title: Brain perfusion and VEP reactivity in occipital and parietal areas are associated to recovery from hypoxic vegetative state.
abstract: Patients in a vegetative state (VS) show a spontaneous wake-sleep-cycle but no evidence of awareness, of interaction with the environment, voluntary action, and language comprehension. The neuropathological conditions underlying VS are still not fully understood. In this retrospective study we focused on VS due to hypoxia and used SPECT, VEP and event related potentials (N100, N200, MMN, and P300) to assess differences between a group of patients moving into a permanent VS (n=13) and a group recovering from VS (n=8). The two groups were matched for age, gender, duration of illness, and on the coma remission scale at admission. The patient groups differed in global uptake of (99m)Tc-ethylencysteine dimer (being reduced in non-recovered VS patients to 2/3 of the recovered group), and in presence of VEP and N100 (recovered patients always had a present VEP and N100). Moreover, analysis of uptake in specific brain areas showed that the recovered group had a higher perfusion in the visual cortex and in the precuneus, whereas no differences were found in the frontal pole and more ventral parts of the brain. Statistical testing revealed a strong association between occipital and parietal perfusion and the presence of a VEP, but no specific results for the N100. We conclude that occipital and parietal lobe perfusion and rudimentary vision may be critical characteristics distinguishing between VS and patients recovered from VS. Although this may just reflect haemodynamics during hypoxia leading to differences in severity of VS, it also may be regarded as a functional precondition for orientation towards stimuli and therefore for conscious actions in general.
authors.affiliation: Klinikum Bremen-Ost, Department of Neurology, Züricher Str. 40, 28325 Bremen, Germany; University of Oldenburg, Institute of Psychology, Germany. helmut.hildebrandt@uni-oldenburg.de
authors.forename: Helmut
authors.initials: H
authors.lastname: Hildebrandt
authors.forename: Svenja
authors.initials: S
authors.lastname: Happe
authors.forename: Angelika
authors.initials: A
authors.lastname: Deutschmann
authors.forename: Canan
authors.initials: C
authors.lastname: Basar-Eroglu
authors.forename: Paul
authors.initials: P
authors.lastname: Eling
authors.forename: Jens
authors.initials: J
authors.lastname: Brunhöber
mesh_terms: D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003128:Coma / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D003937:Diagnosis, Differential; D004569:Electroencephalography; D005071:Evoked Potentials; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D002534:Hypoxia, Brain / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D010296:Parietal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D018458:Persistent Vegetative State / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D011379:Prognosis; D020127:Recovery of Function; D012189:Retrospective Studies; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon; D015354:Vision, Low / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology
chemical_list: D013667:Technetium