Cerebellar infarction--clinical and cranial computerized tomography correlations

Bilateral symmetric junctional infarctions of the cerebellum: a case report

The advances in neuroimaging have improved clinicoanatomic correlations in patients with stroke. Junctional infarct is a distinct term, used to describe border zone infarcts of the posterior fossa. We presented computed tomography (CT) and magnetic resonance imaging (MRI) findings in a rare case of bilateral symmetrical junctional infarcts between the superior cerebellar artery (SCA) and posterior inferior cerebellar artery (PICA) territories. In addition to precise knowledge of arterial territories required to achieve accurate localization of ischemic lesions on CT and MRI, the radiologist must also be aware of radiologic features and geographic territories of cerebellar arteries and their junctional infarctions.

Lesion Patterns and Etiology of Ischemia in Superior Cerebellar Artery Territory Infarcts

BACKGROUND AND PURPOSE

Infarcts in the territory of superior cerebellar artery (SCA) are uncommon. The clinical, and etiological mechanisms of different infarct patterns of SCA are not well known. Diffusion-weighted imaging (DWI) is superior to conventional magnetic resonance imaging for detecting acute small and multiple ischemic lesions.

METHODS

We studied 60 patients with lesions involving SCA territory proved by DWI, which have been selected from 3,800 patients with first ischemic stroke consecutively admitted to our stroke unit over a period of 5 years.

RESULTS

There are 7 distinctive SCA lesion patterns: (1) a lesion was found in the medial (m) branch territory of SCA (mSCA) in 14 patients; (2) a lesion in the lateral (l) branch territory of SCA (lSCA) was seen in 9 patients; (3) a coexisting lesion involving mSCA and lSCA was found in 9 patients; (4) a lesion in cortical borderzones between SCA and m/l branches of the posterior inferior cerebellar artery (PICA) was observed in 6 patients; (5) a lesion in deep borderzones between lSCA and mSCA, and lPICA and mPICA was present in 8 patients; (6) a lesion involving the medial rostral cerebellum between the right and left SCA was found in 4 patients; (7) multiple lesions involving SCA and other vertebrobasilar artery territories were present in 10 patients. The main cause was possible artery-to-artery embolism from atherosclerotic vertebrobasilar arteries to distal branches of SCA in 20 patients (33%). Fourteen patients had a source of cardioembolism (23%), and 6 patients (8%) had concomitant atherosclerotic vertebrobasilar artery disease and a source of cardioembolism.

CONCLUSIONS

An acute ischemic lesion in the SCA territory is mainly multiple. The lSCA territory was the most involved area. Small territorial infarcts were frequently associated with large territorial SCA infarcts. Borderzone SCA infarcts occurred in one third of the patients with transient benign symptoms. Mass effects are unusual despite the large amount of SCA involvement. Our results supported the fact that embolism is the predominant stroke mechanism in the SCA territory infarction.

Isolated lateropulsion of the trunk in cerebellar infarct

MRI in a 63-year-old male with isolated lateropulsion of the trunk disclosed an infarct in the inferior portion of the right cerebellar hemisphere, suggesting an end-zone type infarct in the lateral branch of the right posterior inferior cerebellar artery (1PICA) or a borderzone infarct between 1PICA and superior cerebellar artery. A close clinico-topographical relationship between isolated lateropulsion of the trunk and lesion in the territory of 1PICA was demonstrated.

The clinical and topographic spectrum of cerebellar infarcts: a clinical-magnetic resonance imaging correlation study

We studied 34 consecutive patients with non-mass-producing cerebellar infarcts using a standard protocol of investigations including magnetic resonance imaging (MRI). We analyzed the topography of infarcts to determine the involved arterial territories and we correlated the findings with neurological dysfunction and potential causes of stroke. Sixteen patients had an infarct in the territory of the posterior inferior cerebellar artery (PICA); 2, in the territory of the anterior inferior cerebellar artery (AICA); 13, in the territory of the superior cerebellar artery (SCA); and 8 had junctional infarcts between the territories of the medial and lateral branches of the PICA or PICA/SCA territories. PICA or medial PICA territory infarcts were manifested by acute vertigo and truncal ataxia, while the patients with lateral PICA territory infarcts presented with unsteadiness, limb ataxia and dysmetria without dysarthria. Patients with infarcts in the AICA territory were characterized by limb and trunk ataxia associated with signs of lateropontine involvement. Patients with SCA territory infarcts presented with dysarthria, unsteadiness and/or vertigo, limb ataxia, and dysmetria. Cardiac embolism was the main cause of large infarcts in the territories of the PICA (8/16) or SCA (4/7). Multiple small infarcts were associated with vertebrobasilar atherosclerosis (8/12). These clinical-MRI correlations allow better definition of the topographic and etiological spectrum of cerebellar infarction, which was previously based on pathological studies in subjects with severe infarction.

Cerebellar infarction. Clinical and anatomic observations in 66 cases

BACKGROUND AND PURPOSE

Cerebellar infarction displays different clinical features, depending on the vascular territory involved. We studied patients with infarcts in the territories of the posterior inferior cerebellar artery or the superior cerebellar artery to compare their clinical presentation, course, and prognosis.

METHODS

We retrospectively analyzed the clinical features, laboratory data, and imaging studies of 66 patients with cerebellar infarction collected consecutively at five institutions. All the cerebellar infarcts were documented on computed tomographic scan or magnetic resonance imaging.

RESULTS

Two distinct profiles emerged, depending on the vascular territory involved. In 36 patients with posterior inferior cerebellar artery territory infarcts, a triad of vertigo, headache, and gait imbalance predominated at stroke onset. Computed tomography showed severe cerebellar mass effect in 11 cases (30%), with associated hydrocephalus in seven. In these seven patients (19%), postinfarct swelling led to brain stem compression that resulted in four deaths. In 30 patients with superior cerebellar artery infarcts, gait disturbance predominated at onset; vertigo and headache were significantly less common. The clinical course was usually benign. Computed tomography showed marked cerebellar mass effect, hydrocephalus, and brain stem compression in only two instances (7%). Presumed cerebral embolism was the predominant stroke mechanism in patients with superior cerebellar artery distribution infarcts, whereas in those with posterior inferior cerebellar artery distribution infarcts, the stroke mechanism was equally divided between cardiogenic embolism and posterior circulation arterial disease.

CONCLUSIONS

Cerebellar infarcts in the posterior inferior cerebellar artery and superior cerebellar artery distribution have distinct differences in clinical presentation, course, and prognosis. These differences should help in the selection of appropriate monitoring and treatment strategies.

Cerebellar infarction: comparison of computed tomography and magnetic resonance imaging

We correlated clinical, computed tomographic (CT), and magnetic resonance imaging (MRI) findings in 14 patients with cerebellar infarctions. Before MRI, the diagnosis of cerebellar infarction was made in only 7 patients on the basis of clinical and CT evidence. Cerebellar infarction was bilateral in 3 patients and was associated with brainstem infarction in 6. Infarction occurred in the territory of the posterior inferior cerebellar artery (PICA) in 12 patients. The territory of the superior cerebellar artery (SCA) was involved in 1 patient, and 1 infarction encompassed the watershed between the PICA and the SCA. In patients with infarction of the PICA territory, the medial and intermediate hemispheric segments were most frequently involved. Involvement of the lateral hemispheric segment was infrequent and was independent of brainstem involvement. Because of its fine demonstration of anatomical detail, its lack of bony artifact, and its ability to visualize infarctions readily within the first 24 hours, MRI is an excellent method for demonstrating cerebellar infarction.