USMLE Step 1 Medical Subject Review: Pathology CNS

12-year-old boy is prepubescent and has grown to over two meters tall. An MRI of his head reveals an extrasellar mass. The boy's tall stature is MOST probably due to which of the following physiologic processes? - Answer- pituitary adenoma secreting elevated growth hormone 55-year-old man has had emotional changes consisting of sexual disinhibition and emotional apathy. He later has difficulty with expressing himself and doing his usual routine. The magnetic resonance imaging (MRI) reveals atrophy of the frontal and temporal lobes, along with swollen neurons in the temporal and frontal areas of the brain, and intraneuronal argentophilic inclusion bodies in these same areas. What type of dementia is this patient exhibiting? - Answer- Dementia due to Pick's disease 69-year-old woman suffered a massive stroke 6 weeks ago. She is now recovering from the stroke, but she has residual paralysis and sensory impairment of her right arm. She is also unable to speak and unable to turn her eyes to the right. The most likely site of her lesion is in the area that is supplied by what artery? - Answer- Left middle cerebral artery 65-year-old woman has a long-standing dementing disorder characterized by deterioration in personality, neglect of personal hygiene, impaired judgment, and uninhibited behavior. MRI demonstrates severe cortical atrophy limited to the frontal lobes and anterior two thirds of the temporal lobes, while the remaining cortex is preserved. No evidence of recent or remote infarcts is found. What diagnosis is most consistent with these pathologic and clinical features? - Answer- Frontotemporal dementia 53-year-old man presents with a 2-week history of severe headaches that occur primarily at night. The patient is pacing while he is talking. The pain surrounds one eye and lasts for 30-90 minutes. He also states that there is ipsilateral lacrimation, conjunctival injection, and nasal congestion during the attacks. The patient states that he has had these headaches once a day over the last week. He cannot point to any one thing that causes them. On examination, the patient has features of partial Horner's syndrome. His vital signs are temperature: 97.0°F, heart rate: 80/min, respiration 16/min, and blood pressure: 126/80 mm Hg. What is the most likely diagnosis? - Answer- Cluster headache 3-year-old girl shows a white reflection from the surface of the retina upon ophthalmologic examination. Biopsy of the lesion reveals retinoblastoma (Rb). Underphosphorylated Rb gene product has which significant characteristic? - Answer- prevents mitosis 38-year-old man with uncontrolled facial movements states that he has noticed himself over the la