Publications by authors named "Talal Al Harbi"

Background: Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder of the presynaptic neuromuscular junction associated with antibody mediated dysfunction of voltage-gated calcium channels (VGCCs). LEMS can exist as a paraneoplastic syndrome, paraneoplastic-LEMS (P-LEMS), when associated with tumors, most commonly, small cell lung carcinoma (SCLC) or as a non-paraneoplastic condition (NP-LEMS) when no malignancies are detected.

Methods: A retrospective chart review was conducted in 3 tertiary hospitals in Saudi Arabia for patients diagnosed with LEMS between January 2010 and January 2020.

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Background: The relationship between coronavirus disease 2019 (COVID-19) infection and multiple sclerosis (MS) relapse and disease progression remains unclear. Previous studies are limited by small sample sizes and most lack a propensity-matched control cohort.

Objective: To evaluate the effect of COVID-19 infection on MS disease course with a large propensity-matched cohort.

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Article Synopsis
  • * Machine learning models were applied to predict confirmed disability progression after two years, achieving a ROC-AUC score of 0.71, indicating moderate accuracy, while historical disability was found to be a stronger predictor than treatment or relapse history.
  • * The research followed strict guidelines and made its coding accessible for others to facilitate future benchmarking in predicting disability progression in MS patients.
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Background: The COVID-19 pandemic raised concern amongst clinicians that disease-modifying therapies (DMT), particularly anti-CD20 monoclonal antibodies (mAb) and fingolimod, could worsen COVID-19 in people with multiple sclerosis (pwMS). This study aimed to examine DMT prescribing trends pre- and post-pandemic onset.

Methods: A multi-centre longitudinal study with 8,771 participants from MSBase was conducted.

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Article Synopsis
  • This study investigates the relationship between environmental factors and progressive-onset multiple sclerosis (POMS) compared to relapse-onset multiple sclerosis (ROMS), aiming to better understand the causes of POMS.
  • Data is drawn from two major studies, including a sample of 155 POMS, 204 ROMS, and 558 controls, ensuring that the POMS sample is representative of the broader Australian POMS population.
  • The research addresses various methodological challenges, such as biases and differences between POMS and controls, and will present findings on the associations in future publications.
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  • This study examines the effectiveness of six different therapies for treating relapsing-remitting multiple sclerosis (RRMS) over 5 years, using a large dataset from 74 centers across 35 countries.
  • Researchers found that natalizumab and fingolimod were more effective in reducing relapses and worsening disability compared to other therapies like dimethyl fumarate, teriflunomide, glatiramer acetate, and interferon beta.
  • The findings highlight the potential of marginal structural models (MSMs) to simulate clinical trials and compare various treatment outcomes in real-world patient populations.
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  • The study investigates geographical differences in the risk of secondary progressive multiple sclerosis (SPMS) and how these may be influenced by factors like latitude and treatment types.
  • It utilizes data from a global patient registry, focusing on relapsing-remitting multiple sclerosis patients and factors such as age, sex, and treatment efficacy.
  • The research analyzes data from over 51,000 patients across 27 countries to establish patterns in the progression from relapsing-remitting to secondary progressive phases of the disease.
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Air pollution is recognized as a significant public health problem and is associated with illnesses of the central nervous system (CNS) as well as neuroinflammation and neuropathology. Air pollution may cause chronic brain inflammation, white matter abnormalities, and microglia activation, which increases the risk of autism spectrum disorders, neurodegenerative disorders, stroke, and multiple sclerosis (MS). Methods: A literature review was done on "PubMed, EMBASE and Web of Science" on the relationship of air pollution with MS and stroke, using the keywords "air pollution" OR "pollution"; "ambient air pollution," "particulate matter, ozone, black carbon" AND "stroke" OR "cerebrovascular diseases," "multiple sclerosis," "neuroinflammation," or "neurodegeneration.

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Background: The prognostic significance of non-disabling relapses in people with relapsing-remitting multiple sclerosis (RRMS) is unclear.

Objective: To determine whether early non-disabling relapses predict disability accumulation in RRMS.

Methods: We redefined mild relapses in MSBase as 'non-disabling', and moderate or severe relapses as 'disabling'.

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Background: In the absence of evidence from randomised controlled trials, observational data can be used to emulate clinical trials and guide clinical decisions. Observational studies are, however, susceptible to confounding and bias. Among the used techniques to reduce indication bias are propensity score matching and marginal structural models.

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Background And Purpose: This study assessed the effect of patient characteristics on the response to disease-modifying therapy (DMT) in multiple sclerosis (MS).

Methods: We extracted data from 61,810 patients from 135 centers across 35 countries from the MSBase registry. The selection criteria were: clinically isolated syndrome or definite MS, follow-up ≥ 1 year, and Expanded Disability Status Scale (EDSS) score ≥ 3, with ≥1 score recorded per year.

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Article Synopsis
  • Timely initiation of disease modifying therapy (DMT) is essential for effective management of multiple sclerosis (MS).
  • The study aimed to validate a predictive model for individual treatment responses using data from patients in the Middle East who were not part of the initial model development.
  • The results showed the model had high accuracy (81%-96%) in predicting disability changes, moderate accuracy (73%-91%) for relapses, but lower accuracy (<44%) for treatment discontinuation and variable accuracy (50%-98%) for conversion to secondary progressive MS, indicating its broader applicability across different populations.
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The P106L mutation in the human myeloproliferative leukemia virus oncogene (MPL) was shown to be associated with hereditary thrombocythemia in Arabs. The clinical and bone marrow (BM) features of P106L mutation are unknown. Genetic databases at two tertiary hospitals in Saudi Arabia were searched to identify patients with the MPL P106L mutation.

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Article Synopsis
  • This study looks at how to predict long-term disability in people with multiple sclerosis (MS) after they show signs of worsening over six months.
  • Researchers checked data from thousands of patients to figure out who is more likely to have lasting problems.
  • They found that things like age, sex, and how MS affects the person can help tell if someone will continue to get worse, which can help doctors in future treatments.
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Stroke is a physiological disorder involving a prolonged local interruption of cerebral blood flow. It leads to massive neuronal death and causes short-term or long-lasting functional impairment. Most stroke victims regain some neural function weeks or months following a stroke, but this recovery can plateau six months or more after the injury.

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Colchicine-induced myopathy has been described in patients with chronic renal failure and patients who are using a concomitant drug like a statin. However, pure myopathy caused by colchicine has never been reported in Saudi Arabia. A 64-year-old patient received colchicine for his gout arthritis disease and developed upper and lower limb weakness.

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We report a 38-year-old Saudi male with Ehlers-Danlos Syndrome (EDS). The patient presented with rare and unusual neurological manifestations, including but not limited to ophthalmoplegia and myopathic pattern on his electromyography. In addition to hand weakness, there was skin hyperextensibility, joint hyperflexibility, and frontal baldness.

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Summary: The use of antihypertensive medications in patients with pheochromocytomas and paragangliomas (PCC/PG) is usually a challenge. We report a case of familial paraganglioma that was successfully treated by esmolol and other antihypertensive medications without associated perioperative complications. Our patient was an 11-year-old girl who presented with classic symptoms and signs of PCC/PG and a CT scan of the abdomen that showed a right-sided paravertebral mass.

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Background: Guillain-Barre syndrome (GBS) is an inflammatory polyradiculoneuropathy characterized by rapidly evolving weakness and areflexia, reaching nadir within 4 weeks. Data on the characteristic of GBS in Saudi Arabia are limited. This study aimed to describe the clinical, electrophysiological, and laboratory characteristics and outcome of a multicenter cohort of patients with GBS.

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Background: The multiple sclerosis (MS) landscape has changed over the past two decades across the world and in the Middle East. The Middle East is an ethnically diverse region located between 12° and 42° of latitude and 35° and 54° of longitude and varying altitudes. The magnitude of the shifts observed in the epidemiology and management of MS differ in each region and from country to country.

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Familial thrombocytosis (FT) is a rare hereditary haematological disorder characterised by increased platelet count, usually caused by germ-line mutations in thrombopoietin (THPO), myeloproliferative leukaemia virus oncogene (MPL) or Janus kinase 2 (JAK2) genes, and can be associated with increased risk of thrombosis. We aimed to determine the yield of diagnostic tests, assess treatment received and describe the clinical course of MPL-associated FT. We retrospectively reviewed all paediatric and adult haematology patients diagnosed with MPL-related FT, who were seen in our clinics from March 2013 to February 2021.

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Few studies examine health-related quality of life (HRQoL) in Arabic-speaking multiple sclerosis (MS) patients. However, HRQoL tools such as the Short Form-36 QoL instrument (SF-36) and the Multiple Sclerosis International QoL (MusiQoL) questionnaire have been validated in other languages. The primary objective of this study was to prospectively assess HRQoL using the MusiQoL questionnaire among Arabic-speaking MS patients treated with subcutaneous interferon (sc IFN -1a) over 12 months, as part of a prospective, multinational, multicenter cohort study.

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With the recent pandemic of Coronavirus disease-2019 (COVID-19), there has been a higher number of reported cases in children more than to the prior Corona Virus-related diseases, namely, severe acute respiratory syndrome and the Middle East respiratory syndrome. The rate of COVID-19 in children is lower than adults; however, due to high transmission rate, the number of reported cases in children has been increasing. With the rising numbers among children, it is imperative to develop preparedness plans for the pediatric population at the hospital level, departmental level, and patient care areas.

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Objective: To describe the clinical and radiological characteristics of neuromyelitis optica spectrum disorders (NMOSD) patients from the Arabian Gulf relative to anti-aquaporin 4 antibody serostatus.

Methods: Retrospective multicentre study of hospital records of patients diagnosed with NMOSD based on 2015 International Panel on NMOSD Diagnosis (IPND) consensus criteria.

Results: One hundred forty four patients were evaluated, 64.

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Background: Aquaporin-4-IgG positive (AQP4-IgG+) Neuromyelitis Optica Spectrum Disorder (NMOSD) is an uncommon central nervous system autoimmune disorder. Disease outcomes in AQP4-IgG+NMOSD are typically measured by relapse rate and disability. Using the MSBase, a multi-centre international registry, we aimed to examine the impact immunosuppressive therapies and patient characteristics as predictors of disease outcome measures in AQP4-IgG+NMOSD.

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