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46 APRIL 2016 | EMSWORLD.com neurological exams. More in-depth exams are warranted for stable patients whose initial stroke assessments are negative. Portions of the following neurological exam may already be includ- ed as part of some stroke assessment tools. As an example, the Cin- cinnati Prehospital Stroke Scale (CPSS) includes speech, one cranial nerve and upper-body motor function but does not include vision, cerebellar, sensory or lower-body motor function. The CPSS may not identify less-common posterior or anterior cerebral artery strokes, as these require additional assessments of visual fields, cerebellar function, lower-extremity motor strength and sensory function. The key to any stroke assessment is identifying focal or unilateral find- ings. Bilateral findings that are symmetrical generally are not due to stroke. A patient who is unable to hold up either arm during the stroke assessment does not display a focal one-sided finding; therefore, this is not usually a sign of a stroke. Unilateral weakness is characteristic of a focal neurological disease such as a stroke. A stroke generally involves the brain being affected by disrupted blood flow to a specific artery, and the territory that artery supplies will determine the symptoms. By testing extremity sensory and motor function, cranial nerves, speech and cerebellar function, you ensure each of the major branches of the CNS circulatory sys- tem gets tested. Some of the major prehospital stroke screens can't pick up all strokes because not all of the individual blood vessel territories are evaluated. For example, the Cincinnati Prehospital Stroke Scale, when used by paramedics in an urban EMS system, has been demonstrated to have a sensitivity of only 79%. This means 21% of strokes will be missed by the CPSS. 1 Because it is a far more complete exam, the authors recommend the use of the Miami Emergency Neurologi- cal Deficit (MEND) tool, which this article more closely tracks. By expanding the basic neurological exam, the paramedic can identify patients with less-common types of strokes who would otherwise have gone undiagnosed, resulting in a delay in treatment and loss of chance for improvement. Mental Status Assessment Mental status is the most important indicator of brain function. An altered mental status can occur suddenly or over several days and can range from mild confusion to coma. » Is the patient alert? If not, are they responsive to verbal or painful stimuli, or are they unresponsive (AVPU)? » Is the patient confused? Do they correctly follow commands? Do they know the month and their age? Look for inability to think clearly and disorientation to person, place or time. » Does the patient exhibit signs of delirium (e.g., agitation, hal- lucinations, rambling, delusion)? Unresponsive patients significantly hamper your ability to con- duct an H&P.; Gather as much history and information as you can from friends, family, bystanders, current medications and medical alert tags. The medication list can give the paramedic a clue to the patient's past medical history. As an example, a patient taking strong blood thinners or an antihypertensive may have a problem with atrial fibrillation or hypertension, both of which are known major risk factors for stroke. The physical exam will have to be limited to vital signs, blood glucose levels, SpO 2 , EtCO 2 and ECG. Additionally, a physical exam should look for signs of a seizure (oral trauma and incontinence), head trauma and the size and reactivity of the pupils (see Table 1). Speech Speech is an efficient neurological test since it evaluates many areas of the brain at once. It evaluates the ability to hear words, translate the words into meaning, create a thought to respond, and then transmit that thought via coordinated use of speech musculature. Aphasia and dysarthria are two indicators that speech pathways have been disrupted. Aphasia is a patient's inability to express him- or herself—e.g., speaking or writing sentences that make no sense, using unrecogniz- able or inappropriate words, speaking in short/broken sentences, difficulty comprehending spoken or written words, or misnaming objects. The most common causes of aphasia are stroke, traumatic brain injury, brain tumors and degenerative disorders of the brain. Dysarthria, slurred speech, occurs when the muscles responsible for speech become weak. Causes include stroke, Bell's palsy, TBI, brain tumors, neurological disorders such as multiple sclerosis and drug/alcohol intoxication. To assess a patient's speech, have them repeat a phrase such as "You can't teach an old dog new tricks," or alternatively ask them to count to 10. Then hold up a pen and ask, "What is this?" Anything TABLE 1: POSSIBLE CAUSES OF ALTERED MENTAL STATUS (AEIOUTIPS) Alcohol—Alcohol intoxication. Electrolyte imbalances—Hypocalcemia and hyponatremia secondary to renal failure; hyponatremia secondary to CHF and liver failure (cirrhosis); hyponatremia, hypokalemia or hypocalcemia secondary to dehydration from the improper use of diuretics. Hypo- and hypernatremia, hypercalcemia secondary to dehydration from inadequate fuid intake or excessive vomiting or diarrhea. Insulin, illegal drugs—Hyper- or hypoglycemia, cocaine, PCP, methamphetamine, bath salts, synthetic marijuana. Overdose—Opiates, benzodiazepines, medications that decrease blood pressure. Uremia—Secondary to chronic renal failure. Tumors, trauma—Brain tumors, head trauma (epidural or subdural bleeds). Infection—Sepsis (especially in the elderly), brain abscess, meningitis, encephalitis. Poisoning—Carbon monoxide, cyanide, insecticides. Shock—Brain tumors, head trauma (epidural or subdural bleeds). Some of the major prehospital stroke screens can't pick up all strokes because not all of the individual blood vessel territories are evaluated.