Multiple Cerebellar Infarcts: Clinical and Pathophysiologic Features

Baseline Factors Affecting the Prognosis of Ischemic Cerebellar Stroke Patients in Turkey: A Cross-Sectional Study

BACKGROUND

Cerebellar infarcts are encountered commonly in clinical practice; however, they are likely to be misinterpreted. They cannot be adequately evaluated on scales such as the National Institute of Health Stroke Scale (NIHSS), which can have fatal consequences.

AIM

To evaluate the baseline features, prognosis, and 6-month survival in patients with cerebellar stroke.

METHODS

A total of 200 patients with cerebellar ischemia were included in the study. Patients were analyzed retrospectively from 10 years of data. Both univariate and multivariate analyses were evaluated.

RESULTS

Mean age was 68 years old, and men were more frequently affected. The most common symptoms were dysarthria and vertiginous sensations. Ischemic lesions were usually cortical/juxtacortical, multiple, hemispheric, and small (below 1.5 cm). The most commonly affected artery was the medial branch of the posterior inferior cerebellar artery. Cardioembolism was the more frequent etiology. Gait ataxia was associated with a more favorable prognosis and 6-month modified Rankin Scale (mRS) scores (OR: 0.15, 95% CI, P = 0.03). Older age (OR: 1.75, 95%, P = 0.02), female gender (OR: 6.72, 95%, P = 0.02), multiple (OR: 10.92, 95%, P = 0.01) and large lesions (OR: 6.56, 95% CI, P = 0.01), posterior circulation ischemic lesions extra-cerebellum (OR: 8.33, 95% CI, P = 0.01), left ventricular apical hypokinesia or AF (OR: 5.58, 95% CI, P = 0.02), and a high mRS score on admission (OR: 5.21, 95% CI, P < 0.001) was correlated with higher 6-month mRS and a lower survival rates.

CONCLUSION

The study found that some baseline clinical, neurovascular imaging findings, and the mRS score on admission are useful predictors of cerebellar stroke prognosis and outcome.

Incidence and clinical features of acute multiple small cerebellar infarction

OBJECTIVE

To investigate the clinical and imaging features and to identify possible etiology of acute multiple small cerebellar infarction (MSCI).

METHODS

We retrospectively enrolled 220 patients with acute cerebellar infarction, divided them into MSCI and large cerebellar infarction (LCI) groups, according to the quantity and size of lesions confirmed by MRI analysis. Clinical and imaging features were compared between the two groups to explore the possible etiology and pathogenesis.

RESULTS

Among 220 patients, 90 patients presented MSCI symptoms. The proportions of extracerebellar lesions (P = 0.001) and bilateral infarction (P = 0.001) in the MSCI group were higher than those in the LCI group. No significant differences were found in terms of age, gender, and common vascular risk factors between the two groups. The proportions of vertigo and headache in the MSCI group were significantly lower than those in the LCI group (P < 0.000 and 0.034, respectively), and limb weakness was significantly higher (P = 0.039) in the MSCI patients. Moreover, the proportions of nystagmus and ataxia in the MSCI group were significantly lower than those in the LCI group (P < 0.043 and 0.003, respectively). The MSCI group had higher proportions of ACA and MCA stenosis, while the proportion of posterior circulation stenosis was similar between the two groups. Infarctions involving the posterior inferior cerebellar (PICA) region and mixed territories were far more frequent than those involving the anterior inferior cerebellar artery (AICA) region and superior cerebellar artery (SCA) territory (P < 0.05). Large-artery atherosclerosis and multiple plus undetermined etiology were the main etiological factors of MSCI.

CONCLUSION

In patients with acute cerebellar infarction, 30% of patients presented with MSCI. MSCI and LCI showed similar vascular risk factors and vascular stenosis in the posterior circulation system. Patients with MSCI should pay more attention to evaluating anterior circulation vessels' anatomy. Large-artery atherosclerosis was the main pathogenesis of acute MSCI. Assessment of cerebral vessels might be critically required in patients with MSCI complicated atrial fibrillation.

Frequency, Aetiology, and Outcome of Small Cerebellar Infarction

BACKGROUND AND PURPOSE

Strokes due to small (<2 cm) cerebellar infarction are under-recognised, and their profile and aetiology have not been well characterised. We aimed to determine the frequency, clinical features, aetiology, and outcome of small as compared to large cerebellar infarction.

METHODS

This study is a retrospective analysis of clinical and imaging features of a prospectively assessed series of 108 consecutive patients with acute cerebellar infarction admitted to Liverpool Hospital, Sydney, NSW, Australia, during 2011-2015.

RESULTS

The mean age of the patients was 67 years, and 33 (31%) had small cerebellar infarction. Compared to large cerebellar infarction, those with small cerebellar infarction had a comparable distribution of vascular risk factors but significantly less nausea and vomiting, gait disturbance, limb ataxia, and dysarthria. The posterior (n = 22, 67%) lobe was most commonly affected, followed by the anterior (n = 9, 27%) and flocculonodular (n = 2) lobes. Dizziness, limb ataxia, and nystagmus were significantly more common in patients with anterior lobe infarction. Vertebrobasilar disease was the presumed aetiology in 40 patients (37%), and was less commonly seen in small as compared to large cerebellar infarction. Cardioembolism affected 37% of the patients, irrespective of the size or topography of the cerebellar infarction, and there was no relation of supratentorial white matter lucencies (WMLs) to the size of cerebellar infarction. At 3 months, 65% of the patients were functionally independent (according to modified Rankin Scale scores of 0-2), and having a poor outcome was significantly related to moderate-to-severe supratentorial WML and large cerebellar infarction.

CONCLUSIONS

Small cerebellar infarction accounted for one-third of the ischaemic strokes in this location, most often involved the posterior lobe, causing fewer clinical features, and had a better clinical outcome than large cerebellar infarction. Patients with small cerebellar infarction require appropriate vascular management including investigation for a cardioembolic source.

Cerebellar Cortical Infarct Cavities

Background and Purpose—

Small cerebellar infarct cavities have been recently found on magnetic resonance imaging (MRI) to preferentially involve the cerebellar cortex, but epidemiological studies are lacking. We aimed to determine the prevalence and risk factor profiles of cerebellar cortical infarct cavities (≤1.5 cm) as well as their association with MRI markers of cerebrovascular disease and functioning.

Methods—

We analyzed the 1.5 Tesla MRI of 636 patients (mean age, 62±9 years; 81% men) from the Second Manifestations of Arterial Disease-Memory, Depression and Aging (SMART-Medea) study. Logistic regression analyses were performed to estimate the associations of age, sex, vascular risk factors, MRI markers of cerebrovascular disease, and functioning with cerebellar cortical cavities, adjusted for age and sex.

Results—

Cerebellar cortical infarct cavities occurred on MRI in 10% of patients and were significantly associated with age, intima-media thickness (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.1–3.7), high levels of homocysteinemia (OR, 1.8; 95% CI, 1.0–3.3), cortical infarcts (OR, 2.9; 95% CI, 1.6–5.4), gray matter lacunes of presumed vascular origin (OR, 3.0; 95% CI, 1.6–5.8), brain stem infarcts (OR, 5.1; 95% CI, 1.9–13.6), and decreased brain parenchymal fraction (OR, 0.84; 95% CI, 0.74–0.94), but not with white matter hyperintensities (OR, 1.2; 95% CI, 0.8–1.8) or white matter lacunes of presumed vascular origin (OR, 1.1; 95% CI, 0.5–2.5). They were also associated with worse physical functioning (OR 0.96; 95% CI, 0.94 to 0.99) but not with mental functioning.

Conclusions—

Cerebellar cortical infarct cavities are far more common than previously assumed based on symptomatic case series and are associated with markers of atherothromboembolic cerebrovascular disease.

Cerebellar infarct patterns: The SMART-Medea study

OBJECTIVE

Previous studies on cerebellar infarcts have been largely restricted to acute infarcts in patients with clinical symptoms, and cerebellar infarcts have been evaluated with the almost exclusive use of transversal MR images. We aimed to document the occurrence and 3D-imaging patterns of cerebellar infarcts presenting as an incidental finding on MRI.

METHODS

We analysed the 1.5 Tesla MRI, including 3D T1-weighted datasets, of 636 patients (mean age 62 ± 9 years, 81% male) from the SMART-Medea study. Cerebellar infarct analyses included an assessment of size, cavitation and gliosis, of grey and white matter involvement, and of infarct topography.

RESULTS

One or more cerebellar infarcts (mean 1.97; range 1-11) were detected in 70 out of 636 patients (11%), with a total amount of 138 infarcts identified, 135 of which showed evidence of cavitation. The average mean axial diameter was 7 mm (range 2-54 mm), and 131 infarcts (95%) were smaller than 20 mm. Hundred-thirty-four infarcts (97%) involved the cortex, of which 12 in combination with subcortical white matter. No infarcts were restricted to subcortical branches of white matter. Small cortical infarcts involved the apex of a deep (pattern 1) or shallow fissure (pattern 2), or occurred alongside one (pattern 3) or opposite sides (pattern 4) of a fissure. Most (87%) cerebellar infarcts were situated in the posterior lobe.

CONCLUSIONS

Small cerebellar infarcts proved to be much more common than larger infarcts, and preferentially involved the cortex. Small cortical infarcts predominantly involved the posterior lobes, showed sparing of subcortical white matter and occurred in characteristic topographic patterns.

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.

Cerebellar infarctions mimicking acute peripheral vertigo: how to avoid misdiagnosis?

OBJECTIVE

To determine the prevalence of cases of missed cerebellar stroke mimicking acute peripheral vertigo (APV), the so-called pseudo-APV, and to identify the clinical indicators useful for differentiating APV from cerebellar infarction that presents as isolated vertigo.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

We conducted a retrospective chart review of cases of missed cerebellar infarction over the past 5 years. All patients had first undergone an otoneurological evaluation and computed tomography brain scan in the emergency department before a complete bedside examination was performed in our otoneurological unit.

RESULTS

We identified 11 patients with pseudo-APV (2.8% of all the cases presenting to our unit complaining of acute vertigo). Spontaneous nystagmus (of central type in 2 cases) was recorded in all patients. The Head Impulse Test was clearly negative in 9 cases. The duration of vertigo lasted more than 72 hours in 7 patients. In 4 patients, delayed neurological signs followed acute vertigo 2 to 3 days after the onset. Magnetic resonance imaging showed 8 cases of infarction in the posterior-inferior cerebellar artery territory; in 1 patient, an involvement of the anterior-inferior cerebellar artery territory was recorded; 2 patients showed a hemispheric ischemic cerebellar involvement.

CONCLUSIONS

Pseudo-APV is not an uncommon diagnosis in otoneurological practice. The presence of moderate-severe imbalance and the persistence of vertigo for more than 72 h from the onset, together with the results of bedside examination tests (spontaneous nystagmus and Head Impulse Test), are useful indicators for recognizing a cerebellar ischemic origin in cases of acute vertigo.

Trigemino-autonomic headache related to Gasperini syndrome

We report the association of ipsilateral trigemino-autonomic headache to a case of right-sided nuclear facial and abducens palsy (Gasperini syndrome), ipsilateral hypacusis and right hemiataxia, caused by the occlusion of the right anterior inferior cerebellar artery. Short-lasting attacks of mild to moderate ipsilateral fronto-periorbital head pain, accompanied by lacrimation and mild conjunctival injection during more severe attacks, were present from the onset of symptoms, with a gradual worsening over the next few months and remitting during naproxen therapy. Magnetic resonance imaging showed an infarct in the right cerebellar peduncle, extending toward the pontine tegmentum, also involving the ipsilateral spinal trigeminal nucleus and tract and the trigeminal entry zone. Gasperini syndrome may be accompanied by ipsilateral trigemino-autonomic head pain.

Superior cerebellar artery infarction in endovascular treatment for tentorial dural arteriovenous fistulas

BACKGROUND

Superior cerebellar artery (SCA) syndrome shows ipsilateral cerebellar ataxia and Horner's syndrome, contralateral superficial sensory disturbance, as well as nystagmus toward the impaired side, vertigo, and nausea. Occasionally, unilateral lesions may produce bilateral hypogeusia and contralateral hypoacusia.

OBJECTIVE

To report 2 patients with unilateral lower midbrain ischemic lesions of the inferior colliculus level caused by transarterial embolization for tentorial dural arteriovenous fistulas (TDAVFs).

METHODS

Hospital records for 21 patients with TDAVFs mainly treated by endovascular techniques between 2005 and 2008 were reviewed. Two patients with MRI evidence of unilateral SCA territory infarction were investigated.

RESULTS

Of 21 patients, 2 treated transarterially with Onyx-18 (a nonahesive liquid embolic agent) developed infarctions in the territory of SCA. One patient had lateral SCA infarction characterized by ipsilateral gait ataxia, contralateral hemihypoesthesia, with additional ipsilateral ocular motor palsy and bilateral gustatory loss. And the other patient had medial SCA infarction characterized by ipsilateral ataxia contralateral hemihypoesthesia with additional contralateral hypoacusia.

CONCLUSION

SCA infarction can be caused by transarterial injection of Onyx-18 via SCA or the posterior cerebral artery (PCA) for TDAVFs and additionally presented with gustatory loss and deafness, which is generally not a feature of the SCA syndrome.

Oropharyngeal dysphagia after stroke: incidence, diagnosis, and clinical predictors in patients admitted to a neurorehabilitation unit

OBJECTIVE

We analyzed patients with stroke in a neurorehabilitation unit to define incidence of dysphagia, compare clinical bedside assessment and videofluoroscopy (VFS), and define any correlation between dysphagia and clinical characteristic of patients.

METHODS

In all, 151 consecutive inpatients with recent ischemic or hemorrhagic stroke were enrolled.

RESULTS

Dysphagia was clinically diagnosed in 62 of 151 patients (41%). A total of 49 patients (79% of clinically dysphagic patients) underwent VFS. Six patients clinically suggested to be dysphagic had a normal VFS finding. The correlation between clinical and VFS diagnosis of dysphagia was significant (r = 0.6505). Penetrations and aspirations were observed, respectively, in 42.8% and 26.5% of patients with dysphagia, with 12.2% classified as silent. Lower respiratory tract infections were observed in 5.9%, more frequently in patients with dysphagia (30%). Dysphagia was not influenced by type of stroke. Cortical stroke of nondominant side was associated with dysphagia (P = .0322) and subcortical nondominant stroke showed a reduced frequency of dysphagia (P = .0008). Previous cerebrovascular disease resulted associated to dysphagia (P = .0399). Patients with dysphagia had significantly lower functional independence measurement (FIM) and level of cognitive functioning on admission and lower FIM on discharge, longer hospital stay, and more frequent malnutrition, and they were more frequently aphasic and dysarthric. Percutaneous endoscopic gastrostomy was used in 18 of 151 patients (11.9%) (41.8% of patients with VFS-proved dysphagia).

CONCLUSIONS

Dysphagia occurs in more than a third of patients with stroke admitted to rehabilitation. Clinical assessment demonstrates good correlation with VFS. The grade of dysphagia correlates with dysarthria, aphasia, low FIM, and level of cognitive functioning. Large cortical strokes of nondominant side are associated with dysphagia.