Superior Cerebellar Artery Infarction Research Articles

Endoscopic Far-Lateral Supracerebellar Infratentorial Approach for Petroclival Region Meningioma: Surgical Technique and Clinical Experience.

The management of petroclival region meningioma remains the ultimate achievement in neurosurgery, because of the formidable technical challenges involved. To describe the technique and feasibility of the purely endoscopic far-lateral supracerebellar infratentorial approach (EF-SCITA) for the treatment of petroclival region meningiomas. We reviewed the clinical data of 10 consecutive cases of petroclival region meningiomas treated with the EF-SCITA from August 2018 to August 2020. The clinical outcomes were analyzed. The patient was placed in the lateral position, and then, a "C" shaped incision and craniotomy with exposed sigmoid and transverse sinuses were performed. With the endoscopic holder, endoscopic procedures were performed using standard 2-hand microsurgical techniques. Whether the tentorium or Meckel cave was handled depended on the tumor extension. The mean diameter was 45 × 25 mm. Dizziness and headache were the main symptoms. All 10 patients achieved gross total or subtotal resection (Petroclival Meningioma Grade I-III) with good neurological outcomes. The EF-SCITA provides satisfactory, direct exposure to the petroclival region. Cranial nerve deficits are the main postoperative complications. Two patients had a trochlear nerve injury, 3 patients had transient facial paralysis, and 2 patients had oculomotor paralysis (1 total and 1 incomplete), but both of them recovered during the follow-up period. One patient experienced an ipsilateral superior cerebellar artery infarction, and another patient had transient hemiparesis. The EF-SCITA is effective for most petroclival region meningiomas, except for the cavernous sinus type. This approach simplifies craniotomy procedures, omits burdensome petrosectomy, and avoids crossing posterior neurovascular structures.

Bilateral Superior Cerebellar Artery Infarction after Stent-Angioplasty for Internal Carotid Artery Stenosis

Spontaneous bilateral cerebellar infarction in the territory of the superior cerebellar arteries is extremely rare. Occasionally there have been reports of bilateral cerebellar infarction due to vertebrobasilar atherosclerotic occlusion or stenosis, whereas no report of bilateral cerebellar infarction due to complicated hemodynamic changes. In this report, we present a patient with bilateral cerebral infarctions related to stenoses of bilateral internal carotid arteries, in whom vertebrobasilar system was supplied by multiple collaterals from both posterior communicating arteries and right external carotid artery. We performed stent-angioplasty of bilateral internal cerebral arterial stenosis, and then acute infarction developed on bilateral superior cerebellar artery territories. The authors assumed that the infarction occurred due to hemodynamic change between internal carotid artery and external carotid artery after stent-angioplasty for stenosis of right internal carotid artery.

Hemi- and Monoataxia in Cerebellar Hemispheres and Peduncles Stroke Lesions: Topographical Correlations

Limb ataxia of sudden onset is due to a vascular lesion in either the cerebellum or the brainstem (posterior circulation, PC, territory). This sign can involve both the upper and the lower limb (hemiataxia) or only one limb (monoataxia). The topographical correlates of limb ataxia have been studied only in brainstem strokes. Therefore, it is not yet known whether this sign is useful to localize the lesion within the entire cerebellar system, both the cerebellar hemisphere and the cerebellar brainstem pathways. Limb ataxia was semi-quantified according to the International Cooperative Ataxia Rating Scale in 92 consecutive patients with acute PC stroke. Limb ataxia was present in 70 patients. Four topographical patterns based on magnetic resonance imaging findings were identified: picaCH pattern (posterior inferior cerebellar artery infarct); scaCH pattern (superior cerebellar artery infarct); CH/CP pattern (infarct involving both the cerebellum and the brainstem cerebellar pathways); and CP pattern (infarct involving the brainstem cerebellar pathways). Hemiataxia was present in (47/70; 67.1%) and monoataxia in (23/70; 32.9%) of patients. Monoataxia involved the upper limb in (19/70; 27.1%) and the lower limb in (4/70; 5.7%) of patients. Limb ataxia usually localized the lesion ipsilaterally (picaCH, scaCH, CH/CP, and CP patterns involving the medulla and sometimes the pons) (53/70; 75.7%), but it might be due also to contralateral (CP pattern involving the pons or midbrain) (16/70; 22.9%) or bilateral lesions (1/70). Limb ataxia usually localizes the lesion ipsilaterally but the infarct might be sometimes contralateral. The occurrence of monoataxia may suggest that the cerebellar system is somatotopically organized.

MR-based follow-up of the superior cerebellar artery after radiosurgery for trigeminal neuralgia

Purpose To study with a non invasive method any potential radiological change on the superior cerebellar artery (SCA) in patients treated radiosurgically for classic trigeminal neuralgia (CTN). Materials and methods A retrospective measure of maximal dose received by SCA was performed analyzing the treatment planning in 55 consecutive patients treated by Gamma Knife radiosurgery for an CTN, then, a prospective study was designed using high resolution MR, with T2 SPIR, T1 without and with gadolinium enhancement, Proton density, 3D TONE and MIP reconstructions. Inclusion criteria were: patients followed at our institution, follow-up of one year or more, dose received by the SCA of 15 Gy or more and voluntary patient participation in the study. Patients with repeated Gamma Knife radiosurgery for failure or recurrence were excluded. The end points were: SCA occlusion, stenosis or infarction in the territory supplied by SCA. Results Sixteen patients were studied, with a mean follow-up of 25.2 months (12–42 months). The mean maximal dose received by the SCA was 57.5 Gy. (15–87 Gy). Among these 16 patients studied, neither obstruction of the SCA nor infarction was demonstrated. In one patient a suspicion of asymptomatic SCA stenosis was visualized distant to the irradiation field. Conclusions SCA can receive a high dose of irradiation during radiosurgical treatment for CTN. This study does not confirm any vascular damage to the SCA after radiosurgery for CTN.

Ataxia in posterior circulation stroke: Clinical–MRI correlations

Objective Ataxia is characterized clinically by four signs (gait and limb ataxia, dysarthria and nystagmus). Although ataxia has been described in posterior circulation (PC) stroke series, there are no prospective studies that have investigated a possible differential role of the cerebellum or its input/outputs in causing ataxia. Methods Ataxia was semi-quantified according to the International Cooperative Ataxia Rating Scale (ICARS) in 92 consecutive patients with acute PC stroke. Four topographical patterns based on magnetic resonance imaging (MRI) findings were identified: picaCH pattern (posterior inferior cerebellar artery infarct); scaCH pattern (superior cerebellar artery infarct); CH/CP pattern (infarct involving both the cerebellum and the brainstem cerebellar pathways); and CP pattern (infarct involving the brainstem cerebellar pathways). Results Gait ataxia was present in 95.7%, limb ataxia in 76.1%, dysarthria in 56.5% and nystagmus in 65.2% of patients. Gait ataxia frequency did not differ between the patterns, but was significantly more severe in the CH/CP pattern than in either picaCH (P = 0.0059) or CP (P = 0.0065) pattern. Limb ataxia was significantly less frequent (P < 0.001) and less severe (P < 0.001) in picaCH pattern than other patterns. Dysarthria was less frequent in picaCH pattern than in other patterns (P = 0.018) and less severe than in scaCH (P = 0.0043) or CP (P = 0.0047) pattern. No differences in nystagmus frequency or severity were observed across all four patterns. Conclusion In PC stroke gait ataxia was almost always present, regardless of the lesion site. Limb ataxia and dysarthria were less frequent in the picaCH pattern, whereas nystagmus, when present, did not differ among the topographical patterns.

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.

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

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

Bilateral medial cerebellar infarction in a patient positive for lupus anticoagulant

Bilateral medial cerebellar infarction occurring simultaneously is rare. We describe a middle aged male with bilateral cerebellar infarction complicated by subsequent left superior cerebellar artery infarction. Lupus anticoagulant was positive. Though the prognosis is usually considered good, our patient made poor recovery.

Bilateral infarcts in the territory of the superior cerebellar artery: Clinical presentation, presumed cause, and outcome

Backgrounds and purpose The aim of this study was to document the clinical presentation, vascular topographic patterns, stroke mechanism, and outcome of bilateral infarcts in the territory of the superior cerebellar artery (SCA) based on data collected from a prospective acute stroke registry. Methods We studied the clinical and radiological features of 11 patients with bilateral infarctions in the territory of the SCA diagnosed by brain MRI. Results Bilateral SCA infarcts represented 23.4% (11/47) of all SCA territory infarction. Bilateral SCA infarcts mostly associated with brainstem ( n = 5), cerebral ( n = 5), or non-SCA cerebellar lesions ( n = 4). The most common clinical presentation at onset was sudden fall with axial lateropulsion and dysarthria ( n = 6). In five patients with a coexisting infarct(s) in the brainstem, limb weakness and/or mental change were prominent and often masked the signs of cerebellar dysfunction. Six patients showed no stenosis or occlusion in the vertebrobasilar system on brain MRA. Five had an obvious cardiac source of emboli. Eight patients showed favorable outcomes with complete recovery or minimal disability, but three patients with additional extensive brainstem infarcts died within 1 week. Conclusions Bilateral SCA territory infarcts show variable clinical, vascular topographic, and prognostic features. They usually result from cardiac emboli.

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.

The endovascular management of superior cerebellar artery aneurysms.

Superior cerebellar artery aneurysms are rare. We present a clinical series of twelve of these aneurysms that were treated exclusively with endovascular coils. A retrospective analysis of a prospectively collected database of cerebral aneurysms treated with coil embolization was performed. Clinical notes and radiological images were reviewed. Twelve superior cerebellar artery aneurysms were treated in eleven patients between 1992 and 2001. Seven patients presented with subarachnoid hemorrhage, two with neurologic deficit, and two had asymptomatic aneurysms. Coiling resulted in complete aneurysm obliteration in six patients and incomplete obliteration in the other six. No subsequent hemorrhage occurred with follow-up between 6 and 119 months (mean follow-up 50 months). Procedural morbidity was one superior cerebellar artery infarct with good recovery. Management morbidity was one middle cerebral artery embolus during a follow-up angiogram that required thrombolysis with a good clinical result. Nine out of 11 patients on follow-up were performing at Glasgow Outcome Scale (GOS) 5. One patient with GOS 3 presented with a poor grade subarachnoid hemorrhage and the other patient with GOS 4 presented with a parenchymal hemorrhage due to an arteriovenous malformation. Endovascular treatment of superior cerebellar artery aneurysms is an effective treatment strategy with low morbidity.

Incidence of residual intracranial AVMs after surgical resection and efficacy of immediate surgical re-exploration.

The true incidence of residual lesions after surgical resection of AVMs is not well documented in the literature. Partial surgical resection is thought to not confer any improvement over the natural history risk of hemorrhage of AVMs, and in certain cases may actually increase the risk of hemorrhage. Over the past 11 years, we have adopted a policy of immediate postoperative angiography with immediate surgical re-exploration if a residual lesion is seen. The purpose of the present study was to review our experience to determine the incidence of residual lesions and subsequent outcome. From June 1991 to June 2002, 324 patients underwent craniotomy and surgical AVM resection. As per protocol, all patients underwent immediate postoperative angiography. We have a protocol for immediate surgical re-exploration if a residual lesion is seen on postoperative angiographic exam. There were total six patients (1.8% of patients operated with intracranial AVMs) with residual lesions on postoperative angiography. All six patients underwent immediate surgical re-exploration with complete 100% obliteration; two patients required two re-exploration procedures. There was one operative complication: posterior cerebral artery and superior cerebellar artery infarcts after re-exploration of residual lesion after surgical resection of a large occipito-temperal-parietal AVM. There were no other morbidities and no mortalities. The incidence of residual lesions seen on postoperative angiography after AVM surgery at an experienced center is 1.8%. Because of the potential imminent danger of hemorrhage from a residual lesion, we recommend a policy of immediate postoperative angiography (or intraoperative angiography if image quality is satisfactory) for all AVM surgery and early surgical re-exploration if a residual lesion is seen.

Functional recovery after rehabilitation for cerebellar stroke.

Relatively few data exist concerning functional recovery after ischemic and hemorrhagic cerebellar stroke. We studied patients admitted to a rehabilitation hospital after cerebellar stroke to quantify recovery after rehabilitation therapy and to identify variables that predicted functional outcome. This study was a retrospective review of consecutive cases admitted in a 4-year period with new cerebellar infarct or hemorrhage. Clinical features of stroke were recorded and comorbidities scored with the Charlson Index. Follow-up information was obtained by telephone interview. The Functional Independence Measure (FIM) was scored at admission (AFIM), discharge (DFIM), and follow-up (FFIM). Outcome measures were DFIM and FFIM. Univariate and multivariate analyses were performed. Fifty-eight cases were identified (mean age 69.2 years; 49 infarcts, 9 hemorrhages). Mean AFIM was 65.5, and mean DFIM was 89.8. Mean AFIM was significantly higher in the infarct than in the hemorrhage subgroup (70 versus 43, P:=0.006). Mean DFIM was also higher in the infarct subgroup but did not reach statistical significance (93 versus 74, P:=0.1). Follow-up information was obtained for 45 cases (78%) (mean interval 19.5 months). Median FFIM was 123.5. Outcome was significantly positively correlated with AFIM and initial presenting syndrome of vertigo/vomiting/ataxia/headache. Outcome correlated negatively with preexisting comorbidity score, altered level of consciousness at initial presentation, and superior cerebellar artery infarction. On multivariate analysis, AFIM and comorbidity score were independent predictors of outcome. Substantial improvement of mean FIM score frequently occurs after rehabilitation after cerebellar infarction. Functional outcome is best predicted by preexisting comorbidities and functional status at the time of discharge from acute hospitalization.

Post-stroke violent adventitial movement responsive to levo-dopa/carbi-dopa therapy

Previous reports in the literature concerning cerebrovascular accident have illustrated cases of post-stroke tremor. Treatments of these studies have varied. Trials of levo-dopa have been reported in two such cases. This case study reports on a case of a patient with a left thalamic, left superior cerebellar artery infarction with a lacunar infarction in the basal ganglia. The patient developed a violent tremor/movement disorder which was unresponsive to haloperidol. With this failure, and with the evidence of a basal ganglion lesion, levo-dopa/carbi-dopa was introduced as an intervention. The amplitude of the tremor was dramatically reduced, with protective devices removed, and with complete cessation of the tremor at rest. The medication was withdrawn and reintroduced with a reduction and subsequent resolution of the symptoms. A discussion of the previous studies of movement disorder with cerebrovascular accident is included.

Clinical Features and Prognosis in Young Adults with Infratentorial Infarcts

Background and Purpose: Many comprehensive descriptions of the clinical spectrum of infratentorial infarcts in elderly patients and with a retrospective design have been published. The aim of this study was to describe the clinical characteristics and prognosis in young patients with isolated infratentorial infarcts. Methods: In a prospective series of 105 patients aged 18–44 years with cerebral infarction 24 had a brainstem or cerebellar infarction. The patient selection was validated in a population-based epidemiological survey. The patients were assessed acutely and at 4 and 12 months after onset. Extensive evaluation included CT and MRI scans, angiography, ultrasonic duplex scanning, transesophageal echocardiography and a chemistry panel including hematologic testing. The modified Rankin scale and NIH stroke scale were used for assessment of disability and neurological dysfunction. Results: Eighteen patients had a cerebellar infarct (posterior inferior cerebellar artery territory in 9 patients, superior cerebellar artery in 6, anterior inferior cerebellar artery in 2, nonterritorial in 1). Two patients had lateral medullary infarcts and 2 isolated pontine infarcts. In 2 patients MRI was normal despite repeated investigations. Hearing loss and tinnitus were the only explicit symptoms for superior cerebellar artery infarcts, but it was otherwise impossible to classify each case to a vascular territory according to clinical characteristics. The age-specific incidence of isolated cerebellar infarction was 1.8/100,000/year. The presumed causes were arterial dissection in 8 patients, idiopathic in 7, cardioembolic in 5, oral contraceptive use in 3 and protein S deficiency in 1 patient. One patient died during the acute phase and another developed a locked-in syndrome. At follow-up, 1 patient had a transitory ischemic attack and 1 a silent cerebral infarction. Twenty-two patients had a favorable outcome according to the modified Rankin scale (grade 0–2) and the NIH scale. Conclusions: Cerebellar infarctions are frequent among young stroke patients in northern Sweden. Arterial dissection is the prevailing stroke mechanism in infratentorial infarcts. The prognosis is favorable regarding motor impairment but cognitive deficits may prevent return to work.

Superior cerebellar artery territory stroke.

The purpose of this study was to clarify etiologic factors, prior symptoms and clinical features of isole superior cerebellar artery (SCA) territory infarcts. All data were collected from consecutive 21 patients with isole SCA infarcts involved on computerized tomography. The risk factors including hypertension, cardiopathy and rhythm disturbances, hyperlipidemia, diabetes mellitus, abnormality in homeostasis, smoking, oral contraceptive have been identified. Headache, nausea-vomiting, vertigo, gait imbalance and diplopia were the most common complaints at onset. During the clinical course, the most common findings have been found as dysmetria and dysdiadochokinesia, dysarthria, ataxia and vertigo. Although 19 patients were improved in different degrees, 2 patients died because of cardiorespiratory arrest. Classical syndrome of SCA was only seen in 2 patients. According to our findings, SCA territory infarcts have multiple risk factors, and various clinical features as well as the syndrome of SCA are usually rare and incomplete.

Infarction of superior cerebellar artery presenting as cerebellar symptoms.

MRI of the brain has facilitated the diagnosis of cerebellar infarction in the territory of the superior cerebellar artery (SCA). We analyzed the data on patients with SCA infarction who presented with only cerebellar symptoms in an attempt to define its underlying pathophysiology. Ten patients with SCA infarction who presented with cerebellar symptoms were studied by brain MRI, angiography, and underlying pathology. Brain MRI demonstrated an infarct in the SCA territory in the anterior rostral cerebellum of all patients. None had abnormalities in the brain stem. In four patients, a hemorrhagic infarct was present in the same region. Cerebral angiography revealed no obvious SCA occlusion or atherosclerotic vascular disease in any patient. Eight of the 10 patients had heart disease, such as atrial fibrillation or old myocardial infarction. The presumed diagnosis was occlusion of the SCA in its periphery due to cardiogenic embolism. When a patient presents with only cerebellar symptoms and has cerebellar infarction demonstrated by brain MRI, the SCA branch is probably occluded by cardiogenic embolism.

Neuropsychological Functioning in Unilateral Cerebellar Damage

A woman had a left superior cerebellar artery infarct associated with reduced hexamethylpropileneamine oxime uptake on SPECT scan of the basal ganglia and frontoparietal areas of the opposite hemisphere performed poorly in some neuropsychological tests indicating right hemisphere dysfunction. There was a lengthening of reaction and movement times with the hand ipsilateral to the lesion. These deficits were temporary. A unilateral cerebellar lesion can produce neuropsychological deficits, possibly because of hypoperfusion in contralateral frontoparietal regions, but spontaneous neuropsychological remissions may occur.

Cerebellar infarction. Clinical and neuroimaging analysis in 293 patients. The Tohoku Cerebellar Infarction Study Group.

We performed this multicenter study to explore the full spectrum of the clinical characteristics and neuroimaging findings of cerebellar infarction, including patients with mild to severe illnesses. We studied 293 consecutive patients with cerebellar infarction diagnosed by computed tomography and/or magnetic resonance imaging who were admitted to 36 hospitals during 5 years. Cerebellar infarcts constituted 2.3% of the total patients with acute brain infarction. The backgrounds and risk factors were similar to those in patients with infarctions of the cerebral hemispheres. At least 24% were embolic, and the diagnosis of embolism could not be ruled out in 27%. Infarcts involving the superior cerebellar artery (SCA) region (52%) and the posterior inferior cerebellar artery (PICA) region (49%) were far more frequent than those involving the anterior inferior cerebellar artery (AICA) region (20%). Patients with SCA infarcts exhibited obtunded consciousness and ataxia more frequently than those with PICA infarcts (P < .05). Infarcts in the PICA regions were associated with abnormalities of the PICA (64%) or the vertebral arteries (57%), whereas infarcts in the SCA and AICA regions were associated with abnormalities in the SCA or AICA, respectively, in approximately 30% of patients, in the basilar artery in approximately 16%, and in the vertebral artery in more than 60% of patients. Outcomes were poorer with SCA infarcts than with AICA and PICA infarcts. These data indicate similar frequencies of SCA and PICA infarcts and illustrate the difference in clinical presentation and outcomes between SCA and PICA infarcts. They also indicate that not only in situ thrombosis but also cardiogenic or artery-to-artery embolism and the insufficiency of collateral circulation play important roles in the pathogenesis of cerebellar infarction.

Cerebellar infarction. Clinical and anatomic observations in 66 cases.

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. 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. 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. 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.