MyMedR

Displaying all 12 publications

Abstract:

Sort:

Neuroimaging Systematic Review in Persistent Postural-Perceptual Dizziness: The Elaborate Alterations in the Delicate Network to Remain Balanced

Teh CS, Mah MC, Rahmat K, Prepageran N

Otol Neurotol, 2022 Jan 01;43(1):12-22.
PMID: 34669685 DOI: 10.1097/MAO.0000000000003389

OBJECTIVES: Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder that may have normal physical examination, clinical laboratory testing and vestibular evaluation. However, advances in neuroimaging have provided new insights in brain functional connectivity and structure in patients with PPPD. This systematic review was aimed at identifying significant structural or alterations in functional connectivity in patients with PPPD.
DATABASES REVIEWED: Science Direct, Pubmed, Embase via Ovid databases, and Cochrane library.
METHODS: This review following the guidelines of PRISMA, systematically and independently examined papers published up to March 2021 which fulfilled the predetermined criteria. PROSPERO Registration (CRD42020222334).
RESULTS: A total of 15 studies were included (MRI = 4, SPECT = 1, resting state fMRI = 4, task-based fMRI = 5, task-based fMRI + MRI = 1). Significant changes in the gray matter volume, cortical folding, blood flow, and connectivity were seen at different brain regions involved in vestibular, visual, emotion, and motor processing.
CONCLUSION: There is a multisensory dimension to the impairment resulting in chronic compensatory changes in PPPD that is evident by the significant alterations in multiple networks involved in maintaining balance. These changes observed offer some explanation for the symptoms that a PPPD patient may experience.Systematic Review Registration: This study is registered with PROSPERO (CRD42020222334).

Matched MeSH terms: Gray Matter
Fulltext Modelling the differential effects of age on transcranial magnetic stimulation induced electric fields

Alawi M, Lee PF, Deng ZD, Goh YK, Croarkin PE

J Neural Eng, 2023 Mar 16;20(2).
PMID: 36240726 DOI: 10.1088/1741-2552/ac9a76

Objective. The therapeutic application of noninvasive brain stimulation modalities such as transcranial magnetic stimulation (TMS) has expanded in terms of indications and patient populations. Often neurodevelopmental and neurodegenerative changes are not considered in research studies and clinical applications. This study sought to examine TMS dosing across time points in the life cycle.Approach. TMS induced electric fields with a figure-of-eight coil was simulated at left dorsolateral prefrontal cortex regions and taken in vertex as a control region. Realistic magnetic resonance imaging-based head models (N= 48) were concurrently examined in a cross-sectional study of three different age groups (children, adults, and elderlies).Main results. Age had a negative correlation with electric field peaks in white matter, grey matter and cerebrospinal fluid (P< 0.001). Notably, the electric field map in children displayed the widest cortical surface spread of TMS induced electric fields.Significance. Age-related anatomical geometry beneath the coil stimulation site had a significant impact on the TMS induced electric fields for different age groups. Safety considerations for TMS applications and protocols in children are warranted based on the present electric field findings.

Matched MeSH terms: Gray Matter/physiology
Fulltext Reevaluation of the odd chrysidid genus Atoposega Krombein (Hymenoptera, Chrysididae, Amiseginae)

Kimsey LS

Zookeys, 2014.
PMID: 24899842 DOI: 10.3897/zookeys.409.7414

The south Asian amisegine genus Atoposega Krombein, 1957, is reevaluated. Three new species, A. rufithorax, A. striata and A. thailandica are described from Thailand and the previously described species, A. lineata (Krombein, 1957) from Borneo, A. rieki (Krombein, 1957) from Myanmar and A. simulans Kimsey, 1986 from Malaysia are redescribed. The species, A. decorata Kimsey, 1995, was found to lack the generic characters diagnostic for Atoposega. Atoposega is only known from females.

Matched MeSH terms: Gray Matter
Fulltext Schizencephaly: psychosis, a rare manifestation

Aloysius, A., Seed, H.F., Thong, K.S.

Malaysian Journal of Psychiatry, 2017;26(2):0-0.
MyJurnal

Schizencephaly is an uncommon congenital malformation of the central
nervous system which affects the development of the cerebral cortex. It is
defined as the gray matter lined filled cleft with cerebrospinal fluid that
extends from the pial surface to the ventricle. There exists a paucity in
scientific literature regarding the association between schizencephaly and
psychosis. We report a case of a 36-year-old male, presented with worsening
crisis of aggression, disorganized behavior and auditory hallucinations over
20 years. CT brain scan revealed unilateral left open lip schizencephaly, a
finding during his recent admission to the psychiatry ward.

Matched MeSH terms: Gray Matter
Fulltext Atretic cephalocele - an uncommon cause of cystic scalp mass

Wong SL, Law HL, Tan S

Malays J Med Sci, 2010 Jul;17(3):61-3.
PMID: 22135551

A 6 year-old girl presented with a midline parietal scalp swelling that had been gradually enlarging since birth. Magnetic resonance imaging revealed communication of the cyst with the subarachnoid space through a calvarial defect, with concomitant findings of vertically positioned straight venous sinus and subependymal grey matter heterotopia. A diagnosis of atretic cephalocele was thus made based on these classical imaging findings.

Matched MeSH terms: Gray Matter
Fulltext Magnetic resonance image tissue classification using an automatic method

Yazdani S, Yusof R, Riazi A, Karimian A

Diagn Pathol, 2014;9:207.
PMID: 25540017 DOI: 10.1186/s13000-014-0207-7

Brain segmentation in magnetic resonance images (MRI) is an important stage in clinical studies for different issues such as diagnosis, analysis, 3-D visualizations for treatment and surgical planning. MR Image segmentation remains a challenging problem in spite of different existing artifacts such as noise, bias field, partial volume effects and complexity of the images. Some of the automatic brain segmentation techniques are complex and some of them are not sufficiently accurate for certain applications. The goal of this paper is proposing an algorithm that is more accurate and less complex).

Matched MeSH terms: Gray Matter/pathology*
Fulltext Median nerve stimulation induces analgesia via orexin-initiated endocannabinoid disinhibition in the periaqueductal gray

Chen YH, Lee HJ, Lee MT, Wu YT, Lee YH, Hwang LL, et al.

Proc Natl Acad Sci U S A, 2018 11 06;115(45):E10720-E10729.
PMID: 30348772 DOI: 10.1073/pnas.1807991115

Adequate pain management remains an unmet medical need. We previously revealed an opioid-independent analgesic mechanism mediated by orexin 1 receptor (OX1R)-initiated 2-arachidonoylglycerol (2-AG) signaling in the ventrolateral periaqueductal gray (vlPAG). Here, we found that low-frequency median nerve stimulation (MNS) through acupuncture needles at the PC6 (Neiguan) acupoint (MNS-PC6) induced an antinociceptive effect that engaged this mechanism. In mice, MNS-PC6 reduced acute thermal nociceptive responses and neuropathy-induced mechanical allodynia, increased the number of c-Fos-immunoreactive hypothalamic orexin neurons, and led to higher orexin A and lower GABA levels in the vlPAG. Such responses were not seen in mice with PC6 needle insertion only or electrical stimulation of the lateral deltoid, a nonmedian nerve-innervated location. Directly stimulating the surgically exposed median nerve also increased vlPAG orexin A levels. MNS-PC6-induced antinociception (MNS-PC6-IA) was prevented by proximal block of the median nerve with lidocaine as well as by systemic or intravlPAG injection of an antagonist of OX1Rs or cannabinoid 1 receptors (CB1Rs) but not by opioid receptor antagonists. Systemic blockade of OX1Rs or CB1Rs also restored vlPAG GABA levels after MNS-PC6. A cannabinoid (2-AG)-dependent mechanism was also implicated by the observations that MNS-PC6-IA was prevented by intravlPAG inhibition of 2-AG synthesis and was attenuated in Cnr1-/- mice. These findings suggest that PC6-targeting low-frequency MNS activates hypothalamic orexin neurons, releasing orexins to induce analgesia through a CB1R-dependent cascade mediated by OX1R-initiated 2-AG retrograde disinhibition in the vlPAG. The opioid-independent characteristic of MNS-PC6-induced analgesia may provide a strategy for pain management in opioid-tolerant patients.

Matched MeSH terms: Gray Matter/metabolism*
A Rare Case of an Infant with Left Hemiparesis: A Case Report of Bilateral Open-lip Schizencephaly

Siti BC, Zulkifli MM, Mohd Yusoff SS, Muhamad R, Ahmad TM

Malays Fam Physician, 2020;15(3):90-94.
PMID: 33329869

Schizencephaly is a very rare congenital birth defect. It is characterized by a cortical brain malformation that manifests as a grey-matter-lined cleft extending from the ependyma to the pia mater. It is a rare condition, and few cases have been reported in the literature. The exact cause is unknown. Herein, we report a case of an infant presenting with left side hemiparesis. The CT scan of her brain revealed right fronto-temporal and left parieto-temporal open-lip schizencephaly; thus, urgent referral to a pediatric neurologist was made for early intervention.

Matched MeSH terms: Gray Matter
Improved spinal cord gray matter morphology induced by Spirulina platensis following spinal cord injury in rat models

Abdullahi D, Ahmad Annuar A, Sanusi J

Ultrastruct Pathol, 2020 Nov 20;44(4-6):359-371.
PMID: 32686973 DOI: 10.1080/01913123.2020.1792597

Despite intense preclinical research focusing on developing potential strategies of mitigating spinal cord injury (SCI), SCI still results in permanent, debilitating symptoms for which there are currently no effective pharmacological interventions to improve the recovery of the fine ultrastructure of the spinal cord. Spirulina platensis is thought to have potential neuroprotective effects. We have previously demonstrated its protective potential on the lesioned corticospinal tracts and behavioral recovery. In this study, spirulina, known for its neuroprotective properties was used to further explore its protective effects on spinal cord gray matter ultrastructural. Twenty-four Sprague-Dawley rats were used and divided into sham group (laminectomy without SCI), control group (SCI without S. platensis), and S. platensis group (SCI + 180 mg/kg S. platensis). All animals were anesthetized via intramuscular injection. A partial crush injury was induced at the level of T12. The rats were humanely sacrificed for 28 days postinjury for ultrastructural study. There were significant mean differences with respect to pairwise comparisons between the ultrastructural grading score of neuronal perikarya of control and the S. platensis following injury at day 28, which correlates with the functional locomotor recovery at this timepoint in our previous study. The group supplemented with spirulina, thus, revealed a better improvement in the fine ultrastructure of the spinal cord gray matter when compared to the control group thereby suggesting neuroprotective potentials of spirulina in mitigating the effects of spinal cord injury and inducing functional recovery.

Matched MeSH terms: Gray Matter
Fulltext Diffusion tensor imaging of Leukoaraiosis, normal appearing brain tissue, and normal brain tissue

Nur Hartini Mohd Taib, Wan Ahmad Kamil Wan Abdullah, Ibrahim Lutfi Shuaib

Malaysian Journal of Medicine and Health Sciences, 2015;11(1):1-10.
MyJurnal

Diffusion Tensor Imaging (DTI) is an advanced magnetic resonance imaging (MRI) technique. DTI provides quantitative information at microstuructural level via its parameter indices e.g. mean diffusivity (MD) and fractional anisotropy (FA). It also allows for visualization of neuron fibres through a specific technique called fibre tractography. Leukoaraiosis is an asymptomatic pathological condition of the brain white matter which appears hyperintense on T2-weighted MRI images. Association of leukoaraiosis with age and ischemic heart disease have been previously reported. The objective of this study is to compare MD and FA values measured in various areas of the brain white matter (WM), grey matter (GM), and cerebrospinal fluid (CSF) in humans using DTI. 30 subjects with leukoaraiosis and 12 subjects without leukoaraiosis underwent brain scan using GE 1.5 Tesla MRI system. Region of interests were located in the CSF and various WM and GM areas. Comparison of MD and FA values was made between leukoaraiosis tissue (LA) and normal appearing brain tissue (NABT) measured within the same leukoaraiosis subjects, and with normal brain tissue (CONTROL) of healthy control subjects. LA demonstrated a significantly higher MD and lower FA compared to NABT and CONTROL in frontal and occipital WM areas. No differences were observed in MD in any brain region between NABT and CONTROL. Whereas no differences were observed in FA between NABT and CONTROL except in the occipital WM. Fibre tractography showed 31.7% to 56.1% lesser fibre tracts in LA subjects compared to CONTROL subjects. Significant differences were found between pathological tissue compared to normal appearing brain tissue and normal brain tissue. Fibre tractography exposed reduced number of neural fibres in leukoaraiosis subjects as compared to normal subjects.

Matched MeSH terms: Gray Matter
Neonatal hypoxic encephalopathy: Correlation between post-cooling brain MRI findings and 2 years neurodevelopmental outcome

Rusli ERM, Ismail J, Wei WS, Ishak S, Jaafar R, Zaki FM

Indian J Radiol Imaging, 2019 12 31;29(4):350-355.
PMID: 31949335 DOI: 10.4103/ijri.IJRI_62_19

Objective: This study aims to evaluate the magnetic resonance imaging (MRI) brain patterns among hypoxic-ischemic encephalopathy (HIE) babies who underwent post-cooling MRI brain as well as to correlate the post-cooling brain scoring with patient's neurodevelopmental outcome at 2 years.
Subjects and Methods: It was a retrospective cross sectional study carried out at a tertiary university hospital. Record of patients diagnosed with neonatal HIE from 2007 until 2016 who completed 72 h of cooling therapy and had MRI brain within 2 weeks of life were included in this study. A new scoring system by Trivedi et al. that emphasizes on subcortical deep gray matter and posterior limb internal capsule injury were utilized upon MRI assessment, using TW, T2W, and diffusion-weighted imaging (DWI) sequences. Cumulative MRI brain score was obtained and graded as none, mild, moderate, and severe brain injury. The MRI brain scoring was then correlated with patient's 2 years neurodevelopmental outcome using Fisher's Exact Test.
Results: A total of 23 patients were eligible of which 19 term neonates were included. 13% of these neonates (n = 3) had mild MRI brain injury grading with 52.2% (n = 12) moderate and 34.8% (n = 8) severe. There was no significant correlation seen between MRI brain grading and developmental outcome at 2 years old (P > 0.05).
Conclusion: There was no significant correlation between neonatal MRI brain injury grading and 2 years neurodevelopmental outcome. Nevertheless, the new MRI brain scoring by Trivedi et al. is reproducible and comprehensive as it involves various important brain structures, assessed from different MRI sequences.

Matched MeSH terms: Gray Matter
Fulltext Limited Evaluation of Image Quality Produced by a Portable Head CT Scanner (CereTom) in a Neurosurgery Centre

Abdullah AC, Adnan JS, Rahman NA, Palur R

Malays J Med Sci, 2017 Mar;24(1):104-112.
PMID: 28381933 DOI: 10.21315/mjms2017.24.1.11

INTRODUCTION: Computed tomography (CT) is the preferred diagnostic toolkit for head and brain imaging of head injury. A recent development is the invention of a portable CT scanner that can be beneficial from a clinical point of view.
AIM: To compare the quality of CT brain images produced by a fixed CT scanner and a portable CT scanner (CereTom).
METHODS: This work was a single-centre retrospective study of CT brain images from 112 neurosurgical patients. Hounsfield units (HUs) of the images from CereTom were measured for air, water and bone. Three assessors independently evaluated the images from the fixed CT scanner and CereTom. Streak artefacts, visualisation of lesions and grey-white matter differentiation were evaluated at three different levels (centrum semiovale, basal ganglia and middle cerebellar peduncles). Each evaluation was scored 1 (poor), 2 (average) or 3 (good) and summed up to form an ordinal reading of 3 to 9.
RESULTS: HUs for air, water and bone from CereTom were within the recommended value by the American College of Radiology (ACR). Streak artefact evaluation scores for the fixed CT scanner was 8.54 versus 7.46 (Z = -5.67) for CereTom at the centrum semiovale, 8.38 (SD = 1.12) versus 7.32 (SD = 1.63) at the basal ganglia and 8.21 (SD = 1.30) versus 6.97 (SD = 2.77) at the middle cerebellar peduncles. Grey-white matter differentiation showed scores of 8.27 (SD = 1.04) versus 7.21 (SD = 1.41) at the centrum semiovale, 8.26 (SD = 1.07) versus 7.00 (SD = 1.47) at the basal ganglia and 8.38 (SD = 1.11) versus 6.74 (SD = 1.55) at the middle cerebellar peduncles. Visualisation of lesions showed scores of 8.86 versus 8.21 (Z = -4.24) at the centrum semiovale, 8.93 versus 8.18 (Z = -5.32) at the basal ganglia and 8.79 versus 8.06 (Z = -4.93) at the middle cerebellar peduncles. All results were significant with P-value < 0.01.
CONCLUSIONS: Results of the study showed a significant difference in image quality produced by the fixed CT scanner and CereTom, with the latter being more inferior than the former. However, HUs of the images produced by CereTom do fulfil the recommendation of the ACR.

Matched MeSH terms: Gray Matter

Filters

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links