An 84-year-old woman is brought to the emergency department due to 2 weeks of progressive confusion. She has a history of mild dementia and lives in an assisted living facility. Her caregiver reports that during the past several months she has become progressively weaker, and she has fallen down on several occasions and is now using a walker. In her usual state, the patient recognizes most of the staff, converses appropriately, and performs daily activities with minimal assistance; however, for the past week, she has been more confused and sleeping most of the time. She has also developed a mild headache. The patient has had no fever, vomiting, or urinary symptoms. Her other medical problems include hypertension and osteoarthritis. Blood pressure is 138/76 mm Hg and pulse is 74/min and regular. She is somnolent but arousable. The patient does not recognize her caregiver and gives several inaccurate answers but is able to follow simple instructions. Muscle strength is 4/5 on the right side and 3/5 on the left. Plantar reflex is upgoing on the left. Which of the following is the most likely diagnosis?
Subdural hematoma | |
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This elderly patient with a history of falls has most likely developed a chronic subdural hematoma (SDH) due to traumatic head injury. SDH occurs when shearing forces tear the bridging veins, causing them to slowly bleed into the subdural space.
Symptoms of SDH develop gradually as they occur secondary to the rupture of low-pressure vessels. Acute SDH typically produces symptoms 1-2 days after onset, whereas chronic SDH presents insidiously, weeks after the initial injury. Clinical manifestations of chronic SDH often include headache, somnolence, and confusion. Patients may also have focal neurologic deficits (eg, contralateral hemiparesis) due to compression of the underlying cerebral cortex. Non-contrast head CT usually shows a crescent-shaped hypodensity that crosses the suture lines.
(Choice A) Dementia typically presents with progressive cognitive dysfunction (eg, memory loss, language abnormalities) that interferes with the ability to perform activities of daily living. Decreased level of consciousness and focal neurologic deficits are not characteristic.
(Choice B) Infarction of the internal capsule typically occurs due to lacunar stroke and can result in acute contralateral hemiparesis due to corticospinal tract injury in the posterior limb. However, lacunar infarcts typically lack impaired consciousness or cortical signs (eg, aphasia, neglect).
(Choice C) Toxic-metabolic encephalopathy can be caused by infection, toxins, or metabolic derangements (eg, electrolytes disturbance, uremia, hyperammonemia). Patients typically present with confusion, lethargy, and neuromuscular findings (eg, bradykinesia, asterixis) due to global cerebral dysfunction. Focal neurologic deficits are not characteristic.
(Choice D) Normal-pressure hydrocephalus can cause cognitive disturbances, although headaches and weakness worse on one side than the other is atypical. Gait difficulties would be characterized by ataxia, and urinary incontinence is classic. Brain imaging reveals ventricular enlargement that is out of proportion to sulci enlargement.
(Choice E) Transient limb weakness following partial seizure activity is known as postictal (Todd) paralysis. Although subdural hematoma may cause seizure with postictal paresis and confusion, other features of seizure (eg, convulsions, tongue-biting, incontinence) are not evident in this patient.
Educational objective:
Elderly patients are at higher risk for subdural hematoma due to increased fall risk and cerebral atrophy. Chronic subdural hematoma often presents insidiously weeks after the initial injury with headache, somnolence, confusion, and focal neurologic deficits.