Clinical Reasoning: A case of subacute cognitive decline in a 76-year-old man.

SECTION 1 A 76-year-old, right-handed man presented to our emergency department with a 3-day history of cognitive decline following a motor vehicle collision. Medical history included hypertension, atrial fibrillation, and renal dysfunction. He was a high-functioning retired advertising executive who formerly smoked cigarettes, and used neither recreational drugs nor alcohol. His family reported he was stuttering, having wordfinding difficulties, taking longer to do simple tasks such as dressing, and had trouble using objects, such as cutlery. He described difficulty in reading, and simple math had become more challenging. Upon further questioning, these changes may have started 3 weeks before presentation, but were more pronounced following the accident. There were no other new focal neurologic or systemic symptoms. At presentation, he was alert, although hypertensive at 190/106; other vital signs were normal. Montreal Cognitive Assessment total score was 12/30, scoring 0/5 in visuospatial/executive, 1/3 in naming, 3/6 in attention, 3/3 in language, 1/2 in abstraction, 0/5 in delayed recall, and 4/6 in orientation. Speech was fluent with occasional word-finding difficulties, circumlocution, and phonemic paraphasias. Naming to low-frequency words was impaired, as was object recognition. He displayed evidence of finger agnosia. Comprehension of simple and complex commands was intact. Writing and reading were impaired, including words he had himself written, although he did not have letter agnosia. He had difficulty with simple arithmetic and difficulty distinguishing left from right. Tests of praxis revealed hand-as-tool errors. Cranial nerve examination was normal, including visual fields to confrontation and normal visual acuity. Motor and sensory examinations were normal. Cortical sensation was intact but processing was slow. Sensory inattention, extinction, and tactile neglect were absent. Coordination and gait were normal.