Displaying publications 1 - 20 of 27 in total

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  1. Amini E, Rezaei M, Mohamed Ibrahim N, Golpich M, Ghasemi R, Mohamed Z, et al.
    Mol Neurobiol, 2015 Aug;52(1):492-513.
    PMID: 25195699 DOI: 10.1007/s12035-014-8876-5
    Epilepsy is the most common and chronic neurological disorder characterized by recurrent unprovoked seizures. The key aim in treating patients with epilepsy is the suppression of seizures. An understanding of focal changes that are involved in epileptogenesis may therefore provide novel approaches for optimal treatment of the seizure. Although the actual pathogenesis of epilepsy is still uncertain, recently growing lines of evidence declare that microglia and astrocyte activation, oxidative stress and reactive oxygen species (ROS) production, mitochondria dysfunction, and damage of blood-brain barrier (BBB) are involved in its pathogenesis. Impaired GABAergic function in the brain is probably the most accepted hypothesis regarding the pathogenesis of epilepsy. Clinical neuroimaging of patients and experimental modeling have demonstrated that seizures may induce neuronal apoptosis. Apoptosis signaling pathways are involved in the pathogenesis of several types of epilepsy such as temporal lobe epilepsy (TLE). The quality of life of patients is seriously affected by treatment-related problems and also by unpredictability of epileptic seizures. Moreover, the available antiepileptic drugs (AED) are not significantly effective to prevent epileptogenesis. Thus, novel therapies that are proficient to control seizure in people who are suffering from epilepsy are needed. The preconditioning method promises to serve as an alternative therapeutic approach because this strategy has demonstrated the capability to curtail epileptogenesis. For this reason, understanding of molecular mechanisms underlying brain tolerance induced by preconditioning is crucial to delineate new neuroprotective ways against seizure damage and epileptogenesis. In this review, we summarize the work to date on the pathogenesis of epilepsy and discuss recent therapeutic strategies in the treatment of epilepsy. We will highlight that novel therapy targeting such as preconditioning process holds great promise. In addition, we will also highlight the role of gene reprogramming and mitochondrial biogenesis in the preconditioning-mediated neuroprotective events.
  2. Che Mohd Nassir CMN, Damodaran T, Yusof SR, Norazit A, Chilla G, Huen I, et al.
    Pharmaceutics, 2021 Aug 05;13(8).
    PMID: 34452169 DOI: 10.3390/pharmaceutics13081207
    The distinctive anatomical assemble and functionally discrete multicellular cerebrovasculature dynamics confer varying rheological and blood-brain barrier permeabilities to preserve the integrity of cerebral white matter and its neural microenvironment. This homeostasis intricately involves the glymphatic system that manages the flow of interstitial solutes, metabolic waste, and clearance through the venous circulation. As a physiologically integrated neurogliovascular unit (NGVU) serving a particularly vulnerable cerebral white matter (from hypoxia, metabolic insults, infection, and inflammation), a likely insidious process over a lifetime could inflict microenvironment damages that may lead to pathological conditions. Two such conditions, cerebral small vessel disease (CSVD) and vascular parkinsonism (VaP), with poorly understood pathomechanisms, are frequently linked to this brain-wide NGVU. VaP is widely regarded as an atypical parkinsonism, described by cardinal motor manifestations and the presence of cerebrovascular disease, particularly white matter hyperintensities (WMHs) in the basal ganglia and subcortical region. WMHs, in turn, are a recognised imaging spectrum of CSVD manifestations, and in relation to disrupted NGVU, also include enlarged perivascular spaces. Here, in this narrative review, we present and discuss on recent findings that argue for plausible clues between CSVD and VaP by focusing on aberrant multicellular dynamics of a unique integrated NGVU-a crossroad of the immune-vascular-nervous system-which may also extend fresher insights into the elusive interplay between cerebral microvasculature and neurodegeneration, and the potential therapeutic targets.
  3. Zulkifli NAF, Mohd Saaid NAS, Alias A, Mohamed Ibrahim N, Woon CK, Kurniawan A, et al.
    J Taibah Univ Med Sci, 2023 Dec;18(6):1435-1445.
    PMID: 38162871 DOI: 10.1016/j.jtumed.2023.05.020
    OBJECTIVES: In this study, the sizes and forms of mandibles in various age groups of the Malay population were measured and compared.

    METHODS: Geometric morphometric (GM) analysis of mandibles from 400 dental panoramic tomography (DPT) specimens was conducted. The MorphoJ program was used to perform generalized Procrustes analysis (GPA), Procrustes ANOVA, principal component analysis (PCA), discriminant function analysis (DFA), and canonical variate analysis (CVA). In the tpsDig2 program, the 27 landmarks were applied to the DPT radiographs. Variations in mandibular size and form were categorized into four age groups: group 1 (15-24 years), group 2 (25-34 years), group 3 (35-44 years), and group 4 (45-54 years).

    RESULTS: The diversity in mandibular shape among the first eight principal components was 81%. Procrustes ANOVA revealed significant shape differences (P 

  4. Samat NA, Abdul Murad NA, Mohamad K, Abdul Razak MR, Mohamed Ibrahim N
    Front Neurosci, 2017;11:712.
    PMID: 29326545 DOI: 10.3389/fnins.2017.00712
    Background: Cognitive impairment is prevalent in Parkinson's disease (PD), affecting 15-20% of patients at diagnosis. α-synuclein expression and genetic polymorphisms of Apolipoprotein E (ApoE) have been associated with the presence of cognitive impairment in PD although data have been inconsistent. Objectives: To determine the prevalence of cognitive impairment in patients with PD using Montreal Cognitive Assessment (MoCA), Comprehensive Trail Making Test (CTMT) and Parkinson's disease-cognitive rating scale (PDCRS), and its association with plasma α-synuclein and ApoE genetic polymorphisms. Methods: This was across-sectional study involving 46 PD patients. Patients were evaluated using Montreal cognitive assessment test (MoCA), and detailed neuropsychological tests. The Parkinson's disease cognitive rating scale (PDCRS) was used for cognitive function and comprehensive trail making test (CTMT) for executive function. Blood was drawn for plasma α-synuclein measurements and ApoE genetic analysis. ApoE polymorphism was detected using MutaGELAPoE from ImmunDiagnostik. Plasma α-synuclein was detected using the ELISA Technique (USCN Life Science Inc.) according to the standard protocol. Results: Based on MoCA, 26 (56.5%) patients had mild cognitive impairment (PD-MCI) and 20 (43.5%) had normal cognition (PD-NC). Based on the PDCRS, 18 (39.1%) had normal cognition (PDCRS-NC), 17 (37%) had mild cognitive impairment (PDCRS-MCI), and 11 (23.9%) had dementia (PDCRS-PDD). In the PDCRS-MCI group, 5 (25%) patients were from PD-NC group and all PDCRS-PDD patients were from PD-MCI group. CTMT scores were significantly different between patients with MCI and normal cognition on MoCA (p = 0.003). Twenty one patients (72.4%) with executive dysfunction were from the PD-MCI group; 17 (77.3%) with severe executive dysfunction and 4 (57.1%) had mild to moderate executive dysfunction. There were no differences in the plasma α-synuclein concentration between the presence or types of cognitive impairment based on MoCA, PDCRS, and CTMT. TheApoEe4 allele carrier frequency was significantly higher in patients with executive dysfunction (p = 0.014). Conclusion: MCI was prevalent in our PD population. PDCRS appeared to be more discriminatory in detecting MCI and PDD than MoCA. Plasma α-synuclein level was not associated with presence nor type of cognitive impairment, but the ApoEe4 allele carrier status was significantly associated with executive dysfunction in PD.
  5. Hii CST, Gan KB, Zainal N, Mohamed Ibrahim N, Azmin S, Mat Desa SH, et al.
    Sensors (Basel), 2023 Jul 18;23(14).
    PMID: 37514783 DOI: 10.3390/s23146489
    Gait analysis is an essential tool for detecting biomechanical irregularities, designing personalized rehabilitation plans, and enhancing athletic performance. Currently, gait assessment depends on either visual observation, which lacks consistency between raters and requires clinical expertise, or instrumented evaluation, which is costly, invasive, time-consuming, and requires specialized equipment and trained personnel. Markerless gait analysis using 2D pose estimation techniques has emerged as a potential solution, but it still requires significant computational resources and human involvement, making it challenging to use. This research proposes an automated method for temporal gait analysis that employs the MediaPipe Pose, a low-computational-resource pose estimation model. The study validated this approach against the Vicon motion capture system to evaluate its reliability. The findings reveal that this approach demonstrates good (ICC(2,1) > 0.75) to excellent (ICC(2,1) > 0.90) agreement in all temporal gait parameters except for double support time (right leg switched to left leg) and swing time (right), which only exhibit a moderate (ICC(2,1) > 0.50) agreement. Additionally, this approach produces temporal gait parameters with low mean absolute error. It will be useful in monitoring changes in gait and evaluating the effectiveness of interventions such as rehabilitation or training programs in the community.
  6. Hemmati F, Ghasemi R, Mohamed Ibrahim N, Dargahi L, Mohamed Z, Raymond AA, et al.
    Mol Neurobiol, 2014 Dec;50(3):797-810.
    PMID: 24464263 DOI: 10.1007/s12035-013-8631-3
    Neuroinflammation is known as a key player in a variety of neurodegenerative and/or neurological diseases. Brain Toll-like receptors (TLRs) are leading elements in the initiation and progression of neuroinflammation and the development of different neuronal diseases. Furthermore, TLR activation is one of the most important elements in the induction of insulin resistance in different organs such as the central nervous system. Involvement of insulin signaling dysregulation and insulin resistance are also shown to contribute to the pathology of neurological diseases. Considering the important roles of TLRs in neuroinflammation and central insulin resistance and the effects of these processes in the initiation and progression of neurodegenerative and neurological diseases, here we are going to review current knowledge about the potential crosstalk between TLRs and insulin signaling pathways in neuroinflammatory disorders of the central nervous system.
  7. Zainal Abidin S, Tan EL, Chan SC, Jaafar A, Lee AX, Abd Hamid MH, et al.
    BMC Neurol, 2015;15:59.
    PMID: 25896831 DOI: 10.1186/s12883-015-0316-2
    Impulse control disorder (ICD) and behaviours (ICB) represent a group of behavioural disorders that have become increasingly recognised in Parkinson's disease (PD) patients who previously used dopaminergic medications, particularly dopamine agonists and levodopa. It has been suggested that these medications can lead to the development of ICB through the abnormal modulation of dopaminergic transmission and signalling in the mesocorticolimbic dopaminergic system. Several studies have reported an association between polymorphisms in the dopamine receptor (DRD) and N-methyl-D-aspartate 2B (GRIN2B) genes with the development of ICB in PD (PD-ICB) patients. Thus, this study aimed to investigate the association of selected polymorphisms within the DRD and GRIN2B genes with the development of ICB among PD patients using high resolution melt (HRM) analysis.
  8. Abdul Murad NA, Sulaiman SA, Ahmad-Annuar A, Mohamed Ibrahim N, Mohamed W, Md Rani SA, et al.
    Front Aging Neurosci, 2022;14:1094914.
    PMID: 36589546 DOI: 10.3389/fnagi.2022.1094914
  9. Mohamed Fuad Z, Mahadzir H, Syed Zakaria SZ, Mohamed Ibrahim N
    Front Public Health, 2020;8:577940.
    PMID: 33282811 DOI: 10.3389/fpubh.2020.577940
    Background: Stroke is highly prevalent globally and is an important cause of cognitive impairment and dementia. Aims: We determined the frequency of post-stroke cognitive impairment (PSCI) at 1, 3, and 6 months among patients with first clinical ischemic stroke compared to risk and age-matched controls. Methods: This study involved 32 cases and 32 controls, and was conducted over 6 months. Cases were inpatients aged >60 with first clinical ischemic stroke. Controls were age-matched subjects without prior stroke. Montreal Cognitive Assessment (MoCA) was performed in all patients at 1, 3, and 6 month post stroke. A MoCA score of <26 was used for mild PSCI and <22 for moderate PSCI (post stroke dementia). Results: Post-stroke dementia was detected in 12 patients (37.5%) at 1st month, in 13 (40.6%) at 3rd month and 15 (48.4%) at 6th months. Mild PSCI was present in 7 patients (21.6%) at 1 month, 16 patients (50%) at 3 months, and 15 patients (48%) at 6 months. The odds ratio (OR) for post-stroke dementia was 3.2 (95%CI 0.98-10.68; p = 0.05) at 1 month; 3.69(95% CI 1.13-12.11; p = 0.031) at 3 months, and 4.88 (95% CI 1.49-15.99; p = 0.009) at 6 months. Years of education was an independent predictor for dementia (OR 0.60; p = 0.046). The OR for post-stroke dementia at 6th month was 7.23 with education level adjusted (95%CI 1.46-35.86, p = 0.015). Conclusion: The frequency of PSCI was high as early as 1 month after stroke. Stroke alone conferred a 7.2 times risk for post-stroke dementia compared to controls.
  10. Mohamed Ibrahim N, Lau YH, Ariffin N, Md Desa SH, Azizan E, Chin LK, et al.
    PMID: 32922823 DOI: 10.1186/s40673-020-00120-2
    Spinocerebellar ataxias (SCA) are highly heterogenous group of neurodegenerative diseases causing progressive cerebellar dysfunction. We report the first description of relative frequencies of the common SCA mutations and of phenotypic characteristics of SCA3 patients among Malaysians. Pooled data from adult Malaysian patients who had undergone genetic testing for SCA 1,2,3,6 and 7 at UKM Medical Centre and Institute for Medical Research from 2017 to 2020 were analysed. Fifteen patients with SCA 3 had detailed clinical phenotype evaluation using Inventory for Non -Ataxia Signs (INAS) and Ataxia Severity evaluation using the Scale for Assessment and Rating of Ataxia (SARA). Out of 152 adults patients who were tested for common SCA mutations, 64(42.1%) patients were tested positive for either SCA 1,2,3,6 or 7. Of the 64 positive cases, 44 (68.9%) patients were diagnosed with SCA 3 followed by SCA 2 in 13(20.3%) patients and SCA 1 in 5 (7.8%) patients. Our findings suggest that Malay race had the highest frequency of SCA (n = 34, 50%), followed by the Chinese (n = 16, 23.5%) and approximately 60 (93.8%) SCA patients had first degree family history. In conclusion, SCA 3 is the commonest SCA in Malaysia, followed by SCA 2 and SCA 1. It is important to develop a proper registry of SCA patients to further understand the true prevalence and local impact of the disease in Malaysia.
  11. Jagota P, Lim SY, Pal PK, Lee JY, Kukkle PL, Fujioka S, et al.
    Mov Disord Clin Pract, 2023 Jun;10(6):878-895.
    PMID: 37332644 DOI: 10.1002/mdc3.13737
    The increasing availability of molecular genetic testing has changed the landscape of both genetic research and clinical practice. Not only is the pace of discovery of novel disease-causing genes accelerating but also the phenotypic spectra associated with previously known genes are expanding. These advancements lead to the awareness that some genetic movement disorders may cluster in certain ethnic populations and genetic pleiotropy may result in unique clinical presentations in specific ethnic groups. Thus, the characteristics, genetics and risk factors of movement disorders may differ between populations. Recognition of a particular clinical phenotype, combined with information about the ethnic origin of patients could lead to early and correct diagnosis and assist the development of future personalized medicine for patients with these disorders. Here, the Movement Disorders in Asia Task Force sought to review genetic movement disorders that are commonly seen in Asia, including Wilson's disease, spinocerebellar ataxias (SCA) types 12, 31, and 36, Gerstmann-Sträussler-Scheinker disease, PLA2G6-related parkinsonism, adult-onset neuronal intranuclear inclusion disease (NIID), and paroxysmal kinesigenic dyskinesia. We also review common disorders seen worldwide with specific mutations or presentations that occur frequently in Asians.
  12. Woon CK, Jamal NAA, Noor MNIM, Abdullah SM, Mohamed Ibrahim N, Norman NH, et al.
    Anat Cell Biol, 2019 12;52(4):397-405.
    PMID: 31949978 DOI: 10.5115/acb.19.118
    Geometric morphometrics is a new approach for shape identification in diagnosis of malocclusion. Lateral cephalogram is an X-ray that taken for diagnosing malocclusion in dental setting. The aim of this study was to determine the differences of craniofacial shape in malocclusion by application of two-dimensional geometric morphometrics and to compile the database of malocclusion in adult Malaysian population. Lateral cephalogram radiographs of 381 adults Malaysia (age 18-45) were retrieved retrospectively and assigned to three groups according to their occlusion: class I, class II, and class III. The geometric morphometric shape study incorporated nine landmarks and was analyzed in details using tpsUtil p software. Geometric morphometric analysis such was done using MorphoJ software. The results of the principal component's analysis (PCA) yielded 14 main components responsible for 100% of the variation exhibited by the malocclusion with three highly significant PCA. The highest Mahalanobis distances were exhibited by the malocclusion class II and III population. The Procrustes ANOVA showed that the shape effect was highly significant (P<0.01). The discriminant function analysis showed the high percentage of 80% discriminate among the malocclusions after cross-validation. There are significant differences for ANB angle (A point-Nasion-B point) in all malocclusion groups. Class II has the widest ANB angle while class III has the most acute ANB angle. Skeletal shape was clearly associated with dental malocclusion and showed considerable variation. Geometric morphometrics is an alternative research tool and can be used for diagnosing individual classification of malocclusion.
  13. Gopalai AA, Lim SY, Chua JY, Tey S, Lim TT, Mohamed Ibrahim N, et al.
    Biomed Res Int, 2014;2014:867321.
    PMID: 25243190 DOI: 10.1155/2014/867321
    The LRRK2 gene has been associated with both familial and sporadic forms of Parkinson's disease (PD). The G2019S variant is commonly found in North African Arab and Caucasian PD patients, but this locus is monomorphic in Asians. The G2385R and R1628P variants are associated with a higher risk of developing PD in certain Asian populations but have not been studied in the Malaysian population. Therefore, we screened the G2385R and R1628P variants in 1,202 Malaysian subjects consisting of 695 cases and 507 controls. The G2385R and R1628P variants were associated with a 2.2-fold (P = 0.019) and 1.2-fold (P = 0.054) increased risk of PD, respectively. Our data concur with other reported findings in Chinese, Taiwanese, Singaporean, and Korean studies.
  14. Arshad AR, Sulaiman SA, Saperi AA, Jamal R, Mohamed Ibrahim N, Abdul Murad NA
    Front Mol Neurosci, 2017;10:352.
    PMID: 29163029 DOI: 10.3389/fnmol.2017.00352
    Among the neurodegenerative disorders, Parkinson's disease (PD) ranks as the second most common disorder with a higher prevalence in individuals aged over 60 years old. Younger individuals may also be affected with PD which is known as early onset PD (EOPD). Despite similarities between the characteristics of EOPD and late onset PD (LODP), EOPD patients experience much longer disease manifestations and poorer quality of life. Although some individuals are more prone to have EOPD due to certain genetic alterations, the molecular mechanisms that differentiate between EOPD and LOPD remains unclear. Recent findings in PD patients revealed that there were differences in the genetic profiles of PD patients compared to healthy controls, as well as between EOPD and LOPD patients. There were variants identified that correlated with the decline of cognitive and motor symptoms as well as non-motor symptoms in PD. There were also specific microRNAs that correlated with PD progression, and since microRNAs have been shown to be involved in the maintenance of neuronal development, mitochondrial dysfunction and oxidative stress, there is a strong possibility that these microRNAs can be potentially used to differentiate between subsets of PD patients. PD is mainly diagnosed at the late stage, when almost majority of the dopaminergic neurons are lost. Therefore, identification of molecular biomarkers for early detection of PD is important. Given that miRNAs are crucial in controlling the gene expression, these regulatory microRNAs and their target genes could be used as biomarkers for early diagnosis of PD. In this article, we discussed the genes involved and their regulatory miRNAs, regarding their roles in PD progression, based on the findings of significantly altered microRNAs in EOPD studies. We also discussed the potential of these miRNAs as molecular biomarkers for early diagnosis.
  15. Golpich M, Amini E, Mohamed Z, Azman Ali R, Mohamed Ibrahim N, Ahmadiani A
    CNS Neurosci Ther, 2017 Jan;23(1):5-22.
    PMID: 27873462 DOI: 10.1111/cns.12655
    Neurodegenerative diseases are a heterogeneous group of disorders that are incurable and characterized by the progressive degeneration of the function and structure of the central nervous system (CNS) for reasons that are not yet understood. Neurodegeneration is the umbrella term for the progressive death of nerve cells and loss of brain tissue. Because of their high energy requirements, neurons are especially vulnerable to injury and death from dysfunctional mitochondria. Widespread damage to mitochondria causes cells to die because they can no longer produce enough energy. Several lines of pathological and physiological evidence reveal that impaired mitochondrial function and dynamics play crucial roles in aging and pathogenesis of neurodegenerative diseases. As mitochondria are the major intracellular organelles that regulate both cell survival and death, they are highly considered as a potential target for pharmacological-based therapies. The purpose of this review was to present the current status of our knowledge and understanding of the involvement of mitochondrial dysfunction in pathogenesis of neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) and the importance of mitochondrial biogenesis as a potential novel therapeutic target for their treatment. Likewise, we highlight a concise overview of the key roles of mitochondrial electron transport chain (ETC.) complexes as well as mitochondrial biogenesis regulators regarding those diseases.
  16. Yap KH, Kessels RPC, Azmin S, van de Warrenburg B, Mohamed Ibrahim N
    Cerebellum, 2021 Jul 07.
    PMID: 34231180 DOI: 10.1007/s12311-021-01282-3
    Spinocerebellar ataxia type 3 (SCA3), the commonest dominantly inherited ataxia worldwide, is characterized by disruption in the cerebellar-cerebral and striatal-cortical networks. Findings on SCA3-associated cognitive impairments are mixed. The classification models, tests and scoring systems used, language, culture, ataxia severity, and depressive symptoms are all potential confounders in neuropsychological assessments and may have contributed to the heterogeneity of the neurocognitive profile of SCA3. We conducted a systematic review of studies evaluating neurocognitive function in SCA3 patients. Of 1304 articles identified, 15 articles met the eligibility criteria. All articles were of excellent quality according to the National Institutes of Health quality assessment tool for case-control studies. In line with the disrupted cerebellar-cerebral and striatal-cortical networks in SCA3, this systematic review found that the neurocognitive profile of SCA3 is characterized by a core impairment of executive function that affects processes such as nonverbal reasoning, executive aspects of language, and recall. Conversely, neurocognitive domains such as general intelligence, verbal reasoning, semantic aspect of language, attention/processing speed, recognition, and visuospatial perception and construction are relatively preserved. This review highlights the importance of evaluating neurocognitive function in SCA3 patients. Considering the negative impact of cognitive and affective impairment on quality of life, this review points to the profound impairments that existing or future treatments should prioritize.
  17. Tan HJ, Goh CH, Khoo CS, Ng CF, Tan JK, Wan Zaidi WA, et al.
    Neurol Clin Neurosci, 2023 Jan;11(1):17-26.
    PMID: 36714457 DOI: 10.1111/ncn3.12677
    BACKGROUND: Neurological involvement associated with SARS-CoV-2 infection has been reported from different regions of the world. However, data from South East Asia are scarce. We described the neurological manifestations and their associated factors among the hospitalized COVID-19 patients from an academic tertiary hospital in Malaysia.

    METHODS: A cross-sectional observational study of hospitalized COVID-19 patients was conducted. The neurological manifestations were divided into the self-reported central nervous system (CNS) symptoms, stroke associated symptoms, symptoms of encephalitis or encephalopathy and specific neurological complications. Multiple logistic regression was performed using demographic and clinical variables to determine the factors associated with outcome.

    RESULTS: Of 156 hospitalized COVID-19 patients with mean age of 55.88 ± 6.11 (SD) years, 23.7% developed neurological complications, which included stroke, encephalitis and encephalopathy. Patients with neurological complications were more likely to have diabetes mellitus (p = 0.033), symptoms of stroke [limb weakness (p 

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