Cognitive disconnective syndrome by single strategic strokes in vascular dementia

Abstract

Strategic regions correspond to associative, limbic and paralimbic structures and related circuits, that underpin cognitive/behavioral functions. Strokes in these eloquent sites produce pictures of vascular dementia with syndromic features due to specific site lesion and/or interruption of their interconnections. This study aims at analysing subcortical strategic strokes that express similar cognitive/behavioral elements, by sharing common pathways. Patients (n=6) who attended in specialized ambulatory, were submitted to neuropsychological and neuroimaging assessments through MRI (GE Signa Horizon 1.5T) and brain SPECT (Millennium MG, ECD [TC-99m]). Stroke locations and respective main symptoms were: 1. anteromedian thalamus [L]: anterograde and retrograde amnesia (ARA), expression aphasia (EA), executive dysfunction (ED), apathy, and depression; 2. anterior thalamus [R]: ARA, inattention, apathy, and aggressiveness; 3. dorsomedian thalamus [L]: inattention, ED, anosognosia, and aggressiveness; 4. central paramedian thalamus [R]: EA, visual perception deficits (VPD), ED, infantility, and personality disorder; 5. caudate nucleus (ventral-head) [L]: VPD, ED, delirium, visual hallucinations, and personality disorder; and 6. anterior capsule [L]: VPD, ED, apathy, and depression. Vascular strategic syndromes connote the predominantly impaired cognitive/behavioral symptom of each site. Temporal and frontal disconnection symptoms were produced by disrupted MTT/hippocampal and IML/amygdala circuits expressing amnesic syndrome associated with heterogeneous dysexecutive syndrome, in all the cases, by disrupting frontal-basal ganglia-thalamus-cortical net, in three different levels of their pathway.