Displaying publications 1 - 20 of 83 in total

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  1. Yong SJ
    ACS Chem Neurosci, 2021 Feb 17;12(4):573-580.
    PMID: 33538586 DOI: 10.1021/acschemneuro.0c00793
    Long-COVID is a postviral illness that can affect survivors of COVID-19, regardless of initial disease severity or age. Symptoms of long-COVID include fatigue, dyspnea, gastrointestinal and cardiac problems, cognitive impairments, myalgia, and others. While the possible causes of long-COVID include long-term tissue damage, viral persistence, and chronic inflammation, the review proposes, perhaps for the first time, that persistent brainstem dysfunction may also be involved. This hypothesis can be split into two parts. The first is the brainstem tropism and damage in COVID-19. As the brainstem has a relatively high expression of ACE2 receptor compared with other brain regions, SARS-CoV-2 may exhibit tropism therein. Evidence also exists that neuropilin-1, a co-receptor of SARS-CoV-2, may be expressed in the brainstem. Indeed, autopsy studies have found SARS-CoV-2 RNA and proteins in the brainstem. The brainstem is also highly prone to damage from pathological immune or vascular activation, which has also been observed in autopsy of COVID-19 cases. The second part concerns functions of the brainstem that overlap with symptoms of long-COVID. The brainstem contains numerous distinct nuclei and subparts that regulate the respiratory, cardiovascular, gastrointestinal, and neurological processes, which can be linked to long-COVID. As neurons do not readily regenerate, brainstem dysfunction may be long-lasting and, thus, is long-COVID. Indeed, brainstem dysfunction has been implicated in other similar disorders, such as chronic pain and migraine and myalgic encephalomyelitis or chronic fatigue syndrome.
    Matched MeSH terms: Brain Diseases/metabolism; Brain Diseases/physiopathology*; Brain Diseases/virology
  2. Miyake N, Fukai R, Ohba C, Chihara T, Miura M, Shimizu H, et al.
    Am J Hum Genet, 2016 Oct 06;99(4):950-961.
    PMID: 27666374 DOI: 10.1016/j.ajhg.2016.08.005
    We describe four families with affected siblings showing unique clinical features: early-onset (before 1 year of age) progressive diffuse brain atrophy with regression, postnatal microcephaly, postnatal growth retardation, muscle weakness/atrophy, and respiratory failure. By whole-exome sequencing, we identified biallelic TBCD mutations in eight affected individuals from the four families. TBCD encodes TBCD (tubulin folding co-factor D), which is one of five tubulin-specific chaperones playing a pivotal role in microtubule assembly in all cells. A total of seven mutations were found: five missense mutations, one nonsense, and one splice site mutation resulting in a frameshift. In vitro cell experiments revealed the impaired binding between most mutant TBCD proteins and ARL2, TBCE, and β-tubulin. The in vivo experiments using olfactory projection neurons in Drosophila melanogaster indicated that the TBCD mutations caused loss of function. The wide range of clinical severity seen in this neurodegenerative encephalopathy may result from the residual function of mutant TBCD proteins. Furthermore, the autopsied brain from one deceased individual showed characteristic neurodegenerative findings: cactus and somatic sprout formations in the residual Purkinje cells in the cerebellum, which are also seen in some diseases associated with mitochondrial impairment. Defects of microtubule formation caused by TBCD mutations may underlie the pathomechanism of this neurodegenerative encephalopathy.
    Matched MeSH terms: Brain Diseases/genetics*; Brain Diseases/pathology; Brain Diseases/physiopathology
  3. Reijnders MRF, Ansor NM, Kousi M, Yue WW, Tan PL, Clarkson K, et al.
    Am J Hum Genet, 2017 Sep 07;101(3):466-477.
    PMID: 28886345 DOI: 10.1016/j.ajhg.2017.08.007
    RAC1 is a widely studied Rho GTPase, a class of molecules that modulate numerous cellular functions essential for normal development. RAC1 is highly conserved across species and is under strict mutational constraint. We report seven individuals with distinct de novo missense RAC1 mutations and varying degrees of developmental delay, brain malformations, and additional phenotypes. Four individuals, each harboring one of c.53G>A (p.Cys18Tyr), c.116A>G (p.Asn39Ser), c.218C>T (p.Pro73Leu), and c.470G>A (p.Cys157Tyr) variants, were microcephalic, with head circumferences between -2.5 to -5 SD. In contrast, two individuals with c.151G>A (p.Val51Met) and c.151G>C (p.Val51Leu) alleles were macrocephalic with head circumferences of +4.16 and +4.5 SD. One individual harboring a c.190T>G (p.Tyr64Asp) allele had head circumference in the normal range. Collectively, we observed an extraordinary spread of ∼10 SD of head circumferences orchestrated by distinct mutations in the same gene. In silico modeling, mouse fibroblasts spreading assays, and in vivo overexpression assays using zebrafish as a surrogate model demonstrated that the p.Cys18Tyr and p.Asn39Ser RAC1 variants function as dominant-negative alleles and result in microcephaly, reduced neuronal proliferation, and cerebellar abnormalities in vivo. Conversely, the p.Tyr64Asp substitution is constitutively active. The remaining mutations are probably weakly dominant negative or their effects are context dependent. These findings highlight the importance of RAC1 in neuronal development. Along with TRIO and HACE1, a sub-category of rare developmental disorders is emerging with RAC1 as the central player. We show that ultra-rare disorders caused by private, non-recurrent missense mutations that result in varying phenotypes are challenging to dissect, but can be delineated through focused international collaboration.
    Matched MeSH terms: Brain Diseases/genetics*; Brain Diseases/pathology
  4. Patel DK, Ali NA, Iqbal T, Subrayan V
    Ann Ophthalmol (Skokie), 2008;40(3-4):177-9.
    PMID: 19230359
    Colloid cysts are rare intracranial tumors most commonly found in the third ventricle. We present a case of colloid cyst of the third ventricle that manifested as bilateral advance optic disc cupping, superior hemifield defects in the visual fields and normal intraocular pressure.
    Matched MeSH terms: Brain Diseases/diagnosis*
  5. Lyn PC
    Ann Acad Med Singap, 1987 Apr;16(2):310-2.
    PMID: 3318659
    Of the seventy cases of cerebral malaria seen at the Duchess of Kent Hospital, Sandakan between January 1984 and June 1986, 57 (81.4%) were due to plasmodia falciparum and 13 (18.6%) were due to mixed p. vivax--p. falciparum infections. Mixed infection cerebral malaria was associated with a more severe anaemia and may carry a poorer prognosis. Indigenous children under five years of age are particularly at risk of death from mixed infections.
    Matched MeSH terms: Brain Diseases/mortality*; Brain Diseases/parasitology
  6. Ngiu CS, Ibrahim NM, Yahya WN, Tan HJ, Mustafa N, Basri H, et al.
    BMJ Case Rep, 2009;2009.
    PMID: 21709844 DOI: 10.1136/bcr.01.2009.1501
    Hashimoto encephalopathy (HE) is a poorly recognised steroid-responsive encephalopathy, with prominent neuropsychiatric features. Diagnosis is often difficult due to its heterogeneous clinical presentation, especially since the thyroid status or anti-thyroid antibody titres may not be related to the disease state. Here, the case of a 23-year-old Malay woman with Graves disease who presented with progressive encephalopathy diagnosed as HE is presented. She responded dramatically to high dose intravenous and then oral corticosteroid. A month after the initiation of treatment, she regained full independency.
    Matched MeSH terms: Brain Diseases
  7. Anandakrishnan P, Khoo TB
    BMJ Case Rep, 2018 May 30;2018.
    PMID: 29848532 DOI: 10.1136/bcr-2018-224496
    Cerebral demyelination and optic neuritis are often seen in children with acute disseminated encephalomyelitis following various infections and immunisations. An eight month old girl presented with a left axillary lymph node swelling and an erythematous lace-like rash over her cheeks and trunk. She then developed acute encephalopathy, bilateral nystagmus, right hemiparesis and left facial nerve palsy. Her electroencephalogram showed an encephalopathic process and visual evoked response study were grossly abnormal. Her MRI brain showed hyperintensities in the midbrain, pons and bilateral cerebellar peduncles. She was treated as postinfectious cerebral demyelination with intravenous antibiotics, methylprednisolone and immunoglobulin. Left axillary lymph node excision biopsy and GeneXpert test detected Mycobacterium tuberculosis complex that prompted initiation of antituberculous therapy. Her chest X-ray and cerebrospinal fluid examinations for tuberculosis were normal. She showed significant recovery after 2 weeks. This case illustrates a rare presentation of cerebral demyelination and bilateral optic neuritis following suppurative BCG lymphadenitis.
    Matched MeSH terms: Brain Diseases/drug therapy
  8. Namazi H, Akrami A, Nazeri S, Kulish VV
    Biomed Res Int, 2016;2016:5469587.
    PMID: 27699169
    An important challenge in brain research is to make out the relation between the features of olfactory stimuli and the electroencephalogram (EEG) signal. Yet, no one has discovered any relation between the structures of olfactory stimuli and the EEG signal. This study investigates the relation between the structures of EEG signal and the olfactory stimulus (odorant). We show that the complexity of the EEG signal is coupled with the molecular complexity of the odorant, where more structurally complex odorant causes less fractal EEG signal. Also, odorant having higher entropy causes the EEG signal to have lower approximate entropy. The method discussed here can be applied and investigated in case of patients with brain diseases as the rehabilitation purpose.
    Matched MeSH terms: Brain Diseases/physiopathology
  9. Abdul Wahab SA, Yakob Y, Abdul Azize NA, Md Yunus Z, Huey Yin L, Mohd Khalid MK, et al.
    Biomed Res Int, 2016;2016:4074365.
    PMID: 27672653
    Glutaric aciduria type 1 (GA1) is an autosomal recessive metabolic disorder caused by deficiency of glutaryl-CoA dehydrogenase enzyme encoded by the GCDH gene. In this study, we presented the clinical and molecular findings of seven GA1 patients in Malaysia. All the patients were symptomatic from infancy and diagnosed clinically from large excretion of glutaric and 3-hydroxyglutaric acids. Bidirectional sequencing of the GCDH gene revealed ten mutations, three of which were novel (Gln76Pro, Glu131Val, and Gly390Trp). The spectrum of mutations included eight missense mutations, a nonsense mutation, and a splice site mutation. Two mutations (Gln76Pro and Arg386Gln) were homozygous in two patients with parental consanguinity. All mutations were predicted to be disease causing by MutationTaster2. In conclusion, this is the first report of both clinical and molecular aspects of GA1 in Malaysian patients. Despite the lack of genotype and phenotype correlation, early diagnosis and timely treatment remained the most important determinant of patient outcome.
    Matched MeSH terms: Brain Diseases, Metabolic
  10. Muhammad Ismail HI, Teh CM, Lee YL, National Paediatric H1N1 Study Group
    Brain Dev, 2015 Jan;37(1):120-9.
    PMID: 24746706 DOI: 10.1016/j.braindev.2014.03.008
    In 2009, pandemic influenza A H1N1 emerged in Mexico and subsequently spread worldwide. In Malaysia, there were more than a thousand of confirmed cases among children. The general clinical characteristics of these children have been well-published. However, the description of neurologic complications is scarce.
    Matched MeSH terms: Brain Diseases/epidemiology; Brain Diseases/virology*
  11. Haji Muhammad Ismail Hussain I, Loh WF, Sofiah A
    Brain Dev, 1999 Jun;21(4):229-35.
    PMID: 10392744
    In a cross-sectional study of 24 Oriental children with systemic lupus erythematosus (SLE) with a mean age of 11.25 years, 75% were found to have clinical and neurophysiological evidence of cerebral lupus. Seizures were the most common manifestation affecting 11 (61%) of the cases, followed by psychosis in five (27.7%), encephalopathy in five (27.7%), headaches in five (27.7%), personality changes in four (22.2%), stroke in three (16.6%), movement disorders in three (16.6%) and myelitis in one child (5.5%). Four children had cerebral lupus as the presenting manifestation of SLE. Twenty-one children had an electroencephalogram (EEG) of which 11 were normal. Abnormalities detected in the rest included focal sharps, slowing of background and electrodecremental changes. There was a poor correlation of EEG with the clinical presentation. Sixteen children with cerebral lupus had a computed tomogram (CT) of which three were normal. The commonest abnormality was cerebral atrophy with or without infarcts. Only four of the cases had lupus anticoagulant but compliment was reduced in 13. Sixteen of the cases also had renal involvement. Treatment was generally with steroids with only two patients receiving cyclophosphamide for cerebral relapse. Eight children (44%) made a full recovery. Learning disability was the most frequent sequelae affecting one-third of children seen at a 1-year follow up. Four (22%) had epilepsy, two (11%) had motor deficits and one child had optic atrophy. One child died of cerebral haemorrhage during a hypertensive crisis.
    Matched MeSH terms: Brain Diseases/complications*; Brain Diseases/epidemiology*
  12. Anuar MA, Lee JX, Musa H, Abd Hadi D, Majawit E, Anandakrishnan P, et al.
    Brain Dev, 2023 Nov;45(10):547-553.
    PMID: 37661525 DOI: 10.1016/j.braindev.2023.06.004
    INTRODUCTION: Since the emergence of COVID-19, we have experienced potent variants and sub-variants of the virus with non-specific neurological manifestations. We observed a surge of the Omicron variant of COVID-19 patients with neurological manifestations where less cases of multisystem inflammatory syndrome in children (MIS-C) were reported. This article describes our experience of children with severe and rare neurological manifestations following COVID-19 infection.

    METHODS: This is a retrospective observational case series of patients under 18 years old who fulfilled the WHO COVID-19 case definition and were referred to our paediatric neurology unit at Hospital Tunku Azizah Kuala Lumpur. Their demographic data, neurological symptoms, laboratory and supporting investigations, neuroimaging, treatment and outcomes were collected and analysed.

    RESULTS: There were eleven patients with neurological manifestations who fulfilled the WHO COVID-19 case definition. Nine patients presented with seizures and/or encephalopathy, one patient with eye opsoclonus and another patient with persistent limbs myokymia. Based on the history, clinical, electrophysiological and radiological findings, two of them had febrile infection-related epilepsy syndrome, two had acute disseminated encephalomyelitis, two had acute necrotising encephalopathy of childhood, one each had hemiconvulsion-hemiplegia-epilepsy syndrome, acute encephalopathy with bilateral striatal necrosis, hemi-acute encephalopathy with biphasic seizures and reduced diffusion, infection-associated opsoclonus and myokymia.

    CONCLUSIONS: This case series highlighted a wide spectrum of neurological manifestations of COVID-19 infection. Early recognition and prompt investigations are important to provide appropriate interventions. It is essential that these investigations should take place in a timely fashion and COVID-19 quarantine period should not hinder the confirmation of various presenting clinical syndromes.

    Matched MeSH terms: Brain Diseases*
  13. Fong SL, Wong KT, Tan CT
    Brain, 2024 Mar 01;147(3):830-838.
    PMID: 38079534 DOI: 10.1093/brain/awad415
    Dengue virus is a flavivirus transmitted by the mosquitoes, Aedes aegypti and Aedes albopictus. Dengue infection by all four serotypes (DEN 1 to 4) is endemic globally in regions with tropical and subtropical climates, with an estimated 100-400 million infections annually. Among those hospitalized, the mortality is about 1%. Neurological involvement has been reported to be about 5%. The spectrum of neurological manifestations spans both the peripheral and central nervous systems. These manifestations could possibly be categorized into those directly related to dengue infection, i.e. acute and chronic encephalitis, indirect complications leading to dengue encephalopathy, and post-infectious syndrome due to immune-mediated reactions, and manifestations with uncertain mechanisms, such as acute transverse myelitis, acute cerebellitis and myositis. The rising trend in global dengue incidence calls for attention to a more explicit definition of each neurological manifestation for more accurate epidemiological data. The actual global burden of dengue infection with neurological manifestation is essential for future planning and execution of strategies, especially in the development of effective antivirals and vaccines against the dengue virus. In this article, we discuss the recent findings of different spectrums of neurological manifestations in dengue infection and provide an update on antiviral and vaccine development and their challenges.
    Matched MeSH terms: Brain Diseases*
  14. Mansor NI, Nordin N, Mohamed F, Ling KH, Rosli R, Hassan Z
    Curr Drug Deliv, 2019;16(8):698-711.
    PMID: 31456519 DOI: 10.2174/1567201816666190828153017
    Many drugs have been designed to treat diseases of the central nervous system (CNS), especially neurodegenerative diseases. However, the presence of tight junctions at the blood-brain barrier has often compromised the efficiency of drug delivery to target sites in the brain. The principles of drug delivery systems across the blood-brain barrier are dependent on substrate-specific (i.e. protein transport and transcytosis) and non-specific (i.e. transcellular and paracellular) transport pathways, which are crucial factors in attempts to design efficient drug delivery strategies. This review describes how the blood-brain barrier presents the main challenge in delivering drugs to treat brain diseases and discusses the advantages and disadvantages of ongoing neurotherapeutic delivery strategies in overcoming this limitation. In addition, we discuss the application of colloidal carrier systems, particularly nanoparticles, as potential tools for therapy for the CNS diseases.
    Matched MeSH terms: Brain Diseases
  15. Lee VWM, Khoo TB, Teh CM, Heng HS, Li L, Yusof YLM, et al.
    Dev Med Child Neurol, 2023 Sep;65(9):1256-1263.
    PMID: 36748407 DOI: 10.1111/dmcn.15536
    This case series compared clinical variables and various combinations of immunotherapy received with outcomes of patients with severe acute necrotizing encephalopathy (ANE). We performed a retrospective review of clinical variables, immunotherapy received, and outcomes (based on the modified Rankin Scale) in Malaysia between February 2019 and January 2020. Twenty-seven children (12 male), aged 7 months to 14 years (mean 4 years) at diagnosis were included. Of these, 23 had an ANE severity score of 5 to 9 out of 9 (high risk). Eleven patients received tocilizumab (four in combination with methylprednisolone [MTP], seven with MTP + intravenous immunoglobulin [IVIG]) and 16 did not (two received MTP alone, 14 received MTP + IVIG). Nine died. Among the survivors, six had good outcomes (modified Rankin Score 0-2) at 6 months follow-up. All patients who received tocilizumab in combination with MTP + IVIG survived. Twenty children received first immunotherapy within 48 hours of admission. No significant association was found between the timing of first immunotherapy with outcomes. Those with brainstem dysfunction (p = 0.016) were observed to have poorer outcomes. This study showed a trend towards better survival when those with severe ANE were treated with tocilizumab in combination with MTP + IVIG. However, larger studies will be needed to determine the effect of this regime on the long-term outcomes.
    Matched MeSH terms: Brain Diseases*
  16. Md S, Mustafa G, Baboota S, Ali J
    Drug Dev Ind Pharm, 2015;41(12):1922-34.
    PMID: 26057769 DOI: 10.3109/03639045.2015.1052081
    Brain disorders remain the world's leading cause of disability, and account for more hospitalizations and prolonged care than almost all other diseases combined. The majority of drugs, proteins and peptides do not readily permeate into brain due to the presence of the blood-brain barrier (BBB), thus impeding treatment of these conditions.
    Matched MeSH terms: Brain Diseases
  17. Raymond AA, Gilmore WV, Scott CA, Fish DR, Smith SJ
    Epileptic Disord, 1999 Jun;1(2):101-6.
    PMID: 10937139
    Video-EEG telemetry is often used to support the diagnosis of non-epileptic seizures (NES). Although rare, some patients may have both epileptic seizures (ES) and NES. It is crucially important to identify such patients to avoid the hazards of inappropriate anticonvulsant withdrawal. To delineate the electroclinical characteristics and diagnostic problems in this group of patients, we studied the clinical, EEG and MRI features of 14 consecutive patients in whom separate attacks, considered to be both NES and ES were recorded using video-EEG telemetry. Only two patients were drug-reduced during the telemetry. Most patients had their first seizure (ES or NES) in childhood (median age 7 years; range: 6 months-24 years); 8/14 patients were female. Brain MRI was abnormal in 10/14 patients. Interictal EEG abnormalities were present in all patients; 13/14 had epileptiform and 1/14 only background abnormalities. Over 70 seizures were recorded in these 14 patients: in 12/14 patients, the first recorded seizure was a NES (p < 0.001), and 7 of these patients had at least one more NES before an ES was recorded. Only 3/14 patients had more than 5 NES before an ES was recorded. Recording a small number of apparently NES in an individual by no means precludes the possibility of additional epilepsy. Particular care should be taken, and multiple (> 5) seizure recording may be advisable, in patients with a young age of seizure onset, interictal EEG abnormalities, or a clear, potential aetiology for epilepsy.
    Matched MeSH terms: Brain Diseases/complications; Brain Diseases/diagnosis
  18. Wang CY, Chee CP, Delilkan AE
    Eur J Anaesthesiol, 1991 Nov;8(6):469-70.
    PMID: 1765045
    Matched MeSH terms: Brain Diseases/etiology
  19. Sodhi RK, Singh R, Bansal Y, Bishnoi M, Parhar I, Kuhad A, et al.
    PMID: 34912298 DOI: 10.3389/fendo.2021.771575
    Neuropsychiatric disorders (NPDs) are a huge burden to the patient, their family, and society. NPDs have been greatly associated with cardio-metabolic comorbidities such as obesity, type-2 diabetes mellitus, dysglycaemia, insulin resistance, dyslipidemia, atherosclerosis, and other cardiovascular disorders. Antipsychotics, which are frontline drugs in the treatment of schizophrenia and off-label use in other NPDs, also add to this burden by causing severe metabolic perturbations. Despite decades of research, the mechanism deciphering the link between neuropsychiatric and metabolic disorders is still unclear. In recent years, transient receptor potential Ankyrin 1 (TRPA1) channel has emerged as a potential therapeutic target for modulators. TRPA1 agonists/antagonists have shown efficacy in both neuropsychiatric disorders and appetite regulation and thus provide a crucial link between both. TRPA1 channels are activated by compounds such as cinnamaldehyde, allyl isothiocyanate, allicin and methyl syringate, which are present naturally in food items such as cinnamon, wasabi, mustard, garlic, etc. As these are present in many daily food items, it could also improve patient compliance and reduce the patients' monetary burden. In this review, we have tried to present evidence of the possible involvement of TRPA1 channels in neuropsychiatric and metabolic disorders and a possible hint towards using TRPA1 modulators to target appetite, lipid metabolism, glucose and insulin homeostasis and inflammation associated with NPDs.
    Matched MeSH terms: Brain Diseases, Metabolic/complications; Brain Diseases, Metabolic/metabolism*
  20. Wong PK, Cheah FC, Syafruddin SE, Mohtar MA, Azmi N, Ng PY, et al.
    Front Pediatr, 2021;9:592571.
    PMID: 33791256 DOI: 10.3389/fped.2021.592571
    Hereditary or developmental neurological disorders (HNDs or DNDs) affect the quality of life and contribute to the high mortality rates among neonates. Most HNDs are incurable, and the search for new and effective treatments is hampered by challenges peculiar to the human brain, which is guarded by the near-impervious blood-brain barrier. Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR), a gene-editing tool repurposed from bacterial defense systems against viruses, has been touted by some as a panacea for genetic diseases. CRISPR has expedited the research into HNDs, enabling the generation of in vitro and in vivo models to simulate the changes in human physiology caused by genetic variation. In this review, we describe the basic principles and workings of CRISPR and the modifications that have been made to broaden its applications. Then, we review important CRISPR-based studies that have opened new doors to the treatment of HNDs such as fragile X syndrome and Down syndrome. We also discuss how CRISPR can be used to generate research models to examine the effects of genetic variation and caffeine therapy on the developing brain. Several drawbacks of CRISPR may preclude its use at the clinics, particularly the vulnerability of neuronal cells to the adverse effect of gene editing, and the inefficiency of CRISPR delivery into the brain. In concluding the review, we offer some suggestions for enhancing the gene-editing efficacy of CRISPR and how it may be morphed into safe and effective therapy for HNDs and other brain disorders.
    Matched MeSH terms: Brain Diseases
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