Cerebellar infarction: natural history, prognosis, and pathology

Left Cerebellar Lesions may be Associated with an Increase in Spatial Neglect-like Symptoms

Each cerebellar hemisphere projects to the contralateral cerebral hemisphere. Previous research suggests a lateralization of cognitive functions in the cerebellum that mirrors the cerebral cortex, with attention/visuospatial functions represented in the left cerebellar hemisphere, and language functions in the right cerebellar hemisphere. Although there is good evidence supporting the role of the right cerebellum with language functions, the evidence supporting the notion that attention and visuospatial functions are left lateralized is less clear. Given that spatial neglect is one of the most common disorders arising from right cortical damage, we reasoned that damage to the left cerebellum would result in increased spatial neglect-like symptoms, without necessarily leading to an official diagnosis of spatial neglect. To examine this disconnection hypothesis, we analyzed neglect screening data (line bisection, cancellation, figure copying) from 20 patients with isolated unilateral cerebellar stroke. Results indicated that left cerebellar patients (n = 9) missed significantly more targets on the left side of cancellation tasks compared to a normative sample. No significant effects were observed for right cerebellar patients (n = 11). A lesion overlap analysis indicated that Crus II (78% overlap), and lobules VII and IX (66% overlap) were the regions most commonly damaged in left cerebellar patients. Our results are consistent with the notion that the left cerebellum may be important for attention and visuospatial functions. Given the poor prognosis typically associated with neglect, we suggest that screening for neglect symptoms, and visuospatial deficits more generally, may be important for tailoring rehabilitative efforts to help maximize recovery in cerebellar patients.

Necrosectomy Versus Stand-Alone Suboccipital Decompressive Craniectomy for the Management of Space-Occupying Cerebellar Infarctions-A Retrospective Multicenter Study

BACKGROUND AND OBJECTIVES

Space-occupying cerebellar stroke (SOCS) when coupled with neurological deterioration represents a neurosurgical emergency. Although current evidence supports surgical intervention in such patients with SOCS and rapid neurological deterioration, the optimal surgical methods/techniques to be applied remain a matter of debate.

METHODS

We conducted a retrospective, multicenter study of patients undergoing surgery for SOCS. Patients were stratified according to the type of surgery as (1) suboccipital decompressive craniectomy (SDC) or (2) suboccipital craniotomy with concurrent necrosectomy. The primary end point examined was functional outcome using the modified Rankin Scale (mRS) at discharge and at 3 months (mRS 0-3 defined as favorable and mRS 4-6 as unfavorable outcome). Secondary end points included the analysis of in-house postoperative complications, mortality, and length of hospitalization.

RESULTS

Ninety-two patients were included in the final analysis: 49 underwent necrosectomy and 43 underwent SDC. Those with necrosectomy displayed significantly higher rate of favorable outcome at discharge as compared with those who underwent SDC alone: 65.3% vs 27.9%, respectively ( P < .001, odds ratios 4.9, 95% CI 2.0-11.8). This difference was also observed at 3 months: 65.3% vs 41.7% ( P = .030, odds ratios 2.7, 95% CI 1.1-6.7). No significant differences were observed in mortality and/or postoperative complications, such as hemorrhagic transformation, infection, and/or the development of cerebrospinal fluid leaks/fistulas.

CONCLUSION

In the setting of SOCS, patients treated with necrosectomy displayed better functional outcomes than those patients who underwent SDC alone. Ultimately, prospective, randomized studies will be needed to confirm this finding.

Safe and time-saving treatment method for acute cerebellar infarction: Navigation-guided burr-hole aspiration - 6-years single center experience

OBJECTIVE

While patients with medically intractable acute cerebellar infarction typically undergo suboccipital craniectomy and removal of the infarcted tissue, this procedure is associated with long operating times and postoperative complications. This study aimed to investigate the effectiveness of minimally invasive navigationguided burr hole aspiration surgery for the treatment of acute cerebellar infarction.

METHODS

Between January 2015 and December 2021, 14 patients with acute cerebellar infarction, who underwent navigation-guided burr hole aspiration surgery, were enrolled in this study.

RESULTS

The preoperative mean Glasgow Coma Scale (GCS) score was 12.7, and the postoperative mean GCS score was 14.3. The mean infarction volume was 34.3 cc at admission and 23.5 cc immediately following surgery. Seven days after surgery, the mean infarction volume was 15.6 cc. There were no surgery-related complications during the 6-month follow-up period and no evidence of clinical deterioration. The mean operation time from skin incision to catheter insertion was 28 min, with approximately an additional 13 min for extra-ventricular drainage. The mean Glasgow Outcome Scale score after 6 months was 4.8.

CONCLUSIONS

Navigation-guided burr hole aspiration surgery is less time-consuming and invasive than conventional craniectomy, and is a safe and effective treatment option for acute cerebellar infarction in selected cases, with no surgery-related complication.

Assessment and recovery of visually guided reaching deficits following cerebellar stroke

The cerebellum is known to play an important role in the coordination and timing of limb movements. The present study focused on how reach kinematics are affected by cerebellar lesions to quantify both the presence of motor impairment, and recovery of motor function over time. In the current study, 12 patients with isolated cerebellar stroke completed clinical measures of cognitive and motor function, as well as a visually guided reaching (VGR) task using the Kinarm exoskeleton at baseline (∼2 weeks), as well as 6, 12, and 24-weeks post-stroke. During the VGR task, patients made unassisted reaches with visual feedback from a central 'start' position to one of eight targets arranged in a circle. At baseline, 6/12 patients were impaired across several parameters of the VGR task compared to a Kinarm normative sample (n = 307), revealing deficits in both feed-forward and feedback control. The only clinical measures that consistently demonstrated impairment were the Purdue Pegboard Task (PPT; 9/12 patients) and the Montreal Cognitive Assessment (6/11 patients). Overall, patients who were impaired at baseline showed significant recovery by the 24-week follow-up for both VGR and the PPT. A lesion overlap analysis indicated that the regions most commonly damaged in 5/12 patients (42% overlap) were lobule IX and Crus II of the right cerebellum. A lesion subtraction analysis comparing patients who were impaired (n = 6) vs. unimpaired (n = 6) on the VGR task at baseline showed that the region most commonly damaged in impaired patients was lobule VIII of the right cerebellum (40% overlap). Our results lend further support to the notion that the cerebellum is involved in both feedforward and feedback control during reaching, and that cerebellar patients tend to recover relatively quickly overall. In addition, we argue that future research should study the effects of cerebellar damage on visuomotor control from a perception-action theoretical framework to better understand how the cerebellum works with the dorsal stream to control visually guided action.

Comparative examination of the pons and corpus callosum as reference regions for quantitative evaluation in positron emission tomography imaging for Alzheimer's disease using 11C-Pittsburgh Compound-B

OBJECTIVES

Standardised uptake value ratio (SUVR) is usually obtained by dividing the SUV of the region of interest (ROI) by that of the cerebellar cortex. Cerebellar cortex is not a valid reference in cases where amyloid β deposition or lesions are present. Only few studies have evaluated the use of other regions as references. We compared the validity of the pons and corpus callosum as reference regions for the quantitative evaluation of brain positron emission tomography (PET) using ¹¹C-PiB compared to the cerebellar cortex.

METHODS

We retrospectively evaluated data from 86 subjects with or without Alzheimer's disease (AD). All subjects underwent magnetic resonance imaging, PET imaging, and cognitive function testing. For the quantitative analysis, three-dimensional ROIs were automatically placed, and SUV and SUVR were obtained. We compared these values between AD and healthy control (HC) groups.

RESULTS

SUVR data obtained using the pons and corpus callosum as reference regions strongly correlated with that using the cerebellar cortex. The sensitivity and specificity were high when either the pons or corpus callosum was used as the reference region. However, the SUV values of the corpus callosum were different between AD and HC (p < 0.01).

CONCLUSIONS

Our data suggest that the pons and corpus callosum might be valid reference regions.

Misdiagnosis of Cerebellar Infarcts and Its Outcome

Cerebellar infarction, a rare category of stroke, is often misdiagnosed but not given much importance in the available literature. Its presentation overlaps with symptoms of other neurologic, cardiovascular, gastrointestinal, and systemic conditions and therefore is nonspecific. Early diagnosis and management of cerebellar strokes are of utmost importance as the lack of a proper diagnosis may increase overall morbidity and mortality. Lack of awareness of the warning signs and symptoms, non-specificity of symptoms, absence of neurological deficits, and imaging discrepancies are some of the factors contributing to misdiagnosis and delayed treatment. If symptomatology is considered, it is found that symptoms of posterior circulation stroke were more frequently misdiagnosed compared to anterior circulation. Nausea and vomiting increased the chance further. Some other rare presentations include gastrointestinal symptoms, isolated vertigo, and symptoms of inner ear disease. Overdependence on radiological investigations often masks the significance of clinical examination. Ischemic stroke may appear normal in the initial 48 hours in the computed tomography scan of the brain or bony artefacts may hide the lesion. Permanent disabling deficits can follow a cerebellar stroke and the complications, which include hydrocephalus, brain stem compression, and gait abnormalities, necessitate prompt identification and management. In this review article, we aim at analysing various case reports of cerebellar infarction, the most common presentations that were under-evaluated, and their outcomes, thereby highlighting the importance of proper diagnosis and reporting of cerebellar infarction in the future. A thorough knowledge of the association between various clinical presentations of cerebellar stroke and its misdiagnosis helps clinicians to be more vigilant about the disease.

Cerebellar infarction risk in a mild COVID-19 case

Thrombotic events in SARS-COV-2 disease patients are frequent, especially in patients with comorbidities such as heart failure, hypertension, cancer, diabetes mellitus, kidney failure, vascular disease, and other pulmonary illnesses. In severe cases, in particular those of hospitalized patients with other comorbidities, the development of thrombotic events in spite of anticoagulation therapy has been observed. The main thrombotic events are pulmonary thromboembolism, cerebral ischemic stroke, and peripheral artery thrombosis. Despite the severity of SARS-COV-2 disease, some patients with the aforementioned comorbidities develop thrombotic events regardless of the severity of their SARS-COV-2 infection. In this setting, the cerebellum makes no exception as an uncommon, but still possible target for thrombotic events.

Predictors of clinical outcomes in space-occupying cerebellar infarction undergoing suboccipital decompressive craniectomy

Introduction

Despite current clinical guidelines recommending suboccipital decompressive craniectomy (SDC) in cerebellar infarction when patients present with neurological deterioration, the precise definition of neurological deterioration remains unclear and accurate timing of SDC can be challenging. The current study aimed at characterizing whether clinical outcomes can be predicted by the GCS score immediately prior to SDC and whether higher GCS scores are associated with better clinical outcomes.

Methods

In a single-center, retrospective analysis of 51 patients treated with SDC for space-occupying cerebellar infarction, clinical and imaging data were evaluated at the time points of symptom onset, hospital admission, and preoperatively. Clinical outcomes were measured by the mRS. Preoperative GCS scores were stratified into three groups (GCS, 3-8, 9-11, and 12-15). Univariate and multivariate Cox regression analyses were performed using clinical and radiological parameters as predictors of clinical outcomes.

Results

In cox regression analysis GCS scores of 12-15 at surgery were significant predictors of positive clinical outcomes (mRS, 1-2). For GCS scores of 3-8 and 9-11, no significant increase in proportional hazard ratios was observed. Negative clinical outcomes (mRS, 3-6) were associated with infarct volume above 6.0 cm³, tonsillar herniation, brainstem compression, and a preoperative GCS score of 3-8 [HR, 2.386 (CI, 1.160-4.906); p = 0.018].

Conclusion

Our preliminary findings suggest that SDC should be considered in patients with infarct volumes above 6.0 cm³ and with GCS between 12 and 15, as these patients may show better long-term outcomes than those in whom surgery is delayed until a GCS score below 11.

Cerebellar cognitive affective syndrome after acute cerebellar stroke

Introduction

The cerebellum modulates both motor and cognitive behaviors, and a cerebellar cognitive affective syndrome (CCAS) was described after a cerebellar stroke in 1998. Yet, a CCAS is seldom sought for, due to a lack of practical screening scales. Therefore, we aimed at assessing both the prevalence of CCAS after cerebellar acute vascular lesion and the yield of the CCAS-Scale (CCAS-S) in an acute stroke setting.

Materials and methods

All patients admitted between January 2020 and January 2022 with acute onset of a cerebellar ischemic or haemorrhagic first stroke at the CUB-Hôpital Erasme and who could be evaluated by the CCAS-S within a week of symptom onset were included.

Results

Cerebellar acute vascular lesion occurred in 25/1,580 patients. All patients could complete the CCAS-S. A definite CCAS was evidenced in 21/25 patients. Patients failed 5.2 ± 2.12 items out of 8 and had a mean raw score of 68.2 ± 21.3 (normal values 82–120). Most failed items of the CCAS-S were related to verbal fluency, attention, and working memory.

Conclusion

A definite CCAS is present in almost all patients with acute cerebellar vascular lesions. CCAS is efficiently assessed by CCAS-S at bedside tests in acute stroke settings. The magnitude of CCAS likely reflects a cerebello-cortical diaschisis.

Differences in hippocampal plasticity and memory outcomes in anterior versus posterior cerebellar stroke

Neurological symptoms following cerebellar stroke can range from motor to cognitive-affective impairments. Topographic imaging studies from patients with lesions confined to the cerebellum have shown evidence linking anterior cerebellar lobules with motor function and posterior lobules with cognitive function. Damage to the cerebellum can disrupt functional connectivity in cerebellar stroke patients, as it is highly interconnected with forebrain motor and cognitive areas. The hippocampus plays a key role in memory acquisition, a cognitive domain that is negatively impacted by posterior cerebellar stroke, and there is increasing evidence that the cerebellum can affect hippocampal function in health and disease. To study these topographical dissociations, we developed a mouse photo-thrombosis model to produce unilateral strokes in anterior (lobules III-V) or posterior (lobules VI-VIII) cerebellar cortex to examine hippocampal plasticity and behavior. Histological and MRI data demonstrate reproducible injury that is confined to the targeted lobules. We then measured hippocampal long-term potentiation (LTP) ex-vivo with extracellular field recording experiments in acute brain slices obtained from mice 7 days post-cerebellar stroke. Interestingly, we found that a unilateral posterior stroke resulted in a contralateral hippocampal impairment, matching the cerebellothalamic pathway trajectory, while LTP was intact in both hippocampi of mice with anterior strokes. We also assessed motor coordination and memory function at 7 days post-stroke using a balance beam, contextual and delay fear conditioning (CFC and DFC), and novel object recognition (NOR) tasks. Mice with anterior strokes showed lack of coordination evaluated as an increased number of missteps, while mice with posterior strokes did not. Mice with anterior or posterior cerebellar strokes demonstrated similar freezing behavior to shams in CFC and DFC, while only posterior stroke mice displayed a reduced discrimination index in the NOR task. These data suggest that a unilateral LTP impairment observed in mice with posterior strokes produces a mild memory impairment. Our results demonstrate that our model recapitulates aspects of clinical lesion-symptom mapping, with anterior cerebellar strokes producing impaired motor coordination and posterior cerebellar strokes producing an object-recognition memory impairment. Further studies are warranted to interrogate other motor and cognitive-affective behaviors and brain region specific alterations following focal cerebellar stroke. The novel model presented herein will allow for future preclinical translational studies to improve neurological deficits after cerebellar stroke.

Clinical and Computerized Volumetric Analysis of Posterior Fossa Decompression for Space-Occupying Cerebellar Infarction

Background and Purpose

Surgical decompression of the posterior fossa is often performed in cases with a space-occupying cerebellar infarction to prevent coma and death. In this study, we analyzed our institutional experience with this condition. We specifically attempted to address timing issues and investigated the role of cerebellar necrosectomy using imaging data and conducting volumetric analyses.

Methods

We retrospectively studied pertinent clinical and imaging data, including computerized volumetric analyses (preoperative/postoperative infarction volume, necrosectomy volume, and posterior fossa volume), from all 49 patients who underwent posterior fossa decompression surgery for cerebellar infarction in our department from January 2012 to January 2021.

Results

Thirty-five (71%) patients had a Glasgow Coma Scale (GCS) of 14–15 at admission vs. only 14 (29%) before vs. 41 (84%) following surgery. Seven (14%) patients had preventive surgery (initial GCS 14–15, preoperative GCS change ≤ 1). Only 18 (37%) patients had an mRS score of 0–3 at discharge. Estimated overall survival was 70.5% at 1 year. Interestingly, 18/20 (90%) surviving cases had a modified Rankin Scale (mRS) outcome of 0–3 (mRS 0–2: 12/20 [60%]) 1 year after surgery. Surgical timing, including preventive surgery and mass effect of the infarct, in the posterior fossa assessed semi-quantitatively (Kirollos grade) and with volumetric parameters that were not predictive of the patients' (functional) outcomes.

Conclusion

Posterior fossa decompression for cerebellar infarction is a life-saving procedure, but rapid recovery of the GCS after surgery does not necessarily translate into good functional outcome. Many patients died during follow-up, but long-term mRS outcomes of 4–5 are rare. Surgery should probably aim primarily at pressure relief, and our clinical as well as volumetric data suggest that the impact of removing an infarcted tissue may be limited. It is presumably relatively safe to initially withhold surgery in cases with a GCS of 14–15.

Right cerebral motor areas that support accurate speech production following damage to cerebellar speech areas

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Participants with damage to cerebellar speech regions were studied with fMRI.

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At the time of test, their speech production was accurate and precise.

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Their speech production activation was enhanced in right hemisphere motor regions.

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We provide hypotheses for targeting future fMRI and brain stimulation studies.

Specific regions of the cerebellum are activated when neurologically intact adults speak, and cerebellar damage can impair speech production early after stroke, but how the brain supports accurate speech production years after cerebellar damage remains unknown. We investigated this in patients with cerebellar lesions affecting regions that are normally recruited during speech production. Functional MRI activation in these patients, measured during various single word production tasks, was compared to that of neurologically intact controls, and patient controls with lesions that spared the cerebellar speech production regions. Our analyses revealed that, during a range of speech production tasks, patients with damage to cerebellar speech production regions had greater activation in the right dorsal premotor cortex (r-PMd) and right supplementary motor area (r-SMA) compared to neurologically intact controls.

The loci of increased activation in cerebral motor speech areas motivate future studies to delineate the functional contributions of different parts of the speech production network, and test whether non-invasive stimulation to r-PMd and r-SMA facilitates speech recovery after cerebellar stroke.

Heparin for Vertebral Intraluminal Thrombus Causing Retroperitoneal Hemorrhage from Occult Renal Angiomyolipoma

Stroke is a common cause of mortality and serious long-term disability worldwide. In the acute setting, current American Heart Association/American Stroke Association guidelines do not recommend routine anticoagulation for the management of acute ischemic strokes. However, short-term use of unfractionated heparin (UFH) in select subpopulations has demonstrated improved outcomes. While tools such as CHADSVASC and HASBLED scores are useful in stratifying risk of long-term anticoagulation in patients with nonvalvular atrial fibrillation and additional risk factors, the carefully selected patient populations for the design of these studies do not account for risk of hemorrhage from other preexisting conditions. Here, we present a patient with a posterior circulation intraluminal thrombus treated with UFH, who manifested with a near-fatal intra-abdominal hemorrhage from a previously undetected renal angiomyolipoma (AML).

The Effect of Focal Damage to the Right Medial Posterior Cerebellum on Word and Sentence Comprehension and Production

Functional imaging studies of neurologically intact adults have demonstrated that the right posterior cerebellum is activated during verb generation, semantic processing, sentence processing, and verbal fluency. Studies of patients with cerebellar damage converge to show that the cerebellum supports sentence processing and verbal fluency. However, to date there are no patient studies that investigated the specific importance of the right posterior cerebellum in language processing, because: (i) case studies presented patients with lesions affecting the anterior cerebellum (with or without damage to the posterior cerebellum), and (ii) group studies combined patients with lesions to different cerebellar regions, without specifically reporting the effects of right posterior cerebellar damage. Here we investigated whether damage to the right posterior cerebellum is critical for sentence processing and verbal fluency in four patients with focal stroke damage to different parts of the right posterior cerebellum (all involving Crus II, and lobules VII and VIII). We examined detailed lesion location by going beyond common anatomical definitions of cerebellar anatomy (i.e., according to lobules or vascular territory), and employed a recently proposed functional parcellation of the cerebellum. All four patients experienced language difficulties that persisted for at least a month after stroke but three performed in the normal range within a year. In contrast, one patient with more damage to lobule IX than the other patients had profound long-lasting impairments in the comprehension and repetition of sentences, and the production of spoken sentences during picture description. Spoken and written word comprehension and visual recognition memory were also impaired, however, verbal fluency was within the normal range, together with object naming, visual perception and verbal short-term memory. This is the first study to show that focal damage to the right posterior cerebellum leads to language difficulties after stroke; and that processing impairments persisted in the case with most damage to lobule IX. We discuss these results in relation to current theories of cerebellar contribution to language processing. Overall, our study highlights the need for longitudinal studies of language function in patients with focal damage to different cerebellar regions, with functional imaging to understand the mechanisms that support recovery.

Delayed Obstructive Hydrocephalus After Cardiac Surgery With Cardiopulmonary Bypass in a Patient With Cerebellar Infarction: A Case Report

Obstructive hydrocephalus caused by brainstem compression is a life-threatening complication and usually occurs within 6 days, with peak on day 3 after onset of cerebellar infarction. We present a case of obstructive hydrocephalus that developed on day 8 in a patient with cerebellar infarction. A 39-year-old man with cerebellar infarction caused by myocardial infarction-related intraventricular thrombus underwent left ventricular thrombectomy under cardiopulmonary bypass. He was lucid postoperatively, but his consciousness was diminished on day 8 because of obstructive hydrocephalus. Cerebral edema due to cardiopulmonary bypass may contribute to delayed onset of obstructive hydrocephalus, especially in patients with large-sized cerebellar infarction.

Cerebellar lesions disrupt spatial and temporal visual attention

The current study represents the first comprehensive examination of spatial, temporal and sustained attention following cerebellar damage. Results indicated that, compared to controls, cerebellar damage resulted in a larger cueing effect at the longest SOA - possibly reflecting a slowed the onset of inhibition of return (IOR) during a reflexive covert attention task, and reduced the ability to detect successive targets during an attentional blink task. However, there was little evidence to support the notion that cerebellar damage disrupted voluntary covert attention or the sustained attention to response task (SART). Lesion overlay data and supplementary voxel-based lesion symptom mapping (VLSM) analyses indicated that impaired performance on the reflexive covert attention and attentional blink tasks were related to damage to Crus II of the left posterior cerebellum. In addition, subsequent analyses indicated our results are not due to either general motor impairments or to damage to the deep cerebellar nuclei. Collectively these data demonstrate, for the first time, that the same cerebellar regions may be involved in both spatial and temporal visual attention.

Multimodal Computed Tomography Increases the Detection of Posterior Fossa Strokes Compared to Brain Non-contrast Computed Tomography

Aims: Multimodal computed tomography (mCT) (non-contrast CT, CT angiography, and CT perfusion) is not routinely used to assess posterior fossa strokes. We described the area under the curve (AUC) of brain NCCT, WB-CTP automated core-penumbra maps and comprehensive CTP analysis (automated core-penumbra maps and all perfusion maps) for posterior fossa strokes. Methods: We included consecutive patients with signs and symptoms of posterior fossa stroke who underwent acute mCT and follow up magnetic resonance diffusion weighted imaging (DWI). Multimodal CT images were reviewed blindly and independently by two stroke neurologists and area under the receiver operating characteristic curve (AUC) was used to compare imaging modalities. Results: From January 2014 to December 2019, 83 patients presented with symptoms suggestive of posterior fossa strokes and had complete imaging suitable for inclusion (49 posterior fossa strokes and 34 DWI negative patients). For posterior fossa strokes, comprehensive CTP analysis had an AUC of 0.68 vs. 0.62 for automated core-penumbra maps and 0.55 for NCCT. For cerebellar lesions >5 mL, the AUC was 0.87, 0.81, and 0.66, respectively. Conclusion: Comprehensive CTP analysis increases the detection of posterior fossa lesions compared to NCCT and should be implemented as part of the routine imaging assessment in posterior fossa strokes.

Cerebellar Necrosectomy Instead of Suboccipital Decompression: A Suitable Alternative for Patients with Space-Occupying Cerebellar Infarction

OBJECTIVE

Space-occupying cerebellar ischemic strokes (SOCSs) often lead to neurological deterioration and require surgical intervention to release pressure from the posterior fossa. Current guidelines recommend suboccipital decompressive craniectomy (SDC) with dural expansion when medical therapy is not sufficient. However, no good-quality evidence is available to support this surgical practice, and the surgical timing and technique both remain controversial. We have described an alternative to SDC, surgical evacuation of infarcted tissue (necrosectomy) and its clinical outcomes.

METHODS

In the present retrospective, single-center study, 34 consecutive patients with SOCS undergoing necrosectomy via osteoplastic craniotomy were included. The patient characteristics and radiological findings were evaluated. To differentiate the effects of age on the functional outcomes, the patients were divided into 2 groups (group I, age ≤60 years; and group II, age >60 years). Functional outcomes were assessed using the Glasgow outcome scale, modified Rankin scale, and Barthel index at discharge and 30 days postoperatively.

RESULTS

In our cohort, we observed overall mortality of 21%, with good functional outcomes (Glasgow outcome scale score ≥4) for 76% of the patients. No statistically significant differences in mortality or functional outcomes were observed between the 2 patient groups. Comparing our data with a recent meta-analysis of SDC, the number of adverse events and unfavorable outcome showed equipoise between the 2 treatment modalities.

CONCLUSIONS

Necrosectomy appears to be a suitable alternative to SDC for SOCS, achieving comparable mortality and functional outcomes. Further trials are necessary to evaluate which surgical technique is more beneficial in the setting of SOCSs.

Traditional Korean Medical Treatment for Dizziness and Gait Instability due to Cerebellar Infarction: A Case Report

This case study reports the effect of Korean medicine treatments on a 73 year-old female who had a cerebellar infarction. She was hospitalized for 120 days (without visiting Western medicine hospital) where she was treated with acupuncture, herbal decoction, pharmacopuncture, chuna, moxibustion and physiotherapy. Following treatment, her symptoms of dizziness were evaluated using the numeric rating scale and showed pain had reduced (3 to 0). The K-Modified Barthel, showed that life performance had improved (15 to 74), and the Berg balance scale showed an improved balance (2 to 32). Steps per minute and gait posture at stance phase for ataxia also showed improvement. This case report shows that Korean medicine treatment is effective in alleviating dizziness and improved gait instability caused by cerebellar infarction.

Predicting Surgical Intervention in Cerebellar Stroke: A Quantitative Retrospective Analysis

BACKGROUND

Debate still exists regarding whether preventive surgical decompression should be offered to high-risk patients experiencing cerebellar stroke. This study aimed to predict neurologic decline based on risk factors, volumetric analysis, and imaging characteristics.

METHODS

This retrospective cohort study comprised patients ≥18 years who presented with acute cerebellar ischemic stroke (CIS) between January 2011 and December 2016. Diagnostic imaging was used to calculate metrics based on individual stroke, cerebellar, and posterior fossa volumes. Head computed tomography scans on presentation and day of peak swelling were used to tabulate a CIS score.

RESULTS

The study included 86 patients; most were male and African American. Posterior inferior communicating artery stroke was most common (50%). On initial presentation imaging, 18.6% had documented hydrocephalus, 20.9% had brainstem compression, 22.1% had brainstem stroke, and 39.5% had stroke in another vascular territory. Cardioembolic stroke was the most common etiology, followed by cryptogenic stroke. Overall, patients who underwent surgical intervention had larger stroke volumes on presentation. Patients undergoing surgical intervention also experienced faster cerebellar swelling compared with patients without intervention. Total CIS scores were statistically significant and remained significant on the peak day of swelling. CIS score was independently associated with neurosurgical intervention; patients in this group with delayed interventions (median CIS score, 6; range, 4-8) later deteriorated and required emergent surgical decompression. Eleven patients without intervention had CIS score >6; 4 patients died of stroke complications.

CONCLUSIONS

Volumetric studies and CIS score are objective measures that may help predict decline on imaging before clinical deterioration.

[Malignant cerebellar infarction: clinical course and surgical treatment]

AIM

To clarify the indications for surgical treatment of malignant cerebellar infarction (CI).

MATERIAL AND METHODS

Eighty patients with CI were studied. The malignancy of CI was understood as the development of mass effect in the posterior cranial fossa, accompanied by the decrease in consciousness due to compression of the brain stem and/or the development of occlusive hydrocephalus. The patients were divided into 2 groups. The group of malignant CI included 55 patients (68.75%) (group I), the group of benign CI included 25 patients (31.25%) (group II). Patients of group I were divided into subgroups, one of them underwent surgical treatment (surgical subgroup), and another only conservative (conservative subgroup) treatment. Surgery efficacy criteria were: restoration of consciousness to 15 points according to GCS and/or restoration of the fourth ventricle and the quadrigeminal cistern configurations. Results of treatment were assessed according to the Glasgow outcome scale.

RESULTS

Malignant CI occurred more frequently in patients with the volume of ischemia exceeding 20 cm³ (p<0.05) in the first day of the disease. The threshold value of mass effect, which can cause further a malignant CI, was 3 points according to the M. Jauss scale. In the group of patients with malignant CI, surgical treatment reduced the mortality rate from occlusion and dislocation syndrome by 35.8%. The most effective type of intervention was a combination of decompressive trepanation of the posterior cranial fossa and external ventricular drainage.

CONCLUSION

In patients with CI with the volume more than 20 cm³ and signs of mass effect in the posterior cranial fossa on the scale of M. Jauss 3 points or more, the malignant course of the disease develops in 67% of cases. These patients require careful monitoring, and, in case of development of malignant CI, surgical treatment is necessary.

Small obliquely oriented cortical cerebellar infarctions are associated with cardioembolic stroke

Background

A revised classification of cerebellar infarctions (CI) may uncover unrecognized associations with etiologic stroke subtypes. We hypothesized that obliquely oriented small cortical cerebellar infarction (SCCI) representing end zone infarctions on MRI would be associated with cardiac embolism.

Methods

We retrospectively analyzed consecutive stroke patients recruited between January–December 2016 in our center. Analyzed baseline characteristics: sex, age, cardiovascular risk factors, history of stroke or atrial fibrillation (AF). TOAST classification was used for determining stroke subtype. Acute infarction location (anterior/posterior/mixed anterior-posterior circulation), acute uni- or multiterritorial infarction, and acute or chronic CI/SCCI/non-SCCI were assessed by MRI, and vertebrobasilar stenosis/occlusion by vessel imaging. Pre-specified analysis was also performed in patients without known high cardioembolic risk (known AF history or acute multiterritorial infarction).

Results

We included 452 patients (CI in 154, isolated SCCI in 55, isolated non-SCCI in 50, and mixed SCCI/non-SCCI in 49). Both SCCI and non-SCCI were associated with AF history (SCCI, p = 0.021; non-SCCI, p = 0.004), additional acute posterior circulation infarction (p < 0.001 both CI-subtypes), multiterritorial infarctions (SCCI, p = 0.003; non-SCCI, p < 0.001) and cardioembolic more frequent than large-artery atherosclerosis origin (p < 0.001 for both CI-subtypes). SCCI was associated with older age (p < 0.001), whereas non-SCCI was associated with stroke history (p = 0.036) and vertebrobasilar stenosis/occlusion (p = 0.002). SCCI were older (p = 0.046) than non-SCCI patients, had less frequently prior stroke (p < 0.001), and more frequent cardioembolic infarction (p = 0.025).

In patients without known high cardioembolic risk (n = 348), SCCI was strongly associated with subsequent cardioembolism diagnosis (OR 3.00 [CI 1.58–5.73, p < 0.001]). No such association was present in non-SCCI.

Conclusions

Acute or chronic SCCI are strongly associated with a cardioembolic origin.

Focal Ischaemic Infarcts Expand Faster in Cerebellar Cortex than Cerebral Cortex in a Mouse Photothrombotic Stroke Model

It is generally accepted that the cerebellum is particularly vulnerable to ischaemic injury, and this may contribute to the high mortality arising from posterior circulation strokes. However, this has not been systematically examined in an animal model. This study compared the development and resolution of matched photothrombotic microvascular infarcts in the cerebellar and cerebral cortices in adult 129/SvEv mice of both sexes. The photothrombotic lesions were made using tail vein injection of Rose Bengal with a 532 nm laser projected onto a 2 mm diameter aperture over the target region of the brain (with skull thinning). Infarct size was then imaged histologically following 2 h to 30-day survival using serial reconstruction of haematoxylin and eosin stained cryosections. This was complemented with immunohistochemistry for neuron and glial markers. At 2 h post-injury, the cerebellar infarct volume averaged ~ 2.7 times that of the cerebral cortex infarcts. Infarct volume reached maximum in the cerebellum in a quarter of the time (24 h) taken in the cerebral cortex (4 days). Remodelling resolved the infarcts within a month, leaving significantly larger residual injury volume in the cerebellum. The death of neurons in the core lesion at 2 h was confirmed by NeuN and Calbindin immunofluorescence, alongside activation of astrocytes and microglia. The latter persisted in the region within and surrounding the residual infarct at 30 days. This comparison of acute focal ischaemic injuries in cerebellar and cerebral cortices provides direct confirmation of exacerbation of neuropathology and faster kinetics in the cerebellum.

Compare the Intracranial Pressure Trend after the Decompressive Craniectomy between Massive Intracerebral Hemorrhagic and Major Ischemic Stroke Patients

Objective

Massive intracerebral hemorrhage (ICH) and major infarction (MI) are devastating cerebral vascular diseases. Decompression craniectomy (DC) is a common treatment approach for these diseases and acceptable clinical results have been reported. Author experienced the postoperative intracranaial pressure (ICP) trend is somewhat different between the ICH and MI patients. In this study, we compare the ICP trend following DC and evaluate the clinical significance.

Methods

One hundred forty-three patients who underwent DC following massive ICH (81 cases) or MI (62 cases) were analyzed retrospectively. The mean age was 56.3±14.3 (median=57, male : female=89 : 54). DC was applied using consistent criteria in both diseases patients; Glasgow coma scale (GCS) score less than 8 and a midline shift more than 6 mm on brain computed tomography. In all patients, ventricular puncture was done before the DC and ICP trends were monitored during and after the surgery. Outcome comparisons included the ictus to operation time (OP-time), postoperative ICP trend, favorable outcomes and mortality.

Results

Initial GCS (p=0.364) and initial ventricular ICP (p=0.783) were similar among the ICH and MI patients. The postoperative ICP of ICH patients were drop rapidly and maintained within physiological range if greater than 80% of the hematoma was removed. While in MI patients, the postoperative ICP were not drop rapidly and maintained above the physiologic range (MI=18.8 vs. ICH=13.6 mmHg, p=0.000). The OP-times were faster in ICH patients (ICH=7.3 vs. MI=40.9 hours, p=0.000) and the mortality rate was higher in MI patients (MI=37.1% vs. ICH=17.3%, p=0.007).

Conclusion

The results of this study suggest that if greater than 80% of the hematoma was removed in ICH patients, the postoperative ICP rarely over the physiologic range. But in MI patients, the postoperative ICP was above the physiologic range for several days after the DC. Authors propose that DC is no need for the massive ICH patient if a significant portion of their hematoma is removed. But DC might be essential to improve the MI patients’ outcome and timely treatment decision.

Recent Advances in Cerebellar Ischemic Stroke Syndromes Causing Vertigo and Hearing Loss

Cerebellar ischemic stroke is one of the common causes of vascular vertigo. It usually accompanies other neurological symptoms or signs, but a small infarct in the cerebellum can present with vertigo without other localizing symptoms. Approximately 11 % of the patients with isolated cerebellar infarction simulated acute peripheral vestibulopathy, and most patients had an infarct in the territory of the medial branch of the posterior inferior cerebellar artery (PICA). A head impulse test can differentiate acute isolated vertigo associated with PICA territory cerebellar infarction from more benign disorders involving the inner ear. Acute hearing loss (AHL) of a vascular cause is mostly associated with cerebellar infarction in the territory of the anterior inferior cerebellar artery (AICA), but PICA territory cerebellar infarction rarely causes AHL. To date, at least eight subgroups of AICA territory infarction have been identified according to the pattern of neurotological presentations, among which the most common pattern of audiovestibular dysfunction is the combined loss of auditory and vestibular functions. Sometimes acute isolated audiovestibular loss can be the initial symptom of impending posterior circulation ischemic stroke (particularly within the territory of the AICA). Audiovestibular loss from cerebellar infarction has a good long-term outcome than previously thought. Approximately half of patients with superior cerebellar artery territory (SCA) cerebellar infarction experienced true vertigo, suggesting that the vertigo and nystagmus in the SCA territory cerebellar infarctions are more common than previously thought. In this article, recent findings on clinical features of vertigo and hearing loss from cerebellar ischemic stroke syndrome are summarized.

Injury of the dentato-rubro-thalamic tract in patients with cerebellar infarct: Case report

RATIONALE

Several studies using diffusion tensor tractography (DTT) have reported on injury in the dentato-rubro-thalamic tract (DRTT) in patients with brain injury. However, there is no study of injury in the DRTT following cerebellar infarct. We report on patients with injury in the DRTT following cerebellar infarct, demonstrated on DTT.

PATIENT CONCERNS

Three patients with cerebellar infarct were enrolled in this study. Diffusion tensor imaging data were acquired at 3 weeks (patient 1) and 2 weeks (patients 2 and 3) after onset and the DRTT was reconstructed. The Scale for Assessment and Rating of Ataxiaand the Functional Ambulation Category were used for evaluation of ataxia and gait function.

DIAGNOSES AND OUTCOMES

With clinical evaluation, patient 1 scored 18, patient 2 scored 22, and patient 3 scored 28 points on the Scale for Assessment and Rating of Ataxia. On the Functional Ambulation Category patient 1 scored 2, patient 2 scored 2, and patient 3 scored 1 point. DRTT abnormalities were as follows: discontinuation (the upper portion of the left DRTT in the patient 1), narrowing (the lower portion of the left DRTT in patient 2, and the whole right DRTT in the patient 3), and nonreconstruction (the left DRTT in the patient 3).

LESSONS

Using DTT, we demonstrated injury in the DRTT in 3 patients with severe ataxia following cerebellar infarct. We believe that evaluation of the DRTT would be helpful in patients who develop ataxia following cerebellar infarct.

Association and differences in genetic polymorphisms in PCSK9 gene in subjects with lacunar infarction in the Han and Uygur populations of Xinjiang Uygur Autonomous Region of China

Polymorphisms in the proprotein convertase subtilisin/kexin type 9 (PCSK9) gene are associated with severe hypercholesterolemia and stroke. Here, we investigated the relationship between single nucleotide polymorphisms in PCSK9 and stroke in 237 patients with lacunar infarction in the Uygur and Han populations in Xinjiang Uygur Autonomous Region of China. Using the SNaPshot single-base terminal extension method, four PCSK9 gene polymorphisms were analyzed. We found a significantly strong relationship between the PCSK9 rs17111503 (G > A) polymorphism and increased susceptibility to lacunar infarction by variant homozygote comparison, and using the dominant and recessive models in the Han population but not in the Uygur population. Low triglyceride levels were found in AA carriers (rs17111503, G > A) in the Han population but not in the Uygur population. Association analysis revealed that the rs17111503 (G > A) polymorphism was not significantly associated with smoking, alcohol drinking, history of hypertension or diabetes in the Han or Uygur lacunar infarction patients. rs11583680, rs483462 and rs505151 were not associated with risk of lacunar infarction in the Han or Uygur populations. Our findings suggest that the PCSK9 rs17111503 (G > A) polymorphism is associated with susceptibility to lacunar infarction in the Han population but not in the Uygur population.

Clinical and radiologic features and their relationships with neurofunctional scores in patients with acute cerebellar infarct

Background:

Cerebellar infarct is a rare condition with very nonspecific clinical features. The aim of this study was to assess the full spectrum of the clinical characteristics, neuroimaging findings and neurofunctional analyses of cerebellar infarction, and the relationship between them.

Materials and Methods:

Data were collected from 59 patients admitted to our department during an 8-year period. We retrospectively analyzed the relationship between demographic characteristics, clinical symptomatology, etiological factors, functional condition, vascular distribution, frequency of subcortical white matter lesions (WMLs), and concomitant lesion outside the cerebellum in patients with acute cerebellar infarct (ACI) at time of admission.

Results:

The mean age in our series was 65.2 years, with most being male (57.6%). The posterior inferior cerebellar (PICA) artery was the most commonly affected territory at 62.7%. There was concomitant lesion outside the cerebellum in 45.7%. The main etiology in PICA was cardioembolism. While mean National Institutes of Health Stroke Scale on admission was 2.08 ± 1.67 in study group, modified Rankin Scale (mRS) on admission was detected to be mRS1 (n: 44, 74.5%) and mRS2 (n: 12, 20.3%) most frequently. Fourteen (35%) patients were detected to be in Fazekas stage 0; 11 (27.5%) patients in Fazekas stage 1; 6 (15%) patients in Fazekas stage 2; and 9 (22.5%) patients in Fazekas stage 3.

Conclusion:

Cerebellar infarct is very heterogeneous. The other cerebral area infarcts which accompany ACI negatively affect neurologic functional scores. Although it is difficult to detect the relationship between WMLs and neurologic functional severity, timely detection of risk factors and their modulation may be associated with prevention and treatability of WMLs, and this may be one of the important points for prevention of stroke-related disability.

Neurological signs in 23 dogs with suspected rostral cerebellar ischaemic stroke

BACKGROUND

In dogs with ischaemic stroke, a very common site of infarction is the cerebellum. The aim of this study was to characterise neurological signs in relation to infarct topography in dogs with suspected cerebellar ischaemic stroke and to report short-term outcome confined to the hospitalisation period. A retrospective multicentre study of dogs with suspected cerebellar ischaemic stroke examined from 2010-2015 at five veterinary referral hospitals was performed. Findings from clinical, neurological, and paraclinical investigations including magnetic resonance imaging were assessed.

RESULTS

Twenty-three dogs, 13 females and 10 males with a median age of 8 years and 8 months, were included in the study. The Cavalier King Charles Spaniel (n = 9) was a commonly represented breed. All ischaemic strokes were located to the vascular territory of the rostral cerebellar artery including four extensive and 19 limited occlusions. The most prominent neurological deficits were gait abnormalities (ataxia with hypermetria n = 11, ataxia without hypermetria n = 4, non-ambulatory n = 6), head tilt (n = 13), nystagmus (n = 8), decreased menace response (n = 7), postural reaction deficits (n = 7), and proprioceptive deficits (n = 5). Neurological signs appeared irrespective of the infarct being classified as extensive or limited. All dogs survived and were discharged within 1-10 days of hospitalisation.

CONCLUSIONS

Dogs affected by rostral cerebellar ischaemic stroke typically present with a collection of neurological deficits characterised by ataxia, head tilt, and nystagmus irrespective of the specific cerebellar infarct topography. In dogs with peracute to acute onset of these neurological deficits, cerebellar ischaemic stroke should be considered an important differential diagnosis, and neuroimaging investigations are indicated. Although dogs are often severely compromised at presentation, short-term prognosis is excellent and rapid clinical improvement may be observed within the first week following the ischaemic stroke.

The Usefulness of the TOAST Classification and Prognostic Significance of Pyramidal Symptoms During the Acute Phase of Cerebellar Ischemic Stroke

Cerebellar stroke is a rare condition with very nonspecific clinical features. The symptoms in the acute phase could imitate acute peripheral vestibular disorders or a brainstem lesion. The aim of this study was to assess the usefulness of the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification in cerebellar stroke and the impact of clinical features on the prognosis. We retrospectively analyzed 107 patients with diagnosed ischemic cerebellar infarction. We studied the clinical features and compared them based on the location of the ischemic lesion and its distribution in the posterior interior cerebellar artery (PICA), superior cerebellar artery (SCA), and anterior inferior cerebellar artery (AICA) territories. According to the TOAST classification, stroke was more prevalent in atrial fibrillation (26/107) and when the lesion was in the PICA territory (39/107). Pyramidal signs occurred in 29/107 of patients and were more prevalent when the lesion was distributed in more than two vascular regions (p = 0.00640). Mortality was higher among patients with ischemic lesion caused by cardiac sources (p = 0.00094) and with pyramidal signs (p = 0.00640). The TOAST classification is less useful in assessing supratentorial ischemic infarcts. Cardioembolic etiology, location of the ischemic lesion, and pyramidal signs support a negative prognosis.

Infratentorial posterior circulation stroke in a Nigerian population: Clinical characteristics, risk factors, and predictors of outcome

Background:

Posterior circulation stroke (PCS), though less common, differs from stroke in anterior circulation in many aspects. Relatively, it portends a poorer prognosis. However, there is a paucity of data from African countries, in particular, where stroke is a menace.

Objective:

The study aimed to evaluate the etiology, clinical characteristics, outcome, and predictors of outcome in a cohort of patients with IPCS in Northwestern Nigeria.

Materials and Methods:

Out of 595 patients with stroke, we prospectively analyzed 57 patients with PCS in a Tertiary Care Center in Kano, Northwestern Nigeria. Patients were analyzed for demographic data, risk factors, clinical characteristics, stroke subtypes, mortality, and predictors of mortality.

Results:

Posterior circulation ischemic stroke accounted for 57 (9.6%) of 595 of all strokes seen in the study period. They comprised 44 males (mean age 47.8 ± 17.7) and 13 females (mean age 46.3 ± 13.7). Overall, their age ranged between 24 and 90 (mean age 47.4 ± 16.7). However, 52.7% of the patients were < 45 years of age. The most common site affected was the cerebellum seen in 33 (57.9%) patients. Hypertension was the most common risk factor (86%). Headache and vertigo were the most common features accounting for 83.6% and 86.3%, respectively. Thirty-eight (66.7%) patients had an ischemic stroke. Twenty-one (36.8%) of the patients died during the 1-month period of follow-up. Independent predictors of death in the study were hyperglycemia on admission and hemorrhagic stroke.

Conclusions:

IPCS occurred in a relatively younger age group. Headache and vertigo were the most common symptoms. The independent predictors of death in the study were hyperglycemia at presentation and hemorrhagic stroke.

Ischemic syndromes causing dizziness and vertigo

Dizziness/vertigo and imbalance are the most common symptoms of vertebrobasilar ischemia. Even though dizziness/vertigo usually accompanies other neurologic symptoms and signs in cerebrovascular disorders, a diagnosis of isolated vascular vertigo is increasing markedly by virtue of recent developments in clinical neurotology and neuroimaging. It is important to differentiate isolated vertigo of a vascular cause from more benign disorders involving the inner ear, since therapeutic strategies and prognosis differ between these two conditions. Over the last decade, we have achieved a marked development in the understanding and diagnosis of vascular dizziness/vertigo. Introduction of diffusion-weighted magnetic resonance imaging (MRI) has greatly enhanced detection of infarctions in patients with vascular dizziness/vertigo, especially in the posterior-circulation territories. However, well-organized bedside neurotologic evaluation is even more sensitive than MRI in detecting acute infarction as a cause of spontaneous prolonged vertigo. Furthermore, detailed evaluation of strategic infarctions has elucidated the function of various vestibular structures of the brainstem and cerebellum. In contrast, diagnosis of isolated labyrinthine infarction still remains a challenge. This diagnostic difficulty also applies to isolated transient dizziness/vertigo of vascular origin. Regarding the common nonlacunar mechanisms in the acute vestibular syndrome from small infarctions, individual strategies may be indicated to prevent recurrences of stroke in patients with vascular vertigo.

Noncommunicating Hydrocephalus

Noncommunicating hydrocephalus is often referred to as obstructive hydrocephalus and is by definition an intraventricular obstruction of cerebrospinal fluid flow. Patient symptoms depend on the rapidity of onset. Acute obstructive hydrocephalus causes sudden rise in the intracranial pressure, which may lead to death, whereas in chronic hydrocephalus there may not be any symptoms. Computed tomography and magnetic resonance imaging play important roles in the diagnosis and management of hydrocephalus. Advances in magnetic resonance imaging such as the 3D sequences and phase-contrast imaging have revolutionized the preoperative and postoperative assessment of noncommunicating hydrocephalus. We would be discussing the various causes of noncommunicating hydrocephalus and their imaging.

Cerebellar strokes: a clinical outcome review of 79 cases

INTRODUCTION

Cerebellar infarcts and haemorrhages are relatively uncommon, accounting for less than 10% of all strokes. The objective of the present study was to quantify and compare the outcomes of patients with cerebellar infarct and those of patients with cerebellar haemorrhage, as well as to identify the risk factors that predict poor outcome in patients with cerebellar stroke.

METHODS

We retrospectively reviewed the medical records of consecutive patients admitted to National University Hospital, Singapore, between 2004 and 2006, within one week of cerebellar stroke onset. Baseline data included demographics, concomitant comorbidities, and the presence or absence of brainstem compression and hydrocephalus (on computed tomography or magnetic resonance imaging). The Glasgow Outcome Scale and modified Rankin Score were used to assess outcome at discharge and at six months after discharge.

RESULTS

A total of 79 patients with cerebellar stroke were admitted during the study period. Of these 79 patients, 17.7% died and 31.6% had poor outcomes at six months after discharge. Patients with cerebellar haemorrhage were found to be more likely to have poor outcomes as compared to patients with cerebellar infarct, both at discharge (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.3-14.1) and at six months after discharge (OR 5.2, 95% CI 1.6-17.2). When compared to small lesions (< 5 cm(3)), lesions > 20 cm(3) were significantly associated with poorer outcomes and the development of hydrocephalus and brainstem compression.

CONCLUSION

Cerebellar strokes are a significant cause of morbidity and mortality. The outcomes of patients with cerebellar haemorrhage are more likely to be worse than those of patients with cerebellar infarct.

Nystagmus-based approach to vertebrobasilar stroke presenting as vertigo without initial neurologic signs

BACKGROUND

We aimed to investigate the clinical courses and common nystagmus of isolated vertigo patients with vertebrobasilar stroke.

METHODS

The patients who presented with isolated acute spontaneous vertigo with spontaneous nystagmus (acute vestibular syndrome) at the Emergency Department were retrospectively analyzed. They were referred to the Otolaryngology Department due to the absence of neurologic signs or even of imaging abnormalities after the initial examination at the Emergency Department. Various clinical features, including presenting symptoms, delayed neurologic signs, the site of infarction, and videonystagmographic (VNG) findings were analyzed.

RESULTS

Of the 468 cases of acute vestibular syndrome, 23 (4.9%) cases of radiologically proven vertebrobasilar stroke were identified. Of the 23 patients, 17 (74%) showed aggravation of vertigo or delayed neurologic signs during the admission. In the analysis of VNG, 11 (48%) cases of direction-changing gaze-evoked nystagmus, 7 (30%) cases of fixation failure in the caloric test, 6 (27%) cases of periodic alternating nystagmus, and 4 (17%) cases of atypical head-shaking nystagmus were presented. Stroke occurred in the cerebellum (n=18, 78%), medulla (n=4, 17%), and pons (n=1, 4%).

CONCLUSION

In the early stage of vertebrobasilar stroke, an accurate diagnosis was difficult in the Emergency Department even though a radiologic study was performed, but various VNG abnormalities and delayed neurologic signs could help to diagnose whether the origin is central or not.

Very small cerebellar infarcts: integration of recent insights into a functional topographic classification

BACKGROUND

Very small cerebellar infarcts (diameter <2 cm) are a frequent finding on MRI. With an increasing scientific interest in cerebral microinfarcts, very small infarcts in the cerebellum deserve more of our attention as well. The goal of the present article was to review infarct terminology and mechanisms, as well as to critically appraise the current classification system for very small cerebellar infarcts.

METHODS

A search strategy was designed to identify all relevant studies on very small cerebellar infarcts in the English language. This search was restricted to papers published up to February 21, 2013. Studies were initially identified from the MEDLINE/PubMed database using the search terms 'small cerebellar infarct', 'lacunar infarct', 'microinfarct', 'end zone infarct', 'border zone infarct', 'watershed infarct', 'territorial infarct', and 'nonterritorial infarct'. Furthermore, a similar search strategy was directed to identify all relevant articles on (descriptive and functional) neuroanatomy and neuroimaging of the cerebellum.

RESULTS

Very small cerebellar infarcts have been referred to as lacunar infarcts, as junctional, border zone or watershed infarcts, as nonterritorial infarcts, as very small territorial or end zone infarcts, or simply as (very) small cerebellar infarcts. Since the original clinicoradiological study on these small infarcts, the classification into border zones remains in common use. This classification is based upon the assumption that these infarcts occur secondary to low flow in between arterial perfusion territories, where flow is believed to be the lowest. Later studies, however, have suggested occlusion of small (end-) arteries as a prerequisite for the pathogenesis of even small cerebellar infarcts, with low flow merely as a potential contributor. Therefore, it is likely that infarcts may as well occur in a nonborder zone distribution. Moreover, the classification into border zones may be considered unreliable since the location of border zones is highly variable among individuals and is not known in a particular patient. Recently, a functional topographic organization has been found in the cerebellum with evidence for a motor-nonmotor dichotomy between the anterior and posterior lobe. Since the cerebellar lobes can be easily and reliably distinguished with both CT and MRI, we recommend the classification of very small cerebellar infarcts according to topographic location.

CONCLUSION

There are several fundamental concerns with the current classification of very small cerebellar infarcts according to border zones, which we would like to overcome by recommending a new classification system based on topography. This will allow for a reliable and reproducible way of classifying very small cerebellar infarcts and is expected to improve clinicoradiological correlation.

Clinical significance of pathological eye movements in diagnosing posterior fossa stroke

CONCLUSION

Close observation of pathological eye movements such as disconjugate eye movements, multi-directional gaze nystagmus, and persistent unilateral gaze nystagmus may facilitate the effort of clinicians to arrange magnetic resonance imaging (MRI) study, because physical examinations may overlook the posterior fossa lesions.

OBJECTIVE

This paper reviews our experience of patients with posterior fossa stroke via observation of pathological eye movements over the past 10 years.

METHODS

Seventy patients with posterior fossa stroke manifested as acute vertiginous attack were admitted. All patients underwent examination of eye movements, MRI, and a battery of audiovestibular function tests.

RESULTS

Of the 70 patients, 22 (31%) demonstrated pathological eye movements including persistent (>24 h) unilateral gaze nystagmus in 12 patients, and multi-directional gaze nystagmus in 10 patients. Conjugate eyes movements were identified in 18 patients, and disconjugate eye movements were shown in 4 patients including medial longitudinal fasciculus syndrome in 1, paramedian pontine reticular formation syndrome in 1, and one and a half syndrome in 2. The vestibular test battery revealed abnormal responses for >85% of the patients in each test. MRI demonstrated infarction or hemorrhage involving the brainstem in 12 patients, cerebellum in 8 patients, and both in 2 patients.