General Pathology — MCQs

Question 21: A 65-year-old man with no significant medical history begins to have memory loss and personality changes. Rapidly, over the next few months his symptoms increase in severity. He experiences a rapid mental deterioration associated with sudden, jerking movements, particularly in response to being startled. He has gait disturbances as well. Eventually, he lapses into a coma and dies approximately ten months after the onset of symptoms. Which of the following would most likely be seen on autopsy of the brain in this patient?

• A. Neurofibrillary tangles
• B. Amyloid plaques
• C. Spongiform changes (Correct Answer)
• D. Vascular lesions
• E. Lewy bodies

Explanation: ***Spongiform changes*** - This patient's **rapidly progressive dementia**, associated with **myoclonus (jerking movements)** and **gait disturbances**, culminating in death within months, is highly suggestive of **Creutzfeldt-Jakob disease (CJD)**. - CJD is characterized by the accumulation of abnormally folded prion proteins (PrPSc), leading to **spongiform degeneration** (vacuolation) of neurons and neuropil, **neuronal loss**, and **astrogliosis** in the brain. *Neurofibrillary tangles* - **Neurofibrillary tangles**, composed primarily of hyperphosphorylated **tau protein**, are a hallmark of **Alzheimer's disease**. - Alzheimer's disease typically has a much **slower progression** over several years, unlike the rapid deterioration seen in this patient. *Amyloid plaques* - **Amyloid plaques**, formed by the extracellular deposition of **beta-amyloid protein**, are also characteristic features of **Alzheimer's disease**. - Like neurofibrillary tangles, amyloid plaques are associated with a chronic, progressive course of dementia, not the **rapidly fatal trajectory** described. *Vascular lesions* - **Vascular lesions**, such as infarcts or hemorrhages, are the underlying pathology in **vascular dementia**. - While vascular dementia can cause cognitive decline, its presentation often involves **step-wise deterioration** and may be associated with focal neurological deficits, which are not the primary features here. *Lewy bodies* - **Lewy bodies**, which are intracellular cytoplasmic inclusions of **alpha-synuclein protein**, are characteristic of **Lewy body dementia** and **Parkinson's disease**. - Lewy body dementia presents with fluctuating cognition, visual hallucinations, and parkinsonism, but typically does not show the **rapid progression** and prominent myoclonus seen in CJD.