392 Emergency Medicine
patients with the same symptoms in the setting of exposure to combustible
products. It is not appropriate to do nothing (e)since the patient is clearly
in need of medical attention.
358.The answer is a.(Rosen, pp 1436-1437.)The middle cerebral artery
is the most common site of intracranial cerebral artery thrombosis. Clinical
findings can include contralateral hemiplegia, hemianesthesia, and homony-
moushemianopsia. The upper extremity deficit is usually more severe than
the lower extremity deficit. Aphasia occurs if the dominant hemisphere is
involved. Gaze preference is in the direction of the lesion.
Choice(b)is incorrect since the findings are ipsilateral to the area of
injury. Choice (c)describes deficits in the anterior cerebral artery (ACA)
distribution with greater deficits in lower extremity and altered mentation
because of frontal lobe involvement. Crossed deficits, such as contralateral
motor and ipsilateral cranial nerve findings (d)occur in brainstem strokes,
which are supplied by the posterior circulation. Pure motor (e)or sensory
loss occurs in lacunar infarcts, which involve small penetrating arteries.
359.The answer is e.(Rosen, pp 1437-1438.)Do not get confused with
the multiple signs and symptoms in this case! They involve three distinct
areas of the brain; the brainstem (facial droop, dysphagia, vertigo, and vertical
nystagmus), cerebellum (ataxia, vertigo, and vertical nystagmus), and visual
cortex (diplopia). All of these anatomical areas are supplied by the posterior
circulation, specifically the vertebrobasilar artery.A mnemonic to help
remember the presentation of a vertebrobasilar stroke is the “three D’s”:
dizziness (vertigo), dysphagia, and diplopia.There are cerebellar and
cranial nerve deficits observed on both sides of the body.
(a)Lacunar infarcts are small infarcts that are usually caused by a
hypertensive vasculopathy but may occur in diabetics and can affect both the
anterior and posterior cerebral vessels. Lacunar strokes involve penetrating
cerebral arterial vessels lying deep in the grey matter (internal capsule) or
brain stem. BPV (b)is a transient positional vertigo associated with nystag-
mus.Neurologicdeficits are absent in BPV. Note that horizontal, vertical, or
rotary nystagmus can occur in BPV; however vertical nystagmus is always
worrisome as it may indicate a brainstem or cerebellum lesion. Labyrinthitis
(c), an infection of the labyrinth, presents with hearing loss and sudden brief
positional vertigo attacks and does not involve other neurologic deficits. The
posterior cerebral artery (d)delivers blood supply to the occipital cortex and
upper midbrain. Clinical findings include contralateral homonymous