Approach To Patient With Stroke

by Matevž Privšek and Gregor Prosen

 

Introduction

Stroke or cerebrovascular accident (CVA) is a syndrome of any vascular injury that diminishes cerebral blood flow (CBF) to a specific region of the brain, causing ischemia and thereby consequently causing focal neurologic impairment. Emergency physicians’ main goals are early recognition of stroke symptoms, objectification of complaints and prompt diagnostics and treatment.

According to some data, stroke is the third leading cause of death and a leading cause of long-term disability in the United States. Around 2-4 % of hospital admissions are due to potential strokes. Depending on the cause of stroke, in-hospital mortality rates vary between 5-10 % for ischemic stroke and up to 45 % for hemorrhagic stroke. Up to 50-70% of stroke survivors regain functional independence, while 15-30% be permanently disabled and another 30% eventually require institutional care.

Etiopathogenesis. 80 % of all strokes are ischemic in origin; the rest are hemorrhagic. In the ischemic stroke, a clot stops the blood supply to a specific area of the brain. However, in hemorrhagic stroke, blood leaks into brain tissue. It is highly important to differentiate between them since treatment is completely different.

In the ischemic stroke, a causative clot can originate from large blood vessels of the brain (thrombus) or elsewhere in the body (usually from the heart due to atrial fibrillation; embolus). Rarely, the cause of ischaemic stroke is hypoperfusion of the brain, due to a systemic problem (e.g., myocardial infarction, dysrhythmias). In hemorrhagic stroke, the main causes are intracerebral (ICH) and subarachnoid hemorrhage (SAH).

Brains are highly sensitive to any alterations in the blood supply of oxygen and glucose that are needed for their metabolism. Immediate alterations in CBF and cellular homeostasis follows a stroke. A complete interruption of CBF (rare) causes loss of consciousness within 10 seconds and death of pyramidal cells follows within minutes. More often, collateral circulation helps to maintain some CBF to the ischaemic region. When CBF drops below a certain point, loss of electrical activity of the affected area occurs, which is clinically seen as a neurologic deficit (but the brain cells remain viable; integrity and function of the neuronal membrane are intact). Area of the brains with electrical silence but viable cells is called penumbra; irreversible changes have not yet occurred. With further occlusion irreversibility and scope of cerebral infarction increase. Studies have shown that occlusion longer than 6 hours leads to irreversible neurologic deficits.

In hemorrhagic stroke, events beside alterations in CBF, such as red blood cells lysis and increased permeability of the blood-brain barrier lead to brain edema and secondary injury.

Case Presentation

A 56-year old female is brought to the ED by the paramedics due to weakness in her left arm and left leg. She is conscious, GCS 15, painless, normal skin color. Vitals are: BP 132/84, pulse 78/min, 14 breaths/min, SpO2 99 %, temperature 36,4 °C, blood glucose 5,4 mmol/L. She says that weakness started about 2 hours ago, while she was watching TV when she suddenly realized she was unable to pick up a glass of juice. She wanted to stand up and almost fell because her right leg did not move. She thought it would go away, but it did not, so she called an ambulance. She denies dizziness, vertigo, nausea, vomiting, headache, visual disturbances. She is otherwise healthy, not taking any medications or drugs. She smokes half a pack of cigarettes daily.

The focused neurological exam is performed: pupils are equal and reactive, bulbomotorics and facial mimic seem appropriate except slight drift of right mouth angle. She also has decreased muscle power in her left arm as well as slightly decreased muscle power in her left leg. She denies any sensory deficits. The rest of physical exam is unremarkable.

You set up an intravenous cannula, draw some blood for testing, and order emergency non-contrast head CT scan, due to a high suspicion of an acute CVA. The results of the CT scan are back in 35 minutes: radiologist describes no intracranial hemorrhage or ischemic areas. A neurologist is consulted; upon repeated examination, he advises highly for acute ischemic stroke, most likely due to occlusion of the right middle cerebral artery. You immediately start with thrombolysis and transfer her to the neurology ward.

Critical Bedside Actions And General Approach

Regardless of the patients’ chief complaint emergency physicians’ first task is to rapidly asses patients’ condition and vital signs (do not forget blood glucose!), and stabilize them, if necessary. After patients’ condition is stable, we continue with establishing chief complaint, focused, but thorough history and physical exam, setting the working diagnosis and list differential diagnoses, and diagnostic and treatment plan. All patients with a suspected CVA should have their complaints objectified by a focused neurologic exam, and efforts should be made to perform urgent diagnostics.

Differential Diagnosis

A physician must be well aware of “stroke mimics,” which are defined as non-vascular diseases that present with stroke-like symptoms. Since the majority of strokes are treated with thrombolysis, accurate diagnosis due to harmful effects of thrombolytics (significant intracranial bleed in 1 %) is essential.

Possible stroke mimics which may be misdiagnosed as a stroke;

  • Migraine
  • Seizures
  • Psychiatric
  • Syncope
  • Sepsis
  • Brain tumor
  • Metabolic
  • Transient global amnesia
  • Labyrinthitis

Depending on the affected area of the brain and type of stroke CVA can present with a vast list of chief complaints: altered mental status, confusion, syncope, weakness, dizziness, vertigo, ataxia, aphasia, diplopia.

Differential diagnosis of some stroke-related chief complaint

AEIOU TIPS: Causes of altered mental status

A = Alcohol
E = Epilepsy, electrolytes
I = Infection
O = Overdose
U = Urea
T = Trauma
I = Insulin
P = Psychiatric
S = Sepsis, stroke, shock, Syncope

HEAD HEART VESSELS: Syncope causes, by system

CNS causes include HEAD:
H = Hypoxia/ Hypoglycemia
E = Epilepsy
A = Anxiety
D = Dysfunctional brain stem (basivertebral TIA)

Cardiac causes are HEART:
H = Heart attack
E = Embolism (PE)
A = Aortic obstruction (IHSS, AS or myxoma)
R = Rhythm disturbance
T = ventricular Tachycardia

Vascular causes are VESSELS:
V = Vasovagal
E = Ectopic (reminds one of hypovolemia)
S = Situational
S = Subclavian steal
E = ENT (glossopharyngeal neuralgia)
L = Low systemic vascular resistance (Addison’s, diabetic vascular neuropathy, calcium channel blockers, anti-hypertensives)
S = Sensitive carotid sinüs

History And Physical Examination Hints

The thorough history must be quickly obtained and focus neurological, and general clinical exam must be performed. History should include thorough “dissection” of the complaint (use modified SOCRATES and SAMPLE), especially the exact time and rate of symptom onset (e.g., sudden onset suggest an embolic or hemorrhagic cause, while gradual onset suggests thrombotic stroke or hypoperfusion). It is also essential to identify any risk factors for thrombotic (hypertension, diabetes, coronary artery disease) or embolic cause (atrial fibrillation, valve replacement, recent MI).

The focused neurological exam can be performed within 4 minutes:

  • check mental status,
  • cranial nerves,
  • motor and sensory function,
  • coordination, and
  • reflexes

Guide For A Quick Neurological Exam

StepComments
mental status“fogs”
family history, orientation, general info, spelling (back & forth), also count backwards from 100 by 3, repeat 7 digit number, recall 3 objects after few minutes
cranial nervesCN 1: smell tobacco or soap
CN 2: visual acuity, gross visual field, ophthalmologic (background) exam
CN 3, 4, 6: pupillary light response, lateral and vertical gaze
CN 5: double simultaneous stimulation, also corneal reflex
CN 8: does he/she hear fingertips moving near ears
CN 9, 10: gag reflex
CN 11: shoulder elevation
CN 12: stick out tongue
motordrift of upper (and lower, if indicated) extremity
hand grasp
toe and foot dorsiflexion
additional: assessment of individual muscles
sensorydouble simultaneous stimulation with needle pin on hands and feet
proprioception in big toe
additional: check involving dermatomes, light touch, vibration
coordinationfinger-to-nose
heel-to-sheen
rapid alternating movements of hand and feet
additional: Romberg, tandem gait
reflexesbiceps (C5-6), triceps (C6-7), knee (L2-4), ankle (S1)
Babinski response
additional: Kernig and Brudzinski signs
provided by authors

 

In comatose patients, we can perform modified (neurological) exam: vital signs, drop hand overhead, pupils, abnormal eye movements, grimacing, withdrawal from noxious stimuli, Babinski response.

How to clinically differentiate between ischemic and hemorrhagic stroke? Despite clues and suggestions for one cause of symptoms or another, clinical differentiation alone is unreliable! A patient with hemorrhagic stroke typically complains about headache, sudden onset of symptoms that are gradually worsening, nausea and vomiting. Clinical exam often reveals decreased level of consciousness, hypertension, bradycardia, seizures, meningism, fever. Often patients with hemorrhagic stroke present with similar focal deficits as in ischemic stroke, but tend to look sicker. Other clues suggestive of hemorrhagic cause are uncontrolled hypertension, use of anticoagulants, coagulopathies (advanced liver disease), known vascular malformations, brain tumors.

In prehospital setting Cincinnati Prehospital Stroke Scale (CPSS) is highly useful tool to diagnose a potential stroke; if any of tests is abnormal, it suggests possible stroke and this patient should be transferred to hospital as soon as possible. CPSS with 1 abnormal finding has 72 % probability of ischemic stroke and 85 % probability if all 3 tests are abnormal.

Cincinnati Prehospital Stroke Scale

facial droparm driftspeech
person should smile or show his/her teeth


normal: both sides of face move equally		person should close eyes and straight out arms in front for 10 seconds

normal: both arms move equally or not at all		person should repeat a simple sentence


normal: repeats the sentence using the correct word and no slurring

 

Emergency Diagnostic Tests And Interpretation

As soon as possibility of stroke has been established, the patient has to be transferred to a facility where emergency non-contrast head CT scan can be performed, mainly to exclude hemorrhage as a cause of symptoms so proper treatment can commence.

Laboratory tests are directed to exclude possible stroke mimics and should include blood glucose, complete blood count, basic metabolic panel, cardiac enzymes, and coagulation studies, as well as EKG and chest X-ray.

American Heart Association recommends that workup should be completed within 3 hours between symptoms onset and beginning of thrombolysis.

Recommended Time Frame In Management Of Ishemic Stroke

actiontime frame
Symptom onset to ER doors< 3 hours
Door to lab work completed45 minutes
Door to non-contrast head CT ordered25 minutes
Door to CT being read45 minutes
Door to decision to give thrombolysis45 minutes
Door to drug administration60 minutes (& < 3 hours from onset)
American Heart Association recommendations.

 

An NIH Stroke Scale/Score calculator is a useful tool for quantifying neurologic deficit.

A diagnosis of an acute stroke is often based solely on the patients’ history and physical exam, since head CT does not show an acute infarction until at least 6 hours after the occlusion (but it helps to rule out intracranial hemorrhage).

Emergency treatment options. Treatment of stroke is based on the cause of symptoms. If an ischemic stroke is confirmed (or suspected and hemorrhage has been ruled-out) the next step is to determine if a patient is a candidate for thrombolysis.

 

Criteria To Become A Candidate For Thrombolysis

QuestionsYesNo
all answers must be »yes«
is the time of onset of symptoms clearly defined?YES
will thrombolysis be possible within 4,5 hours of onset?YES
has the patient had a good quality of life until now?YES
all answers must be »no«
seizures at the beginning of symptoms?NO
is this minor/isolated disability (e.g. just disarthria, ataxia)?NO
are symptomes rapidly improving?NO
gastro-intestinal or genito-urinary bleed within the last 3 weeks?NO
larger surgery within the last 2 weeks?NO
prior ischemic CVA or severe head injury in the past 3 months?NO
prior intracranial bleed anytime in the past?NO
BP > 185/110 (despite therapy)?NO

 

Contraindications for thrombolysis

  • Absolute contraindications
    • Hemorrhagic (or unknown) CVA anytime
    • Ischemic CVA within the past six months
    • Malignancy of CNS
    • Major (head) trauma or surgery within the past three weeks
    • Gastrointestinal bleed in the last month
    • Known coagulopathy
    • Aortic dissection
  • Relative contraindications
    • TIA in the past six months
    • Peroral anticoagulation therapy
    • Pregnancy up to less than a week postpartum
    • Refractory hypertension
    • Advanced liver disease
    • Infective endocarditis
    • Active peptic ulcer
    • Recent arterial puncture (at the noncompressible site)

If a patient fulfills above criteria for thrombolysis, recombinant t-PA is given at a dose of 0,9 mg/kg IV up to a maximum of 90 mg. 10 % of the dose is given as a bolus, followed by a 60 minutes infusion. Also, blood pressure must be treated before thrombolysis if it exceeds 185/110 (use captopril 12,5 mg SL).

When hemorrhagic stroke is suspected (or confirmed), one must do an urgent consultation with neurosurgeon to decide on further treatment options and plan (e.g., craniotomy and evacuation of hematoma, endovascular aneurysm repair).

Pediatric, Geriatric, Pregnant Patient, And Other Considerations

Stroke in pediatric population is an extremely rare occasion, but all the principles for adults apply for the pediatric population. Generally, incidence of stroke increases with age, so physicians have to maintain a high level of suspicion for stroke when managing undifferentiated geriatric patient who is “just unwell.” Stroke in pregnant patient can occur due to predisposition to hypercoagulability, but one must be aware that thrombolysis is contraindicated in pregnancy until the first week after Labor has passed.

Disposition Decisions

All patients suffering acute stroke should be admitted to stroke care unit or intensive care unit, depending on local policy, abilities and patients’ condition. Patient has to be on a monitor and have frequent assessment of neurologic system.

Links To More Information

References and Further Reading