Are Multiple Cerebral Infarcts Synergistic? Nicola Wolfe, PhD; Viken L. Babikian, MD; Richard T. Linn, PhD; Janice E. Knoefel, MD; Mark D'Esposito, MD; Martin L. Albert, MD Objective: The goal of this study was to character- ize the cumulative effects of multiple strokes on cognition. Design: We conducted a prospective, longitudinal case study with neuropsychological, neurological, and radio- logical evaluations. Setting: Research was conducted at the Boston (Mass) Veterans Administration Medical Center, Neurology Ser- vice, on successive inpatient hospital admissions. Patient: We followed up a 66-year-old right-handed man with multiple subcortical lacunae during a 3.5-year period during which he suffered two additional cortical infarctions. Main Outcome Measures: Each evaluation included approximately 3 hours of neuropsychological testing span- ning a range of cognitive domains (attention, language, memory, visuospatial functions, response inhibition, and mental flexibility), full neurological examination, and com- puted tomographic scan. Results: The patient's stepwise cognitive decline was char- acterized by unexpected exacerbation of "frontal" neu- robehavioral features following the occurrence of two pos- terior cortical lesions. At initial evaluation, the computed tomographic scan showed bilateral subcortical lacunae in basal ganglia and periventricular white matter, and symptoms included dysarthria and perseveration. The sec- ond evaluation, following a left posterior parietal lesion, revealed a range of new frontal features, including im- pulsivity, pull-to-stimulus, and difficulty shifting set. Fol- lowing a subsequent right occipital infarct, further fron- tal lobe impairments emerged: forced grasp reflex and incontinence. Conclusions: We hypothesize that the cumulative ef- fects of infarcts were synergistic. That is, the posterior cortical infarcts elicited frontal features that would not be expected from a simple sum of these lesions' effects. (Arch Neurol. 1994;51:211-215) The cumulative effects of multiple strokes on cogni¬ tion have proved difficult to characterize. While single infarctions have been clearly associated with specific neurobehavioral syn¬ dromes, ' cases of multiple lesions have been more difficult to describe due to individual differences in the number, the extent, and the location of lesions. Hachinski2 has noted that although the effects of multiple lesions on mental function depend on size, site, num¬ ber, and nature of lesions, their cumulative effects seem not to be simply additive. To characterize the longitudinal course of cognitive decline with multiple infarcts, we conducted a prospective, longitudinal study of a 66-year-old, right-handed man with multiple subcortical lacunae during a 3.5- year period in which he suffered two addi¬ tional cortical infarctions. REPORT OF A CASE The patient, a retired postal worker with a seventh-grade education, was first seen at age 66 years after a Veterans Adminis¬ tration Medical Center admission for sud¬ den onset of light-headedness, slurred speech, and unsteady gait. The medical his¬ tory was significant for hypertension and From the Department of Neurology, University of California at Davis, School of Medicine, and the Northern California Alzheimer's Disease Center, Berkeley (Dr Wolfe); Department of Neurology, Boston (Mass) University School of Medicine and Boston Veterans Administration Medical Center (Drs Babikian, Knoefel, D'Esposito, and Albert); and the Department of Psychiatry, State University of New York at Buffalo, School of Medicine (Dr Linn). DownloadedFrom:http://archneur.jamanetwork.com/byaUniversityofCalifornia-BerkeleyUseron11/01/2013