Parietal Lobe White Matter Research Articles

Cerebral Microstructural and Microvascular Changes in Non-Neuropsychiatric Systemic Lupus Erythematosus: A Study Using Diffusion Kurtosis Imaging and 3D Pseudo-Continuous Arterial Spin Labeling.

The purpose of this study was to observe cerebral microstructure and microcirculation features, as well as changes in white matter (WM) and gray matter (GM) among patients with non-neuropsychiatric systemic lupus erythematosus (non-NPSLE). We compared 36 female patients with non-NPSLE and 20 age- and gender-matched healthy controls (HCs) who underwent 3.0T MRI imaging with diffusion kurtosis imaging (DKI) and 3D pseudo-continuous Arterial Spin Labeling (pCASL). Mean kurtosis (MK), mean kurtosis tensor (MKT), and cerebral blood flow (CBF) values were obtained from 25 brain regions, including WM and GM. We analyzed the correlation between imaging indicators and clinical data. When compared with HCs, patients with non-NPSLE had reduced MK and MKT values in regional WM, deep GM, and the left frontal lobe cortical GM, and increased CBF in the right parietal lobe WM and right semioval center (SOC). The MK and MKT values were weakly correlated with CBF in some regions, including WM and GM. Complement 3 (C3) and Complement 4 (C4) showed a weak positive correlation with MK and MKT in some regions, including WM and deep GM, while platelet (PLT) was positively correlated with MKT in the left frontal lobe WM; dsDNA antibody was correlated negatively with MK in the right occipital lobe WM; and erythrocyte sedimentation rate (ESR) was correlated negatively with CBF in the left SOC. Our findings revealed the presence of brain microstructural and microvascular abnormalities in non-NPSLE patients, indicating microstructural damage in the cortical GM, which was less commonly reported. We found DKI and pCASL useful in detecting early brain lesions, and MK was a more sensitive and beneficial indicator.

71-year Old Male Patient with 20 Hour Onset of Infarct Stroke that was Performed with Intra-Arterial Thrombolysis, Mechanical Thrombectomy, Balloon Angioplasty, and Carotid Stenting: A Case Report

Introduction: For above 2 decades, the definitive management for acute ischemic stroke is intravenous or intra-arterial thrombolysis (IAT), using recombinant tissue-type plasminogen activator. Recently mechanical thrombectomy (MT) was developed to overcome the problem that intravenous thrombolysis is only effective in removing large artery occlusions in the range of 10-30%. Early treatment with intra-arterial thrombolysis, permanent stent insertion and clot extraction devices evolved into the stent-retriever device used in most of the important trials and, recently, emerged aspiration tool. This case report presented 71-year-old male patient with infarct stroke who performed with MT. Case presentation: This case report presented 71-year-old male patient with the main complaint of right limbs weakness. A non-contrast head CT scan found infarction in the cortical-subcortical left parietal lobe, posterior pericornu of the right lateral ventricle and right temporal cornu periventricular; lacunar infarction in the right and left paramedian pons; old lacunar infarction in the left and right centrum semiovale, left corona radiata, right internal capsule, right parietal lobe white matter, left lentiform nucleus, left posterior crus of the internal capsule-thalamus, right thalamus, right lateral ventricular pericornu and left paramedian pons. The patient underwent cerebral digital substraction angiography (DSA), as well as IAT, MT, balloon angioplasty, and carotid stenting with good clinical outcome. Conclusion: With the overwhelming positive results of studies evaluating the safety, efficiency, and efficacy of mechanical thrombectomy; the standard of care for the treatment of patients with anterior circulation vessel occlusion is becoming clear.

White matter hyperintensities in former American football players.

The presentation, risk factors, and etiologies of white matter hyperintensities (WMH) in people exposed to repetitive head impacts are unknown. We examined the burden and distribution of WMH, and their association with years of play, age of first exposure, and clinical function in former American football players. A total of 149 former football players and 53 asymptomatic unexposed participants (all men, 45-74 years) completed fluid-attenuated inversion recovery magnetic resonance imaging, neuropsychological testing, and self-report neuropsychiatric measures. Lesion Segmentation Toolbox estimated WMH. Analyses were performed in the total sample and stratified by age 60. In older but not younger participants, former football players had greater total, frontal, temporal, and parietal log-WMH compared to asymptomatic unexposed men. In older but not younger former football players, greater log-WMH was associated with younger age of first exposure to football and worse executive function. In older former football players, WMH may have unique presentations, risk factors, and etiologies. Older but not younger former football players had greater total, frontal, temporal, and parietal lobe white matter hyperintensities (WMH) compared to same-age asymptomatic unexposed men. Younger age of first exposure to football was associated with greater WMH in older but not younger former American football players. In former football players, greater WMH was associated with worse executive function and verbal memory.

Regional white matter hyperintensities in posterior cortical atrophy and logopenic progressive aphasia

White matter hyperintensities (WMH) are markers of cerebral small vessel disease and are associated with higher risk of typical amnestic Alzheimer's disease (tAD). Little is known about the frequency and distribution of WMH in atypical variants of AD, including logopenic progressive aphasia (LPA) and posterior cortical atrophy (PCA). We investigated WMHs in 75 LPA, 39 PCA, and 50 tAD patients and associations with age, beta-amyloid PET burden, and cognition. PCA had greater subcortical WMHs in right occipital, parietal, and temporal lobes compared to LPA, and greater parieto-occipital subcortical and occipital periventricular WMHs than tAD. LPA had greater subcortical WMHs in left parietal lobe and deep white matter WMHs than PCA, and greater fronto-occipital subcortical and occipital periventricular WMHs than tAD. Total WMH increased with increasing age but was not related to beta-amyloid burden. Greater WMH was associated with visuoperceptual performance in LPA and PCA after correcting for atrophy. WMH topography differs across AD variants. Further work is needed to determine whether they reflect cerebrovascular disease or regionally specific neurodegenerative changes.

A human calculator: a case report of a 27-year-old male with hypercalculia

ABSTRACT Calculation is one of the higher brain functions, which has been linked to the inferior parietal lobule and part of the frontal lobe. Cases of hypercalculia have been reported, usually in the setting of Autism-Spectrum Disorder or Savant syndrome. We report the case of a 27-year-old male undergraduate who had hypercalculia with normal clinical neurological findings. His brain MRI showed a nonspecific lesion in the right parietal lobe white matter. Further functional neuroimaging is suggested.

The impact of cerebrovascular disease on blood‐based biomarkers of Alzheimer’s disease

AbstractBackgroundThe development of ultrasensitive assays for blood‐based biomarkers may allow for detection of Alzheimer’s disease (AD)‐related pathology in large‐scale community‐based cohorts. We previously showed in the Washington Heights Inwood Columbia Aging Project (WHICAP) an association of plasma biomarker concentrations with clinical and pathological AD diagnosis, and that MRI markers of cerebrovascular disease, particularly parietal lobe white matter hyperintensities (WMH), increase the risk and progression of clinical AD. Here, we test the hypothesis that cerebrovascular disease has a direct impact on AD‐related pathology by examining the association of MRI markers of cerebrovascular disease and plasma biomarker concentrations in WHICAP.MethodAmong 300 WHICAP participants with available structural MRI (mean age 81.87+6.45 years, 67% women, 33.3% non‐Hispanic white, 33.3% African American, 33.3% Hispanic, 42% with cognitive impairment) we used SIMOA and MSD technology to measure plasma concentrations of Aβ42, Aβ40, ptau181, ptau217, total tau, and NfL from banked plasma samples. MRI scans were analyzed for regional WMH, presence of infarct, and presence of microbleeds. We first examined bivariate correlations between MRI cerebrovascular measures and plasma biomarker concentrations. For markers that were associated, we conducted demographically adjusted analyses and examined interactions with cognitive diagnostic status.ResultIncreased parietal lobe WMH, specifically, was associated with higher ptau181 (r=0.21, p=0.008) and ptau217 (r=0.13, p=0.05) concentrations. Increased WMH in frontal, temporal, and parietal regions was associated with increased NfL concentrations (rs=0.21‐0.25, ps<0.001‐0.002). Presence of one or more microbleed was associated with increased NfL (r=0.19, p=0.02). In adjusted models the associations of regional WMH with ptau181 and NfL concentrations were independent of and did not interact with diagnosis.ConclusionMarkers of small vessel cerebrovascular disease, particularly parietal lobe WMH, are associated with AD blood‐based biomarkers of phosphorylated tau pathology and neurodegeneration.

Presurgical language mapping in bilingual children using transcranial magnetic stimulation: illustrative case.

BACKGROUNDPresurgical mapping of eloquent cortex in young patients undergoing neurosurgery is critical but presents challenges unique to the pediatric population, including motion artifact, noncompliance, and sedation requirements. Furthermore, as bilingualism in children increases, functional mapping of more than one language is becoming increasingly critical. Transcranial magnetic stimulation (TMS), a noninvasive brain stimulation technique, is well suited to evaluate language areas in children since it does not require the patient to remain still during mapping.OBSERVATIONSA 13-year-old bilingual male with glioblastoma multiforme involving the left parietal lobe and deep occipital white matter underwent preoperative language mapping using magnetic resonance imaging-guided TMS. Language-specific cortices were successfully identified in both hemispheres. TMS findings aided in discussing with the family the risks of postsurgical deficits of tumor resection; postoperatively, the patient had intact bilingual speech and was referred for chemotherapy and radiation.LESSONSThe authors’ findings add to the evolving case for preoperative dual language mapping in bilingual neurosurgical candidates. The authors illustrate the feasibility and utility of TMS as a noninvasive functional mapping tool in this child. TMS is safe, effective, and can be used for preoperative mapping of language cortex in bilingual children to aid in surgical planning and discussion with families.

Frontal white matter lesions in Alzheimer\u2019s disease are associated with both small vessel disease and AD-associated cortical pathology

Cerebral white matter lesions (WML) encompass axonal loss and demyelination and are assumed to be associated with small vessel disease (SVD)-related ischaemia. However, our previous study in the parietal lobe white matter revealed that WML in Alzheimer’s disease (AD) are linked with degenerative axonal loss secondary to the deposition of cortical AD pathology. Furthermore, neuroimaging data suggest that pathomechanisms for the development of WML differ between anterior and posterior lobes with AD-associated degenerative mechanism driving posterior white matter disruption, and both AD-associated degenerative and vascular mechanisms contributed to anterior matter disruption. In this pilot study, we used human post-mortem brain tissue to investigate the composition and aetiology of frontal WML from AD and non-demented controls to determine if frontal WML are SVD-associated and to reveal any regional differences in the pathogenesis of WML. Frontal WML tissue sections from 40 human post-mortem brains (AD, n = 19; controls, n = 21) were quantitatively assessed for demyelination, axonal loss, cortical hyperphosphorylated tau (HPτ) and amyloid-beta (Aβ) burden, and arteriolosclerosis as a measure of SVD. Biochemical assessment included Wallerian degeneration-associated protease calpain and the myelin-associated glycoprotein to proteolipid protein ratio as a measure of ante-mortem ischaemia. Arteriolosclerosis severity was found to be associated with and a significant predictor of frontal WML severity in both AD and non-demented controls. Interesting, frontal axonal loss was also associated with HPτ and calpain levels were associated with increasing Aβ burden in the AD group, suggestive of an additional degenerative influence. To conclude, this pilot data suggest that frontal WML in AD may result from both increased arteriolosclerosis and AD-associated degenerative changes. These preliminary findings in combination with previously published data tentatively indicate regional differences in the aetiology of WML in AD, which should be considered in the clinical diagnosis of dementia subtypes: posterior WML maybe associated with degenerative mechanisms secondary to AD pathology, while anterior WML could be associated with both SVD-associated and degenerative mechanisms.

Lesions Responsible for Impaired Visual Perception in Poststroke Patients Using Voxel-Based Lesion Symptom Mapping.

We aimed to clarify the clinical characteristics that affect visual perception (VP) and elucidate lesion locations correlated with impaired VP. We reviewed 61 patients with stroke. Clinical assessments of a motor-free VP test were used to evaluate VP after stroke. Regression analyses were performed to examine predictors of impaired VP. We generated statistical maps of lesions related to impaired VP using voxel-based lesion symptom mapping (VLSM). The group of patients who had right hemispheric lesions had significantly low VP function. In a regression model, impaired VP was predicted by cognitive function, age, lesion volume, and right hemispheric lesion. Using VLSM, we found lesion location associated with impaired VP after adjusting for age, lesion volume, and Korean version of mini mental status exam. The results showed a lesion pattern with predominant distribution in the right parietal lobe and deep white matter. Age, lesion volume, and cognitive impairment affected the results of VP tests. Even after adjustments, we found that lesions responsible for impaired VP were located in the right parietal lobe and deep white matter. This result confirmed right hemispheric dominance for VP using VLSM. Clin. Anat. 32:689-696, 2019. © 2019 Wiley Periodicals, Inc.

Structural MRI research in patients with nasopharyngeal carcinoma following radiotherapy: A DTI and VBM study.

The aim of the present study was to investigate the microstructural characteristics of the brain lobes following radiotherapy (RT) for patients with nasopharyngeal carcinoma (NPC) at distinct times. Diffusion tensor imaging (DTI) and 3D-T1-weighted imaging was performed in 70 age- and sex-matched subjects, 24 of whom were pre-treatment patients. The patients were divided into three groups, according to the time following completion of RT. Fractional anisotropy (FA) and gray matter (GM) volume were determined. The DTI data were analyzed using tract-based spatial statistics and the GM volume was analyzed using voxel-based morphometry (VBM). Compared with the pre-RT group, the mean FA values in the left parietal lobe white matter (WM) and right cerebellum decreased significantly in the post-RT 0-6 month group (P<0.05). In addition, the mean FA values in the right parietal lobe WM decreased significantly in the post-RT 6-12 month group (P<0.05), compared with the pre-RT group. The FA level in the right temporal lobe remained significantly decreased, compared with that in the pre-RT group (P<0.05) for 1 year after RT. Furthermore, compared with pre-RT group, the GM volume in the bilateral frontal lobe, right occipital lobe, left parietal lobe, right temporal lobe and left cerebellum decreased significantly in the post-RT 0-6 month group (P<0.05), and in the bilateral temporal lobe, parietal lobe, right frontal lobe and left cerebellum, the GM volume decreased significantly in the post-RT 6-12 month group (P<0.05). The GM volume in the right temporal lobe, bilateral frontal lobe and bilateral cerebellum remained significantly decreased compared with that in the pre-RT group (P<0.05) for 1 year after RT. A combination of DTI and VBM may be used to determine radiation-induced brain injury in patients treated for NPC.

Longitudinal investigation of the parietal lobe anatomy in bipolar disorder and its association with general functioning

The parietal lobe (PL) supports cognitive domains, including attention and memory, which are impaired in bipolar disorder (BD). Although cross-sectional voxel-based morphometry studies found reduced PL grey matter (GM) in BD, none has longitudinally focused on PL anatomy in BD, relating it to patients’ functioning. Thirty-eight right-handed BD patients and 42 matched healthy subjects (HS) underwent a Magnetic Resonance Imaging (MRI) scan at baseline. Seventeen BD patients and 16 matched HS underwent a follow-up MRI. PL white matter (WM) and GM volumes were measured. The trajectory of parietal volumes over time and the possible relation with the global functioning were investigated in both BD patients and HS. At baseline, BD patients showed significant reduced PL WM and GM and different WM laterality compared with HS. Furthermore, smaller PL WM volumes predicted lower global functioning in BD, but not in HS. At follow-up, although BD patients reported reduced PL WM compared with HS, no different pattern of volume changes over time was detected between groups. This study suggests the involvement of the PL in the pathophysiology of BD. In particular, PL WM reductions seem to predict an impairment in general functioning in BD and might represent a marker of functional outcome.

A PROSPECTIVE STUDY OF CLINICAL PROFILE OF STROKE IN A TERTIARY CARE HOSPITAL

ABSTRACTObjective: The objective of the work was to study the clinical profile of stroke in a tertiary care hospital.Methods: A prospective observational study on stroke was carried out for a period of 6-month (May 2015 to October 2015). A total of 241 inpatientsfrom Shri Preethi Hospital were incorporated in the study. The data were collected and evaluated by reviewing case files and patient interview.Result and Conclusion: Out of 241 patients, an incidence of ischemic stroke was found to be higher. The occurrence of stroke steeply rises with agewith male predominance. The burden of stroke tends to be more in rural, illiterate, and low socioeconomic status population. The study reveals riskfactors such as sedentary lifestyle, previous and family history of stroke, underlying disease like hypertension, diabetes. The circadian pattern in onsetshowed a significant peak in morning (6 am-12 pm) for Ischemic and afternoon (12 pm-6 pm) for hemorrhagic stroke. Topographic distribution ofcerebral infract and hemorrhage was found to be in parietal lobe and periventricular white matter, respectively. Mostly prescribed medication forischemic and hemorrhagic patients was antihypertensive and mannitol, respectively. The contraindication for thrombolytic therapy was found to below economic status and average delay in time of presentation to hospital. The study highlights the need for aggressive management of traditionalrisk factors, need for extensive work up in patient to find etiologies and need for more active interventions in community for the prevention of stroke.Keywords: Ischemic, Hemorrhagic, Circadian pattern, Antihypertensive.

A study of diffusion tensor imaging in Duchenne muscular dystrophy

Objective To observe the white matter and gray matter impairment of Duchenne muscular dstrophy (DMD) patients with diffusion tensor imaging (DTI). Methods Forteen male patients with DMD (6-11 years old) and 10 age-matched healthy boys participated into this study. All patients' diagnosis was based on typical signs and symptoms, serum creatine kinase (CK), electromyography, multiplex ligation-dependent probe amplification (MLPA) for DMD gene test and muscle biopsy results. All participants were scanned by DTI. The fractional anisotropy (FA) values of regions of interest (ROIs), including bilateral parietal lobe white matter, bilateral frontal lobe white matter, genu of corpus callosum, splenium of corpus callosum, bilateral caput nuclei caudati, bilateral anterior cingulate gyrus, bilateral cingulate gyrus, bilateral posterior cingulate gyrus, bilateral lenticular nucleus, bilateral anterior limb of internal capsule, bilateral posterior limb of internal capsule, bilateral thalamus, bilateral occipital lobe whitematter, bilateral temporal lobe white matter, bilateral hippocampus, bilateral superior cerebellar peduncle and bilateral middle cerebellar peduncle, were measured. The data was analyzed and compared between control group and DMD group. Results Compared with control group, the FA value of splenium of corpuscallosum in DMD group was significantly reduced (t = -2.187, P = 0.045). No significant difference was found in FA values of other ROIs between 2 groups (P > 0.05, for all). Conclusions It is found in China for the first time that DMD patients had microstructural changes in splenium of corpus callosum. However, the correlation between this change and cognitive changes of DMD patients remains to be further studied. DOI: 10.3969/j.issn.1672-6731.2015.05.006

Atlas-based diffusion tensor imaging correlates of executive function.

Impairment in executive function (EF) is commonly found in Alzheimer's disease (AD) and mild cognitive impairment (MCI). Atlas-based diffusion tensor imaging (DTI) methods may be useful in relating regional integrity to EF measures in MCI and AD. Sixty-six participants (25 normal controls, 22 MCI, and 19 AD) received DTI scans and clinical evaluation. DTI scans were applied to a pre-segmented atlas and fractional anisotropy (FA) and mean diffusivity (MD) were calculated. ANOVA was used to assess group differences in frontal, parietal, and cerebellar regions. For regions differing between groups (p < 0.01), linear regression examined the relationship between EF scores and regional FA and MD. Anisotropy and diffusivity in frontal and parietal lobe white matter structures were associated with EF scores in MCI and only frontal lobe structures in AD. EF was more strongly associated with FA than MD. The relationship between EF and anisotropy and diffusivity was strongest in MCI. These results suggest that regional white matter integrity is compromised in MCI and AD and that FA may be a better correlate of EF than MD.

APOE ε4 and risk for Alzheimer's disease: Do regionally distributed white matter hyperintensities play a role?

BackgroundWe previously demonstrated that parietal lobe white matter hyperintensities (WMH) increase the risk for Alzheimer's disease (AD). Here, we examined whether individuals with apolipoprotein E gene (APOE ε4) have increased parietal WMH volume. MethodsParticipants were from the Washington Heights-Inwood Columbia Aging Project (WHICAP; n = 694, 47 with dementia) in northern Manhattan and the Etude Santé Psychologique Prévalence Risques et Traitement study (ESPRIT; n = 539, 8 with dementia) in Montpellier. The association between regional WMH and APOE ε4 was examined separately in each group and then in a combined analysis. ResultsIn WHICAP, ε4 carriers had higher WMH volume particularly in parietal and occipital lobes. In ESPRIT, ε4 carriers had elevated WMH particularly in parietal and temporal lobes. In the combined analysis, ε4 carriers had higher WMH in parietal and occipital lobes. Increased WMH volume was associated with increased frequency of dementia irrespective of APOE ε4 status; those with the ε4 were more likely to have dementia if they also had increased parietal WMH. ConclusionsAPOE ε4 is associated with increased parietal lobe WMH.

Metabolic Evidence for Cerebral Neurodegeneration in Spinocerebellar Ataxia Type 1

Autosomal-dominant spinocerebellar ataxia type 1 (SCA1) is an adult-onset progressive disorder with well-characterized neurodegeneration in the cerebellum and brainstem. The objective of this study is to evaluate neurochemical changes associated with neurodegeneration in cerebral tissue in SCA1 patients compared to age- and gender-matched healthy controls. Nine patients with genetically proven SCA1 and nine gender- and age-matched healthy controls were prospectively recruited from the ataxia clinic and received clinical examination. A 1.5 T single-voxel brain proton MR spectroscopy was performed for total N-acetyl aspartate (tNAA) in cerebellum, parietofrontal lobe white matter, sensory cortex, and visual cortex. In the patients, tNAA was severely decreased in the cerebellar voxel; however, in the voxels positioned in sensory cortex, parietofrontal lobe white matter and visual cortex tNAA was reduced in comparison to controls. In addition to the profoundly affected cerebellum, we also found evidence for cerebral neurodegeneration in parietal lobe white matter, sensory cortex, and visual cortex in SCA1 patients illustrating a multisystem neurodegenerative character of the disease.

Clinical and neuropathological findings in Hashimoto’s encephalopathy: a case report

Hashimoto’s encephalopathy (HE) is a controversial autoimmune condition of the central nervous system (CNS) characterized by focal and/or diffuse symptoms concomitant with raised levels of anti-thyroid antibodies, in particular anti-thyroperoxidase (TPO) and/or anti-thyroglobulin (TG) antibodies [1]. Hereby, we provide the full clinical and neuropathological description of an HE patient with a rapid and fatal course. A 67-year-old man with autoimmune hypothyroidism taking L-thyroxine 100 lg/day came to our observation because of 1-month history of apathy and speech difficulties. At admission in the neurological ward, fluent aphasia, disorientation, and spontaneous diffuse myoclonic jerks were present. Cranial CT and brain MRI were unremarkable. EEG evidenced rare diffuse theta-delta bursts. On laboratory investigations, we detected only a markedly raised titer of serum anti-TPO antibodies (3,790 UI/ml). CSF analysis disclosed very high protein concentration (126 mg/dL) with moderate alteration of blood–brain barrier permeability. Virological analyses were all negative. Total tau CSF concentration was normal, whereas the 14-33 protein was present in traces. To rule out a neurological paraneoplastic syndrome, the patient’s serum was analyzed by an indirect immunofluorescence assay on monkey cerebellum slides. We evidenced a Tr-like pattern, characterized by a prominent staining of cytoplasm and dendrites of Purkinje cells, but with no positive dots in the molecular layer (Fig. 1). No paraneoplastic antibody specificity (Hu, Yo, Ri, amphiphysin, Ma2, Ta) was detected by dot blot. Serum anti-VGKC and anti-NMDA-R antibodies were absent. A total body contrast-enhanced CT ruled out occult neoplasms. Given the subacute encephalopathy picture with no evident causes and the very raised serum titer of anti-TPO antibodies, a presumptive diagnosis of HE was made. A high-dose systemic methylprednisolone pulse (1,000 mg/ day) was started. After 5 days from steroid initiation, the patient was intubated and transferred to the intensive care unit (ICU) because of a refractory convulsive status epilepticus. Thiopentone was administered to get a suppression-burst pattern on EEG recordings. After 1 week the patient’s clinical conditions markedly ameliorated and no seizure relapses were observed. Therefore, he was readmitted to our neurologic ward. In the following 5 days, diffuse myoclonic jerks progressively increased, leading to convulsive status epilepticus. The patient entered again the ICU to employ intravenous thiopentone. A new brain MRI study evidenced diffuse hyperintensity of cortical white matter of parietal lobes in T2 and FLAIR scans with no contrast enhancement in T1 sequences. MRI signs of bilateral hippocampal sclerosis were also present. The patient’s neurologic status deteriorated in spite of a 10-day systemic methylprednisolone (1,000 mg/day) and 5-day intravenous human immunoglobulin pulse (400 mg/kg/ day). Exitus occurred from a multiorgan failure syndrome after 3 weeks. The autopsy procedure was limited to the intracranial content, since the remote suspect of a prion disease. On gross inspection, cortical gyri were slightly flattened. On microscopic examination, areas of neuropil vacuolation with congestion and swollen endothelial cells D. Imperiale (&) R. Testi A. Romito S. Taraglio Centro Regionale Diagnosi ed Osservazione Malattie Prioniche DOMP, ASL To2, Via Cibrario 72, 10144 Turin, Italy e-mail: daniele.imperiale@aslto2.piemonte.it

Diffusional kurtosis imaging of normal-appearing white matter in multiple sclerosis: preliminary clinical experience

We evaluated diffusional changes in normal-appearing white matter (NAWM) regions remote from multiple sclerosis (MS) plaques by using diffusional kurtosis imaging (DKI) to investigate the non-Gaussian behavior of water diffusion. Participants were 11 MS patients and 6 age-matched healthy volunteers. DKI was performed on a 3-T MR imager. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and diffusional kurtosis (DK) maps were computed. Regions of interest (ROIs) were compared in 24 cerebral regions, including the frontal, parietal, and temporal lobe white matter (WM) in controls and NAWM in MS patients. The mean FA of all ROIs was 0.468 ± 0.014 (SD) (controls) or 0.431 ± 0.029 (MS group) (P = 0.016). Mean ADC was 0.785 ± 0.034 × 10(-3) mm(2)/s (controls) or 0.805 ± 0.041 × 10(-3) mm(2)/s (MS group). The mean DK of all ROIs was 0.878 ± 0.020 (controls) or 0.823 ± 0.032 (MS group) (P = 0.002). Analysis of individual ROIs revealed significant differences in DK in 3 ROIs between normal WM and NAWM, but significant differences in ADC and FA in only one ROI each. DKI may be a new sensitive indicator for detecting tissue damage in MS patients in addition to conventional diffusional evaluations, for example diffusion tensor imaging.

White matter impairment in the basal ganglia-thalamocortical circuit of drug-naïve childhood absence epilepsy

It is unknown whether white matter abnormalities exist in childhood absence epilepsy (CAE), a syndrome of idiopathic epilepsy (IGE). Diffusion tensor imaging (DTI) can noninvasively quantify white matter integrity. This study used DTI to investigate abnormal changes in white matter of untreated CAE patients. Subjects included nine patients with untreated CAE and nine age-and sex-matched healthy controls. Diffusion tensor imaging parameters were voxel based and statistically compared between patients and controls. The correlations between DTI parameters in regions of interest (ROIs) and age of seizure onset or duration of epilepsy were analyzed. Untreated CAE patients had a significantly higher fractional anisotropy (FA) value in the bilateral thalamus, anterior corpus callosum and upper brainstem, while also displaying a lower FA value in prefrontal white matter, anterior cingulate, and bilateral posterior limbs of the internal capsule compared to control subjects. An increase in mean diffusivity (MD) value was observed in parietal lobe white matter, prefrontal white matter, and posterior cerebellar hemispheres, in addition to subcortical structures including bilateral putamen and posterior limb of internal capsule. MD significant correlations between ROI diffusion parameters and the duration of the disease or the age of onset. The results showed white matter integrity impairment in the basal ganglia-thalamocortical circuit of drug-naïve CAE patients. These abnormalities in white matter may be related to increased cortical excitability and cause cognitive, linguistic, and behavioral/emotional deficits both during and between seizures.

Experience-dependent plasticity in white matter microstructure: reasoning training alters structural connectivity

Diffusion tensor imaging (DTI) techniques have made it possible to investigate white matter plasticity in humans. Changes in DTI measures, principally increases in fractional anisotropy (FA), have been observed following training programs as diverse as juggling, meditation, and working memory. Here, we sought to test whether three months of reasoning training could alter white matter microstructure. We recruited participants (n = 23) who were enrolled in a course to prepare for the Law School Admission Test (LSAT), a test that places strong demands on reasoning skills, as well as age- and IQ-matched controls planning to take the LSAT in the future (n = 22). DTI data were collected at two scan sessions scheduled three months apart. In trained participants but not controls, we observed decreases in radial diffusivity (RD) in white matter connecting frontal cortices, and in mean diffusivity (MD) within frontal and parietal lobe white matter. Further, participants exhibiting larger gains on the LSAT exhibited greater decreases in MD in the right internal capsule. In summary, reasoning training altered multiple measures of white matter structure in young adults. While the cellular underpinnings are unknown, these results provide evidence of experience-dependent white matter changes that may not be limited to myelination.