Cerebral Diaschisis Research Articles

Цереброспінальний та комісуральний діашиз у пацієнтів iз гострим інсультом: аналіз клінічних випадків

Актуальність. Інсульт залишається другою основною причиною інвалідності та смертності з найвищими показниками захворюваності та летальності в країнах Східної Європі порівняно з Західною Європою та США. Раннє відновлення неврологічних функцій після інсульту пов’язане з реорганізацією в моторних і премоторних ділянках кори головного мозку та пояснюється феноменом діашизу. Проте на сьогодні опубліковано недостатньо проспективних досліджень щодо клінічного аналізу та порівняння різних варіантів церебрального діашизу, особливо в пацієнтів iз гострим ішемічним інсультом. Мета дослідження: динамічний аналіз клінічних проявів цереброспінального та коміссурального варіантів церебрального діашизу в пацієнтів iз гострим ішемічним інсультом на основі презентації клінічних випадків. Матеріали та методи. Ми провели проспективне госпітальне когортне дослідження хворих на гострий інсульт (n = 124), якi надійшли до відділення цереброваскулярних захворювань Університетської лікарні (Олександрівська клінічна лікарня, м. Київ, Україна) протягом перших 24 годин після розвитку інсульту. Під час госпіталізації всі пацієнти пройшли комплексне клініко­неврологічне, лабораторне, ультразвукове та нейровізуалізаційне обстеження. Результати. Серед 124 обстежених iз гострим інсультом церебральний діашиз було діагностовано в 26 пацієнтів (цереброспінальний (n = 22) та комісуральний (n = 4)). Ми провели детальний клінічний аналіз проявів мозкового діашизу. Описано специфічні неврологічні зміни за територіальних інфарктів мозку та дзеркальних інсультів, викликаних діашизом. Висновки. Семіотика гострого церебрального інсульту визначається не тільки первинним інфарктом мозку, але й діашизом, що обумовлює більш серйозний неврологічний дефіцит. Церебральний діашиз пов’язаний з розвитком дзеркальних інфарктів мозку, пригніченням сухожилкових та періостальних рефлексів, атонією м’язів кінцівок.

Diffusion Imaging of Cerebral Diaschisis in Neonatal Arterial Ischemic Stroke

BackgroundNeonatal arterial ischemic stroke is a leading cause of cerebral palsy and lifelong disability. Diffusion-weighted imaging has revolutionized diagnosis and facilitated outcome prognostication in acute neonatal arterial ischemic stroke. Diaschisis refers to changes in brain areas functionally connected but structurally remote from primary injury. We hypothesized that acute diffusion-weighted imaging can quantify cerebral diaschisis and is associated with outcome from neonatal arterial ischemic stroke. MethodsSubjects were identified from a prospective, population-based research cohort (Alberta Perinatal Stroke Project). Inclusion criteria were unilateral middle cerebral artery neonatal arterial ischemic stroke, diffusion-weighted magnetic resonance imaging within 10 days of birth, and more than 12-months follow-up (pediatric stroke outcome measure). Diaschisis was characterized and quantified using a validated software method (ImageJ). Volumetric analysis assessed atrophy of affected structures. Diaschisis scores were corrected for infarct size and compared with outcomes (Mann-Whitney). ResultsFrom 20 eligible neonatal arterial ischemic strokes, two were excluded for poor image quality. Of 18 remaining (61% male, median age 3.2 days), 16 (89%) demonstrated diaschisis. Thalamus (88%) was the most common location in addition to corpus callosum (50%). Age at imaging was not associated with diaschisis. Affected structures demonstrated atrophy on imaging. Long-term outcomes available in 81% (median age 7.5 years) were not associated with diaschisis scores. ConclusionsCerebral diaschisis occurs in neonatal arterial ischemic stroke and can be quantified with diffusion-weighted imaging. Occurrence is common and should not be mistaken for additional infarction. Determining clinical significance will require larger samples with well-characterized long-term outcomes.

Prognostic Implications of Total Hemispheric Glucose Metabolism Ratio in Cerebrocerebellar Diaschisis.

Diaschisis denotes brain dysfunction remote from a focal brain lesion. We have quantified diaschisis and investigated its prognostic value in glioma. Methods: We compared 50 18F-FDG PET/CT studies collected prospectively from 14 patients with supratentorial glioma (5 men and 9 women; age range, 35-77 y) with 10 single scans from healthy controls (age range, 43-75 y). Dedicated 3-dimensional segmentation software was used to obtain total hemispheric glucose metabolic ratios (THGr) by dividing total hemispheric 18F-FDG uptake in each diaschitic hemisphere-that is, the ipsilateral cerebral hemisphere (THGr(Ce)) and the contralateral cerebellar hemisphere (THGr(Cb))-by its respective contralateral side. Receiver-operating-characteristic (ROC) analysis was performed to determine optimal cut-offs for combinations of THGr(Ce) and THGr(Cb). Two independent observers obtained data for reproducibility analysis, and THGr values were compared with qualitative assessment of diaschisis performed by a PET neuroimaging specialist. Results: Qualitative analysis confirmed cerebrocerebellar diaschisis in all glioblastoma PET studies performed within 1 y of death. Healthy subjects had significantly higher THGr(Ce) values (P = 0.0007) and THGr(Cb) values (P = 0.02) than glioblastoma patients. ROC analysis yielded diaschisis thresholds of 0.62 for THGr(Ce) and 0.84 for THGr (Cb). Qualitative assessment demonstrated cerebral diaschisis in 16 of 17 (94%) cases with THGr(Ce) below the determined threshold and cerebellar diaschisis in 25 of 26 (96%) cases with THGr(Cb) below the determined threshold. When both THGr(Ce) and THGr(Cb) were below the ROC threshold, the combined diaschisis measures had a positive predictive value for survival below 1 y of 100%. When one parameter was below the threshold, it had a positive predictive value of 75%, and when both parameters exceeded thresholds, the negative predictive value for survival above 1 y was 79%. Median interrater variability was 3.3% and 5.9% for THGr(Ce) and THGr(Cb), respectively. Conclusion: The THGr measures demonstrated diaschisis in the cerebrum and cerebellum of patients with glioma. Combined cerebrocerebellar diaschisis ratios with ROC thresholds for both forebrain and hindbrain had high negative and positive predictive values for survival for less than a year. The THGr method allows comparison of data obtained at different institutions and is now open for further validation in gliomas and other cerebral diseases.

Diffusion imaging of cerebral diaschisis in childhood arterial ischemic stroke.

Diffusion-weighted imaging magnetic resonance imaging may detect changes in brain structures remote but connected to stroke consistent with neuropathological descriptions of diaschisis. Early diffusion-weighted imaging demonstrates restriction in corticospinal pathways after arterial ischemic stroke of all ages that correlates with motor outcome. We hypothesized that cerebral diaschisis is measurable in childhood arterial ischemic stroke and explored associations with outcome. This sub-study of the validation of the Pediatric NIH Stroke Scale study prospectively enrolled children with acute arterial ischemic stroke and both acute and early follow-up (5-14 days) diffusion-weighted imaging. Inclusion criteria were (1) unilateral middle cerebral artery arterial ischemic stroke, (2) acute and subacute diffusion-weighted imaging (b = 1000), and (3) 12 month neurological follow-up (Pediatric Stroke Outcome Measure). A validated method using ImageJ software quantified diffusion-weighted imaging diaschisis in anatomically connected structures. Diaschisis measures were corrected for infarct volume, compared to age, imaging timing, and outcomes (Chi square/Fisher, Mann-Whitney test). Nineteen children (53% male, median 8.1 years) had magnetic resonance imaging at medians of 21 and 168 h post-stroke onset. Diaschisis was common and evolved over time, observed in one (5%) on acute but eight (42%) by follow-up diffusion-weighted imaging. Thalamic and callosal diaschisis were most common (5, 26%). Estimates of perilesional diaschisis varied (54 ± 18% of infarct volume). Children with diaschisis tended to be younger (7.02 ± 5.4 vs. 11.82 ± 4.3 years, p = 0.08). Total diaschisis score was associated with poor cognitive outcomes (p = 0.03). Corticospinal tract diaschisis was associated with motor outcome (p = 0.004). Method reliability was excellent. Diffusion-weighted imaging diaschisis occurs in childhood arterial ischemic stroke. Mistaking diaschisis for new areas of infarction carries important clinical implications. Improved recognition and study are required to establish clinical relevance.

Thalamic neglect through mechanism of cerebral diaschisis in a patient with thalamic infarct

Thalamic neglect through mechanism of cerebral diaschisis in a patient with thalamic infarct

Arterial spin-labeling MR imaging of cerebral hemorrhages

The purpose of this study is to identify the characteristics of brain perfusion measured by arterial spin-labeling magnetic resonance imaging (ASL-MRI) in cerebral hemorrhages. Brain blood flow values (CBF-ASL values) for cerebral and cerebellar hemispheres and segmented cerebral regions were measured by ASL-MRI in 19 putaminal hemorrhage patients and 20 thalamic hemorrhage patients in acute or subacute stages. We assessed the lateralities of CBF-ASL values and the relationships between CBF-ASL values and other imaging findings and clinical manifestations. Both the 19 putaminal hemorrhage patients and the 20 thalamic hemorrhage patients had significantly low CBF-ASL values of the contralateral cerebellum in subacute stage, suggesting that ASL-MRI might delineate crossed cerebellar diaschisis (CCD). Ipsilateral low CBF-ASL values were observed in frontal lobes and thalami with a putaminal hemorrhage and lentiform nuclei, temporal lobes, and parietal lobes with a thalamic hemorrhage, suggesting that ASL-MRI showed the ipsilateral cerebral diaschisis (ICD). In the putaminal hemorrhage patients, the hematoma volume negatively affected both the bilateral cerebellar and cerebral hemispheric CBF-ASL values. In the thalamic hemorrhage patients, a concomitant intraventricular hemorrhage caused low cerebral hemispheric CBF-ASL values. The use of ASL-MRI is sensitive to the perfusion abnormalities and could thus be helpful to estimate functional abnormalities in cerebral hemorrhage patients.

Diffusion imaging of cerebral diaschisis in neonatal arterial ischemic stroke

Background: Neonatal arterial ischemic stroke (NAIS) is a leading cause of brain injury and cerebral palsy. Diffusion-weighted imaging (DWI) has revolutionized NAIS diagnosis and outcome prognostication. Diaschisis refers to changes in brain areas functionally connected but structurally remote from primary injury. We hypothesized that acute DWI can demonstrate cerebral diaschisis and evaluated associations with outcome. Methods: Subjects were identified from a prospective, population-based research cohort (Calgary Pediatric Stroke Program). Inclusion criteria were unilateral middle cerebral artery NAIS, DWI MRI within 10 days of birth, and >12-month follow-up (Pediatric Stroke Outcome Measure, PSOM). Diaschisis was quantified using a validated software method. Diaschisis-scores were corrected for infarct size and compared to outcomes (Mann-Whitney). Results: From 20 eligible NAIS, 2 were excluded for image quality. Of 18 remaining, 16 (89%) demonstrated diaschisis. Thalamus (88%) was most often involved. Age at imaging was not associated with diaschisis. Long-term outcomes available on 13 (81%) demonstrated no association between diaschisis score and PSOM categories. Conclusion: Cerebral diaschisis occurs in NAIS and can be quantified with DWI. Occurrence is common and should not be mistaken for additional infarction. Determining additional clinical significance will depend on larger samples with long-term outcomes.

Cognitive, linguistic and affective disturbances following a right superior cerebellar artery infarction: A case study

The cerebellar cognitive affective syndrome (CCAS) is a neurobehavioral syndrome that may develop after congenital and acquired cerebellar lesions. The syndrome consists of deficits in executive functioning, spatial cognition, visual–spatial memory and language and also involves personality and behavioral changes. We describe a 58-year-old right-handed man who in addition to affective disturbances presented with a unique combination of cognitive and linguistic deficits following an ischemic infarction in the vascular territory of the right superior cerebellar artery (SCA). Neurocognitive and neurolinguistic examinations were performed in the acute phase (10 days post-onset) and lesion phase (four weeks post-onset) of the stroke. A Tc-99m-ECD SPECT study was performed five weeks after the stroke. Acute phase data revealed a generalized cognitive decline and mild transcortical sensory aphasia. In the lesion phase, the neurobehavioral tableau was dominated by executive dysfunctions, disrupted divided attention, disturbed visual–spatial organization and behavioral abnormalities. Neurolinguistic investigations disclosed visual dyslexia and surface dysgraphia. Reading of words and visual lexical decision tasks of words and nonwords were severely defective and predominantly characterized by visual errors. In addition, writing irregular and ambiguous words resulted in regularization errors (phonologically plausible errors based on phoneme-grapheme correspondence rules). In the absence of any structural damage in the supratentorial brain regions, a quantified SPECT study showed a relative hypoperfusion in the right cerebellar hemisphere and the left medial frontal lobe. CCAS is for the first time reported in association with visual dyslexia and surface dysgraphia. We hypothesize that the cognitive and linguistic deficits might result from functional disruption of the cerebellar-encephalic pathways, connecting the cerebellum to the frontal supratentorial areas which subserve attentional and planning processes. This phenomenon of crossed cerebellar–cerebral diaschisis is supported by SPECT findings revealing a hypoperfusion in the anatomoclinically suspected brain regions. The constellation of cognitive, linguistic and behavioral symptoms adds new evidence to the multifaceted area of cerebellar neurocognition and demonstrates that the cerebellum might play a crucial role in cognitive, linguistic, and affective processing.

The Lateralized Linguistic Cerebellum: A Review and a New Hypothesis

During the past 2 decades the collaboration across disciplines and the methodologic and conceptual advances of contemporary neuroscience have brought about a substantial modification of the traditional view of the cerebellum as a mere coordinator of autonomic and somatic motor functions. Growing insights in the neuroanatomy of the cerebellum and its interconnections, evidence from functional neuroimaging and neurophysiological research, and advancements in clinical and experimental neuropsychology have established the view that the cerebellum participates in a much wider range of functions than conventionally accepted. This increase of insight has brought to the fore that the cerebellum modulates cognitive functioning of at least those parts of the brain to which it is reciprocally connected. This article reviews the recently acknowledged role of the cerebellum in cognition and addresses in more detail experimental and clinical data disclosing the modulatory role of the cerebellum in various non-motor language processes such as lexical retrieval, syntax, and language dynamics. In agreement with the findings indicating a topographical organization of the cerebellar structures involved in language pathology we advance the concept of a “lateralized linguistic cerebellum.” In our view crossed cerebral diaschisis processes, reflecting a functional depression of supratentorial language areas due to reduced input via cerebellocortical pathways, might represent the relevant pathomechanism for linguistic deficits associated with cerebellar pathology.

Hypertension and cerebrovascular diseases: a specific role of vascular protection for the prevention of dementia.

Despite the use of antihypertensive drugs, mortality (but not morbidity) from cerebrovascular diseases has been reduced significantly. As a consequence, an increasing number of patients suffer from recurring strokes and from the debilitating consequences of cerebrovascular diseases and develop progressive cognitive impairment. Its pathological substrates are regional alteration of cerebral perfusion, lacunae, white matter lesions, progressive cortical atrophy, even in the asymptomatic patient and in the absence of extracranial carotid artery stenosis. Lacunar infarction and white matter lesions are particularly frequent in the hypertensive diabetic patient. Lacunae and white matter lesions sometimes coexist and may favour the development of dementia in the hypertensive patient, through focal ischaemia, perivascular oedema, disruption of the blood-brain barrier, cerebral diaschisis and cortical deafferentation. Treatment with calcium channel blockers, angiotensin converting enzyme inhibitors and diuretics smooth the patchy hypoperfusion despite the fall in pressure. However, the time course and the extent of this effect vary according to the drug administered. In particular, only a calcium channel blocker increased perfusion of both cortical and subcortical areas, while diuretic treatment increased perfusion only after prolonged treatment, and this effect was limited to the cortical areas. Such differences may explain the discrepant results on risk reduction for dementia observed in large intervention trials.

Characterization of cerebral diaschisis post-stroke by rest and diamox rCBF brain SPECT and 4.1 T 1H spectroscopy imaging

Characterization of cerebral diaschisis post-stroke by rest and diamox rCBF brain SPECT and 4.1 T 1H spectroscopy imaging

Diaschisis and Neuropsychological Performance after Cerebellar Stroke

The cerebellum has been implicated in higher-order behavior. Blood flow studies (SPECT) have shown that cerebral diaschisis can appear after cerebellar lesions and this phenomenon could serve as a basis for a potential neuropsychological derangement after cerebellar insults. Our objectives in this study were to delineate the neuropsychological profile after cerebellar stroke, to evaluate cerebral diaschisis as measured by SPECT and to correlate the findings. We prospectively studied 26 patients with cerebellar stroke and 16 subjects matched for age, sex and educational level as a control group. A neuropsychological battery test, MRI and cerebral SPECT were performed in both groups. We found that cerebellar stroke results in motor control impairment and mild naming deficit, whereas no dysfunction in declarative memory, language, visuospatial or executive abilities is evident. The anatomical distribution of the lesion does not seem relevant in terms of neuropsychological impairment or diaschisis. Both ipsilateral and contralateral diaschisis as a result of a cerebellar stroke are found, but this phenomenon does not seem to result in overt neuropsychological derangement.

Bilateral simultaneous hypertensive intracerebral hemorrhages.

Bilateral simultaneous hypertensive intracerebral hemorrhages (HICH) are a rare occurrence. Computed tomography (CT) enables us to diagnose such a condition which is difficult to recognize clinically. In the series, six patients (2.6%) from a series of 553 HICH cases had suffered from simultaneous rehemorrhage in the contralateral hemisphere. It comprised four males and two females. Their ages ranged from 54 to 64 years with a mean age of 58 years. The clinical symptoms were excessively sever and were characterized by severe consciousness disturbance (semicoma to coma, 6 cases), aphasia (5 cases) and bilateral paresis (3 cases). CT density profiles were identical, implying that the hematomas were of similar age but located areas; two were bilateral basal ganglia, one was bilateral specular thalamus, pontine-ganglia (right), thalamo (left)-ganglia (right) and occipito (right)-thalamus (left) individually. All of the hematomas had ruptured into the ventricles. The predominant sites of hemorrhage were in the putamen (50%, 6/12) and the thalamus (33%, 4/12). Two patients received emergency craniotomy for evacuation of the hematomas. However, they died soon after the operations. In the remaining four non-surgical cases, two died of central failure, another died of pneumonia and the remain one survived but retained hemiplegia sequelae. The serious surgical results and outcome in bilateral HICH was compared that of unilateral HICH. Hemodynamically, poor cerebral blood flow and diaschisis phenomenon may contribute to the poor prognosis in these patients.

High Spatial Resolution Tc-99m HMPAO Brain SPECT in Cerebellar Embolic Infarction

Oblique Tc-99m HMPAO brain SPECT images of a 54-year-old man with brainstem and cerebellar infarcts are presented. Features of particular interest include the high spatial resolution, the embolic nature and the wedge-shaped appearance of the cerebellar infarct, and the presence of reversed cerebral diaschisis without neuropsychologic impairment

The Distribution of Radioiodine-Labeled N-Isopropyl-plodoamphetamine in Permanently Ischemic Brain of the Mongolian Gerbil

In a study of the distribution of N-isopropyl-p-131I-iodoamphetamine (IMP) in the permanently ischemic brain of 35 mongolian gerbils, the right common carotid artery was ligated under ether anesthesia. After given time intervals, 1.35 MBq (50 microCi) of IMP was injected into 17 gerbils which had severe neurological symptoms, and into 3 normal gerbils for controls. One minute there after each gerbil was sacrificed and brain autoradiography was performed. The activity of IMP in various parts of the brain was calculated from each autoradiogram. Low perfusion areas were observed in the right cerebral hemisphere and the brain stem (5-25% of normal value) from the first minute up to 24 h after ligation. In addition, low perfusion areas were also observed in the left cerebral hemisphere (40-60% of normal value) which represented a remote effect. These results suggest the usefulness of IMP for demonstrating cerebral ischemia and diaschisis.