Clinically Presenting Acute/subacute Ischemic Stroke: Differential Diagnosis of the Non-Enhanced CT Hypodensity by Advanced Neuroimaging

OBJECTIVES:Patients presenting to the emergency room with an acute or subacute onset of focal neurological deficits are evaluated initially by non-contrast computed tomogram (CT) of the brain. This is primarily carried out to differentiate an ischemic from hemorrhagic stroke. However, other neurological conditions may have a similar clinical presentation as well as only hypodensities on CT scan, thus mimicking ischemic stroke. This review focuses on the advanced neuroimaging modalities that help differentiate these other conditions from a cerebral infarction.METHODS:The literature was reviewed in order to ascertain what conditions would clinically and by CT mimic an acute/subacute ischemic infarction, and what advanced neuroimaging techniques would be most useful in differentiating these conditions.RESULTS:Several infectious, inflammatory, metabolic and vascular diseases were found with clinical presentations identical to subacute/acute ischemic cerebral infarction, which also could demonstrate only hypodensities on a non-enhanced CT scan. However, advanced neuroimaging techniques could readily differentiate these conditions from ischemic infarction.CONCLUSIONS:As presented in this review, although several diseases initially present a diagnostic dilemma upon presentation because of their clinical and non-enhanced CT similarities to cerebral infarction, advanced diagnostic neuroimaging readily establishes their unique pathologies.