Regarding the use of the National Institute of Health Stroke Scale (NIHSS) to assess a patient presenting with a stroke to the ED, which ONE of the following statements is FALSE?
Answer: A: The NIHSS is an easy-to-use tool for assessing and documenting neurological deficits in a patient with a stroke. It can be repeated during the course of the hospital stay and later (e.g. at 90 days) to assess the progression and the extent of recovery and functional outcome. It has been shown to have a high interrater reliability. A score over 22 is considered a severe stroke because the score correlates well with infarct volume. However, it gives more weight to the symptoms and signs of anterior circulation than posterior circulation. A score of 0 does not exclude a stroke.
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Regarding an ischaemic stroke involving the middle cerebral artery territory, which ONE of the following is TRUE?
Answer: D: The majority of ischaemic strokes involve the middle cerebral artery territory. The typical clinical features of MCA occlusion are contralateral hemiplegia affecting the face, arms and legs (arms are more affected than legs – compare this with anterior cerebral artery occlusion where the lower extremity is more affected ANSWERS 165 with sparing of the hand and face), contralateral hemisensory loss, homonymous hemianopia and gaze preference towards the side of the infarct. If the dominant hemisphere is affected (left in right-handed people and 80% of left-handed), aphasia or dysphasia (receptive, expressive or both) can be expected. Inattention, neglect, constructional apraxia and dysarthria (without aphasia) may occur if the nondominant hemisphere is affected. In the absence of other exclusion criteria, to be eligible for thrombolytic therapy, the patient’s non-contrast head CT should rule out any haemorrhage and should show no evidence or very minimal evidence of a recent stroke. The stroke is considered severe and/or of delayed presentation if the CT shows involvement of more than one-third of the middle cerebral artery (MCA) territory. The aim of thrombolysis is to salvage the potentially salvageable ischaemic penumbra surrounding the infarcted brain tissue. The hyperdense sign, which can be seen on non-contrast CT, is occasionally due to the presence of a thrombus at that site. This, in itself, is not an eligibility criterion for thrombolysis.
Regarding symptoms of a posterior circulation stroke, which ONE of the following is TRUE?
Answer: B: The most common symptom of a posterior circulation stroke is an occipital headache. Symptoms can be unilateral or bilateral, depending on the extent of involvement in the brainstem, cerebellum, thalamus, medial temporal and occipital lobes. Unilateral or bilateral weakness, or sensory disturbance, may occur. Homonymous hemianopia may be due to posterior cerebral artery occlusion or middle cerebral artery occlusion. In posterior cerebral artery occlusion this is usually associated with macular sparing as this area is supplied by the middle cerebral artery. In any type of stroke, the significant altered level of consciousness is due to direct involvement of the medulla, as in posterior circulation stroke, or indirect involvement of the medulla due to mass effect and/or increased intracranial pressure from ischaemic or haemorrhagic stroke involving other parts of the brain. This can also occur with extensive involvement of cerebral hemispheres.
Regarding the prediction of stroke in a patient with symptoms of a transient ischemic attack (TIA), which ONE of the following is TRUE?
Answer: A: Patients with TIAs have substantial overall short-term risks of developing ischaemic strokes. Overall 2-day stroke risk is 3.9%, 7-day risk is 5.5% and 90-day risk is 9.2%. The ABCD2 risk assessment tool has been validated to predict short-term risk at 2, 7 and 90 days. The ABCD2 score is useful to determine which patients need to be admitted for observation and, above all, for arrangement of urgent investigations such as head CT and imaging of the carotid arteries. In these patients, antiplatelet and statin therapy can be started early. As the 2- and 7-day stroke risk is substantial, these investigations should be done as early as practical. Early carotid endarterectomy reduces high stroke risk in symptomatic patients with significant stenosis. The finding of an infarct on imaging in a patient who otherwise had transient symptoms and now is asymptomatic (as in a TIA), puts them in the category of minor stroke. This predicts an increased short-term risk of further strokes. There is an increased chance of finding a new infarct on imaging in patients with diabetes who have transient neurological symptoms.
ABCD2 score:
1- Age:
2- BP:
3- Clinical features:
4- Duration:
5- Presence of diabetes: 1 point
Interpretation of ABCD2 score:
1- Score 1–3: low risk
2- Score 4–5: moderate risk
3- Score 6–7: high risk
The following conditions are likely to result in poor outcome in ischaemic stroke, EXCEPT:
Answer: B: Both very high blood pressures and too aggressive reduction of blood pressure are associated with poor 166 CHAPTER 4 Neurological and Neurosurgical Emergencies outcomes in ischaemic stroke. However, there is no consensus about an ideal BP during the treatment of ischaemic stroke. According to the National Institute of Neurological Disorders and Stroke (NINDS) eligibility criteria for thrombolysis in stroke, a BP over 185/110 is a contraindication for thrombolysis and a reduction in BP below this level should be carefully attempted, using titratable intravenous agents. BP should also be maintained during and after thrombolysis to reduce the chance of haemorrhagic transformation of the ischaemic stroke. In a patient who is not a candidate for thrombolysis, too aggressive attempts at BP control may cause poor outcomes because this reduces perfusion to the already vulnerable ischaemic penumbra. Therefore, in this situation, BP reduction is not advised unless the BP is over 220/120 and there is no evidence of other end-organ damage. Dehydration is known to result in poor outcomes. Consequently, adequate hydration of the patient in the ED is essential. Routine oxygen administration has not shown to improve the outcome in stroke patients.
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