The initial clinical evaluation of a suspected<unk>  involves obtaining a history and physical exam (including a neurological exam). History taking includes defining the symptoms and looking for mimicking symptoms as described above. Bystanders can be very helpful in describing the symptoms and giving details about when they started and how long they lasted. The time course (onset, duration, and resolution), precipitating events, and risk factors are particularly important. The definition, and therefore the diagnosis, has changed over time.<unk>  was classically based on duration of neurological symptoms. The current widely accepted definition is called "tissue-based" because it is based on imaging, not time. The American Heart Association and the American Stroke Association (AHA/ASA) now define<unk>  as a brief episode of neurological dysfunction with a vascular cause, with clinical symptoms typically lasting less than one hour, and without evidence of significant infarction on imaging. Laboratory workup Laboratory tests should focus on ruling out metabolic conditions that may mimic<unk>  (e.g. hypoglycemia causing altered mental status), in addition to further evaluating a patient's risk factors for<unk>  events. All patients should receive a complete blood count with platelet count, blood glucose, basic metabolic panel, prothrombin time/international normalized ratio, and activated partial thromboplastin time as part of their initial workup. These tests help with screening for bleeding or hypercoagulable conditions. Other lab tests, such as a full hypercoagulable state workup or serum drug screening, should be considered based on the clinical situation and factors, such as age of the patient and family history. A fasting lipid panel is also appropriate to thoroughly evaluate the patient's risk for atherosclerotic disease and<unk>  events in the future. Other lab tests may be indicated based on the history and presentation; such as obtaining inflammatory markers (erythrocyte sedimentation rate and C-reactive protein) to evaluate for giant cell arteritis (which can mimic a<unk>  in those presenting with headaches and monocular blindness. Cardiac rhythm monitoring An electrocardiogram is necessary to rule out abnormal heart rhythms, such as atrial fibrillation, that can predispose patients to clot formation and embolic events. Hospitalized patients should be placed on heart rhythm telemetry, which is a continuous form of monitoring that can detect abnormal heart rhythms. Prolonged heart rhythm monitoring (such as with a Holter monitor or implantable heart monitoring) can be considered to rule out arrhythmias like paroxysmal atrial fibrillation that may lead to clot formation and<unk> s, however this should be considered if other causes of<unk>  have not been found. Imaging According to guidelines from the American Heart Association and American Stroke Association Stroke Council, patients with<unk>  should have head imaging "within 24 hours of symptom onset, preferably with magnetic resonance imaging, including diffusion sequences". MRI is a better imaging modality for<unk>  than computed tomography (CT), as it is better able to pick up both new and old<unk>  lesions than CT. CT, however, is more widely available and can be used particularly to rule out intracranial hemorrhage. Diffusion sequences can help further localize the area of<unk>  and can serve as prognostic indicators. Presence of<unk>  lesions on diffusion weighted imaging has been correlated with a higher risk of stroke after a<unk> . Vessels in the head and neck may also be evaluated to look for atherosclerotic lesions that may benefit from interventions, such as carotid endarterectomy. The vasculature can be evaluated through the following imaging modalities: magnetic resonance angiography (MRA), CT angiography (CTA), and carotid ultrasonography/transcranial doppler ultrasonography. Carotid ultrasonography is often used to screen for carotid artery stenosis, as it is more readily available, is noninvasive, and does not expose the person being evaluated to radiation. However, all of the above imaging methods have variable sensitivities and specificities, making it important to supplement one of the imaging methods with another to help confirm the diagnosis (for example: screen for the disease with ultrasonography, and confirm with CTA). Confirming a diagnosis of carotid artery stenosis is important because the treatment for this condition, carotid endarterectomy, can pose significant risk to the patient, including heart<unk> s and strokes after the procedure. For this reason, the U.S. Preventive Services Task Force (USPSTF) "recommends against screening for asymptomatic carotid artery stenosis in the general adult population". This recommendation is for asymptomatic patients, so it does not necessarily apply to patients with<unk> s as these may in fact be a symptom of underlying carotid artery disease (see "Causes and Pathogenesis" above). Therefore, patients who have had a<unk>  may opt to have a discussion with their clinician about the risks and benefits of screening for carotid artery stenosis, including the risks of surgical treatment of this condition. Cardiac imaging can be performed if head and neck imaging do not reveal a vascular cause for the patient's<unk>  (such as atherosclerosis of the carotid artery or other major vessels of the head and neck). Echocardiography can be performed to identify patent foramen ovale (PFO), valvular stenosis, and atherosclerosis of the aortic arch that could be sources of clots causing<unk> s, with transesophageal echocardiography being more sensitive than transthoracic echocardiography in identifying these lesions. Differential diagnosis Diagnosis Findings Brain tumor Severe unilateral headache with nausea and vomiting Central nervous system infection (e.g., meningitis, encephalitis) Fever, headache, confusion, neck stiffness, nausea, vomiting, photophobia, change in mental status Falls/trauma Headache, confusion, bruising Hypoglycemia Confusion, weakness, diaphoresis Migraines Severe headaches with or without photophobia, younger age Multiple sclerosis Diplopia, limb weakness, paresthesia, urinary retention, optic neuritis Seizure disorder Confusion with or without loss of consciousness, urinary incontinence, tongue biting, tonic-clonic movements Subarachnoid hemorrhage Severe headache with sudden onset and photophobia Vertigo (central or peripheral) Generalized dizziness and diaphoresis with or without hearing loss
Transient ischemic attack
Seizure
Subarachnoid hemorrhage
Epidural hematoma
Hemiplegic migraine
Ménière's disease  Ménière's disease  1
Watershed stroke
Migraine