In patients with delirium, brain MRI without and with IV contrast may be helpful for the definitive characterization of a focal lesion identified on initial noncontrast CT or in patients with known cancer history [10]. In a simulated decision-making study using a prospective intensive care unit cohort, a panel of neurocritical experts first reviewed clinical information (without MRI) from 75 patients with acute disorder of consciousness patients and made decisions about diagnosis, prognosis, and treatment. Review of head MRI examinations led to changes in clinical management of 76% of patients including revised diagnoses in 20%, revised levels of care in 21%, improved diagnostic confidence in 43%, and improved prognostications in 33% [37]. However, decisions were revised more often with stroke (which commonly presents with focal neurological deficits) than with other brain injuries. Many of the abnormal findings in the literature for this topic included small ischemic infarcts [29,35,36]. Notably, a retrospective study found that 70% of patients who had a missed ischemic stroke diagnosis presented with AMS [33]. MRI of the brain is complementary to an abnormal head CT for the evaluation of suspected intracranial mass lesions, intracranial infection, nonspecific regions of edema, ischemia, and cases of ICH when an underlying lesion is suspected [38]. MRI may also be considered as a first-line test in certain situations, such as a clinically stable patient with known malignancy, HIV, or endocarditis. Noncontrast MRI examinations of the brain are usually sufficient in the assessment of intracranial complications related to hypertensive emergency, including posterior reversible encephalopathy syndrome. In patients with new onset delirium, the reported yield of brain MRI is very low in the absence of a focal neurologic deficit or history of recent falls.
Altered Mental Status Coma Delirium and Psychosis. In patients with delirium, brain MRI without and with IV contrast may be helpful for the definitive characterization of a focal lesion identified on initial noncontrast CT or in patients with known cancer history [10]. In a simulated decision-making study using a prospective intensive care unit cohort, a panel of neurocritical experts first reviewed clinical information (without MRI) from 75 patients with acute disorder of consciousness patients and made decisions about diagnosis, prognosis, and treatment. Review of head MRI examinations led to changes in clinical management of 76% of patients including revised diagnoses in 20%, revised levels of care in 21%, improved diagnostic confidence in 43%, and improved prognostications in 33% [37]. However, decisions were revised more often with stroke (which commonly presents with focal neurological deficits) than with other brain injuries. Many of the abnormal findings in the literature for this topic included small ischemic infarcts [29,35,36]. Notably, a retrospective study found that 70% of patients who had a missed ischemic stroke diagnosis presented with AMS [33]. MRI of the brain is complementary to an abnormal head CT for the evaluation of suspected intracranial mass lesions, intracranial infection, nonspecific regions of edema, ischemia, and cases of ICH when an underlying lesion is suspected [38]. MRI may also be considered as a first-line test in certain situations, such as a clinically stable patient with known malignancy, HIV, or endocarditis. Noncontrast MRI examinations of the brain are usually sufficient in the assessment of intracranial complications related to hypertensive emergency, including posterior reversible encephalopathy syndrome. In patients with new onset delirium, the reported yield of brain MRI is very low in the absence of a focal neurologic deficit or history of recent falls.