N-acetylaspartate Peak Research Articles

Validity and specificity of BOLD effects and their correction in 1H-fMRS.

This study aimed to characterize blood oxygen level-dependent (BOLD) effects in proton magnetic resonance (1H-MR) spectra obtained during optogenetic activation of the rat forelimb cortex to correct and estimate the accurate changes in metabolite concentration. For a more comprehensive understanding of BOLD effects detected with functional magnetic resonance spectroscopy (fMRS) and to optimize the correction method, a 1 Hz line-narrowing effect was simulated. Then, proton functional magnetic resonance spectroscopy (1H-fMRS) data acquired using stimulated echo acquisition mode (STEAM) at 9.4T in rats (n = 8) upon optogenetic stimulation of the primary somatosensory cortex were utilized. The data were analyzed using MATLAB routines and LCModel. Uncorrected and corrected 1H-MR spectra from the simulated and in vivo data were quantified and compared. BOLD-corrected difference spectra were also calculated and analyzed. Additionally, the effects of stimulated and non-stimulated water on the quantification of metabolite concentration swere investigated. Significant mean increases in water and N-acetylaspartate (NAA) peak heights (+1.1% and +4.5%, respectively) were found to be accompanied by decreased linewidths (-0.5 Hz and -2.8%) upon optogenetic stimulation. These estimates were used for further defining an accurate line-broadening (lb) factor. The usage of a non-data-driven lb introduced false-positive errors in the metabolite concentration change estimates, thereby altering the specificity of the findings. The water and metabolite BOLD contributions were separated using different water scalings within LCModel. The linewidth-matching procedure using a precise lb factor remains the most effective approach for accurately quantifying small (±0.3 μmol/g) metabolic changes in 1H-fMRS studies. A simple and preliminary compartmentation of BOLD effects was proposed, but it will require validation.

Clinical value of magnetic resonance spectroscopy in assessment of early curing impact of concurrent chemoradiotherapy after high-grade glioma surgery

Background/Aim. High-grade glioma (HGG) is an interstitial cell-derived primary tumor of the nervous system. The current guidelines for the diagnosis and treatment of glioma recommend the maximum safe range of tumor resection for treatment methods. Adjuvant concurrent chemoradiotherapy is recommended after surgery, followed by six cycles of single-drug chemotherapy, temozolomide. Evaluation of the early efficacy of concurrent chemoradiotherapy after HGG surgery, especially for patients with a high risk of recurrence, is a crucial step in enhancing the treatment efficiency for patients diagnosed with HGG. In this study, we investigated the clinical utility of magnetic resonance (MR) spectroscopy (MRS) in assessing the early curing impact of concurrent chemoradiotherapy following HGG surgery. Methods. A total of 50 patients with incomplete resection or suspected residual postoperative HGG, treated in the radiotherapy department of our hospital between January 2016 and June 2021, were selected for routine concurrent chemoradiotherapy. Conventional MR imaging and MRS were performed one week prior to treatment and one month after treatment to assess changes in specific brain metabolites. All 50 patients were followed up for 6 to 12 months. Based on the follow-up results, the patients were divided into two groups: the tumor recurrence group and the tumor suppression group. One month after the end of the treatment, the differences in levels of brain metabolites between the two groups were analyzed using MRS. Results. The levels of N-acetylaspartate (NAA) and creatine (Cr) increased after radiotherapy, while choline (Cho) peak value, and Cho/Cr, NAA/Cr, and Cho/NAA ratios decreased compared to pre-treatment levels. There were statistically significant differences in the NAA peak value, and Cho/Cr, and Cho/NAA ratios in the tumor enhancement area before and after treatment (p < 0.05). There were also statistically significant differences in Cho/Cr ratio in the peritumoral edema area before and after treatment (p < 0.05). Conclusion. After concurrent chemoradiotherapy, MRS can be used to detect early metabolic changes in the tumor enhancement and peritumoral edema areas of HGG.

Assessment of Cerebral Hypoxemia and Its Impact on Cognitive and Psychological Functions in Patients With Obstructive Sleep Apnea Syndrome

Background and Objective The precise pathophysiology of cognitive impedance and mental illness in obstructive sleep apnea (OSA) patients remains elusive. Therefore, there is a need for studies on novel diagnoses and therapeutic strategies for cognitive impairment in OSA patients. This work aimed to evaluate cerebral hypoxemia, its consequences on brain metabolism, and local and systemic inflammation, and their subsequent impact on cognitive and psychological functioning.Methods This cross-sectional case-control study was conducted on 30 eligible OSA patients and 20 age/sex-matched healthy controls. All the participants underwent one-night polysomnography, and cognitive evaluation was done using the Mini-Mental State Examination, Montreal Cognitive Assessment, Brief Kingston Standardized Cognitive Assessment, D2 Test of Consideration (to evaluate attention problems), and Wisconsin card sorting test. The psychiatric assessment included the Arabic form of the Hamilton Depression Rating Scale and Beck Depression Inventory-II. A radiology assessment was done using proton magnetic resonance spectroscopy. Neurophysiological assessment was done using the potential cortical (N20) latency and amplitude of somatosensory evoked potential. Laboratory examinations included serum levels of NF-κB, HMGB1, and HIF-1α.Results Polysomnography demonstrated noteworthy increase in the apnea-hypopnea index, respiratory disturbance index, arousal index, snoring index, and wake after sleep onset. It also showed diminished sleep efficiency, total sleep time, and SaO2 nadir in the OSA group. Neuropsychological scales demonstrated poor performance in global cognitive tests, particular cognitive domains impedance, and depression in the OSA group, with noteworthy differences within the group. Magnetic resonance spectroscopy highlighted that OSA patients had a noteworthy bilateral decrement in N-acetylaspartate (NAA) peak, creatine peak, and NAA/choline proportion and an increment in choline peak, lipid peak, lactate peak, choline/creatine proportion, and NAA/creatine proportion in the frontal white matter, hippocampus, and parieto-occipital cortex. Moreover. OSA patients had either missing or decreased amplitude and delayed latency of N20. There was a noteworthy rise of serum inflammatory marker NF-κB, HMGB1, and oxidative stress marker HIF-1α in OSA patients.Conclusions Chronic intermittent hypoxia with resulting amplified inflammatory and oxidative stress in OSA patients may affect brain metabolism; consequently, leading to cognitive and psychological dysfunctions.

The anti-inflammatory effects of atorvastatin upon the outcome of traumatic brain injury patients: A randomized-controlled double-blind clinical trial

ABSTRACT Background Traumatic brain injury (TBI) is a quite common health problem. A lot of delayed complications are related to inflammatory responses that occurred within the brain itself. Atorvastatin is related to lipid lowering drugs carrying some anti-inflammatory properties and upon this fact this study hypothesis was built. Methods Twenty adult patients with TBI, Glasgow coma scale (GCS) 9–11. Patients were equally and randomly allocated into two groups (group C as control group and group S received atorvastatin 40 mg once daily for 48 h). After 48 h, participants have undergone magnetic resonance imaging brain spectroscopy examination (MRS). The spectral peaks of N-Acetyl aspartate (NAA), Choline, and Creatinine (Cr) were assessed in brain tissue. The primary outcome was presented as ratios of NAA/Cr), Cho/Cr, and NAA/Cho. Other outcomes included GCS and ICU stay. Results There were insignificant variations between groups were found in the MRS results for metabolite alterations (NAA, Cr, and Cho). Contrasted with the control group, the statin group’s Cho/Cr ratio was significantly lower (P = 0.005), and NAA/Cho was significantly greater in the statin group than control group (P = 0.022). Statin group showed higher GCS the 1st day (P = 0.01), and lesser ICU stay (P = 0.04) Conclusion Atorvastatin can be used safely in mild-to-moderate TBI patients with a favourable outcome in the form of decreased Cho/Cr ratio and increased NAA/Cho ratio, higher GCS, and decreased ICU length of stay.

Whole-Body Hypothermia, Cerebral Magnetic Resonance Biomarkers, and Outcomes in Neonates With Moderate or Severe Hypoxic-Ischemic Encephalopathy Born at Tertiary Care Centers vs Other Facilities

The association between place of birth and hypothermic neuroprotection after hypoxic-ischemic encephalopathy (HIE) in low- and middle-income countries (LMICs) is unknown. To ascertain the association between place of birth and the efficacy of whole-body hypothermia for protection against brain injury measured by magnetic resonance (MR) biomarkers among neonates born at a tertiary care center (inborn) or other facilities (outborn). This nested cohort study within a randomized clinical trial involved neonates at 7 tertiary neonatal intensive care units in India, Sri Lanka, and Bangladesh between August 15, 2015, and February 15, 2019. A total of 408 neonates born at or after 36 weeks' gestation with moderate or severe HIE were randomized to receive whole-body hypothermia (reduction of rectal temperatures to between 33.0 °C and 34.0 °C; hypothermia group) for 72 hours or no whole-body hypothermia (rectal temperatures maintained between 36.0 °C and 37.0 °C; control group) within 6 hours of birth, with follow-up until September 27, 2020. 3T MR imaging, MR spectroscopy, and diffusion tensor imaging. Thalamic N-acetyl aspartate (NAA) mmol/kg wet weight, thalamic lactate to NAA peak area ratios, brain injury scores, and white matter fractional anisotropy at 1 to 2 weeks and death or moderate or severe disability at 18 to 22 months. Among 408 neonates, the mean (SD) gestational age was 38.7 (1.3) weeks; 267 (65.4%) were male. A total of 123 neonates were inborn and 285 were outborn. Inborn neonates were smaller (mean [SD], 2.8 [0.5] kg vs 2.9 [0.4] kg; P = .02), more likely to have instrumental or cesarean deliveries (43.1% vs 24.7%; P = .01), and more likely to be intubated at birth (78.9% vs 29.1%; P = .001) than outborn neonates, although the rate of severe HIE was not different (23.6% vs 17.9%; P = .22). Magnetic resonance data from 267 neonates (80 inborn and 187 outborn) were analyzed. In the hypothermia vs control groups, the mean (SD) thalamic NAA levels were 8.04 (1.98) vs 8.31 (1.13) among inborn neonates (odds ratio [OR], -0.28; 95% CI, -1.62 to 1.07; P = .68) and 8.03 (1.89) vs 7.99 (1.72) among outborn neonates (OR, 0.05; 95% CI, -0.62 to 0.71; P = .89); the median (IQR) thalamic lactate to NAA peak area ratios were 0.13 (0.10-0.20) vs 0.12 (0.09-0.18) among inborn neonates (OR, 1.02; 95% CI, 0.96-1.08; P = .59) and 0.14 (0.11-0.20) vs 0.14 (0.10-0.17) among outborn neonates (OR, 1.03; 95% CI, 0.98-1.09; P = .18). There was no difference in brain injury scores or white matter fractional anisotropy between the hypothermia and control groups among inborn or outborn neonates. Whole-body hypothermia was not associated with reductions in death or disability, either among 123 inborn neonates (hypothermia vs control group: 34 neonates [58.6%] vs 34 [56.7%]; risk ratio, 1.03; 95% CI, 0.76-1.41), or 285 outborn neonates (hypothermia vs control group: 64 neonates [46.7%] vs 60 [43.2%]; risk ratio, 1.08; 95% CI, 0.83-1.41). In this nested cohort study, whole-body hypothermia was not associated with reductions in brain injury after HIE among neonates in South Asia, irrespective of place of birth. These findings do not support the use of whole-body hypothermia for HIE among neonates in LMICs. ClinicalTrials.gov Identifier: NCT02387385.

A Rare Case of Rhombencephalitis after Covid-19 infection: A Case Report (P6-10.002)

<h3>Objective:</h3> COVID-19 has been associated with multiple neurological presentations. We present a unique case of rhombencephalitis secondary to COVID-19. <h3>Background:</h3> Rhombencephalitis, interchangeably used term brainstem-encephalitis is the inflammation of brainstem and cerebellum. Infectious, autoimmune, and paraneoplastic are common etiological categories. Listeria is the most common infectious cause. In this era of pandemic, COVID-19 has been reported as a cause of rhombencephalitis in 5 cases. <h3>Design/Methods:</h3> Case-report <h3>Results:</h3> A 62-year-old female with past medical history of recent COVID-19 infection, diabetes, B-12 deficiency, and breast cancer presented with nausea, blurry vision, and dysarthria. CT head and CTA head/neck were normal. MRI brain without contrast showed abnormal signal in the midbrain and pons. She was initially treated as suspected Wernicke’s with minimal improvement. Repeat MRI brain with contrast one week later showed progression of hyperintensity within the brainstem. She developed worsening encephalopathy, bilateral ptosis with ophthalmoplegia, dis-conjugate gaze, diminished left-sided sensation, and scanning dysarthria. She was treated with high dose steroids with minimal response. She continued to test positive for COVID-19 despite infection one month prior. Repeat MRI brain 2 weeks later showed continued progression of signal abnormality in brainstem and right cerebellum. MRI Spectroscopy showed reduced N-acetyl aspartate peak with elevated choline and creatinine peaks, inconsistent with malignancy. MRI of the spinal axis was normal. Lumbar puncture showed elevated protein and myelin basic protein. CSF NMO/AQ4-IgG, paraneoplastic, and autoimmune panel were negative. Given progression of symptoms, she underwent plasmapheresis with notable improvement overtime. She was eventually discharged to a rehab. <h3>Conclusions:</h3> Our case adds a post-infectious neurological-sequalae of the COVID-19 to the literature. One should be vigilant for such rare manifestation. In cases of possible COVID-19 related rhombencephalitis, early initiation of immunosuppressive treatment should be considered while excluding other infectious mimics to minimize the devastating complications. <b>Disclosure:</b> Dr. Zahra has nothing to disclose. Dr. Huang has nothing to disclose. Dr. Choudhary has nothing to disclose.

MR-spectroscopy in metachromatic leukodystrophy: A model free approach and clinical correlation

Background and purposeMetachromatic leukodystrophy (MLD) is a lysosomal enzyme deficiency disorder leading to demyelination and subsequently to a progressive decline in cognitive and motor function. It affects mainly white matter where changes during the course of the disease can be visualized on T2-weighted MRI as hyperintense areas. Associated changes in brain metabolism can be quantified by MR spectroscopy (MRS) and may give complementary information as biomarkers for disease characterisation and progression. Our study aimed to further investigate the correlation of MRS with clinical parameters for motor and cognitive function by using a model free MRS analysis approach that would be precise and straightforward to implement. Materials and methods53 MRS datasets derived from 29 patients (10 late-infantile, 19 juvenile) and 12 controls were acquired using a semi-LASER CSI sequence covering a slice through the centrum semiovale above the corpus callosum. We defined four regions of interest in the white matter (frontal white matter [FWM] and the cortico-spinal tract [CST] area, each left and right) and one in cortical grey matter. Spectra were analysed using a model and fitting free approach by calculating the definite integral of 10 intervals which were distributed along the whole spectrum. These 10 intervals were orientated towards the main peaks of the metabolites N-acetylaspartate (NAA), creatine, myo-inositol, choline, glutamine/glutamate and aspartate to approximately attribute changes in the intervals to corresponding metabolites. Their ratios to the main creatine peak integral were correlated with clinical parameters assessing motor and cognitive abilities. Furthermore, in a post-hoc analysis, NAA levels of a subset of 21 MR datasets were correlated to NAA levels in urine measured by 1H (proton) nuclear magnetic resonance (NMR) spectroscopy.The applied interval integration method was validated in the control cohort against the standard approach, using spectral profile templates of known metabolites (LCModel). Both methods showed good agreement, with coefficients of variance being slightly lower for our approach compared to the related LCModel results. Moreover, the new approach was able to extract information out of the frequency range around the main peaks of aspartate and glutamine where LCModel showed only few usable values for the respective metabolites. ResultsMLD spectra clearly differed from controls. The most pronounced differences were found in white matter (much less in grey matter), with larger values corresponding to main peaks of myo-inositol, choline and aspartate, and smaller values associated with NAA and glutamine. Late-infantile patients had more severe changes compared to later-onset patients, especially in intervals corresponding to NAA, aspartate, myo-inositol, choline and glutamine.There was a high correlation of several intervals in the corticospinal tract region with motor function (with the most relevant interval corresponding to NAA peak with a correlation coefficient of −0.75; p < 0.001), while cognitive function, by means of IQ, was found to be most correlating in frontal white matter corresponding to the NAA peak (r = 0.84, p < 0.001).The post-hoc analysis showed that the main NAA peak interval correlated negatively with the NAA in urine (r = −0.584, p < 0.001). ConclusionThe applied model and fitting free interval integration approach to analyse MRS data of a semi-LASER sequence at 3T suits well to detect and quantify pathological changes in MLD patients through the different courses of the disease and correlates well with clinical symptoms while showing smaller dimensions of variation compared to the more sophisticated single metabolite analysis using LCModel. NAA seems the most clinically meaningful biomarker to use in this context. Its correlation with urine measurements further underlines its potential as a clinically and biologically useful parameter of disease progression in MLD.

Progression of alternating hemiplegia of childhood‐related focal epilepsy to electrical status epilepticus in sleep with reversible encephalopathy

Mutations in the ATP1A3 gene (which encodes the main α subunit in neuronal Na+/K+-ATPases) cause various neurological syndromes including alternating hemiplegia of childhood. This rare disorder is characterized by paroxysmal episodes of hemiplegia, dystonia, oculomotor abnormalities, and occasionally developmental regression. Approximately 50% of alternating hemiplegia of childhood patients also have epilepsy, which is either focal or generalized. Seizures are often drug resistant. We report a 10-year-old girl with the D801N ATP1A3 mutation and alternating hemiplegia of childhood who manifested with drug-resistant focal seizures as an infant and throughout childhood. At the age of about10.5 years, her epilepsy evolved into electrical status epilepticus in sleep with generalized discharges. These changes coincided with developmental regression consistent with epileptic encephalopathy. Additionally, MRI and MR spectroscopy showed new cortical atrophy and markedly depressed N-acetyl aspartate peaks compared to previous normal studies. Electrical status epilepticus in sleep resolved after medication adjustments. She, now, only four months after her diagnosis of electrical status epilepticus in sleep, has regained most of the skills that were lost only a few months earlier. Our observations document that alternating hemiplegia of childhood can result in the above-described unique features; particularly, progression of focal epilepsy to electrical status epilepticus in sleep with generalized features and reversible epileptic encephalopathy.

Prof K C Dube Poster Award

BACKGROUNDRecent studies have shown altered N-Acetyl Aspartate (NAA) levels in the anterior cingulate cortex (ACC). Magnetic Resonance Spectroscopy (MRS) is a non-invasive method to examine the brain metabolites. In adult patients, most of the studies reported abnormalities in terms of decreased NAA levels in the ACC. Schizophrenia patients also show impaired performance on neurocognitive measures. These impairments are also seen in first episode patients.AIMS and OBJECTIVESThe purpose of the current study was to investigate the levels of NAA in the ACC along with neurocognitive deficits in patients of first episode schizophrenia, and if 6 weeks of usual treatment was able to produce any changes in the same.METHODOLOGY20 drug free or drug naïve patients of first episode schizophrenia and 10 healthy controls were taken. Single-voxel 1H-MRS was performed using the PRESS sequence with number of scans (NS) of 160, TR of 1500 ms and TE of 80 ms. Neurocognitive test was performed using Wisconsin Card Sorting test (WCST) and Montreal Cognitive Assessment (MoCA). Tests were repeated after 6 weeks of treatment. Statistical analysis was performed by SPSS 25.RESULTSThe peak height of NAA in the ACC and performance of the patients on the WCST and MoCA showed significant difference compared to healthy controls at baseline. The peak height of NAA in the ACC showed significant improvement after 6 weeks of treatment. Correlation studies showed significant positive correlation between MoCA total score and NAA height at baseline.DISCUSSION and CONCLUSIONThe study findings provide evidence in support of cognitive dysfunction in first episode schizophrenia, which is associated with neuronal loss, as evidenced by lower NAA peaks in the ACC in patients. The improvement in the metabolite levels after 6 weeks of antipsychotic treatment demonstrates neuroplastic effects of drug therapy.

Advanced Magnetic Resonance Imaging Findings of Multinodular and Vacuolating Neuronal Tumor.

To present the magnetic resonance imaging (MRI) findings of a multinodular and vacuolating neuronal tumor (MVNT). The authors identified four patients with MVNT in the hospital between January 2015 and October 2019. Both the clinical and radiological data of the patients were collected for analysis. Three patients complained of non-specific headaches. One patient had vertigo and imbalance. MRI sequences, including spectroscopy, perfusion, and DWI sequences, were retrospectively evaluated. The lesions were located in the subcortical and periventricular white matter of the parietal and temporal lobes, showed confluency, and comprised nodular pattern. The lesions appeared isointense to the cerebral cortex on T1 weighted imaging and hyperintense on T2 weighted and FLAIR sequences. None of the lesions showed diffusion restriction or contrast enhancement. Three of the lesions demonstrated a slight increase in choline peak and a slight decrease in N-acetyl aspartate peak. One lesion showed a noticeable increase in the Cho peak and a decrease in the NAA peak. Radiological features of MVNT are specific. Recognizing the MRI findings would help avoid unnecessary interventions in these patients, who are usually asymptomatic.

Usefulness of Magnetic Resonance Spectroscopy for the Initial Diagnosis of Mitochondrial DNA-Associated Leigh Syndrome

Purpose: Diagnosing Leigh syndrome (LS), a representative mitochondrial disease, remains challenging. Mitochondrial DNA (mtDNA)-associated LS, which is maternally inherited, has relatively well-known genetic variants. We evaluated the usefulness of brain magnetic resonance spectroscopy (MRS) for the initial diagnosis of mtDNA-associated LS using data from LS patients.Methods: The study involved LS patients who visited Gangnam Severance Hospital between 2006 and 2018. Based on patients’ clinical findings, genetic evaluations, brain magnetic resonance imaging, and brain MRS findings, 24 mtDNA-associated and 49 gene-negative LS patients were included in the current study. Lactate peaks and decreased N-acetyl aspartate (NAA) peaks in brain MRS were compared between both groups. Results: In total, 11 mtDNA mutation subtypes were detected. Our findings showed a higher proportion of brain MRS abnormalities in mtDNA-associated LS patients than in gene-negative LS patients, but no statistically significant differences were observed between the two groups (lactate peak, P=0.080; decreased NAA peak, P=0.115). Conclusion: Brain MRS is currently limited as an initial diagnostic test for mtDNA-associated LS. However, it may be a useful non-invasive test for the follow-up evaluation of mtDNA-associated LS treatment. Ultra-high-field MRS technology is expected in the future.

Canavan Disease: Clinical and Laboratory Profile from Southern Part of India.

Background:Canavan disease (CD) is an autosomal recessively inherited leukodystrophy. It affects one in 6,400 to 13,500 people in the Jewish population. However, prevalence and presentation of the disease in India is largely unknown; hence, we are reporting this series.Methods:This is a retrospective chart review in a tertiary care hospital from January 2015 to March 2020. CD was confirmed by elevated N- acetyl aspartate (NAA) levels in urinary gas chromatography and mass spectrometry (GCMS)/increased NAA peak in magnetic resonance spectroscopy (MRS) and/or detection of mutations. The data was extracted in a predesigned proforma and analyzed.Results:We had 12 children with mean age at presentation being 6.8 months (range 3 months to 10 months.). Males were more commonly affected (83.3%, n = 10). Ten children (83.3%) were born out of consanguineous parentage. All of them had visual impairment and pyramidal signs. Seizures were noted in five (42%) children. Normal head size in three (25%) and microcephaly in two (16.66%) cases were noted. Magnetic resonance imaging (MRI) revealed signal changes with bilateral symmetric T2W white matter (WM) hyperintensities in subcortical U fibers in all cases. MRS was done in ten children, all of which showed increased NAA peak. Increased level of NAA in urinary GCMS was noted in six out of eight children. Six cases had homozygous pathogenic variants in ASPA gene. Antenatal diagnosis helped in prevention of recurrence in three families.Conclusion:Urinary NAA and MRS showing NAA peak are useful in diagnosis of CD. Macrocephaly is not a necessary finding to diagnose CD. Early diagnosis helps in genetic counseling and prevention of subsequent conceptions.

Magnetic Resonance Spectroscopy for Prediction of Grades of Diffusely Infiltrating Intracranial Astrocytomas.

Abstarct Objective Gliomas, the most frequent primary brain tumors, have various grades, among which grade II, III, and IV are diffusely infiltrating astrocytomas. As therapeutic approaches and outcome differ considerably, depending on the grade of these tumors, prediction is important regarding outcome. Magnetic resonance spectroscopy (MRS) can be of help in understanding of the biochemical changes of pathological state to study, monitor, predict grading and outcome of gliomas. Materials and Methods All the 30 patients in the study with intracranial diffusely infiltrating astrocytoma had MRS study using 1.5 Tesla MR scanner. The study population was divided into three groups on the basis of the grades of the tumor according to histopathology. Mean height of choline (Ch), N-acetyl aspartate (NAA), creatine (Cr) peak, and choline/creatine (Ch/Cr) ratio was documented. Mean value of each variable among three grades was analyzed and compared with analysis of variance (ANOVA) test (F-test). Results There was positive relationship regarding Ch/Cr ratio among astrocytomas grade II to IV and the result was significant ( p = 0.047). A positive relationship of Ch peak was also observed for grade II to IV astrocytoma, though the result was not significant ( p = 0.578). The result was nonsignificant for NAA ( p = 0.696) and Cr ( p = 0.740) peak also. Conclusion We recommend Ch/Cr ratio to be considered as a dependable MRS data to comment on low- or high-grade astrocytomas. MRS can be done as a routine investigation in the developing countries for astrocytomas where other facilities are less accessible for reliable prediction and counseling.

Role of Magnetic Resonance Spectroscopy in the Evaluation of Ring Enhancing Lesions of the Brain

Introduction: The ring enhancing lesions of the brain are a challenging group of lesions with the variable possibilities of diagnosis under conventional Magnetic Resonance Imaging (MRI). Employing advanced techniques such as Magnetic Resonance Spectroscopy (MRS) could increase the success rates of the diagnosis. Aim: To assess the role of MRS in evaluating varying ring enhancing lesions of the brain. Materials and Methods: This prospective observational study involved 50 patients aged between 3-82 years who were detected with ring enhancing lesions of the brain on contrast MR studies. The patients underwent MRS evaluation. Categorical data was represented as frequency (%). The metabolite peaks of choline, lipid, lactate, N-Acetyl Aspartate (NAA), succinate and amino acids were recorded. The choline/creatine ratio was calculated and associated with the type of lesion the patients exhibited. Results: Among the 50 patients screened, the most prevalent pathologies were tuberculoma (36%) and neurocysticercosis (22%). While the patients diagnosed with tuberculoma presented with higher peak level of lipids and choline/creatine ratio of &gt;1-2. Increased lactate, succinate, choline peak concomitant with no or insignificant lipid peak, were noted in the cases of neurocysticercosis. Primary brain tumour showed high choline peaks and elevated choline/creatine ratio (&gt;2). Metastasis showed increased choline peak. Cerebral abscess showed increased amino acids and lactate peak. Conclusion: The diagnosis of varying ring enhancing lesions of the brain was accurately investigated by MRS. This accuracy enables delineating a treatment plan void of any dilemma.

Multicystic Encephalomalacia:Report of One Case

The magnetic resonance imaging findings of multicystic encephalomalacia are featured by bilateral frontal large cystic lesion with corpus callosum involvement,evident heterogeneous enhancement of the lesion margin,ring hyperintensity on diffusion weighted imaging,and high choline peak and low N-acetylaspartate peak of the enhanced lesion margin on magnetic resonance spectroscopy.This article reports a case of multicystic encephalomalacia.

The role of magnetic resonance spectroscopy in the differentiation of benign and malignant adnexal masses

BackgroundOvarian cancer is the seventh most common cancer diagnosis among women worldwide (Prat J, Int J Gynaecol Obstet 124:1–5, 2014) .Although magnetic resonance imaging has been proved to be accurate in characterizing adnexal masses (Pretorius E, et al. Top Magn Reson Imaging 12:131–46, 2001), it is still not conclusive in a considerable number of cases (Fujii S, et al. J Magn Reson Imaging 28:1149–1156, 2008, Thomassin-Naggara I, et al. Eur Radiol 19:1544–1552, 2009) .The aim of this study is to differentiate between benign and malignant adnexal tumors by MR spectroscopy.MethodsThis is a prospective study including 24 patients, with histopathologically proven adnexal masses. Single-voxel MR spectroscopy was performed on a 1.5-T MRI after localizing the mass by T2-weighted images. Analysis of choline, N-acetylaspartate, lactate, and lipid peaks were performed. Comparison between choline-to-creatine ratios of the benign and malignant masses was examined using receiver operating characteristic curve. Comparison between the choline-to-creatine ratios of primary and metastatic tumors was done using (ROC) curve.ResultsThe mean (± SD) choline-to-creatine ratio was 1.73 ± 3.16 in benign lesions versus 5.46 ± 3.91 in malignant lesions with statistically significant difference (p = 0.019). When the choline-to-creatine threshold was 3.6 for differentiating benign from malignant adnexal lesions, the sensitivity, specificity, positive predictive value, and negative predictive value were 69.2%, 90.9%, 90%, and 71.4% respectively. The ROC curve analysis of choline-to-creatine ratio yielded a threshold of 6 for differentiating primary from metastatic tumors, with a sensitivity, specificity, positive predictive value, and negative predictive value of 100%, 83%, 80%, and 100% respectively.ConclusionProton 1H-MR spectroscopy can help in differentiation between benign and malignant adnexal masses.

Proton MR spectroscopy and the detection of malignancy in ovarian masses.

To assess the impact of MR spectroscopy (MRS) on the detection of malignancy in ovarian masses. This prospective work included 230 females that had 245 adnexal/ovarian masses. Tumours were spotted by preliminary pelvic ultrasound. Masses assessed by MRI, multi- or single-voxel spectroscopy. Patients' spectra were assessed for peaks of lactate (Lac, 1.31 ppm), lipid (Lip, 1.33 ppm), N-acetyl aspartate (2.0 ppm), acetone (A, 2.05 ppm), choline (Cho, 3.23 ppm) and creatinine (Cr, 3.4 ppm) and the mean values of the (Cho/Cr) ratios were performed by a semi-quantitative approach. The operative pathology served as the standard of reference. Cho peak twofold higher than the average noise level was detected in 72% of the malignant and only 5.4% of the benign masses with an accuracy of 83%. Adding lactate to the choline enhanced the accuracy to 93%. The mean Cho/Cr ratios of the malignant ovarian masses (2.8) were significantly higher than that of the benign ones (1.2) . We used a receiver operating characteristic curve to determine the best cut-off value (1.7) for the mean Cho/Cr ratio to discriminate malignancy with sensitivity: 81.2%, specificity: 93.3 %, positive-predictive value: 92.9 %, negative-predictive value: 82.4% and accuracy: 87.1%. The simultaneous presence of choline and lactate peaks in MRS examination of the ovarian masses minimizes the overlap between benign and malignant categories. N-acetyl aspartate and acetone are the metabolites for diagnosing complex cystic masses as benign teratoma, endomterioma and tubo- ovarian abscess. MRS is a non-contrast based and fast MR sequence that gives an idea about tissue components could be used to improve the sensitivity and the accuracy of detecting malignancy in ovarian masses.

Ataxia with novel compound heterozygous PEX10 mutations and a literature review of PEX10-related peroxisome biogenesis disorders

ObjectivesTo describe the clinical and genetic features of a Chinese peroxisome biogenesis disorder 6B patient with PEX10 mutations and review PEX10–related peroxisomal disorders. Patients and methodsThe proband is a 7-year-old boy with mild mental retardation and gait instability, intention tremor and nystagmus. An extensive clinical and laboratory evaluation including molecular genetic studies was performed. Genomic DNA was extracted from peripheral blood using the standardized phenol/chloroform extraction method, and the coding region of the PEX10 gene was sequenced in three family members. ResultsCerebral MRI showed cerebellar atrophy. Magnetic resonance spectroscopy revealed a decreased N-acetyl aspartate peak in the cerebellum. Nerve conduction velocity examination found prolonged motor and sensory nerve potential latencies (proximal obvious), decreased potential amplitude, and slow nerve conduction velocity. Routine blood tests and biochemistries were abnormal. The PEX10 gene test showed compound heterozygous mutations (c.209 G > A, p. G70E and c.830 T > C, p. L277 P). The mutation c.830 T > C, p. L277 P has been previously reported, whereas c.209 G > A, p. G70E is novel. ConclusionWe identified an ataxia case of peroxisome biogenesis disorder 6B caused by novel compound heterozygous mutations of the PEX10 gene. Peroxisome biogenesis disorders should be considered in the differential diagnosis of autosomal recessive ataxia, especially cases with early onset.

Magnetic Resonance Imaging Features and Their Pathological Mechanisms of Hashimoto's Encephalopathy

Objective To analyze the routine and functional magnetic resonance imaging(MRI) features and their potential pathological mechanisms of Hashimoto's encephalopathy(HE). Methods The clinical data and routine and functional MRI images of 30 HE patients who were treated in our center from January 2010 to April 2017 were retrospectively reviewed. Among them,15 patients were examined with contrast-enhanced MRI,16 with diffusion-weighed imaging(DWI),8 with magnetic resonance angiography,2 with magnetic resonance spectroscopy,and 1 with both arterial spin labeled perfusion imaging and diffusion tensor imaging. Seven patients had consecutive clinical and imaging data. The distribution,MRI signals,and functional MRI features of HE were analyzed. Results Among 30 HE patients,routine MRI showed negative results in 8 cases and abnormal findings in 22 cases. Among 22 abnormal cases,9 were characterized by small cerebral vascular disease and 13 had non-specific abnormalities;of these 13 cases,12 had lesions mainly located at the supratentorial white matter,11 had multiple lesions,and 2 had lesions complicated with cerebellum atrophy. The lesions were focal or confluent,punctate or small patchy,showing abnormal signal intensity with iso-or hypo-intensity on T1-weighed imaging,hyper-intensity on both T2-weighed imaging and fluid-attenuated inversion recovery. Most of the lesions had no enhancement(12/15). Among 7 cases with abnormalities on DWI,hyper-intensity on DWI and hypo-intensity on apparent diffusion coefficient were seen in 3 sudden acute cases and hyper-intensity on DWI and increased apparent diffusion coefficient value in 4 sub-acute or slow onset cases. Three cases showed localized intracranial artery stenosis. In 2 cases,magnetic resonance spectroscopy revealed significant lower N-acetylaspartate peak,higher choline peak,and visible lactate peak or lipid peak. Of 7 cases with follow-up data,3 cases had no change,4 cases had changes including softening lesions(2/4),remitted and relapsed lesions(1/4),and rapid progression of brain atrophy with negative finding on the initial MRI(1/4). Conclusion Routine MRI combined with functional imaging can show the features of HE from different perspectives. Routine MRI shows multifocal or confluent lesions in the white matter,mostly without enhancement,while functional imaging may reveal pathological characteristics of different phases of acute or chronic ischemia and demyelinating changes of HE. Combined with clinical data,MRI can differentiate HE from other diseases based on routine and functional MRI appearances.

Involvement of Cerebellum in Leigh Syndrome: Case Report and Review of the Literature

BackgroundLeigh syndrome is an early-onset progressive neurodegenerative disorder typically involving lesions of the bilateral basal ganglia, thalami, and brainstem. Isolated involvement of the cerebellum is uncommon. Patient DescriptionWe present a six-year-old boy with Leigh syndrome who presented with recurrent episodes of ataxia and dysarthria. He was diagnosed with Leigh syndrome at two years of age with bilateral basal ganglia lesions on brain magnetic resonance imaging (MRI). Genetic testing confirmed a diagnosis of Leigh syndrome secondary to a homoplasmic mitochondrial DNA mutation (m.9176T>C). He experienced regressive episodes (ages five and six years). Each regressive episode had a similar presentation with worsening of baseline ataxia and dysarthria. The first episode mimicked infectious cerebellitis, with elevated cerebral spinal fluid (CSF) protein and white blood cell count. No organisms were isolated from the CSF/blood during any of the regressive episodes. Brain MRI consistently showed cerebellar lesions, however cerebellar spectroscopy during the second episode found an elevated lactate peak, a decrease of the N-acetylaspartate peak, and elevation of the choline peak; consistent with an acute exacerbation of Leigh syndrome. ConclusionsLeigh syndrome can present primarily with involvement of the cerebellum, and it should be considered in the differential diagnosis for acute cerebellitis