CASE OF THE MONTH – JUNE 2023
EMS is dispatched to the home of a 39-year-old male with no significant past medical history for concern for stroke. According to the patient’s wife, the patient became acutely confused approximately 45 minutes prior to her 9-1-1 call. On arrival, they find an awake and alert male who complains of lightheadedness, vision changes, nausea, and is slow to communicate. The wife states that the patient waved her down as if he was in distress. She states that he seems confused and unable to speak normally. He and his wife deny any history of drug or alcohol use and report that he was normal immediately prior to this acute event.
His initial vital signs are BP 126/74, HR 90, RR 16, SPO2 96%.
It is clear that this patient’s behavior is not at his baseline. While an initial provider impression of Altered Level of Consciousness (ALOC) may be appropriate, further assessment should be immediately performed to determine if there is an underlying cause. Per TP-1229-ALOC, one should initiate cardiac monitoring, check blood glucose, assess for signs of trauma, and perform a modified Los Angeles Prehospital Stroke Screen (mLAPSS) to evaluate for underlying causes.
In accordance with MCG 1320, one should assess the patient’s level of consciousness by asking the patient to state their name, where they live/where they are, and the day of the week/year/date. Patients who are unable to reasonably answer one or more of the above questions shall be considered to have ALOC if this is not their baseline. One should also assess GCS and possible causes of ALOC using the mnemonic AEIOUTIPS as described in special considerations, TP-1229-ALOC.
In this case, one should also consider that the patient may have aphasia – difficulty in speaking – which can be caused by a stroke that affects the language center of the brain. Given this patient’s presentation, an etiology of stroke should be strongly considered. Even though mLAPSS will be negative because of the patients age, one should still perform the remainder of the exam to assess for any focal deficits and, if stroke remains a concern, calculate Los Angeles Motor Score (LAMS) to inform destination. A Last Known Well Time (LKWT) including contact information of the informant (in this case the wife) is also critical because it helps hospital providers determine eligibility for time-sensitive interventions such as tPA and/or mechanical thrombectomy.
On paramedic assessment, the patient is alert and oriented to person and place. He is able to state his date of birth, but cannot state the current day of week or year when asked. He is hesitant in his speech and unable to answer questions in full sentences. He seems frustrated by this. He is able to nod yes or no to answer questions and can follow all commands. Strength is normal throughout and he ambulates with steady gait.
Cardiac monitoring demonstrates a normal sinus rhythm. Blood glucose is 99 mg/dL. There are no signs of trauma on assessment. mLAPSS is negative given his age <40 and lack of unilateral weakness with facial smile, arm strength and grip strength.
The patients etiology remains unclear. Provider Impression of ALOC is still considered. Syncope could also be considered, given the patient complaints of lightheadedness and nausea, which might briefly cause confusion and slow speech, but this should resolve rapidly as the patient is now conscious. The astute paramedic recognizes that mLAPSS does not address strokes that primarily affect speech, vision or balance. Symptoms such as aphasia, ataxia, and vertigo may be caused by a stroke but are not captured by this stroke screening tool. Therefore, despite the negative mLAPSS, Base Contact is made to discuss this case. Base Contact is required for all cases of persistent ALOC of unknown etiology in order to determine if another PI should be considered that would benefit from field treatment or specialty center destination.
The discussion between paramedics and the Base helps to clarify that the patient’s difficulty speaking may be a sign of stroke. Word finding difficulty is a sign of expressive aphasia, meaning that the patient loses the ability to produce language. This results from reduced or absent blood flow to the language center of the brain. Speech is affected in that the patient cannot find words. Because they cannot produce language, they will have difficulty writing as well. These difficulties are not due to motor deficits as seen in a large territory stroke where patients cannot speak because of loss of motor function to the face and tongue (dysarthria). This type of aphasia is also known as Broca’s aphasia. Speech may stop frequently and seem to take tremendous effort. Patients may only produce single words or words in small groups with long pauses between words.
Suspected stroke should be managed in accordance with TP-1232 – Stroke/CVA/TIA. Determine the patient’s destination based on mLAPSS, LAMS, and LKWT. If mLAPSS is positive, LAMS ≥ 4, and LKWT < 24 hours, transport to the nearest comprehensive stroke center (CSC) within 30 minutes. If mLAPSS is positive, LAMS ≤ 3, LKWT < 24 hours, transport to the closet Stroke Center. If mLAPSS is negative but acute stroke is suspected, contact base for destination. The base determination should be based on if the symptoms are likely related to a large vessel occlusion that would benefit from thrombectomy. Patient transport should be with the head of bed elevated 30-40 degrees to reduce risk of aspiration and to optimize intracranial pressure. Monitor respiratory and mental status for changes during transport.
Last known well time (LKWT) is confirmed as 45 minutes prior to EMS arrival. Because of concern for a stroke, the patient is transported to the nearest stroke center as directed by the Base. The patient’s symptoms are improving on arrival to the Emergency Department. He reports to the physician that he had a 10 minute episode of speech arrest where he describes knowing the words he wanted to say but not being able to say them. He also reports headache and double vision. On physical exam, partial loss of his visual fields are noted. An MRI of his brain shows an acute infarction of the left parietal and temporal lobes. Further work up reveals a patent foramen ovale (PFO), which is a defect in the septum of the heart that allowed blood flow to shunt left to right as determined by echocardiogram. PFOs are a risk factor for stroke because a blood clot can form in a vein, travel through the PFO and enter the arterial circulation leading to an embolic stroke. This patient was not a candidate for thrombolytic or reperfusion therapy because of his improving symptoms. After a weeklong admission, the patient was discharged on medications for future stroke prevention and with cardiology follow up evaluate for outpatient closure of the PFO.
- mLAPSS is a screening tool for stroke but does not rule out acute stroke. If a stroke is suspected, despite negative mLAPSS, calculate a LAMS score and transport per discussion with Base.
- Strokes can occur in young, otherwise healthy individuals. Oftentimes this is due to underlying conditions that may not be diagnosed yet, such as a patent foramen ovale (PFO) leading to movement of small venous clots to the brain through a hole in the heart.
- For an initial provider impression of ALOC, EMS should look for underlying causes that would lead to a more specific provider impression.
- Base contact is required for persistent ALOC for the purpose of determining if prehospital treatments or specialty center hospital destination is indicated.
- Patients with speech difficulty may be aphasic which should trigger a neurologic exam and stroke assessment.
- Yew KS, Cheng E. Acute Stroke Diagnosis. Am Fam Physician. 2009; 80(1): 33-40. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2722757/
- Caplan LR. Overview of the evaluation of stroke. UpToDate. 2023. https://www.uptodate.com/contents/overview-of-the-evaluation-of-stroke?search=stroke%20symptoms&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H26
Authors: Tianci Liu, MD, Nichole Bosson, MD, MPH and Denise Whitfield, MD, MBA