Hemispheric White Matter Research Articles

Thomas Semple

<b><i><i>Objective:</i></i></b> To determine whether edema can be assessed by MRI using T2-weighted signal intensity of hemispheric white matter in cirrhotic patients. <b><i><i>Methods:</i></i></b> Fast-FLAIR and magnetization transfer images were obtained before...

Prolonged survival to adulthood of an individual with hydranencephaly

Hydranencephaly is a rare condition in which the brain's cerebral hemispheres are absent. The outlook for children with hydranencephaly is generally poor, and many children with this disorder die during infancy. Although rare, patients with prolonged survival have been reported. A 22-year-old female patient was admitted to our hospital in a bedridden state for management of bedsores. The initial brain computed tomography showed complete replacement of the cerebral hemispheres with fluid and no cortical plate or hemispheric white matter. The bilateral brain stem, some of the left cerebellum, and the inferior frontal lobe were spared. Although certain behaviors were observed, such as eye opening in response to sound and painful stimuli, examination identified neither a definite awareness of the environment nor a meaningful action. To our knowledge, this is the longest survival of a patient with hydranencephaly in the world.

Diffusion tensor MRI abnormalities of hemispheric and callosal white matter in euthymic bipolar subjects with executive dysfunction

Diffusion tensor MRI abnormalities of hemispheric and callosal white matter in euthymic bipolar subjects with executive dysfunction

A Case of Panhypopituitarism and Central Diabetes Insipidus Caused by Primary Central Nervous System Lymphoma

Primary central nervous system (CNS) lymphoma is an uncommon neoplasm. However, the incidence of primary CNS lymphoma has increased more than 10-fold over the past three decades, and continues to accelerate. Currently, primary CNS lymphoma represents 4 to 7 percent of all newly diagnosed primary CNS tumors. Primary CNS lymphoma may arise from different parts of the brain, with deep hemispheric periventricular white matter being the most common site of origin. The presenting symptoms in primary CNS lymphoma vary depending on the location of the mass. Involvement of the hypothalamic-pituitary axis may cause hypopituitarism, diabetes insipidus, headache, diplopia, and blurred vision. We experienced a case of a 58-year-old woman who developed central diabetes insipidus and panhypopituitarism secondary to primary CNS lymphoma. Hypothalamic and thalamic involvement were suspected based on brain MRI, and primary CNS lymphoma was confirmed by a CT-guided stereotactic biopsy. Through performing a water deprivation test and a combined pituitary stimulation test, we diagnosed complete type central diabetes insipidus and panhypopituitarism. Symptomatic relief was obtained with desmopressin, levothyroxine, hydrocortisone, and high-dose methotrexate-based chemotherapy. The thalamic and hypothalamic masses were significantly decreased in size after chemotherapy. We report the details of this case along with a review of the literature concerning primary CNS lymphom (J Korean Endocr Soc 23:260~265, 2008)

The old and the new: supratentorial MR findings in Chiari II malformation

The objective of this study was to use magnetic resonance imaging to develop an improved morphological understanding of the abnormalities of the forebrain in Chiari II malformation. Seventy-four patients with Chiari II malformations investigated between 1999 and 2007 were enrolled. Imaging was retrospectively reviewed by two pediatric neuroradiologists, with special attention given to diencephalon, midline commissures, hemispheric white matter, and cortex. An abnormal gray matter structure that we called hypothalamic adhesion across the anterior-inferior portion of the third ventricle was noted in 48.6%. The anterior commissure was in a low position in the lamina terminalis in 38%. Gross abnormalities of the corpus callosum/hippocampal commissure were found in 57%; they were, however, different from the abnormalities seen in classical commissural agenesis. An abnormal bundle of white matter forming a callosal ridge was noted on the dorsal callosal surface in 60%; it is believed to represent the aberrant cingular bundle recently identified using diffusion tensor imaging. Hemispheric white matter could be considered as normal in 48%, deficient posteriorly in 55%, and globally in 10%. Cortical posterior medial stenogyria was observed in 72%. Gray matter heterotopias were found in 19%. The posterior limbic cortex was thin and dysplastic in 46%. Hippocampi were commonly abnormal (85%), with atypical sulcation of the adjacent temporo-mesial cortex (93%). Major structural abnormalities were common in Chiari II malformation and were probably not related to hydrocephalus. Important anatomical structures involved in neurocognitive function should be considered as factors in the prognostic assessment of Chiari II patients.

Diffusion Tensor Imaging of Spinocerebellar Ataxias Types 1 and 2

Structural MR imaging does not enable reliable differentiation of spinocerebellar ataxia (SCA) types 1 and 2 (SCA1 and SCA2), and imaging may be normal during the first years after the onset of symptoms. We aimed at determining whether measurements of the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) may enable their differentiation. We enrolled 14 patients with SCA1, 11 with SCA2, and 9 age-matched controls. Diffusion tensor imaging (DTI) was performed on a 1.5T scanner, with b = 1000s/mm2 and 12 directions. ADC and FA were measured by means of regions of interest, positioned in the corticospinal tract at the level of the cerebral peduncle and at the level of the pons, in the transverse pontine fibers, in the superior and middle cerebellar peduncle, and in the hemispheric cerebellar white matter. With respect to controls, the ADC was significantly elevated in the middle cerebellar peduncle and in hemispheric white matter in SCA1, and in all regions under consideration in SCA2. It was significantly higher in SCA2 than in SCA1 in all regions under consideration. With respect to controls, the FA was significantly reduced in all regions under consideration in SCA1 and in SCA2. It was significantly lower in SCA2 than in SCA1 in the transverse pontine fibers and in the corticospinal tract at the level of the cerebral peduncle. Correlations with clinical scores were found. DTI did not enable differentiation between SCA1 and SCA2. However, strongly significant differences between the 2 subtypes and with respect to controls and correlations with clinical scores were found.

Tremblement postural et ataxie révélant une prémutation X fragile ou syndrome FXTAS

We report a case of FXTAS in a 58-year-old man who presented with postural tremor, mild ataxia and dysexecutive cognitive signs. The syndrome had a slow progressive course. Brain imaging by MRI showed characteristic abnormalities with mild cerebellar atrophy, symmetric high signals in the middle cerebellar peduncles and in the subcortical white matter of cerebral hemispheres. The diagnosis was confirmed by molecular genetics showing by southern blot a 100-120 expansion repeat of the CGG trinucleotide. FXTAS is a recently described syndrome, still unknown by most neurologists and probably rather frequent in men older than 60. We emphasize the value of clinical evaluation and brain imaging by MRI in some patients presenting with non specific motor or cognitive symptoms. A diagnosis of FXTAS may have implications for genetic counselling of female relatives.

Acute Marchiafava-Bignami disease with callosal, cortical, and white matter involvement

Marchiafava-Bignami disease (MBD) is a rare complication of chronic alcoholism whose main pathology is symmetrical demyelination and necrosis of the corpus callous. The lesion may be found in hemispheric white matter, but the cortical involvement is extremely rare. We reported herein two cases of MBD with magnetic resonance (MR) findings, additional MR spectroscopy, and MR perfusion which revealed acute demyelination at the corpus callosum and symmetrical signal abnormality at cortical gray matter and hemispheric white matter.

Liver transplantion in a patient with rapid onset parkinsonism-dementia complex induced by manganism secondary to liver failure

Bilateral and symmetric globus-pallidus hyperintensities are observed on T1-weighted MRI in most of the patients with chronic liver failure, due to manganese accumulation. We report a 53-year-old man, with rapid onset parkinsonism-dementia complex associated with accumulation of manganese in the brain, secondary to liver failure. A brain MRI was performed and a high signal on T1-weighted images was seen on globus-pallidus, as well as on T2-weighted images on the hemispheric white-matter. He was referred to a liver-transplantation. The patient passed away on the seventh postoperative day. Our findings support the concept of the toxic effects of manganese on the globus-pallidus. The treatment of this form of parkinsonism is controversial and liver-transplantation should not be considered as first line treatment but as an alternative one.

Age‐related white matter lesions are associated with reduction of the apparent diffusion coefficient in the cerebellum

Cerebellar apparent diffusion coefficient (ADC) was found to be increased after acute cerebral hemispheric stroke. There are no data on cerebellar ADC changes in patients with chronic, age-related white matter lesions (ARWML). We aimed to determine longitudinal ADC variations on cerebral hemispheric and cerebellar white matter regions of patients with ARWML in order to study relations between ADC changes in both regions. ADC was measured serially (1-year interval) on lesioned periventricular frontal white matter, frontal and parietoccipital normal appearing white matter and middle cerebellar peduncles, on 19 aged patients with ARWML, which also underwent gait assessment. We compared regional ADC at 0 and 1 year and calculated variation percentages for each region. Correlation analysis was made between ADC variation in cerebellar regions and in contralateral hemispheric regions and between cerebellar ADC at 1 year and walking speed. After 1 year, ADC was higher on lesioned periventricular frontal white matter and lower on cerebellar regions. ADC variations on these regions were negatively correlated. Cerebellar ADC measured after 1 year was positively correlated with walking speed. This suggests a link between vascular disease progression inside frontal lesions and ADC reduction in contralateral cerebellar peduncles. Chronic ischemia in frontal white matter could have interrupted frontal-cerebellar circuits, producing hypometabolism in cerebellar regions (and worse performance on motor tasks), decreased perfusion and hence ADC reduction.

White Matter Volume as a Major Predictor of Cognitive Function in Sturge-Weber Syndrome

To assess the role of gray and white matter volume loss vs seizures in cognitive impairment of children with Sturge-Weber syndrome with unilateral involvement. Patients were enrolled in this prospective cohort during a period of 3 years. Pediatric neurology clinic with national referral through the Sturge-Weber Foundation. Twenty-one children (age range, 1 year 6 months to 10 years 4 months) with unilateral Sturge-Weber syndrome. Cortical gray matter and hemispheric white matter volumes were measured on segmented volumetric magnetic resonance imaging and correlated with the age of the participants. Global intellectual function (IQ) was correlated with magnetic resonance imaging and seizure variables in both univariate and multivariate analyses. Both gray and white matter volumes showed an age-related linear increase. Tissue volumes on the side of the angioma showed a positive correlation with IQ after controlling for age in univariate regression analyses (white matter, r = 0.71, P < .001; gray matter, r = 0.48, P = .03), while seizure variables did not correlate with IQ (P > .1). A multivariate regression showed that hemispheric white matter volume ipsilateral to the angioma was an independent predictor of IQ (R = 61, P = .006), which also showed a negative correlation with age (R = - 0.52, P = .022) but no correlation with gray matter volumes. Early hemispheric white matter loss may play a major role in cognitive impairment in children with Sturge-Weber syndrome. Future therapeutic approaches should aim at preserving white matter integrity in addition to seizure control to improve cognitive outcome.

PROGRESSIVE MEGALENCEPHALY DUE TO SPECIFIC EIF2Bε MUTATIONS IN TWO UNRELATED FAMILIES

We report four patients, from two unrelated families, affected by an infantile form of childhood ataxia with central hypomyelination syndrome1 or vanishing white matter disease2 (CACH/VWM) with large megalencephaly in the three children with a protracted disease course. #### Patient 1. A girl, born in 1990 from unrelated parents, presented two acute episodes of neurologic deterioration during viral infections at ages 10 and 14 months, followed by a progressive decline. Brain MRI showed severe white matter abnormalities. At age 3, a cerebral biopsy was performed and was complicated by a subdural hematoma that did not explain the persistence of an excessive head growth (figure, A and B). Neuropathologic analysis showed an increased oligodendrocyte density but no Rosenthal fibers. Head circumference (HC) reached 58 cm, and she died at age 8.5. Figure Patients 1, 2, and 4 (A and B) Patient 1. Sixteen months after the cerebral biopsy, CT scan (A) shows a right subdural hematoma with collapse of the right hemisphere but without mass effect on the left hemisphere; the left hemispheric white matter appears severely hypodense with swelling and seems to compress the cortex; ventricles are slightly enlarged (arrowheads: ependymal lining). The head circumference (HC) curve shows an increased growth velocity after the age 2 (B) (arrow: …

ADULT-ONSET VANISHING WHITE MATTER LEUKOENCEPHALOPATHY PRESENTING AS PSYCHOSIS

Childhood ataxia with CNS hypomyelination, also called leukoencephalopathy with vanishing white matter (CACH/VWM; OMIM 603896), is an autosomal recessive disease, defined by clinical and neuroradiologic features.1 After usually normal early development, patients aged between 2 and 5 years present with progressive cerebellar ataxia, spasticity, and a relatively mild mental impairment. Disease progression can be exacerbated during febrile illnesses or after head trauma, leading to death usually after 2 to 5 years of evolution. Since recent reports, disease severity seems to be correlated to age at disease onset.1 The most severe forms are the rapidly fatal congenital forms.1 In contrast, adult onset forms are recently recognized.1-6 Cerebral MRI findings in CACH/VWM are very characteristic, with a CSF-like diffuse signal of the cerebral hemispheric white matter. Neuropathologic studies reveal a cavitating orthochromatic leukodystrophy. CACH/VWM is caused by mutations within one of the five EIF2B genes.1 We report on one patient with adult-onset VWM revealed by isolated schizophrenia-like syndrome. This presentation expands the spectrum of phenotypes featuring CACH/VWM. ### Case report. A 32-year-old man with progressive behavioral changes was …

Pattern of Cortex and White Matter Involvement in Severe Middle Cerebral Artery Ischemia

In middle cerebral artery (MCA) stroke, ischemia usually is unevenly distributed within the MCA territory. We sought to investigate which brain structures are critical for the acute neurological deficit in severe MCA stroke. We used magnetic resonance (MR) imaging and statistical parametric mapping in 64 consecutive stroke patients (64 +/-13 years) to study the pattern of the initial perfusion abnormality. Patients with lesion progression had more severe time-to-peak (TTP) abnormalities (P < .0001) in the inferior frontal gyrus, superior temporal gyrus, insula, and underlying hemispheric white matter than those with lesion regression. Also, patients with lesion progression had more severe T2 abnormalities on day 8 than those with lesion regression. In contrast, the changes of water diffusion were similar among the two groups resulting in a perfusion-diffusion mismatch in lesion progression. TTP-lesions were related to the neurological deficit score (r(s)=-0.563, P < .0001), T2-lesions (r= 0.686, P < .0001), and cerebral artery abnormalities assessed on MR-angiography (r(s)= 0.399, P < .01). In major MCA, stroke ischemia was most severe in the central portion of the MCA territory. It is suggested that involvement of hemispheric white matter accentuated the neurological deficit probably by affecting cortico-cortical and cortico-subcortical fibers.

A Rare Case of Epilepsy in a 16-Year-Old Girl With Fallot Tetralogy Attributed to CNS Heterotopia and Pachygyria

Back to table of contents Previous article Next article LETTERFull AccessA Rare Case of Epilepsy in a 16-Year-Old Girl With Fallot Tetralogy Attributed to CNS Heterotopia and PachygyriaSmaragda Katsoulakou M.D.Argyro Kiamili M.D.Dimitris Karaiskos M.D.,Smaragda Katsoulakou M.D.Search for more papers by this authorArgyro Kiamili M.D.Search for more papers by this authorDimitris Karaiskos M.D.Search for more papers by this author,Published Online:1 Apr 2007AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail SIR : We report a case of a 16-year-old girl who was admitted to our clinic because of partial seizures. The clinical neurological examination and the neuropsychological tests were normal. The laboratory tests (i.e., CBC, blood biochemistry, urine tests, immunologic assay tests) were normal. The CSF analysis and cultures, as well as the CSF protein electrophoresis, were normal. Cerebral computed tomography (CT) was normal and ECG showed RBBB (right bundle branch block) and LAH (left anterior hemiblock). However, the EEG revealed abundant generalized slow wave activity with occasional focal and diffuse spikes and spike wave activity. The brain magnetic resonance imaging (MRI) scan revealed subcortical heterotopia of the gray matter extending across the right ventricle. More specifically, along the surface of the occipital horn of the right ventricle and at its posterior part as well as at the right temporal horn, there was an irregularly lobulated mass of gray matter that extended into the hemispheric white matter giving signals similar to the cerebral cortex. There were also similar signals of the cerebral cortex at the temporal horn of the left ventricle. The cortex overlying the heterotopia was abnormal, too. Pachygyria at the cortex of the right temporal parietal occipital area was identified. Both heterotopia and pachygyria which presented at the brain MRI of our patient may reflect possible anatomic epileptogenic areas. 1 The above conditions represent developmental abnormalities of the CNS caused by neuronal migration defects. The embryogenetic period when the above developmental abnormalities took place is estimated to be between the sixth and the seventh gestational week when Fallot tetralogy was developed. CommentThis is the first case report in the literature of comorbid CNS migration defect and Fallot tetralogy. The heart development defect allows us to not only estimate the possible embryogenetic period but also to raise suspicion for implication of the hypoxic blood supply of the defective heart in the etiology of the neuronal migration defect. Defective neuronal migration results in the formation of a disorganized cerebral cortex in which neurons are not normally connected with one another. 2 Neurons that failed to reach their destination at the cortex remain at subcortical positions and differentiate composing islands of mature nerve cells, resembling cortical neurons (subcortical band heterotopia) separated from the overlying cortex by an intervening band of white matter. The gyral pattern is also abnormal and is the basis for the morphologic classification of neuronal migration defects into lissencephaly, pachygyria, and polymicrogyria. Department of Neurology, Tzaneio General Hospital, Pireas, Greece

Repeated Transient Ischemic Attacks Due to Cavernous Sinus Meningiomas and Associated A1 Radiation-Induced Vasculopathy: Report of a Case

Stenosis and thrombosis of the cavernous ICA is well known in cavernous sinus meningiomas. Ischemic events following ICA thrombosis are rare because of the slow process of ICA stenosis and the progressive vascular supply provided by the circle of Willis. We report a case of a patient who developed repeated episodes of cerebral infarction due to left cavernous sinus meningiomas with ICA thrombosis and radiation-induced stenotic change of the left A1 segment. A 56-year-old woman with left intracavernous sinus meningiomas presented with a sudden onset of upper right arm paresis that recovered in 24 hours. She was treated 34 months prior to admission with fractionated stereotactic radiotherapy (50.4 Gy). The MRI size of the left cavernous sinus meningiomas was stable compared with the MRI performed before radiotherapy. However, a complete ICA thrombosis was detected. Several lacunar infarcts were identified in the left hemispheric white matter. Angiogram confirmed intracavernous ICA thrombosis and revealed isolated stenosis and irregularities of the left A1 segment immediately above the tumor, suggesting a radiation-induced vasculopathy. There was no filling of the posterior communicating artery. SPECT and measure of the vasoreactivity using perfusion of acetazolamide revealed a reduced perfusion capacity in the left hemisphere. The patient had no history or clinical or radiological signs of heart and vascular disease that could predispose to cerebrovascular disease. An EC-IC bypass between the left common carotid artery and the M2 segment of the left MCA using the radial artery was performed with good patient recovery.

Cerebellar Gray Matter Volume Correlates with Duration of Cocaine Use in Cocaine-Dependent Subjects

This study was conducted to explore differences in gray and white matter volume between cocaine-dependent and healthy comparison subjects using optimized voxel-based morphometry (VBM). Brain magnetic resonance imaging (MRI) and neuropsychological function tests were performed for 40 cocaine-dependent subjects (41.4+/-6.9 years, 27 men) and 41 healthy age- and sex-matched comparison subjects (38.7+/-8.8 years, 26 men). Optimally normalized whole brain MR images were segmented, modulated, smoothed, and compared between groups with statistical parametric mapping. The cocaine-dependent group had lower gray matter volumes in bilateral premotor cortex (Brodmann area (BA) 6, 8; 16.6%), right orbitofrontal cortex (BA 10, 15.1%), bilateral temporal cortex (BA 20, 38; 15.9%), left thalamus (12.6%), and bilateral cerebellum (13.4%) as well as lower right cerebellar white matter volume (10.0%) relative to the comparison group at a corrected p<0.05 for multiple comparisons. Duration of cocaine use negatively correlated with right and left cerebellar gray matter volumes (r=-0.37, r=-0.39, respectively). In cocaine-dependent subjects, lower cerebellar hemispheric gray and white matter volumes were correlated with deficits in executive function and decreased motor performance. This study reports that cocaine-dependent subjects have lower gray matter volumes in cerebellar hemispheres as well as in frontal, temporal cortex, and thalamus. These findings are the first to suggest that the cerebellum may be vulnerable to cocaine-associated brain volume changes, and that cerebellar deficits may contribute to neuropsychological deficits and motor dysfunction frequently observed in cocaine-dependent subjects.

From Progressive Nonfluent Aphasia to Corticobasal Syndrome: A Case Report of Corticobasal Degeneration

In a previous report, we presented longitudinal clinical, cognitive and anatomical data of a right-handed woman, whose clinical picture evolved from progressive nonfluent aphasia with apraxia of speech to corticobasal syndrome (CBS) in the last stage of the disease. The patient died at age 57 and pathological examination revealed severe atrophy in the left frontal operculum and left premotor area. On histological examination, there was diffuse tau-positive pathology in gray and white cortical hemispheric gray and white matter, basal ganglia and substantia nigra, compatible with corticobasal degeneration (CBD). This case demonstrates the clinical overlap between frontotemporal lobar degeneration and CBD. In this case, early motor speech impairment predicted earlier and more accurately than CBS the presence of underlying tau-pathology and CBD.

Plasma Proteins in Edematous White Matter after Intracerebral Hemorrhage Confound Immunoblots: An ELISA to Quantify Contamination

Intracerebral hemorrhage (ICH) and traumatic brain injury can induce brain tissue edema (i.e., interstitial and/or vasogenic), containing high concentrations of plasma proteins. To understand biochemical processes in edema development following these insults, it would be useful to examine alterations in various proteins (e.g., transcription factors, signaling). However, determining altered protein responses in edematous brain tissue using standard immunoblotting techniques is problematic due to contaminating plasma proteins. To solve this problem, we developed an enzyme-linked immunosorbent assay (ELISA) method to quantify the two major plasma proteins, albumin and immunoglobulin G (IgG), that comprise about 80% of the total plasma proteins. We tested our method on edematous white matter samples from our porcine ICH model. To induce ICH, we infused autologous arterial whole blood (3 mL) into frontal hemispheric white matter of pentobarbital- anesthetized pigs ( approximately 20 kg) over 15 min. We froze brains in situ at various times up to 24 h post- ICH and sampled white matter adjacent and contralateral to hematomas. We prepared cytoplasmic extracts that we subjected to ELISA and immunoblotting analyses. Our results demonstrate that this ELISA method is accurate, reproducible, and enables the concentrations of albumin and IgG in edematous brain tissue samples to be accurately determined. By using this correction method, equal amounts of cellular protein can be loaded onto gels during immunoblotting procedures. This method is applicable to edematous tissue samples in brain injury models in which high plasma protein concentrations result from interstitial or vasogenic edema development.

Anomalies of the Corpus Callosum: An MR Analysis of the Phenotypic Spectrum of Associated Malformations

We sought to categorize the structural brain anomalies associated with abnormalities of the corpus callosum and anterior and hippocampal commissures in a large cohort. Brain MR images of adult and pediatric patients from our institution and from a national support organization (the ACC Network) were retrospectively evaluated for the type and severity of commissural anomalies and the presence and type of other structural abnormalities. Of 142 cases that were reviewed, 82 patients had agenesis of the corpus callosum (ACC), while 60 had hypogenesis of the corpus callosum (HCC). Of the overall cohort, almost all had reduced white matter volume outside the commissures, the majority had malformations of cortical development (most commonly heterotopia or abnormal sulcation), many had noncallosal midline anomalies (including abnormal anterior or hippocampal commissures and interhemispheric cysts and lipomas), and several patients had abnormalities of the cerebellum or brainstem. Sixty-six patients had Probst bundles, which were more common in patients with ACC than in those with HCC. Probst bundles were present in all four patients who had ACC or HCC but no other midline, cortical, or posterior fossa anomalies. Isolated commissural anomalies were rare in the populations of patients examined. Most cases of ACC and HCC were associated with complex telencephalic, diencephalic, or rhombencephalic malformations. Reduced cerebral hemispheric white matter volume and malformations of cortical development were seen in more than half of the patients, suggesting that many commissural anomalies are part of an overall cerebral dysgenesis. ACC and HCC appear to lie along a dysgenetic spectrum, as opposed to representing distinct disorders.