Early Thrombectomy Protects the Internal Capsule in Patients With Proximal Middle Cerebral Artery Occlusion.

BACKGROUND AND PURPOSE: Proximal middle cerebral artery (MCA) occlusions impede blood flow to the noncollateralized lenticulostriate artery territory. Previous work has shown that this almost inevitably leads to infarction of the dependent gray matter territories in the striate even if perfusion is restored by mechanical thrombectomy. Purpose of this analysis was to evaluate potential sparing of neighboring fiber tracts, ie, the internal capsule. METHODS: An observational single-center study of patients with proximal MCA occlusions treated with mechanical thrombectomy and receiving postinterventional high-resolution diffusion-weighted imaging was conducted. Patients were classified according to internal capsule ischemia (IC+ versus IC-) at the postero-superior level of the MCA lenticulostriate artery territory (corticospinal tract correlate). Associations of IC+ versus IC- with baseline variables as well as its clinical impact were evaluated using multivariable logistic or linear regression analyses adjusting for potential confounders. RESULTS: Of 92 included patients with proximal MCA territory infarctions, 45 (48.9%) had an IC+ pattern. Longer time from symptom-onset to groin-puncture (adjusted odds ratio, 2.12 [95% CI, 1.19-3.76] per hour), female sex and more severe strokes were associated with IC+. Patients with IC+ had lower rates of substantial neurological improvement and functional independence (adjusted odds ratio, 0.26 [95% CI, 0.09-0.81] and adjusted odds ratio, 0.25 [95% CI, 0.07-0.86]) after adjustment for confounders. These associations remained unchanged when confining analyses to patients without ischemia in the corona radiata or the motor cortex and here, IC+ was associated with higher National Institutes of Health Stroke Scale motor item scores (ß, +2.8 [95% CI, 1.5 to 4.1]) without a significant increase in nonmotor items (ß, +0.8 [95% CI, -0.2 to 1.9). CONCLUSIONS: Rapid mechanical thrombectomy with successful reperfusion of the lenticulostriate arteries often protects the internal capsule from subsequent ischemia despite early basal ganglia damage. Salvage of this eloquent white matter tract within the MCA lenticulostriate artery territory seems strongly time-dependent, which has clinical and pathophysiological implications.

Acute motor deficit and subsequent remyelination-associated recovery following internal capsule demyelination in mice.

Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system (CNS), characterized by accumulated motor disability. However, whether remyelination promotes motor recovery following demyelinating injury remains unclear. Damage to the internal capsule (IC) is known to result in motor impairment in multiple sclerosis and stroke. Here, we induced focal IC demyelination in mice by lysophosphatidylcholine (LPC) injection, and examined its effect on motor behavior. We also compared the effect of LPC-induced IC damage to that produced by endothelin-1 (ET1), a potent vasoconstrictor used in experimental stroke lesions. We found that LPC or ET1 injections induced asymmetric motor deficit at 7 days post-lesion (dpl), and that both lesion types displayed increased microglia/macrophage density, myelin loss, and axonal dystrophy. The motor deficit and lesion pathology remained in ET1-injected mice at 28 dpl. In contrast, LPC-injected mice regained motor function by 28 dpl, with corresponding reduction in activated microglia/macrophage density, and recovery of myelin staining and axonal integrity in lesions. These results suggest that LPC-induced IC demyelination results in acute motor deficit and subsequent recovery through remyelination, and may be used to complement future drug screens to identify drugs for promoting remyelination.

A fixel-based analysis of micro- and macro-structural changes to white matter following adult traumatic brain injury.

Diffusion tensor imaging is often used to assess white matter (WM) changes following traumatic brain injury (TBI), but is limited in voxels that contain multiple fibre tracts. Fixel-based analysis (FBA) addresses this limitation by using a novel method of analysing high angular resolution diffusion-weighted imaging (HARDI) data. FBA examines three aspects of each fibre tract within a voxel: tissue micro-structure (fibre density [FD]), tissue macro-structure (fibre-bundle cross section [FC]) and a combined measure of both (FD and fibre-bundle cross section [FDC]). This study used FBA to identify the location and extent of micro- and macro-structural changes in WM following TBI. A large TBI sample (Nmild = 133, Nmoderate-severe = 29) and control group (healthy and orthopaedic; N = 107) underwent magnetic resonance imaging with HARDI and completed reaction time tasks approximately 7 months after their injury (range: 98-338 days). The TBI group showed micro-structural differences (lower FD) in the corpus callosum and forceps minor, compared to controls. Subgroup analyses revealed that the mild TBI group did not differ from controls on any fixel metric, but the moderate to severe TBI group had significantly lower FD, FC and FDC in multiple WM tracts, including the corpus callosum, cerebral peduncle, internal and external capsule. The moderate to severe TBI group also had significantly slower reaction times than controls, but the mild TBI group did not. Reaction time was not related to fixel findings. Thus, the WM damage caused by moderate to severe TBI manifested as fewer axons and a reduction in the cross-sectional area of key WM tracts.

Neuroimaging auditory verbal hallucinations in schizophrenia patient and healthy populations.

BACKGROUND: Auditory verbal hallucinations (AVH) are a cardinal feature of schizophrenia, but they can also appear in otherwise healthy individuals. Imaging studies implicate language networks in the generation of AVH; however, it remains unclear if alterations reflect biologic substrates of AVH, irrespective of diagnostic status, age, or illness-related factors. We applied multimodal imaging to identify AVH-specific pathology, evidenced by overlapping gray or white matter deficits between schizophrenia patients and healthy voice-hearers. METHODS: Diffusion-weighted and T1-weighted magnetic resonance images were acquired in 35 schizophrenia patients with AVH (SCZ-AVH), 32 healthy voice-hearers (H-AVH), and 40 age- and sex-matched controls without AVH. White matter fractional anisotropy (FA) and gray matter thickness (GMT) were computed for each region comprising ICBM-DTI and Desikan-Killiany atlases, respectively. Regions were tested for significant alterations affecting both SCZ-AVH and H-AVH groups, relative to controls. RESULTS: Compared with controls, the SCZ-AVH showed widespread FA and GMT reductions; but no significant differences emerged between H-AVH and control groups. While no overlapping pathology appeared in the overall study groups, younger (<40 years) H-AVH and SCZ-AVH subjects displayed overlapping FA deficits across four regions (p < 0.05): the genu and splenium of the corpus callosum, as well as the anterior limbs of the internal capsule. Analyzing these regions with free-water imaging ascribed overlapping FA abnormalities to tissue-specific anisotropy changes. CONCLUSIONS: We identified white matter pathology associated with the presence of AVH, independent of diagnostic status. However, commonalities were constrained to younger and more homogenous groups, after reducing pathologic variance associated with advancing age and chronicity effects.

Deficits of white matter axial diffusivity in bipolar disorder relative to major depressive disorder: No relationship to cerebral perfusion or body mass index.

OBJECTIVE: To compare white matter integrity (WMI) in bipolar disorder (BD) relative to healthy volunteers (HVs) and major depressive disorder (MDD). To determine the relationship of bipolar-specific differences in WMI to cerebral perfusion, body mass index (BMI), and blood pressure as indices of cardiovascular function. METHODS: Thirty-two participants with BD, 44 with MDD, and 41 HV were recruited. All BD and MDD participants were in a major depressive episode, and all but 12 BD participants were medication-free. 64-direction diffusion tensor imaging (DTI) and arterial spin labeling (ASL) sequences were obtained. Tract-based spatial statistics (TBSS) on four DTI indices were employed to distinguish patterns of DTI in BD relative to HV and MDD groups. BMI, blood pressure, and medical histories were also obtained for the BD participants. RESULTS: A cluster of lower axial diffusivity (AD) was found in BD participants in comparison to the HVs in the left posterior thalamic radiation, superior longitudinal fasciculus, inferior longitudinal fasciculus, fronto-occipital fasciculus, and internal capsule. Mean AD in the significant cluster was not associated with cerebral blood flow (CBF) in the region as measured by ASL, and was not associated with BMI or blood pressure. A cluster of lower AD was also found in the BD group when compared to MDD that had spatial overlap with the HV comparison. CONCLUSIONS: The results indicate a deficit of AD in BD when compared to MDD and HV groups. No association between AD values and either cerebral perfusion, BMI, or blood pressure was found in BD.

Repeated Sport-Related Concussion Shows Only Minimal White Matter Differences Many Years After Playing High School Football.

OBJECTIVE: Multiple concussions sustained in youth sport may be associated with later-life brain changes and worse cognitive outcomes. We examined the association between two or more concussions during high school football and later-life white matter (WM) microstructure (i.e., 22-47 years following football retirement) using diffusion tensor imaging (DTI). METHOD: Forty former high school football players aged 40-65 who received 2+ concussions during high school football (N = 20), or denied concussive events (N = 20) were recruited. Participants underwent neurocognitive testing and DTI scanning. RESULTS: Groups did not statistically differ on age, education, or estimated pre-morbid intelligence. Tract-based Spatial Statistics (TBSS) correcting for Family-Wise Error (FWE)(p < .05) did not yield differences between groups at the whole-brain level. Region of interest analyses showed higher mean diffusivity (MD) in the anterior limb of the internal capsule (ALIC) in the concussed group compared to the non-concussed former players. More liberal analyses (i.e., p < .001, uncorrected for multiple comparisons, ≥8 voxels) also revealed that former players endorsing 2+ concussions had higher MD in the ALIC. Analyses that covaried for age did not reveal differences at either threshold. Concussive histories were not associated with worse cognitive functioning, nor did it impact the relationship between neuropsychological scores and DTI metrics. DISCUSSION: Results suggest only minimal neuroanatomical brain differences in former athletes many years following original concussive injuries compared to controls.

Evaluation of changes in magnetic resonance diffusion tensor imaging after treatment of delayed encephalopathy due to carbon monoxide poisoning.

Diffusion tensor imaging of the brain tissue microstructure was performed to predict or diagnose the pathophysiological mechanism underlying delayed encephalopathy after carbon monoxide poisoning and the treatment effect was analyzed. The changes in the diffusion parameters (average diffusion coefficient and fractional anisotropy) in adult patients after hyperbaric oxygen therapy of delayed encephalopathy after carbon monoxide poisoning were not significant differences of the two lateral ventricles or anterior or posterior limb of the internal capsule. In the group exposed to hyperbaric oxygen therapy, the fractional anisotropy values of the white matter in the ventricles of the brain and anterior and posterior limbs of the internal capsule were higher than those recorded before therapy, while the average diffusion coefficient values were significantly lower. These finding provide important monitoring indicators for clinicians.

Serum insulin-like growth factor-I levels are associated with improved white matter recovery after traumatic brain injury.

OBJECTIVE: Traumatic brain injury (TBI) is a common disabling condition with limited treatment options. Diffusion tensor imaging measures recovery of axonal injury in white matter (WM) tracts after TBI. Growth hormone deficiency (GHD) after TBI may impair axonal and neuropsychological recovery, and serum insulin-like growth factor-I (IGF-I) may mediate this effect. We conducted a longitudinal study to determine the effects of baseline serum IGF-I concentrations on WM tract and neuropsychological recovery after TBI. METHODS: Thirty-nine adults after TBI (84.6% male, median age = 30.5 years, 87.2% moderate-severe, median time since TBI = 16.3 months, n = 4 with GHD) were scanned twice, 13.3 months (range = 12.1-14.9) apart, and 35 healthy controls were scanned once. Symptom and quality of life questionnaires and cognitive assessments were completed at both visits (n = 33). Our main outcome measure was fractional anisotropy (FA), a measure of WM tract integrity, in a priori regions of interest: splenium of corpus callosum (SPCC) and posterior limb of internal capsule (PLIC). RESULTS: At baseline, FA was reduced in many WM tracts including SPCC and PLIC following TBI compared to controls, indicating axonal injury, with longitudinal increases indicating axonal recovery. There was a significantly greater increase in SPCC FA over time in patients with serum IGF-I above versus below the median for age. Only the higher IGF-I group had significant improvements in immediate verbal memory recall over time. INTERPRETATION: WM recovery and memory improvements after TBI were greater in patients with higher serum IGF-I at baseline. These findings suggest that the growth hormone/IGF-I system may be a potential therapeutic target following TBI. Ann Neurol 2017;82:30-43.

Can we predict development of impulsive-compulsive behaviours in Parkinson's disease?

OBJECTIVE: To determine clinical and structural imaging predictors of impulsive-compulsive behaviour (ICB) in de novo Parkinson's disease (PD). METHODS: From a cohort of 1116 subjects from the Parkinson's Progression Marker Initiative database, we created a subcohort of 42 de novo PD without ICB at baseline with available 3T MRI and who developed ICB during follow-up. PD-ICB were matched for age, gender and disease duration to 42 patients with PD without ICB over follow-up (PD-no-ICB) and 42 healthy controls (HCs). Baseline demographic and clinical predictors of ICB were analysed. For the longitudinal neuroimaging analysis, we selected 27 patients with PD-ICB with available neuroimaging after ICB onset, who were matched with 32 PD-no-ICB and 35 HCs. Baseline and longitudinal structural differences were compared using voxel-based morphometry and voxel-based quantification. RESULTS: People who went on to develop ICB had more severe anxiety, worse autonomic and global cognitive functions and were more likely to have rapid eye movement sleep behaviour disorder. Logistic regression confirmed that worse autonomic and cognitive functions were predictors of ICB. We could not find any morphological feature on baseline MRI that predicted later onset of ICB. When comparing PD groups at follow-up, a small region of increased atrophy in the anterior limb of the left internal capsule adjacent to the head of the left caudate nucleus was found in PD-ICB, but not surviving correction for multiple comparisons. CONCLUSIONS: Worse autonomic and cognitive functions predict development of ICB at the time of PD diagnosis. Structural imaging fails to identify morphological features associated with the development of ICB.

Perioperative neonatal brain injury is associated with worse school-age neurodevelopment in children with critical congenital heart disease.

AIM: To assess the impact of perioperative neonatal brain injury and brain volumes on neurodevelopment throughout school-age children with critical congenital heart disease (CHD). METHOD: Thirty-four survivors of neonatal cardiac surgery (seven females, 27 males) were included. Neonatal preoperative and postoperative cerebral magnetic resonance imaging was performed and neurodevelopment was assessed at 24 months (SD 0.7, n=32, using Bayley Score of Infant and Toddler Development, Child Behavior Checklist) and 6 years (mean age 5y 11mo; SD 0.3, n=30, using Movement Assessment Battery for Children, Wechsler Preschool and Primary Scale of Intelligence, Child Behavior Checklist, Teacher Report Form). Brain injury, brain volumes, and cortical measures were related to outcome with adjustment for maternal educational level. RESULTS: Two-year cognitive score and 6-year Full-scale IQ were poorer in children with neonatal white matter injury (n=21, all p<0.05), with higher teacher-reported attention problems (p=0.03). Five of six children with involvement of the posterior limb of the internal capsule showed motor problems (p=0.03). Children with a below-average Fulll-scale IQ (<85, n=9) showed smaller volumes of basal ganglia thalami (-8%, p=0.03) and brain stem (-7%, p=0.03). INTERPRETATION: Our findings provide evidence of unfavourable outcome in school-age children with critical CHD who acquire perioperative neonatal brain injury. WHAT THIS PAPER ADDS: This paper extends knowledge about neonatal brain injury and long-term outcome in congenital heart disease. Children with white matter injury show lower IQ and more attention problems at school age. Injury of the posterior limb of the internal capsule increases the risk of motor problems. This study provides evidence for worse outcomes in neonates acquiring brain injury around cardiac surgery.

Anti-MOG antibody-positive ADEM following infectious mononucleosis due to a primary EBV infection: a case report.

BACKGROUND: Anti-Myelin oligodendrocyte glycoprotein (MOG) antibodies are detected in various demyelinating diseases, such as pediatric acute disseminated encephalomyelitis (ADEM), recurrent optic neuritis, and aquaporin-4 antibody-seronegative neuromyelitis optica spectrum disorder. We present a patient who developed anti-MOG antibody-positive ADEM following infectious mononucleosis (IM) due to Epstein-Barr virus (EBV) infection. CASE PRESENTATION: A 36-year-old healthy man developed paresthesia of bilateral lower extremities and urinary retention 8 days after the onset of IM due to primary EBV infection. The MRI revealed the lesions in the cervical spinal cord, the conus medullaris, and the internal capsule. An examination of the cerebrospinal fluid revealed pleocytosis. Cell-based immunoassays revealed positivity for anti-MOG antibody with a titer of 1:1024 and negativity for anti-aquaporin-4 antibody. His symptoms quickly improved after steroid pulse therapy followed by oral betamethasone. Anti-MOG antibody titer at the 6-month follow-up was negative. CONCLUSIONS: This case suggests that primary EBV infection would trigger anti-MOG antibody-positive ADEM. Adult ADEM patients can be positive for anti-MOG antibody, the titers of which correlate well with the neurological symptoms.

Neuropsychological characteristics of encephalopathy in Susac's Syndrome - Case report.

Susac's Syndrome (SS) is a rare, autoimmune angiopathy characterized by hearing loss, retinal artery occlusions and encephalopathy, which is usually expressed in multifocal neurological signs and symptoms, confusion state and cognitive impairment. There have been few descriptions of neuropsychological assessment of SS. We present a case study of 29-year-old woman who developed full SS. During the post-acute stage of disease, she was admitted to neurorehabilitation ward to improve her cognitive-behavioral and motor functioning. The initial assessment revealed attention, memory and executive dysfunctions, as well as behavioral changes including impulsivity, affective dysregulation and reduced self-awareness of disease deficits. After five weeks recovery process supported by rehabilitation program, improvement was observed, although some cognitive-behavioral deficits were still present in the follow-up assessment.

Gray and white matter trajectories in patients with bipolar disorder.

OBJECTIVES: Findings on brain structural abnormalities in patients with bipolar disorder (BP) are inconsistent and little is known about age-related evolution of these changes. We employed a cross-sectional, case-control study to compare structural age-related brain trajectories in patients with BP and healthy control subjects (HC) over a period of approximately 50 years. The primary aim was to understand whether white (WM) and gray matter (GM) abnormalities are present from the beginning of the illness and how they change over time. METHODS: Seventy-eight patients with BP and 78 HC matched for age, gender, and educational level underwent a high-resolution structural magnetic resonance imaging protocol. A voxel-based morphometry (VBM) analysis was used to capture GM and WM differences between subjects with BP and HC. Factorial analysis of covariance was used to compare brain volume alterations at different ages between the groups. RESULTS: We found an age-related atrophy in GM and WM volumes both in patients with BP and HC. A main effect of diagnosis emerged in the posterior cingulate cortex bilaterally, in the right thalamus, in the cerebellum bilaterally, and in the left posterior limb of the internal capsule. No interaction between diagnosis and age emerged, indicating that the volumes of these areas were permanently reduced in subjects with BP throughout the entire age range under investigation. CONCLUSIONS: Brain alterations in patients with BP are present from the beginning of the illness and remain stable over time. All the affected areas are involved in mood and psychomotor control process. This suggests a possible neurodevelopmental involvement in the mechanism of BP.

Regional white matter development in very preterm infants: perinatal predictors and early developmental outcomes.

BACKGROUND: Preterm infants are at risk for white matter (WM) injury and adverse neurodevelopmental outcomes. METHODS: Serial diffusion tensor magnetic resonance imaging data were obtained from very preterm infants (N = 78) born <30 wk gestation imaged up to four times from 26-42 wk postmenstrual age. Slopes were calculated for fractional anisotropy (FA) and mean diffusivity (MD) within regions of interest for infants with ≥2 scans (N = 50). Sixty-five children underwent neurodevelopmental testing at 2 y of age. RESULTS: FA slope for the posterior limb of the internal capsule was greater than other regions. The anterior limb of the internal capsule (ALIC), corpus callosum, and optic radiations demonstrated greater FA slope with increasing gestational age. Infants with patent ductus arteriosus had lower FA slope in the ALIC. MD slope was lower with prolonged ventilation or lack of antenatal steroids. At 2 y of age, lower motor scores were associated with lower FA in the left but higher FA in the right inferior temporal lobe at term-equivalent age. Better social-emotional competence was related to lower FA in the left cingulum bundle. CONCLUSION: This study demonstrates regional variability in the susceptibility/sensitivity of WM maturation to perinatal factors and relationships between altered diffusion measures and developmental outcomes in preterm neonates.

An olfactory groove schwannoma with a pseudocyst compressing the basal ganglia, internal capsule and optic tracts.

INTRODUCTION: Olfactory groove schwannomas (OGSs) are extremely rare tumours, particularly in the paediatric population. CASE REPORT: A 13-year-old girl presented with two epileptic seizures, papilloedema and incomplete binasal quadrantanopia. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a large heterogeneously enhancing tumour of the anterior skull base with a prominent dorsal pseudocyst. Interestingly, the pseudocyst embraced the right ICA bifurcation and displaced the optic tracts, optic chiasm and optic nerves and the ipsilateral basal ganglia. The patient underwent surgery via the frontolateral approach, and the tumour was completely removed. The pseudocyst was opened, and its wall was partially resected. It subsequently resolved completely. Histopathological examination yielded the rare diagnosis of schwannoma of the anterior skull base. CONCLUSION: Although extremely rare, olfactory groove schwannomas can be seen in paediatric patients. Our patient is the youngest ever reported with this histopathological diagnosis along with the formation of a large pseudocyst.

Dengue encephalitis with predominant cerebellar involvement: report of eight cases with MR and CT imaging features.

OBJECTIVES: CNS dengue infection is a rare condition and the pattern of brain involvement has not been well described. We report the MR imaging (MRI) features in eight cases of dengue encephalitis. MATERIALS AND METHODS: We retrospectively searched cases of dengue encephalitis in which imaging was performed. Eight cases (three men, five women; age range: 8-42 years) diagnosed with dengue encephalitis were included in the study. MR studies were performed on 3-T and 1.5-T MR clinical systems. Two neuroradiologists retrospectively reviewed the MR images and analysed the type of lesions, as well as their distribution and imaging features. RESULTS: All eight cases exhibited MRI abnormalities and the cerebellum was involved in all cases. In addition, MRI signal changes were also noted in the brainstem, thalamus, basal ganglia, internal capsule, insula, mesial temporal lobe, and cortical and cerebral white matter. Areas of susceptibility, diffusion restriction, and patchy post-contrast enhancement were the salient imaging features in our cohort of cases. CONCLUSION: A pattern of symmetrical cerebellar involvement and presence of microbleeds/haemorrhage may serve as a useful imaging marker and may help in the diagnosis of dengue encephalitis.

Deficits in tongue motor control are linked to microstructural brain damage in multiple sclerosis: a pilot study.

BACKGROUND: Deterioration of fine motor control of the tongue is common in Multiple Sclerosis (MS) and has a major impact on quality of life. However, the underlying neuronal substrate is largely unknown. Here, we aimed to explore the association of tongue motor dysfunction in MS patients with overall clinical disability and structural brain damage. METHODS: We employed a force transducer based quantitative-motor system (Q-Motor) to objectively assess tongue function in 33 patients with MS. The variability of tongue force output (TFV) and the mean applied tongue force (TF) were measured during an isometric tongue protrusion task. Twenty-three age and gender matched healthy volunteers served as controls. Correlation analyses of motor performance in MS patients with individual disease burden as expressed by the Expanded Disability Status Scale (EDSS) and with microstructural brain damage as measured by the fractional anisotropy (FA) on Diffusion Tensor Imaging were performed. RESULTS: MS patients showed significantly increased TFV and decreased TF compared to controls (p < 0.02). TFV but not TF was correlated with the EDSS (p < 0.04). TFV was inversely correlated with FA in the bilateral posterior limb of the internal capsule expanding to the brain stem (p < 0.001), a region critical to tongue function. TF showed a weaker, positive and unilateral correlation with FA in the same region (p < 0.001). CONCLUSIONS: Changes in TFV were more robust and correlated better with disease phenotype and FA changes than TF. TFV might serve as an objective and non-invasive outcome measure to augment the quantitative assessment of motor dysfunction in MS.

Application of diffusion tensor imaging in multiple system atrophy: the involvement of pontine transverse and longitudinal fibers.

PURPOSE: Many studies have demonstrated the degeneration of pontine transverse and longitudinal tracts in multiple system atrophy (MSA). One purpose of this study was to assess whether diffusion tensor imaging (DTI) can show microstructural abnormalities in these tracts in patients with MSA cerebellar type (MSA-C). Another purpose was to determine the correlation between cross sign progress and pontine fiber degeneration in these patients. MATERIALS AND METHODS: Thirty patients with MSA-C and 30 healthy volunteers underwent conventional magnetic resonance imaging (MRI) and DTI. Regions of interest were placed in both cerebral peduncles, the posterior limbs of the internal capsule and the pontine crossing tract of each subject. Quantitative indexes such as fractional anisotropy (FA) and mean diffusivity (MD) were compared between groups by analysis of variance. Cross sign was divided into three grades as follows: 0, no cross sign; 1, vertical line only; 2, clear cross sign. Spearman rank correlation analysis was used between FA, MD, and the cross grade in patients with MSA-C. RESULTS: FA and MD in the MSA-C group, and each cross grade, showed statistically significant differences compared to control groups. There was a close correlation between all measures. FA decreased and MD increased, and cross grade formed gradually in the patients. CONCLUSION: DTI can identify microstructural abnormalities in pontine transverse and longitudinal fibers even in patients without abnormalities on conventional MRI. Along with pontine transverse tract degeneration, the cross sign develops accompanied by the start of longitudinal tract degeneration, ultimately resulting in the complete formation of a cross sign.

Clinical and imaging features in different inner border-zone infarct patterns.

BACKGROUND AND PURPOSE: The clinical and imaging features of different inner border-zone infarct patterns, corona radiata (CR) and centrum semiovale (CSO), is not quiet clear. Both are mostly reported together in previous studies. We intended to observe their clinical and imaging features. METHOD: We observed 83 patients-47 cases with CR infarct lesion pattern and 36 cases with CSO. The lesion patterns were determined by diffusion-weighted imaging. Basic, clinical and radiologic features were compared between the patients with CR and CSO infarct lesion patterns. RESULTS: There was no significant difference between CR and CSO infarct patterns in terms of risk factors. However, patients with CR infarct had a higher initial National Institutes of Health Stroke Scale (NIHSS) score at admission (5.2 ± 2.3) than with CSO (3.9 ± 2.0, p = 0.009). Early clinical deterioration (OR, 2.42; 95% CI, 1.12-5.21; p = 0.024) and middle cerebral artery (MCA) stenosis (OR, 10.31; 95% CI, 3.30-32.19; p < 0.0001) were independently associated with the CR infarct lesion pattern. Partial infarct lesion shape (OR, 5.95; 95% CI, 1.40-25.33; p = 0.016) and internal carotid artery (ICA) stenosis (OR, 5.28; 95% CI, 1.92-14.51; p = 0.001) were independently correlated with the CSO infarct lesion pattern. CONCLUSIONS: Although CR and CSO infarct patterns might share common etiology and mechanisms, their clinical and imaging features are different.

Characteristics of Diffusion in the Corticospinal Tract of Patients with Early Stage of Schizophrenia: Diffusion Tensor Magnetic Resonance Imaging.

Specific features of diffusion in the cerebral corticospinal tract of patients with early stages of schizophrenia were studied using methods of diffusion tensor magnetic-resonance imaging and magnetic resonance spectroscopy. A decrease in the coefficient of fractional anisotropy in the posterior limb of the internal capsule and an increase in diffusion coefficient in the radiate crown and motor cortex were observed. The results reflect different mechanisms of changes in water diffusion in various areas of the corticospinal tract: changes in nerve fiber microstructure in the internal capsule of the left hemisphere and a decrease in their density in the motor cortex and radiate crown.