Crossed cerebellar diaschisis in patients with acute middle cerebral artery infarction: Occurrence and perfusion characteristics

Prediction of motor outcome based on brain perfusion single photon emission computed tomography in corona radiata infarct

BACKGROUND

There is limited information on brain perfusion single-photon emission computed tomography (SPECT) findings related to motor outcomes in patients with stroke. We aimed to investigate whether brain SPECT can be used to determine motor outcomes after corona radiata infarction.

METHODS

Eighty-nine patients were recruited in this study. Brain SPECT and diffusion tensor tractography (DTT) were conducted to evaluate the state of the corticospinal tract (CST) within 7-30 days of corona radiata infarct. Motor outcome was measured 6 months after infarct onset and was evaluated using the modified Brunnstrom classification (MBC) and functional ambulation category (FAC) for motor function of the upper and lower extremities, respectively. The presence of hypoperfusion on brain SPECT was evaluated in the frontal lobe, temporal lobe, parietal lobe, basal ganglia, thalamus, and cerebellum on both the ipsilesional and contralesional sides. Statistical analysis was performed using multivariate logistic regression, comparing patients in which CST was spared versus interrupted.

RESULTS

Hypoperfusion in the contralesional cerebellum was indicative of poor recovery in both the upper and lower extremities after corona radiata infarction when the CST was interrupted. Additionally, when the CST was preserved, hypoperfusion in the ipsilesional thalamus was indicative of poor recovery of the lower extremities.

CONCLUSION

Brain SPECT evaluation was shown to be a useful tool for predicting motor outcomes in patients with corona radiata infarcts.

Crossed Cerebellar Diaschisis Worsens the Clinical Presentation in Acute Large Vessel Occlusion

INTRODUCTION

Initial NIHSS in anterior large vessel occlusion (LVO) correlates partially with the hypoperfusion volume. We aimed at assessing the contribution of crossed cerebellar diaschisis (CCD) from the hypoperfused territory on LVO initial clinical deficit.

METHODS

CCD was retrospectively identified by brain CT perfusion imaging (CTP) in patients with anterior LVO treated by mechanical thrombectomy from January 2017 to July 2021. CCD was defined by CTP parameter alteration in the contralateral cerebellar hemisphere to the LVO. NIHSS, clinical/perfusion variables, and CCD were included in regression models to assess their interrelationships.

RESULTS

206 patients were included. CCD was present in 90 patients (69%). NIHSS scores were higher on admission and at stroke discharge among patients with CCD (17.90 ± 6.1 vs. 11.4 ± 8.4, p < 0.001; 9.6 ± 7.7 vs. 6.6 ± 7.9, p = 0.049; respectively). Patients with a CCD had higher stroke volumes (118.2 ± 60.3 vs. 69.3 ± 59.7, p < 0.001) and lower rate of known atrial fibrillation (22% vs. 41%, p = 0.021). On multivariable logistic regression, CCD independently worsened the initial NIHSS (OR 4.85 [2.37-7.33]; p < 0.001).

CONCLUSION

CCD is found in 69% of LVO on admission CTP, correlates with stroke volumes, and independently worsens initial NIHSS.

Lateralization of the crossed cerebellar diaschisis-associated metabolic connectivities in cortico-ponto-cerebellar and cortico-rubral pathways

This study aimed to explore the glucose metabolic profile of extrapyramidal system in patients with crossed cerebellar diaschisis (CCD). Furthermore, the metabolic connectivities in cortico-ponto-cerebellar and cortico-rubral pathways associated with CCD were also investigated. A total of 130 CCD positive (CCD+) and 424 CCD negative (CCD-) patients with unilateral cerebral hemisphere hypometabolism on ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) were enrolled. Besides, the control group consisted of 56 subjects without any brain structural and metabolic abnormalities. Apart from the "autocorrelation", metabolic connectivity pattern of right or left affected cerebellar hemisphere involved unilateral (left or right, respectively) caudate, pallidum, putamen, thalamus and red nucleus, in CCD+ patients with left or right supratentorial lesions, respectively (P_uncorrected < 0.001, cluster size > 200). CCD+ group had significantly lower asymmetry index (AI) in cortico-ponto-cerebellar pathway (including ipsilateral cerebral white matter, ipsilateral pons, contralateral cerebellum white matter and contralateral cerebellum exterior cortex) and cortico-rubral pathway (including ipsilateral caudate, thalamus proper, pallidum, putamen, ventral diencephalon and red nucleus) than those of both CCD- and control groups (all P < 0.05). AI in contralateral cerebellum exterior cortex was significantly positively correlated with that in ipsilateral caudate, putamen, pallidum, thalamus proper, ventral diencephalon, red nucleus and pons among CCD+ group (all P < 0.01), but only with that in ipsilateral caudate and putamen among CCD- group (both P < 0.001). These results provide additional insight into the involvement of both cortico-ponto-cerebellar and cortico-rubral pathways in the presence of CCD, underlining the need for further investigation about the role of their aberrant metabolic connectivities in the associated symptoms of CCD.

Crossed cerebellar diaschisis-related supratentorial hemodynamic and metabolic status measured by PET/MR in assessing postoperative prognosis in chronic ischemic cerebrovascular disease patients with bypass surgery

Objective

Cerebral ischemic status is an indicator of bypass surgery. Both hemodynamics and glucose metabolism are significant factors for evaluating cerebral ischemic status. The occurrence of crossed cerebellar diaschisis (CCD) is influenced by the degree of supra-tentorial perfusion and glucose metabolism reduction. This study aimed to investigate the relationship between the CCD-related supra-tentorial blood flow and metabolic status before bypass surgery in patients with chronic and symptomatic ischemic cerebrovascular disease and the prognosis of surgery.

Methods

Twenty-four participants with chronic ischemic cerebrovascular disease who underwent hybrid positron emission tomography (PET)/magnetic resonance (MR) before bypass surgery were included. Arterial spin labeling (ASL)-MR and FDG-PET were used to measure blood flow and metabolism, respectively. The PET images were able to distinguish CCD. The supratentorial asymmetry index (AI) and volume in the decreased blood flow region, decreased metabolism region and co-decreased region on the affected side, except for the infarct area, were respectively obtained before bypass surgery. The neurological status was determined using the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores. Differences between CCD-positive (CCD +) and CCD-negative (CCD−) groups were investigated.

Results

Fourteen (58%) of the 24 patients were diagnosed as CCD +. Before surgery, the NIHSS and mRS scores of the CCD + were significantly higher than those of the CCD− (1.0(1.0) vs. 0.0(1.0), P = 0.013; 1.0(1.5) vs. 0.0(1.5), P = 0.048). After the surgery, the NIHSS and mRS scores of the CCD + showed a significant decrease (0.0(1.0) to 0.0(0.0), P = 0.011; 0.0(0.5) to 0.0(0.0), P = 0.008). Significant differences were observed in the supra-tentorial decreased metabolism region (all Ps ≤ 0.05) between the CCD + and CCD− groups, but no differences were observed in the preprocedural decreased supratentorial blood flow region (P > 0.05). The preprocedural NIHSS score was strongly correlated with the metabolism AI value in the decreased metabolism region (r = 0.621, P = 0.001) and the co-decreased region (r = 0.571, P = 0.004).

Conclusions

Supratentorial blood flow and metabolism are important indicators of CCD. This study showed that CCD + patients benefited more from bypass surgery than CCD− patients. Staging based on CCD-related supra-tentorial blood flow and metabolic status by hybrid PET/MR may help to personalize treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12149-022-01766-0.

Cortico-Cerebellar Connectivity Underlying Motor Control in Chronic Poststroke Individuals

The robust, reciprocal anatomic connections between the cerebellum and contralateral sensorimotor cerebral hemisphere underscore the strong physiological interdependence between these two regions in relation to human behavior. Previous studies have shown that damage to sensorimotor cortex can result in a lasting reduction of cerebellar metabolism, the magnitude of which has been linked to poor rehabilitative outcomes. A better understanding of movement-related cerebellar physiology as well as cortico-cerebellar coherence (CCC) in the chronic, poststroke state may be key to developing novel neuromodulatory techniques that promote upper limb motor rehabilitation. As a part of the first in-human phase I trial investigating the effects of deep brain stimulation of the cerebellar dentate nucleus (DN) on chronic poststroke motor rehabilitation, we collected invasive recordings from DN and scalp EEG in participants (both sexes) with middle cerebral artery stroke during a visuo-motor tracking task. We investigated the excitability of ipsilesional cortex, DN, and their interaction as a function of motor impairment and performance. Our results indicate the following: (1) event-related oscillations in the ipsilesional cortex and DN were significantly correlated at movement onset in the low beta band, with moderately and severely impaired participants showing desynchronization and synchronization, respectively; and (2) significant CCC was observed during the isometric hold period in the low beta band, which was critical for maintaining task accuracy. Our findings support a strong coupling between ipsilesional cortex and DN in the low beta band during motor control across all impairment levels, which encourages the exploitation of the cerebello-thalamo-cortical pathway as a neuromodulation target to promote rehabilitation.SIGNIFICANCE STATEMENT Cerebral infarct because of stroke can lead to lasting reduction in cerebellar metabolism, resulting in poor rehabilitative outcomes. Thorough investigation of the cerebellar electrophysiology, as well as cortico-cerebellar connectivity in humans that could provide key insights to facilitate the development of novel neuromodulatory technologies, has been lacking. As a part of the first in-human phase I trial investigating deep brain stimulation of the cerebellar dentate nucleus (DN) for chronic, poststroke motor rehabilitation, we collected invasive recordings from DN and scalp EEG while stroke survivors performed a motor task. Our data indicate strong coupling between ipsilesional sensorimotor cortex and DN in the low beta band across all impairment levels encouraging the exploration of electrical stimulation of the DN.

Preservation of Cerebellar Afferent Pathway May Be Related to Good Hand Function in Patients with Stroke

Many chronic stroke patients suffer from worsened hand function, and functional recovery of the hand does not occur well after six months of stroke. Therefore, predicting final hand function after stroke through acute phase imaging would be an important issue in counseling with the patients or their family. Thus, we investigated the remaining white matter integrity in the corticospinal tract (CST) and cortico-ponto-cerebellar tract (CPCT) at the acute stage of stroke and chronic hand function after stroke, and present the cut-off value of fiber number (FN) and fractional anisotropy (FA) of CST and CPCT at the acute stage for predicting final hand function after the recovery period. This retrospective case-control study included 18 stroke patients who were classified into two groups: poor hand function with stroke (n = 11) and good hand function with stroke (n = 7). DTI was done within two months ± 15 days after onset, and the Jebson’s Hand Function test was conducted 6–12 months after onset. The investigation of white matter was focused on the values of FN and FA for CST and CPCT, which were measured separately. The normalized (affected/non-affected) FA and FN values in the CPCT in the good hand function group were higher than those in the poor hand function group. The normalized FN and FA values in the CST were not significantly different between the poor hand function group and the good hand function group. The normalized cut-off value that distinguished the good hand function group from the poor hand function group was 0.8889 for FA in the CPCT. The integrity of the CPCT in the acute stage was associated with hand function in the chronic stage after a stroke. Ultimately, the integrity of the CPCT in the early stage after onset can be used to predict chronic hand function. Based on these results, cerebellar afferent fiber measurements may be a useful addition to predict hand function and plan specific rehabilitation strategies in stroke patients.

Voxel-based analysis of the metabolic asymmetrical and network patterns in hypermetabolism-associated crossed cerebellar diaschisis

Crossed cerebellar diaschisis (CCD) has been widely investigated in patients with supratentorial hypometabolism, however, the available evidence about the metabolic feature of CCD in patients with contralateral supratentorial hypermetabolism is lacking. This study aimed to assess the metabolic asymmetrical profile, network pattern and predisposing factors for the hypermetabolism-associated CCD, by using voxel-based asymmetry index (AI) and brain network analyses. Seventy CCD positive (CCD+) and 99 CCD negative (CCD-) patients with unilateral supratentorial hypermetabolism were introduced. Among different brain regions with AI_max or AI_min, striatum & thalamus was accompanied by the highest positive rate of CCD (85.7% or 70.1%, respectively). CCD+ group had significantly greater AI_max (median [IQR], 0.62 [0.44-0.84] vs. 0.47 [0.35-0.61]), supratentorial hypermetabolic volume (1183.5 [399.3-3026.8] vs. 386.0 [152.0-1193.0]) and hypometabolic volume (37796.5 [24741.8-53278.0] vs. 3337.0 [1020.0-17193.0]), and lower AI_min (-0.85 [-1.05--0.73] vs. -0.49 [-0.68--0.35]) compared with CCD- group (all P < 0.001). Logistic regression analysis manifested that patients with AI_min located at striatum & thalamus were 16.4 times more likely to present CCD than those at frontal lobe (OR = 16.393; 95% CI, 4.463-60.207; P < 0.001), and the occurrence of CCD was also associated with AI_max (OR = 49.594; 95% CI, 5.519-445.653; P < 0.001) and AI_min (OR = 3.133 × 10^-4, 95% CI, 1.693 × 10^-5-5.799 × 10^-3, P < 0.001). Brain network analysis indicated that the relative hypermetabolism in the contralateral supplementary motor cortex (SMC) and precuneus gyrus were constant in the CCD related patterns. These results demonstrated that the greater AI_max, lower AI_min and AI_min located at striatum & thalamus should be predisposing factors for CCD in patients with unilateral supratentorial hypermetabolism. Relative increased activities in the contralateral SMC and precuneus gyrus might be attributed to a compensatory mechanism for the abnormal brain network related to CCD.

A review of the natural history of Sturge-Weber syndrome through adulthood

BACKGROUND

Sturge-Weber syndrome (SWS) is a neurocutaneous disorder caused by a somatic mutation in the GNAQ gene, leading to capillary venous malformations with neurological, ocular, and cutaneous abnormalities. Descriptions of adult and elderly patients with SWS are scarce compared to those of neonates or children.

METHODS

We reviewed clinical, neuro-radiological and electroencephalographical findings of adult patients diagnosed with SWS, treated in our tertiary center for rare epilepsies.

RESULTS

Ten adult patients were identified with a median age of 48 years at inclusion. All patients had seizures, with features of temporal lobe involvement for five patients. One patient presented typical drug-resistant mesial temporal seizures with ipsilateral hippocampal sclerosis and leptomeningeal enhancement, and was treated surgically. Other patients presented typical neurological and brain imaging features found in SWS. One patient without visible leptomeningeal angioma or brain calcifications presented neurological symptoms (tonic-clonic generalized seizures) for the first time at the age of 56. Two of the oldest patients in our cohort with supratentorial leptomeningeal angioma displayed contralateral cerebellar atrophy, consistent with crossed cerebellar diaschisis. Over 70 years of follow-up data were available for one patient whose epilepsy started at the age of 6 months, offering a vast overview of the course of SWS, in particular the onset of dementia and contralateral micro-bleeds in relation to the leptomeningeal angioma.

CONCLUSION

The long follow-up of our cohort allows for a description of the course of SWS and a characterization of uncommon neurological features in adult and elderly patients.

AIM2 inflammasome mediates apoptotic and pyroptotic death in the cerebellum following chronic hypoperfusion

Vascular dementia (VaD) is the second most common form of dementia and is caused by vascular pathologies resulting in chronic cerebral hypoperfusion (CCH)- induced brain injury, and ultimately cognitive impairment and memory loss. Several lines of evidence have demonstrated chronic inflammation may be involved in VaD disease progression. It is now recognized that a major contributor to cerebral and systemic chronic inflammation involves the activation of innate immune molecular complexes termed inflammasomes. Whilst previous studies on animal models of VaD have focused on the cortex, hippocampus and striatum, few studies have investigated the effect of CCH on the cerebellum. Emerging studies have found new roles of the cerebellum in cognition, based on its structural interconnectivity with other brain regions and clinical relevance in neuropsychological deficits. In the present study, we conducted our investigation on the cerebellum using a CCH mouse model of VaD following bilateral common carotid artery stenosis (BCAS). This study is the first to characterize an increased expression of inflammasome receptors, adaptor and effector proteins, markers of inflammasome activation, proinflammatory cytokines, and apoptotic and pyroptotic cell death proteins in the cerebellum following CCH. Furthermore, in AIM2 knockout mice, we observed attenuated inflammasome-mediated production of proinflammatory cytokines, apoptosis, and pyroptosis in the cerebellum following CCH. Collectively, our findings provide novel evidence that AIM2 inflammasome activation promotes apoptosis and pyroptosis in the cerebellum following chronic hypoperfusion in a mouse model of VaD.

Crossed cerebellar diaschisis on 18F-FDG PET: Frequency across neurodegenerative syndromes and association with 11C-PIB and 18F-Flortaucipir

We used 18F-FDG-PET to investigate the frequency of crossed cerebellar diaschisis (CCD) in 197 patients with various syndromes associated with neurodegenerative diseases. In a subset of 117 patients, we studied relationships between CCD and cortical asymmetry of Alzheimer's pathology (β-amyloid (11C-PIB) and tau (18F-Flortaucipir)). PET images were processed using MRIs to derive parametric SUVR images and define regions of interest. Indices of asymmetry were calculated in the cerebral cortex, basal ganglia and cerebellar cortex. Across all patients, cerebellar 18F-FDG asymmetry was associated with reverse asymmetry of 18F-FDG in the cerebral cortex (especially frontal and parietal areas) and basal ganglia. Based on our operational definition (cerebellar asymmetry >3% with contralateral supratentorial hypometabolism), significant CCD was present in 47/197 (24%) patients and was most frequent in corticobasal syndrome and semantic and logopenic variants of primary progressive aphasia. In β-amyloid-positive patients, mediation analyses showed that 18F-Flortaucipir cortical asymmetry was associated with cerebellar 18F-FDG asymmetry, but that cortical 18F-FDG asymmetry mediated this relationship. Analysis of 18F-FDG-SUVR values suggested that CCD might also occur in the absence of frank cerebellar 18F-FDG asymmetry due to symmetrical supratentorial degeneration resulting in a bilateral diaschisis process.

Cerebellar Mutism Syndrome: An Overview of the Pathophysiology in Relation to the Cerebrocerebellar Anatomy, Risk Factors, Potential Treatments, and Outcomes

Cerebellar mutism syndrome (CMS) is one the most disabling postoperative neurological complications after posterior fossa surgery in children. CMS is characterized by a transient mutism with a typical onset demonstrated within 2 days postoperatively accompanied by associated ataxia, hypotonia, and irritability. Several hypotheses for the anatomical basis of pathophysiology and risk factors have been suggested. However, a definitive theory and treatment protocols have not yet been determined. Animal histological and electrophysiological studies and more recent human imaging studies have demonstrated the existence of a compartmentalized representation of cerebellar function, the understanding of which might provide more information on the pathophysiology. Damage to the dentatothalamocortical pathway and cerebrocerebellar diaschisis have been described as the anatomical substrate to the CMS. The risk factors, which include tumor type, brainstem invasion, tumor localization, tumor size, and vermal splitting technique, have not yet been clearly elucidated. The efficacy of potential pharmacological and speech therapies has been studied in small trials. Long-term motor speech deficits and associated cognitive and behavioral disturbances have now been found to be common among CMS survivors, affecting their development and requiring rehabilitation, leading to significant financial effects on the healthcare system and distress to the family. The aim of the present review was to outline the cerebellar anatomy and function and its connections in relationship to the pathophysiology and to refine the risk factors and treatment strategies for CMS.

Characterizing Diaschisis-Related Thalamic Perfusion and Diffusion After Middle Cerebral Artery Infarction

[Figure: see text].

Indirect Structural Connectivity Identifies Changes in Brain Networks After Stroke

Background/Purpose: The purpose of this study was (1) to identify changes in structural connectivity after stroke and (2) to relate changes in indirect connectivity to post-stroke impairment. Methods: A novel measure of indirect connectivity was implemented to assess the impact of stroke on brain connectivity. Probabilistic tractography was performed on 13 chronic stroke and 16 control participants to estimate connectivity between gray matter (GM) regions. The Fugl-Meyer assessment of motor impairment was measured for stroke participants. Network measures of direct and indirect connectivity were calculated, and these measures were linearly combined with measures of white matter integrity to predict motor impairment. Results: We found significantly reduced indirect connectivity in the frontal and parietal lobes, ipsilesional subcortical regions, and bilateral cerebellum after stroke. When added to the regression analysis, the volume of GM with reduced indirect connectivity significantly improved the correlation between image parameters and upper extremity motor impairment (R² = 0.71, p < 0.05). Conclusion: This study provides evidence of changes in indirect connectivity in regions remote from the lesion, particularly in the cerebellum and regions in the fronto-parietal cortices, and these changes correlate with upper extremity motor impairment. These results highlight the value of using measures of indirect connectivity to identify the effect of stroke on brain networks. Impact statement Changes in indirect structural connectivity occur in regions distant from a lesion after stroke, highlighting the impact that stroke has on brain functional networks. Specifically, losses in indirect structural connectivity occur in hubs with high centrality, including the fronto-parietal cortices and cerebellum. These losses in indirect connectivity more accurately reflect motor impairments than measures of direct structural connectivity. As a consequence, indirect structural connectivity appears to be important to recovery after stroke and imaging biomarkers that incorporate indirect structural connectivity might improve prognostication of stroke outcomes.

Novel quantitative approach for crossed cerebellar diaschisis detection in acute ischemic stroke using CT perfusion

PURPOSE

Crossed cerebellar diaschisis (CCD) is a common finding in hyper-acute ischemic stroke, related to supratentorial dysfunction of the contralateral hemisphere. Several studies investigated a possible relationship between CCD and clinical outcomes but still no evidence emerged. We proposed a novel quantitative whole cerebellum analysis using CT perfusion (CTP) imaging to investigate the relationship between CCD and stroke severity, hypoperfused volume and outcome measures.

METHODS

55 patients with supratentorial ischemic stroke who underwent CTP evaluation within 4.5 h since symptom onset were enrolled. CCD was evaluated by CTP image-processing and by calculating the mean transit time (MTT)-map asymmetry index in the whole cerebellum. MTT asymmetry correlation with ischemic volume and clinical outcomes was investigated.

RESULTS

MTT asymmetry was found in most of the included patients and significantly correlated with NIH Stroke Scale (NIHSS) score at baseline and CTP ischemic volume. MTT asymmetry was significantly correlated with hemorrhagic transformation, NIHSS and modified Rankin Scale (mRS) score on discharge in treated patients.

CONCLUSIONS

CCD was detectable by CTP in acute supratentorial ischemic stroke by processing the whole cerebellum volume. CCD perfusion asymmetry was significantly correlated with neurological and perfusion deficit on admission as well as with clinical outcomes in treated patients.

Diaschisis revisited: quantitative evaluation of thalamic hypoperfusion in anterior circulation stroke

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CT perfusion reveals thalamic hypoperfusion in acute anterior circulation stroke.

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This indirect phenomenon is referred to as ipsilateral thalamic diaschisis (ITD).

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Quantitative analysis indicates that ITD is a non-binary phenomenon.

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ITD is associated with lesion extent and involvement of the lentiform nucleus.

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Stroke outcome was not associated with ITD parameters.

Purpose

Ipsilateral thalamic diaschisis (ITD) refers to the phenomenon of thalamic hypoperfusion or hypometabolism due to a distant cerebral injury. To further investigate the characteristics and spectrum of ITD, we analyzed quantitative measurements of thalamic hypoperfusion in acute anterior circulation stroke.

Methods

We selected consecutive patients with large-vessel occlusion (LVO) anterior circulation stroke and available CT perfusion (CTP) examination on admission who underwent endovascular thrombectomy. Thalamic perfusion parameters on CTP were tested between ipsi- and contralesional thalamus and ischemic territory. Values were compared with thresholds from CTP analysis software. Associations of thalamic perfusion parameters with acute imaging and clinical data were determined in uni- and multivariate logistic regression analyses.

Results

Ninety-nine patients were included. All perfusion parameters indicated significant non-ischemic hypoperfusion of the thalamus, not reaching the levels of ischemia in the middle cerebral artery territory due to LVO (all p < 0.002). Multiple perfusion parameters exhibited significant association with ischemic lesion extent (relative cerebral blood flow [CBF]: β =  − 0.23, p = 0.022; Δtime to drain: β = 0.33, p < 0.001; ΔTmax: β =  − 0.36, p < 0.001) and involvement of the Lentiform Nucleus (Δmean transit time: β = 0.64, p = 0.04; Δtime to drain: β = 0.81, p = 0.01; ΔTmax: β =  − 0.82, p = 0.01). Symptom severity on admission exhibited minor significant association with reduction of thalamic CBF in uncorrected analysis (Odds ratio: 0.05, p = 0.049), but short- and long-term outcomes were unaffected by perfusion status. ITD reached guideline-based software-threshold levels in only one patient.

Conclusions

ITD in acute stroke is a non-binary phenomenon affected by lesion extent and involvement of the lentiform nucleus. We found uncorrected association of ITD with early clinical presentation, but no association with short- or long-term outcome was evident. Relevant misclassification of ITD by guideline-based CTP software was not indicated, which needs further dedicated testing.

Crossed Cerebellar Diaschisis Indicates Hemodynamic Compromise in Ischemic Stroke Patients

Crossed cerebellar diaschisis (CCD) in internal carotid artery (ICA) stroke refers to attenuated blood flow and energy metabolism in the contralateral cerebellar hemisphere. CCD is associated with an interruption of cerebro-cerebellar tracts, but the precise mechanism is unknown. We hypothesized that in patients with ICA occlusions, CCD might indicate severe hemodynamic impairment in addition to tissue damage. Duplex sonography and clinical data from stroke patients with unilateral ICAO who underwent blood oxygen-level-dependent MRI cerebrovascular reserve (BOLD-CVR) assessment were analysed. The presence of CCD (either CCD+ or CCD−) was inferred from BOLD-CVR. We considered regions with negative BOLD-CVR signal as areas suffering from hemodynamic steal. Twenty-five patients were included (11 CCD+ and 14 CCD−). Stroke deficits on admission and at 3 months were more severe in the CCD+ group. While infarct volumes were similar, CCD+ patients had markedly larger BOLD steal volumes than CCD− patients (median [IQR] 122.2 [111] vs. 11.6 [50.6] ml; p < 0.001). Furthermore, duplex revealed higher peak-systolic flow velocities in the intracranial collateral pathways. Strikingly, posterior cerebral artery (PCA)-P2 velocities strongly correlated with the National Institute of Health Stroke Scale on admission and BOLD-CVR steal volume. In patients with strokes due to ICAO, the presence of CCD indicated hemodynamic impairment with larger BOLD-defined steal volume and higher flow in the ACA/PCA collateral system. Our data support the concept of a vascular component of CCD as an indicator of hemodynamic failure in patients with ICAO.

Pervasive White Matter Fiber Degeneration in Ischemic Stroke

Background and Purpose- We examined if ischemic stroke is associated with white matter degeneration predominantly confined to the ipsi-lesional tracts or with widespread bilateral axonal loss independent of lesion laterality. Methods- We applied a novel fixel-based analysis, sensitive to fiber tract-specific differences within a voxel, to assess axonal loss in stroke (N=104, 32 women) compared to control participants (N=40, 15 women) across the whole brain. We studied microstructural differences in fiber density and macrostructural (morphological) changes in fiber cross-section. Results- In participants with stroke, we observed significantly lower fiber density and cross-section in areas adjacent, or connected, to the lesions (eg, ipsi-lesional corticospinal tract). In addition, the changes extended beyond directly connected tracts, independent of the lesion laterality (eg, corpus callosum, bilateral inferior fronto-occipital fasciculus, right superior longitudinal fasciculus). Conclusions- We conclude that ischemic stroke is associated with extensive neurodegeneration that significantly affects white matter integrity across the whole brain. These findings expand our understanding of the mechanisms of brain volume loss and delayed cognitive decline in stroke.

Crossed cerebellar diaschisis as an indicator of severe cerebral hyperperfusion after direct bypass for moyamoya disease

Cerebral hyperperfusion (HP) complicates the postoperative course of patients with moyamoya disease (MMD) after direct revascularization surgery. Crossed cerebellar diaschisis (CCD) has been considered to be rarely associated with HP after revascularization surgery. This study aimed to describe the clinical features and factors associated with CCD secondary to cerebral HP after revascularization surgery for MMD. We analyzed 150 consecutive hemispheres including 101 in adults and 49 in pediatric patients who underwent combined direct and indirect bypass for MMD. Using single-photon emission computed tomography (SPECT), serial cerebral blood flow (CBF) was measured immediately after the surgery and on postoperative days 2 and 7. Pre- and postoperative voxel-based analysis of SPECT findings was performed to compare the changes in regional CBF. Multivariate logistic regression analysis was performed to test the effect of multiple variables on CCD. Asymptomatic and symptomatic HP was observed in 41.3% (62/150) and 16.7% (25/150) of the operated hemispheres, respectively. CCD was observed in 18.4% (16/87) of these hemispheres with radiological HP. Multivariate analysis revealed that the occurrence of CCD was significantly associated with symptomatic HP (p = 0.0015). Voxel-based analysis showed that the CBF increase in the operated frontal cortex, and the CBF reduction in the contralateral cerebellar hemisphere on day 7 were significantly larger in symptomatic HP than in asymptomatic HP (median 11.3% vs 7.5%; - 6.0% vs - 1.7%, respectively). CCD secondary to postoperative HP is more common than anticipated in MMD. CCD could potentially be used as an indicator of severe postoperative HP in patients with MMD.

Rewiring the Lesioned Brain: Electrical Stimulation for Post-Stroke Motor Restoration

Electrical stimulation has been extensively applied in post-stroke motor restoration, but its treatment mechanisms are not fully understood. Stimulation of neuromotor control system at multiple levels manipulates the corresponding neuronal circuits and results in neuroplasticity changes of stroke survivors. This rewires the lesioned brain and advances functional improvement. This review addresses the therapeutic mechanisms of different stimulation modalities, such as noninvasive brain stimulation, peripheral electrical stimulation, and other emerging techniques. The existing applications, the latest progress, and future directions are discussed. The use of electrical stimulation to facilitate post-stroke motor recovery presents great opportunities in terms of targeted intervention and easy applicability. Further technical improvements and clinical studies are required to reveal the neuromodulatory mechanisms and to enhance rehabilitation therapy efficiency in stroke survivors and people with other movement disorders.

Characteristics of cerebral perfusion and diffusion associated with crossed cerebellar diaschisis after acute ischemic stroke

PURPOSE

We aimed to investigate the possible factors associated with the occurrence of crossed cerebellar diaschisis (CCD) at the hyperacute stage of ischemic stroke using whole-brain volume perfusion CT (VPCT) combined with magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We retrospectively analyzed 108 patients with ischemic stroke within 6 h of onset. The VPCT findings of the patients showed a unilateral perfusion deficit in the supratentorial territory. Follow-up MRI examinations were performed within 24 h after onset. The effects of the supratentorial cerebral ischemia, the location distribution, the final infarct volume and the apparent diffusion coefficient (ADC) value on the occurrence and severity of CCD were analyzed.

RESULTS

Among 108 patients with hyperacute cerebral ischemia, 62 (57.4%) demonstrated a contralateral cerebellar perfusion deficit on the VPCT maps. The occurrence of CCD was related to a reduction in cerebral blood volume (CBV) and prolongation of the mean transit time (MTT). Notably, the decrease in the ADC value in the infarct based on follow-up MRI was closely related to the occurrence and severity of CCD.

CONCLUSION

The occurrence and severity of CCD are related to the degree of low supratentorial perfusion and the decrease in the ADC value of infarct focus.

Simultaneous PET-MRI imaging of cerebral blood flow and glucose metabolism in the symptomatic unilateral internal carotid artery/middle cerebral artery steno-occlusive disease

Purpose

Cerebral blood flow (CBF) and glucose metabolism are important and significant factors in ischaemic cerebrovascular disease. The objective of this study was to use quantitative hybrid PET/MR to evaluate the effects of surgery treatment on the symptomatic unilateral internal carotid artery/middle cerebral artery steno-occlusive disease.

Methods

Fifteen patients diagnosed with ischaemic cerebrovascular disease were evaluated using a hybrid TOF PET/MR system (Signa, GE Healthcare). The CBF value measured by arterial spin labelling (ASL) and the standardized uptake value ratio (SUVR) measured by ¹⁸F-FDG PET were obtained, except for the infarct area and its contralateral side, before and after bypass surgery. The asymmetry index (AI) was calculated from the CBF and SUVR of the ipsilateral and contralateral cerebral hemispheres, respectively. The ΔCBF and ΔSUVR were calculated as the percent changes of CBF and SUVR between before and after surgery, and paired t tests were used to determine whether a significant change occurred. Spearman’s rank correlation was also used to compare CBF with glucose metabolism in the same region.

Results

The analysis primarily revealed that after bypass surgery, a statistically significant increase occurred in the CBF on the affected side (P < 0.01). The postprocedural SUVR was not significantly higher than the preprocedural SUVR (P > 0.05). However, the postprocedural AI values for CBF and SUVR were significantly lower after surgery than before surgery (P < 0.01). A significant correlation was found between the AI values for preoperative CBF and SUVR on the ipsilateral hemisphere (P < 0.01).

Conclusions

The present study demonstrates that a combination of ASL and ¹⁸F-FDG PET could be used to simultaneously analyse changes in patients’ cerebral haemodynamic patterns and metabolism between before and after superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery. This therefore represents an essential tool for the evaluation of critical haemodynamic and metabolic status in patients with symptomatic unilateral ischaemic cerebrovascular disease.

Degeneration of the Inferior Cerebellar Peduncle After Middle Cerebral Artery Stroke: Another Perspective on Crossed Cerebellar Diaschisis

Background and Purpose- Deafferentation of the cortico-ponto-cerebellar pathway has been proposed as a key mechanism of crossed cerebellar diaschisis. Although the cerebellum receives afferent stimuli from both cortico-ponto-cerebellar and spinocerebellar pathways, evidence on whether spinocerebellar deafferentation contributes to a hypofunctional cerebellum is lacking. Therefore, we aimed to determine whether changes in the spinocerebellar pathway occur after middle cerebral artery stroke. Methods- Twenty-three patients admitted to our inpatient rehabilitation facility and 23 age-matched healthy controls were retrospectively enrolled. Patients' functional ambulation category was determined and the Medical Research Council muscle scale test of the lower limb muscles was performed at admission and discharge. The fractional anisotropy (FA) values of the corticospinal tract and the inferior cerebellar peduncle (ICP), as the final route of the dorsal spinocerebellar pathway, were compared between the groups. The FA laterality indices of the ICP and corticospinal tract were calculated as follows: (FA_affected-FA_unaffected)/(FA_affected+FA_unaffected). Pearson correlation analysis and multivariate linear regression models were used to determine the associations between the FA laterality indices and ambulatory function. Results- The FAs of the corticospinal tract and ICP were lower in the patient group than in the control group. The FA laterality index of the corticospinal tract was not correlated with the functional ambulation category or Medical Research Council muscle scale score at admission or discharge. The FA laterality index of the ICP at the pontomedullary junction was positively correlated with the functional ambulation category and Medical Research Council muscle scale scores of all hemiplegic lower limb muscles at admission and discharge. The FA laterality index of the ICP at the pontomedullary junction was independently associated with the functional ambulation category according to the multivariate regression models. Conclusions- ICP degeneration occurs in the subacute and early chronic phase of middle cerebral artery stroke. The lower FA laterality index of the ICP was indicative of poorer ambulatory and lower limb function.

Differential Benefit of Collaterals for Stroke Patients Treated with Thrombolysis or Supportive Care : A Propensity Score Matched Analysis

PURPOSE

Leptomeningeal collaterals can slow down infarction growth; however, despite good collaterals in the DAWN and DEFUSE 3 trials, outcomes were devastating if reperfusion was not attempted. The aim of this study was to compare the influence of collaterals on morphological and functional outcome in patients with acute middle cerebral artery (MCA) stroke undergoing intravenous thrombolysis (IVT) vs. supportive care (non-IVT).

METHODS

Out of 1639 consecutive patients examined with multiparametric computed tomography (CT) for suspected ischemic stroke, all patients with confirmed MCA stroke who did not undergo endovascular thrombectomy were selected. Propensity score matching (PSM) was used to match IVT and non-IVT treated patients for potential confounders including age, sex, National Institutes of Health Stroke Scale (NIHSS) score on admission, Alberta Stroke Program Early CT Score (ASPECTS), and occlusion site. Regression analysis after PSM was performed to identify independent associations.

RESULTS

After PSM, 90 IVT patients were matched with 90 non-IVT patients. In multivariable regression analysis, a high regional leptomeningeal collateral (rLMC) score was independently associated with lower final infarction volume (FIV) in the IVT group (b = -0.472, p < 0.001) but not in the non-IVT group (b = -0.116, p = 0.327). The trichotomized rLMC scores predicted functional outcome in IVT treated patients (adjusted odds ratio, aOR = 4.57, 95% confidence interval, CI, 1.03-20.32, p = 0.046) but showed no independent association with outcome in the non-IVT group (aOR = 0.69, 95% CI 0.07-6.80, p = 0.753).

CONCLUSION

Good collaterals favored smaller FIV and good functional outcome in IVT treated patients but not in non-IVT treated patients. Good collateral flow may have limited prognostic value if IVT is not administered to attempt reperfusion.

Crossed Cerebellar Diaschisis Has an Adverse Effect on Functional Outcome in the Subacute Rehabilitation Phase of Stroke: A Case-Control Study

OBJECTIVE

To investigate whether crossed cerebellar diaschisis (CCD) is associated with functional outcome in the subacute rehabilitation phase of stroke.

DESIGN

Retrospective case-control study.

SETTING

Hospital-based cohort.

PARTICIPANTS

The study enrolled participants who underwent brain single-photon emission computed tomography (N=48). Patients with CCD were identified (n=24). Twenty-four controls were selected for each case-patient by matching age, stroke type (ischemic or hemorrhagic), lesion laterality, and lesion location.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

The functional ambulation category (FAC), modified Barthel Index (MBI), and Mini-Mental State Examination (MMSE) were administered at the initial (initiation of rehabilitation therapy) and the follow-up (4wk after rehabilitation therapy) assessments.

RESULTS

The CCD group had lower MMSE, FAC, MBI, and MMSE scores at the initial assessment (P=.032, .016, and .001, respectively) and lower FAC and MBI scores at the follow-up assessment, than the non-CCD group (P=.001 and .036, respectively). Although CCD was not associated with cognitive impairment, nonambulatory status, and dependent activities of daily living (ADL) at the initial assessment (P=.538, .083, and >.99, respectively), the CCD group had a higher risk of cognitive impairment (adjusted odds ratio [aOR]=4.044; 95% confidence interval [CI], 1.071-15.270; P=.039), nonambulatory status (aOR=7.000; 95% CI, 1.641-29.854; P=.009) and dependent ADL (aOR=13.500; 95% CI, 1.535-118.692; P=.019) at the follow-up assessment.

CONCLUSIONS

CCD is associated with severe functional impairment and may have an adverse effect on functional outcomes related to cognition, ambulatory function, and ADL during the subacute rehabilitation phase of stroke. This suggests that CCD may be a valuable predictor of functional outcome in the subacute rehabilitation phase of stroke.

PET Imaging of Crossed Cerebellar Diaschisis after Long-Term Cerebral Ischemia in Rats

Crossed cerebellar diaschisis (CCD) is a decrease of regional blood flow and metabolism in the cerebellar hemisphere contralateral to the injured brain hemisphere as a common consequence of stroke. Despite CCD has been detected in patients with stroke using neuroimaging modalities, the evaluation of this phenomenon in rodent models of cerebral ischemia has been scarcely evaluated so far. Here, we report the in vivo evaluation of CCD after long-term cerebral ischemia in rats using positron emission tomography (PET) imaging with 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG). Imaging studies were combined with neurological evaluation to assess functional recovery. In the ischemic territory, imaging studies showed a significant decrease in glucose metabolism followed by a progressive recovery later on. Conversely, the cerebellum showed a contralateral hypometabolism from days 7 to 14 after reperfusion. Neurological behavior showed major impaired outcome at day 1 after ischemia followed by a significant recovery of the sensorimotor function from days 7 to 28 after experimental stroke. Taken together, these results suggest that the degree of CCD after cerebral ischemia might be predictive of neurological recovery.

Detection of subthreshold atrophy in crossed cerebellar degeneration via two-compartment mathematical modeling of cell density in DWI: A proof of concept study

Crossed cerebellar diaschisis (CCD) refers to transneuronal degeneration of the corticopontocerebellar pathway, resulting in atrophy of cerebellum contralateral to supratentorial pathology. CCD is traditionally diagnosed on nuclear medicine studies. Our aim is to apply a biexponential diffusion model, composed of intracellular and extracellular compartments, to the detection of subthreshold CCD on DWI, with the calculated fraction of the intracellular compartment as a proposed measure of cell density. At a voxel-by-voxel basis, we solve for intracellular and extracellular coefficients in each side of the cerebellum and compare the distribution of coefficients between each hemisphere. We demonstrate, in all six CCD cases, a significantly lower contribution of the intracellular compartment to the cerebellar hemisphere contralateral to supratentorial pathology (p < 0.01). In a separate, proof-of-concept case of pontine stroke, we also demonstrate reduced intracellular coefficients in bilateral cerebellar hemispheres, excluding middle cerebellar peduncles (p < 0.01). Our findings are consistent with a decreased intracellular fraction, presumably a surrogate for reduced cellular density in corticopontocerebellar degeneration, despite normal-appearing scans. Our approach allows detection of subthreshold structural changes and offers the additional advantage of applicability to most clinical cases, where only three DWI beta values are available.

BOLD cerebrovascular reactivity as a novel marker for crossed cerebellar diaschisis

Objective

To study blood oxygen level–dependent cerebrovascular reactivity (BOLD-CVR) as a surrogate imaging marker for crossed cerebellar diaschisis (CCD).

Methods

Twenty-five participants with symptomatic unilateral cerebrovascular steno-occlusive disease underwent a BOLD-CVR and an acetazolamide challenged (15O)-H2O-PET study. CCD and cerebellar asymmetry index were determined from PET and compared to BOLD-CVR quantitative values. Neurologic status at admission and outcome after 3 months were determined with NIH Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores.

Results

For both the BOLD-CVR and PET examination, a significant cerebellar asymmetry index was found for participants exhibiting CCD (CCD+ vs CCD−: for BOLD-CVR 13.11 ± 9.46 vs 1.52 ± 4.97, p < 0.001; and for PET 7.31 ± 2.75 vs 1.68 ± 2.98, p < 0.001). The area under the curve for BOLD-CVR was 0.89 (95% confidence interval: 0.75–1.0) with 0.91 sensitivity and 0.81 specificity to detect CCD. Participants exhibiting CCD were in poorer clinical condition at baseline (CCD+ vs CCD−: NIHSS 7 vs 1, p = 0.003; mRS 3 vs 1, p = 0.001) and after 3-month follow-up (NIHSS 2 vs 0, p = 0.02; mRS 1 vs 0, p = 0.04). Worse performance on both scores showed an agreement with a larger BOLD-CVR cerebellar asymmetry index. This was not found for PET.

Conclusions

BOLD-CVR demonstrates similar sensitivity to detect CCD as compared to (15O)-H2O-PET in patients with symptomatic unilateral cerebrovascular steno-occlusive disease. Furthermore, participants exhibiting CCD had a poorer baseline neurologic performance and neurologic outcome at 3 months.

Classification of evidence

This study provides Class II evidence that BOLD-CVR identifies CCD in patients with symptomatic unilateral cerebrovascular steno-occlusive disease.

Crossed cerebellar diaschisis in post-treatment glioma patients: A comparative study of arterial spin labelling and dynamic susceptibility contrast

OBJECTIVES

To assess crossed cerebellar diaschisis (CCD) in post-treatment glioma patients, and to compare the performance of arterial spin labelling (ASL) and dynamic susceptibility contrast (DSC) in detecting CCD.

METHODS AND MATERIALS

This retrospective study included 130 patients who had both DSC and ASL. Among them, 16 had underwent fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT). We investigated the relationship between CCD and the location and size of supratentorial lesions, and compared PET diagnostic performance with that of ASL and DSC. We assessed the inter-methods agreement for ASL and DSC, and performed quantitative analysis by calculating the asymmetry index (AI) between bilateral cerebellum and exploring how the AI values for ASL-CBF, DSC-rCBF, and DSC-rCBV maps correlated with each other.

RESULT

Supratentorial lesions affecting the corona radiata (P < 0.001), basal ganglia (P < 0.001), and insula (P = 0.046) were significantly associated with the occurrence of CCD. Lesion size was significantly larger (P = 0.005) in the CCD positive group. With PET as a reference, ASL-CBF and DSC-rCBF maps exhibited the best diagnostic performance compared with the other DSC-generated maps (diagnostic accuracy = 83.3% for both, area under curve (AUC) of ASL = 0.967, AUC of rCBF = 0.983), although differences were not statistically significant. The κ value for the inter-methods (ASL and DSC) agreement in detecting CCD was 0.893, while the degree of perfusion asymmetry was more significant in ASL- than DSC-generated maps. Bland-Altman plots showed that the AI for ASL-CBF was moderately correlated with those for DSC-rCBF and DSC-rCBV.

CONCLUSIONS

CCD can present in post-treatment glioma patients and is detectable on MR-perfusion images including ASL-CBF, DSC-rCBF, and DSC-rCBV maps.

Modification of Cerebellar Afferent Pathway in the Subacute Phase of Stroke

BACKGROUND

This study aims to identify the relationship between corticopontocerebellar tract (CPCT) and corticospinal tract (CST) integrity as well as motor function after stroke.

MATERIALS AND METHODS

A total of 33 patients with stroke (18 left, 15 right hemispheric lesions) who underwent diffusion tensor imaging within 2 months of stroke onset and 17 age- and sex-matched healthy controls were retrospectively enrolled. Tract volume and the asymmetry index based on tract volume (AI_TV) of the CST and CPCT were used to identify structural changes in individual tracts and the correlation between those tracts. Motor function was assessed using the Medical Research Council (MRC) muscle scale, manual function test (MFT), functional ambulation category, and modified Barthel index.

RESULTS

The volume of the affected CPCT was lower, and that of the unaffected CPCT was higher than the volumes in the control group (P < .001, P = .001, respectively). The CPCT AI_TV showed a strong positive correlation with the CST AI_TV in patients with either left or right hemispheric lesions (r_s = .779, P < .001; r_s = .732, P = .003, respectively). The CPCT AI_TV negatively correlated with the MRC muscle scale of the shoulder, wrist, and ankle muscles (r = -.490, -.490, -.416; P = .004, .004, .016, respectively). A higher unaffected CPCT volume was indicative of less affected upper extremity function, as assessed by MFT (r_s= -.546, P = .029).

CONCLUSIONS

Modification of the CPCT depended on CST integrity and was associated with the severity of hemiplegia and hemiplegic upper extremity function. The CPCT may complement the role of the CST and help to predict the motor function.

Crossed Cerebellar Diaschisis: Risk Factors and Correlation to Functional Recovery in Intracerebral Hemorrhage

Objective

The purpose of this study is to investigate predictors of crossed cerebellar diaschisis (CCD), and the effects of CCD on functional outcomes including motor function, activities of daily living, cognitive function, and ambulation 6 months after onset in patients with intracerebral hemorrhage (ICH).

Methods

A total of 74 patients experiencing their first ICH were recruited. If the asymmetric index was more than 10% using single photon emission computed tomography (SPECT), a diagnosis of CCD was confirmed. Clinical factors were retrospectively assessed by reviewing medical records. Radiologic factors encompassed the concomitance of intraventricular hemorrhage, side and location of the lesion, and hemorrhage volume. Functional outcomes were evaluated using the Fugl-Meyer Assessment, the Korean version of the Mini-Mental State Examination, the Korean version of the Modified Barthel Index, and measurement of the Functional Ambulatory Category at the time of SPECT measurement and 6 months post-ICH.

Results

Lesion location, especially in the basal ganglia (odds ratio [OR]=6.138, p=0.011), and hemorrhagic volume (OR=1.055, p=0.046) were independent predictors for CCD according to multivariate logistic regression analysis. In addition, the presence of CCD was significantly related to the improvement in Fugl-Meyer Assessment score after 6 months (adjusted R²=0.152, p=0.036).

Conclusion

Lesion location and hemorrhagic volume were the predisposing factors for CCD, and the CCD was associated with poor motor recovery over 6 months in patients with hemorrhagic stroke.

Familial and sporadic chronic progressive degenerative parietal ataxia

BACKGROUND & OBJECTIVE

Parietal ataxia has been mainly reported as a consequence of acute ischemic stroke, while degenerative parietal ataxia has not been reported.

METHODS

We investigated clinical characteristics, neuroimaging data, and genetic analysis of patients with cerebellar ataxia plus parietal atrophy.

RESULTS

We identified seven patients, including five patients from two families, with chronic progressive cerebellar ataxia due to degenerative parietal atrophy but not stroke. Age at onset of ataxia was 57.6 ± 6.9 years. All patients showed chronic progressive cerebellar ataxia with severity of ataxic gait > limb ataxia > dysarthria. Patients showed no cognitive dysfunction, muscle weakness, or parkinsonism, and only two patients showed mild sensory disturbances. The seven patients showed lateralized limb ataxia with greater contralateral parietal lobe atrophy by magnetic resonance imaging, and hypoperfusion by single photon emission computed tomography, without any abnormal cerebellar pathology (i.e., crossed cerebellar diaschisis). Pathogenic mutations in the microtubule-associated protein tau gene were not found using two single nucleotide polymorphisms.

CONCLUSIONS

This is the first description showing unique clinical features of familial and sporadic chronic progressive degenerative parietal ataxia.

Crossed cerebellar diaschisis in acute ischemic stroke: Impact on morphologic and functional outcome

Crossed cerebellar diaschisis (CCD) is the phenomenon of hypoperfusion and hypometabolism of the contralateral cerebellar hemisphere caused by dysfunction of the related supratentorial region. Our aim was to analyze its influence on morphologic and functional outcome in acute ischemic stroke. Subjects with stroke caused by a large vessel occlusion of the anterior circulation were selected from an initial cohort of 1644 consecutive patients who underwent multiparametric CT including whole-brain CT perfusion. Two experienced readers evaluated the posterior fossa in terms of CCD absence (CCD-) or presence (CCD+). A total of 156 patients formed the study cohort with 102 patients (65.4%) categorized as CCD- and 54 (34.6%) as CCD+. In linear and logistic regression analyses, no significant association between CCD and final infarction volume (β = -0.440, p = 0.972), discharge mRS ≤ 2 (OR = 1.897, p = 0.320), or 90-day mRS ≤ 2 (OR = 0.531, p = 0.492) was detected. CCD+ patients had larger supratentorial cerebral blood flow deficits (median: 164 ml vs. 115 ml; p = 0.001) compared to CCD-patients. Regarding complications, CCD was associated with a higher rate of parenchymal hematomas (OR = 4.793, p = 0.035). In conclusion, CCD is frequently encountered in acute ischemic stroke caused by large vessel occlusion of the anterior circulation. CCD was associated with the occurrence of parenchymal hematoma in the ipsilateral cerebral infarction but did not prove to significantly influence patient outcome.

Perfusion MR Imaging Using a 3D Pulsed Continuous Arterial Spin-Labeling Method for Acute Cerebral Infarction Classified as Branch Atheromatous Disease Involving the Lenticulostriate Artery Territory

BACKGROUND AND PURPOSE

Branch atheromatous disease is a stroke subtype considered a risk factor for early neurologic deterioration. Meanwhile, crossed cerebellar diaschisis is thought to be influenced by the degree and location of supratentorial perfusion abnormalities and is associated with the clinical outcome in the case of an ischemic stroke. In this article, our aim was to clarify the utility of using a whole-brain 3D pulsed continuous arterial spin-labeling method as an imaging biomarker for predicting neurologic severity in branch atheromatous disease.

MATERIALS AND METHODS

Twenty-three patients with branch atheromatous disease in the lenticulostriate artery territory were enrolled. All patients underwent MR imaging, including DWI, 3D-TOF-MRA, and 3D-arterial spin-labeling. We measured the asymmetry index of CBF in the affected area (branch atheromatous disease), the asymmetry index of the contralateral cerebellar hemisphere (crossed cerebellar diaschisis), and the DWI infarct volume in the lenticulostriate artery territory. We also compared each parameter with the initial NIHSS score with the Pearson correlation coefficient.

RESULTS

Among the 23 patients, we found no correlation between NIHSS score and the asymmetry index of CBF in the affected area (branch atheromatous disease) (r = -0.027, P = .724), whereas the asymmetry index of the contralateral cerebellar hemisphere (crossed cerebellar diaschisis) and DWI infarct volumes were significantly correlated with NIHSS score (r = 0.515, P = .012; r = 0.664, P = .001, respectively).

CONCLUSIONS

In patients with branch atheromatous disease, 3D-arterial spin-labeling can detect crossed cerebellar diaschisis, which is correlated with the degree of neurologic severity.