References for this Review were identified through searches of PubMed with the search terms “cerebell*” [title] AND (“infarct*” [title] OR “stroke” [title]), from 1988 to March 19, 2008. Only papers published in English were reviewed. The bibliographies of the articles and the personal files of the authors were searched. Studies that described primary data in larger numbers of patients with cerebellar stroke were given precendence over case reports and reviews.
ReviewDiagnosis and initial management of cerebellar infarction
Introduction
Cerebellar infarction has not received the same level of attention in medical publications as the well-defined anterior circulation and brainstem stroke syndromes. This paucity of data might be partly because the clinical presentation of cerebellar infarction is diverse, and can resemble many other disorders. The main symptoms—dizziness, nausea and vomiting, gait instability, and headache—are non-specific, and are usually caused by more common and benign disorders. The important components of the neurological examination that help to identify cerebellar stroke—coordination, gait, and eye movements—are commonly omitted or abridged in primary care, particularly when symptoms might not suggest a CNS cause. Additionally, brain CT, which for decades has been the most readily available brain imaging study to identify strokes and is still the most commonly used, rarely identifies early-stage cerebellar infarction.
Accurate diagnosis of cerebellar infarction is important. Early oedema from infarction in the posterior fossa can result in potentially fatal—yet treatable—complications, such as brainstem compression and obstructive hydrocephalus. The identification and treatment of the underlying vascular lesion(s) might also prevent a second and more devastating stroke. Medical therapy (eg, thrombolytic, antiplatelet, and anticoagulant drugs), or vascular procedures (eg, stenting) can result in improved patients' outcomes. The increasing availability of MRI has improved the ability of clinicians to diagnose this disorder definitively, and there have been important advances in bedside examination techniques to identify those patients who are at the highest risk. Physicians must familiarise themselves with the diagnosis and initial management of these patients. Here, we review cerebellar infarction, from diagnosis (and misdiagnosis) to the monitoring, treatment, and potential complications of patients.
Section snippets
Epidemiology
In nine studies of consecutive ischaemic strokes, cerebellar infarction accounted for almost 3% (660 of 23 426) of strokes.1, 2, 3, 4, 5, 6, 7, 8, 9 This proportion, combined with the annual stroke incidence rate, suggests that nearly 20 000 new cerebellar infarctions occur each year in the USA,10 not including patients whose infarcts simultaneously include the cerebellum and other cerebrovascular territories. The average age of patients is 65 years and two-thirds of patients are men.6, 7, 11
Relevant anatomy
The cerebellum, which is composed of two lateral hemispheres and a midline vermis, is important for movement; it modulates the functions of the motor system and corrects for differences between intended and actual movement. Damage to the cerebellum generally leads to inaccurate, erratic, or uncoordinated movements and difficulty with motor learning and adaptation. Many of these functions are regionally specified: the superior parts of the cerebellum are primarily concerned with limb (lateral
Pathogenesis
As is the case with ischaemic stroke in the anterior circulation, the two most common causes of cerebellar infarction are cardioembolism and large vessel atherosclerosis.6, 7, 11, 18, 19, 20, 21 Small artery disease and artery-to-artery embolism are also important causes.20, 21, 22 Vertebral artery atherosclerosis can be intracranial, extracranial, or both.23, 24, 25 The relative occurrence of these different aetiologies and the distribution of large vessel atherosclerosis varies with ethnic
Clinical manifestations
When infarctions are restricted to the cerebellum, patients typically only experience non-specific symptoms (ie, dizziness, nausea, vomiting, unsteady gait, and headache) and show neurological signs (ie, dysarthria, ataxia, and nystagmus) that might be absent, subtle, or difficult to distinguish from benign disorders of the peripheral vestibular system. Clinical presentations of isolated cerebellar infarction are similar across the three main cerebellar vascular areas.
Kase and co-workers found
Differential diagnosis and misdiagnosis
Because the differential diagnosis of dizziness, vomiting, and headache encompasses many disorders, the differential diagnosis of cerebellar infarction is vast and includes many common and benign conditions. For each of these symptoms, cerebellar infarction is a rare cause and some instances of misdiagnosis are probably inevitable. There are two primary consequences of misdiagnosis. The first is that if stroke is not considered, no search for the underlying mechanism will ensue, leaving
Brain imaging
The most commonly used emergent brain imaging test for stroke is CT, which is widely available, acquires images quickly, and accurately excludes acute haemorrhage.89 Unfortunately, CT is usually negative in the first hours after acute ischaemic stroke.90, 91 Because of artifacts that are caused by the bone of the skull base, CT has even lower sensitivity in the posterior fossa.92 Clinicians without access to MRI must understand this intrinsic limitation of CT.13
MRI is the preferred test and is
General therapy and blood pressure control
There are no data from randomised trials that are specific for patients with cerebellar infarction; therefore, treatment guidelines are derived from information on acute ischaemic stroke in general. The first priorities are the standard airway, breathing, and circulation. Hypoxic patients should receive supplemental oxygen. Patients who present with altered mental status and who have lost protective airway reflexes might need endotracheal intubation, not only to prevent aspiration but also to
Conclusions
Cerebellar infarction can be difficult to diagnose because the dominant clinical manifestations are common symptoms that do not necessarily raise concern for stroke. Clinicians must develop improved strategies to identify cerebellar infarction. One approach is simply better recognition that younger patients can develop cerebellar stroke, often as a result of vertebral artery dissection. Another potential strategy is to develop clinical algorithms for the approach to dizziness that focus more on
Search strategy and selection criteria
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