Neurology: Case of the Month

Which of the following statements about semantic dementia (SD) is FALSE?

[ A ] SD is a slowly progressive degenerative disorder affecting primarily the lateral temporal lobes.
[ B ] In SD, speech is characterized by an agrammatic, telegram-style verbal output, stringing together mainly nouns.
[ C ] In SD, semantic knowledge becomes progressively impoverished, while episodic memory remains relatively spared.
[ D ] Word-finding difficulties and problems with naming of low-frequency items are seen early in the course of SD.
[ E ] On MR imaging, the most consistent locus of atrophy in patients with SD is the left polar and inferior temporal lobe.

Which of the following statements about the temporal lobes is FALSE?

[ A ] The medial temporal lobes play a crucial role in episodic memory.
[ B ] The left temporal pole has been implicated in the naming of unique entities.
[ C ] The hippocampus has to be intact to retrieve knowledge about the world.
[ D ] Functional MRI has shown activation in the lateral temporal cortex and fusiform gyrus during tasks requiring semantic judgements.
[ E ] Injury to the temporal lobes can lead to a combination of episodic and semantic memory difficulties.

Which of the following statements about neuropsychological performance is FALSE?

[ A ] In lesions of the lateral temporal lobe, letter fluency is usually better preserved than category fluency.
[ B ] List learning performance will be flat, with poor recall and poor recognition, in lesions involving the medial temporal lobe.
[ C ] If during IQ testing, relatively low scores on the verbal knowledge subscales are found in relation to the other subscales, a problem with semantic memory is suggested.
[ D ] If a patient is unable to recall any childhood memories, this indicates a problem with episodic memory.
[ E ] The Famous Persons Test is likely to be abnormal in patients with left temporal pole lesions.

Which of the following statements about radiation injury is FALSE?

[ A ] Early delayed injury is characterized by demyelinating plaques.
[ B ] Late delayed injury rarely shows vascular degeneration.
[ C ] Intense acellular fibrosis can occasionally be seen in delayed radiation injury.
[ D ] Late delayed injury can occur years after radiation.
[ E ] Early delayed injury typically occurs about 3 months after radiation.

Which statement concerning the differentiation between tumor recurrence and radiation injury in the brain is FALSE?

[ A ] On magnetic resonance spectroscopy (MRS), moderately increased choline peaks and reduced N-acetylaspartate signal intensities are consistent with low-grade glioma.
[ B ] Fluorodeoxyglucose (FDG)-PET can reliably make the distinction between tumor recurrence and radiation injury on the basis of the metabolic activity seen in the lesion.
[ C ] On MRS, the presence of lipid signals indicates tissue necrosis.
[ D ] Stereotactic biopsy is problematic in distinguishing between tumor recurrence and radiation injury.
[ E ] Many neurosurgeons will recommend excisional biopsy for metabolically active lesions in a previously irradiated tumor bed.

Test Yourself — Patient 73