Neurologic Emergencies

Published on 14/03/2015 by admin

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Last modified 14/03/2015

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Neurologic Emergencies

Stroke

Stroke is a disease process that disrupts vascular blood flow to a distinct region of the brain. Although the causes of strokes are diverse, ranging from cardiac emboli to rupture of a congenital aneurysm, there are two major mechanisms of brain injury: (1) ischemia caused by vessel occlusion and (2) hemorrhage caused by vessel rupture. From 80% to 85% of all strokes are ischemic. Effective treatment for one stroke type may be disastrous when applied to the other type. A patient in the backcountry suspected of having a stroke should be transported immediately to the nearest medical facility because the anatomic location of the lesion and the mechanism of the stroke must be known before effective treatment can be given. Ischemic (thrombotic) strokes can be effectively treated in many cases with intravenous (IV) tissue plasminogen activator (t-PA) if symptoms have been present for less than 4.5 hours. Mechanical clot removal and intra-arterial t-PA may be effective in reversing stroke manifestations up to 8 hours after symptom onset.

A review of the patient’s demographics and past medical history may suggest the cause of the stroke. A 30-year-old, otherwise healthy patient with a stroke-like syndrome is more likely to have a hemorrhagic stroke. A 65-year-old patient with a history of hypertension, coronary artery disease, and diabetes is more likely to have a thrombotic stroke. Stroke in a patient with underlying atrial fibrillation suggests a cardioembolic source. Stroke in an individual with previous transient ischemic attack (TIA)–like symptoms suggests a thrombotic cause.

Signs and Symptoms

Any or all of the following signs and symptoms may be present:

1. Patient may be alert, drowsy, lethargic, obtunded, or comatose

2. Visual field deficit or gaze preference

3. Sudden onset of unilateral weakness and numbness

4. Unilateral facial motor weakness (facial droop)

5. Dysarthria and/or aphasia

6. Sudden onset of dizziness, vertigo, diplopia, and ataxia

7. Sudden onset of severe headache (“the worst headache of my life”)

Treatment

1. Maintain an adequate airway, and administer oxygen.

2. Dehydration should be corrected with IV normal saline.

3. Assess the patient for hypoglycemia, and give dextrose if indicated (see later). Otherwise, dextrose-containing solutions should be avoided.

4. Keep the patient’s head and torso slightly elevated (at least 30 degrees).

5. Transport the patient immediately to the closest medical facility. Continuously assess the patient’s airway and level of consciousness because the condition can worsen dramatically during transport.

Transient Ischemic Attack

A TIA is a neurologic deficit resembling a stroke that resolves within 24 hours (although most resolve within 30 minutes) and is most commonly associated with thrombotic stroke. Signs, symptoms, and treatment are the same as for stroke.

Seizure

Seizure can result from head injury, heat illness, infection, hyponatremia, hypoglycemia, stroke, epilepsy, drugs, and other causes.

Signs and Symptoms

1. A generalized (grand mal) seizure begins abruptly (there may be an aura) with loss of consciousness as the patient suddenly becomes rigid, with trunk and extremities extended, and falls to the ground. As the rigid (tonic) phase of the seizure subsides, there is increasing coarse trembling that evolves into rhythmic (clonic) jerking of the trunk and extremities. The eyes may deviate to one side, there is difficulty breathing, and occasionally there is loss of bladder and/or bowel control and tongue biting.

2. Most seizures last only 1 or 2 minutes.

3. After most seizures, the patient will be confused or combative (“postictal”) for a period of time (10 to 30 minutes) and then slowly return to normal.

Treatment

1. Protect the patient from injury during the seizure. This may be done with cushions, sleeping bag, or by moving hard objects away from the patient.

2. If possible, the patient should be turned to one side to reduce the risk for aspiration should vomiting occur.

3. Do not attempt to place a bite block or any object between the teeth or into the mouth.

4. Do not give the patient anything orally until he or she is awake and lucid.

5. If the patient is suffering from hypoglycemia, administer sugar as soon as possible.

a. If the patient is conscious and able to swallow, give him or her something containing sugar to drink or eat. This could be fruit juice, a banana, candy, or a nondiet soft drink. As soon as the patient feels better, have him or her eat a meal to avoid a recurrence.

b. If the patient is unconscious, place tiny amounts of sugar granules, cake icing, or Glutose paste (one tube contains 25 g [0.9 oz] glucose) under the patient’s tongue, where it will be passively swallowed and absorbed.

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