An 86-year-old woman is brought to the emergency department due to progressive confusion and lethargy for the past several hours. The patient has a history of Alzheimer dementia, and her family reports that she has been gradually declining in mental and physical capacity for the last 6 months. She also has had several falls and requires assistance with daily activities. Other medical conditions include hypertension and osteoarthritis. Temperature is 38 C (100.4 F), blood pressure is 170/100 mm Hg, and pulse is 70/min. On physical examination, the patient is somnolent but arousable. She withdraws from painful stimuli applied to her right side but not to her left. Noncontrast CT scan of the head is shown in the image below:
Show Explanatory Sources
Which of the following is the most likely underlying cause of this patient's current condition?
Show Explanatory Sources
This patient has had progressive confusion and lethargy over several hours and is not withdrawing from pain on the left side, with a CT scan of the head showing hyperdensity in the right parietal lobe. In an elderly patient with Alzheimer dementia, this is most likely due to cerebral amyloid angiopathy (CAA), the most common cause of lobar intracranial hemorrhage (ICH) and the second most common cause (after hypertension) of ICH (lobar and nonlobar).
CAA is a condition in which abnormal beta-pleated sheet protein (amyloid) infiltrates cerebral blood vessels, increasing fragility and leading to rupture with resultant spontaneous ICH. It most often occurs in patients age >75. The amyloidogenic proteins are usually the same as those seen in Alzheimer dementia; the disease is not associated with systemic amyloidosis.
ICH due to CAA most often involves the occipital and parietal lobes, usually sparing the ventricles and deep brain structures (which helps differentiate it from hypertensive hemorrhage). Hematoma expansion can lead to elevated intracranial pressure, resulting in impaired consciousness, confusion, headache, and nausea/vomiting. Treatment is similar to that for other causes of ICH (eg, reverse anticoagulation, control blood pressure, normalize intracranial pressure).
(Choice B) Arteriovenous malformation rupture is the most common cause of ICH in children. This patient's age, lobar hemorrhage, and Alzheimer dementia make CAA more likely.
(Choice C) Subdural hematoma results from the rupture of bridging veins, most commonly from head trauma. Risk factors include advanced age and chronic alcoholism (due to brain atrophy), as well as anticoagulant use. On noncontrast CT scan of the head, acute subdural hematoma appears as a crescent-shaped hyperdensity that crosses suture lines.
(Choice D) Meningeal artery tears typically occur due to traumatic head injury and result in epidural hematoma. Patients may have altered consciousness, headache, nausea/vomiting, and focal neurologic deficits; however, CT scan typically reveals acute hemorrhage in a biconvex pattern that does not cross suture lines.
(Choice E) Ruptured saccular (berry) aneurysms cause subarachnoid hemorrhage, characterized by the abrupt onset of severe (thunderclap) headache and hyperattenuation of the sulci and basal cisterns on CT scan of the head. Focal neurologic deficits are uncommon.
Educational objective:
Cerebral amyloid angiopathy is associated with Alzheimer dementia and occurs due to the beta-amyloid deposition in the walls of small to medium cerebral arteries that leads to increased fragility of the vessels. The most common manifestation is a spontaneous, lobar intracranial hemorrhage.