This variant encompasses a subgroup of patients presenting with acute mental status changes at low risk of acute intracranial pathology. CT Head With IV Contrast The literature search did not identify any studies regarding the use of contrast-enhanced CT relevant to this variant, and contrast-enhanced CT examinations are not performed as a first-line test in this setting. CT Head Without and With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario. CT Head Without IV Contrast ED physicians are moderately accurate at establishing the correct clinical diagnosis for the cause of AMS within the first 20 minutes of the patient encounter [15]. A large proportion of misdiagnoses in this study were deemed insignificant because of confusing various forms of isolated or mixed intoxication. Although CT head may be useful in this scenario, deferring head CT imaging while observing if intoxicated patients symptomatically improve may be a safe practice and may prevent the need for imaging in large percentage of intoxicated patients [39]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in this clinical scenario.
Altered Mental Status Coma Delirium and Psychosis. This variant encompasses a subgroup of patients presenting with acute mental status changes at low risk of acute intracranial pathology. CT Head With IV Contrast The literature search did not identify any studies regarding the use of contrast-enhanced CT relevant to this variant, and contrast-enhanced CT examinations are not performed as a first-line test in this setting. CT Head Without and With IV Contrast A common practice is to perform a noncontrast screening head CT followed by a more sensitive MRI brain examination performed with and without IV contrast in the setting of AMS. There is no relevant literature to support the use of CT head without and with IV contrast in the initial imaging of this clinical scenario. CT Head Without IV Contrast ED physicians are moderately accurate at establishing the correct clinical diagnosis for the cause of AMS within the first 20 minutes of the patient encounter [15]. A large proportion of misdiagnoses in this study were deemed insignificant because of confusing various forms of isolated or mixed intoxication. Although CT head may be useful in this scenario, deferring head CT imaging while observing if intoxicated patients symptomatically improve may be a safe practice and may prevent the need for imaging in large percentage of intoxicated patients [39]. MRI Head With IV Contrast There is no relevant literature to support the use of MRI head performed only with IV contrast in this clinical scenario. MRI Head Without and With IV Contrast There is no relevant literature to support the use of MRI head without and with IV contrast in this clinical scenario.