title: Are multiple cerebral infarcts synergistic?
abstract: OBJECTIVE
  The goal of this study was to characterize the cumulative effects of multiple strokes on cognition.
  
  
  METHODS
  We conducted a prospective, longitudinal case study with neuropsychological, neurological, and radiological evaluations.
  
  
  METHODS
  Research was conducted at the Boston (Mass) Veterans Administration Medical Center, Neurology Service, on successive inpatient hospital admissions.
  
  
  METHODS
  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.
  
  
  METHODS
  Each evaluation included approximately 3 hours of neuropsychological testing spanning a range of cognitive domains (attention, language, memory, visuospatial functions, response inhibition, and mental flexibility), full neurological examination, and computed tomographic scan.
  
  
  RESULTS
  The patient's stepwise cognitive decline was characterized by unexpected exacerbation of "frontal" neurobehavioral features following the occurrence of two posterior 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 second evaluation, following a left posterior parietal lesion, revealed a range of new frontal features, including impulsivity, pull-to-stimulus, and difficulty shifting set. Following a subsequent right occipital infarct, further frontal lobe impairments emerged: forced grasp reflex and incontinence.
  
  
  CONCLUSIONS
  We hypothesize that the cumulative effects 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.
authors.affiliation: Department of Neurology, University of California at Davis, School of Medicine, Berkeley.
authors.forename: N
authors.initials: N
authors.lastname: Wolfe
authors.forename: V L
authors.initials: VL
authors.lastname: Babikian
authors.forename: R T
authors.initials: RT
authors.lastname: Linn
authors.forename: J E
authors.initials: JE
authors.lastname: Knoefel
authors.forename: M
authors.initials: M
authors.lastname: D'Esposito
authors.forename: M L
authors.initials: ML
authors.lastname: Albert
mesh_terms: D000368:Aged; D002544:Cerebral Infarction / Q000000981:diagnostic imaging* / Q000523:psychology*; D003071:Cognition; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012008:Recurrence; D014057:Tomography, X-Ray Computed