi
SGShadeh Ghaffari-Rafi
Shadeh Ghaffari-Rafi
Jose Leon-RojasJose Leon-Rojas
Jose Leon-Rojas

11 February 2024 in Cureus
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Journal Article
Open access
SHSilvia Grimanesa Revelo Herrera
Silvia Grimanesa Revelo Herrera
Jose Leon-RojasJose Leon-Rojas
Jose Leon-Rojas
This systematic review aims to examine the association between physical activity, neuroplasticity, and cognition. We analyzed an initial dataset consisting of 9935 articles retrieved from three scientific platforms (PubMed, Scopus, and the Virtual Health Library). Various screening filters were applied to refine the information against predefined eligibility criteria, resulting in the inclusion of a total of 17 articles that assessed the effect of aerobic exercise on neuroplasticity. The results suggested that aerobic exercise at various intensities, particularly at high intensity, can influence cortical excitability and result in cognitive improvement; also, exercise was associated with direct cortical and structural changes. Exercise has shown efficacy in individuals of diverse age groups, as well as in people with and without brain disease.

Verified
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DADiana Alvarez-Mejia
Diana Alvarez-Mejia
JRJose A Rodas
Jose A Rodas
Jose Leon-RojasJose Leon-Rojas
Jose Leon-Rojas
The intrauterine environment is increasingly recognised as a critical period for the emergence of mental health vulnerabilities. This review explores how adverse maternal exposures, such as psychological stress, infection, malnutrition, and environmental toxins, can disrupt foetal neurodevelopment via epigenetic mechanisms, contributing to the risk of psychiatric and neurodevelopmental disorders. Focusing primarily on human studies, we synthesise evidence on DNA methylation, histone modifications, and non-coding RNAs as key pathways through which the intrauterine environment influences gene regulation in the developing brain. We examine how timing of exposure, foetal sex, and gene–environment interactions modulate these effects, with particular attention to disorders such as schizophrenia, autism spectrum disorder, depression, and anxiety. The placenta emerges as a central mediator, both reflecting and shaping epigenetic changes in response to maternal signals. We also discuss the reversibility of epigenetic marks and highlight emerging interventions, including nutritional supplementation and maternal mental health support, that may buffer or reverse prenatal epigenetic programming. Methodological challenges are addressed, including tissue specificity and causal inference, and future directions are proposed toward integrating epigenetic biomarkers into early risk assessment and precision mental health and psychiatry. This review emphasises the importance of the prenatal period as a window of vulnerability and opportunity for shaping lifelong mental health.

Verified
Journal Article
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CRCecilia Alejandra García Ríos
Cecilia Alejandra García Ríos
Jose Leon-RojasJose Leon-Rojas
Jose Leon-Rojas
Stroke is a leading global cause of mortality and long-term disability, with cerebral edema constituting a major contributor to early neurological deterioration and poor outcomes. Aquaporin-4 (AQP4), the predominant water channel in the central nervous system, plays a paradoxical role in stroke-related brain edema, facilitating both the formation and clearance of excess fluid depending on the pathological context. This review explores the biphasic function of AQP4 across cytotoxic and vasogenic edema, emphasizing its dynamic regulation, subcellular localization, and implications for therapeutic intervention. Evidence from rodent models shows that AQP4 exacerbates cytotoxic edema in acute ischemia by promoting intracellular water influx into astrocytes, whereas in vasogenic edema, it supports fluid reabsorption and glymphatic clearance, thereby alleviating brain swelling. Human studies corroborate AQP4 upregulation in infarcted regions and suggest a potential role for AQP4 polymorphisms and circulating levels as biomarkers of stroke severity and outcome, although larger cohorts and more robust methodological designs are needed. This review also discusses emerging pharmacological strategies to modulate AQP4 activity, including inhibitors, trafficking modulators, and gene-targeted delivery systems, while highlighting challenges in achieving phase-specific modulation. Given its central role in both injury and recovery, AQP4 emerges as a promising yet complex therapeutic target for personalized management of stroke-induced brain edema. Future directions include real-time imaging of AQP4 function, genotype-stratified clinical trials, and integration of AQP4 modulation with current stroke treatment protocols.