After stroke is suspected based on history and physical examination, prompt imaging of the brain with non-contrast computerized tomography (CT) is indicated. The goal of CT is not necessarily to diagnose AIS, but rather to rule out contraindications to the use of rTPA, such as ICH or mass lesion.¹² A more thorough physical examination should never delay performance of the CT, as this may push the patient outside the 3-hour time window where rTPA is considered safe and effective.

The emergency physician should calculate the National Institutes of Health Stroke Scale (NIHSS) score when the history and physical exam strongly suggest AIS and other diagnoses are excluded by CT. The NIHSS will allow the emergency physician both to quantify the stroke in a validated manner and to assist in communication with neurology consultants.¹³ The NIHSS is available online at www.strokecenter.org/trials/scales/nihss.html.

Outside of the 3-hour symptom window, evaluation should be still be emergent, but can follow the standard protocol of focused history and physical exam followed by diagnostic testing and management based on findings.

P Further diagnostic testing. See the sidebar on page 14 for a list of suggested ancillary testing in the evaluation of AIS. A chest x-ray is not considered mandatory. One retrospective review of 435 patients with AIS concluded that the admission chest radiograph altered patient management in just 3.8% of cases, and that more than three quarters of these radiographs were technically poor studies.¹⁴

Treatment

Management of the patient with AIS begins in the field. Properly trained EMS providers will recognize the possibility of acute stroke and communicate ahead to the receiving emergency department. Priority actions in the emergency department are listed in the sidebar on page 14. It is particularly important to rule out hypoglycemia as a cause of a neurological deficit; the blood glucose should be obtained along with the vital signs and corrected as appropriate.

Once the diagnosis of AIS is confirmed, the emergency physician should make the decision to give rTPA in consultation with neurology specialists (see the “Controversies” section). The specific logistics of rTPA administration are beyond the scope of this article. Instead, the articles will address other management issues related to AIS.