title: The panoply of field-dependent behavior in 1436 stroke patients. The mirror neuron system uncoupled and the consequences of loss of personal autonomy.
abstract: Evaluation of the multifaceted nature of frontal network syndromes is uniquely challenging and rarely tested in the acute/sub-acute stroke period. Field-dependent behavior such as imitation behavior, utilization behavior, and environmental dependency syndrome, as a component of altered environmental autonomy, may be a reliable bedside test. This research focused on the frequency of field-dependent behavior in stroke, the subtypes and relation to frontal lobe lesion location and stroke etiology. A validated frontal network score incorporating a 10-point imitation behavior scale was applied to alert patients without significant aphasia, encephalopathy, dementia, or substance abuse. Discriminative validity assessment with magnetic resonance imaging, diffusion weight imaging (MRI-DWI brain) was performed and correlational validity was established using standard neuropsychological tests. Of the stroke patients (n = 1436), those with frontal network symptoms (335/1203; 28%) were analyzed further. In the 73 patients with lesions restricted to the frontal lobes or the frontal subcortical circuits, 56 complied with the 10-point imitation behavior scale testing. Forty-five of 56 (80%) demonstrated imitation behavior (sensitivity 73% and specificity 94%). Correlational validity testing with four commonly used frontal lobe neuropsychological tests was good. The stroke etiology included 26 (59%) "other" causes, 9 (20%) intracerebral hemorrhages, 3 (7%) cardioembolic causes, 3 (7%) large vessel disease, 2 (4%) small vessel disease, and 2 (4%) unknown etiology. Field-dependent behaviour subtypes included imitation behavior (n = 45), utilization behavior (n = 9), environmental dependency syndrome (n = 4), and complex other forms of environmental dependence syndrome (n = 5). It was concluded that imitation behavior is a relatively common occurrence with lesions in the frontal lobes in the acute/sub-acute stroke period and is associated predominantly with non-mainstream (other) stroke causes and intracerebral hemorrhage.
authors.affiliation: a Neurology Department , James A Haley VA Hospital , Tampa , Florida , USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Hoffmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D007100:Imitative Behavior; D008875:Middle Aged; D059167:Mirror Neurons / Q000502:physiology; D009483:Neuropsychological Tests; D026684:Personal Autonomy; D020521:Stroke / Q000523:psychology*; D055815:Young Adult
keywords: Frontal syndromes; Imitation behavior; Stroke