A case study of hemispatial neglect using finite element analysis and positron emission tomography.
BACKGROUND
The authors present a patient who developed transient hemispatial neglect following surgical drainage of a large right frontotemporal arachnoid cyst. As symptoms evolved in parallel with brain shift over the subsequent months, the authors hypothesized that the disorder was associated with the appearance of mechanical stresses in the cerebral mantle.


METHODS
To map tissue stress at the various stages of deformation, a finite element computer simulation was conducted on the basis of computed tomography scans of the patient.


RESULTS
The authors' results demonstrate substantial shear and compressive stress concentrations in the parietal lobe, a region commonly associated with neglect, and where positron emission tomography confirmed hypoperfusion in this patient. Treatment with combined ventricular-peritoneal and cystoperitoneal shunts was accompanied by clinical recovery and improvement of right parietal lobe cerebral blood flow.


CONCLUSIONS
The authors conclude that brain deformation was a contributing factor in the reversible neglect syndrome by compromising the normal flow of blood and/or the deactivation of subcortical circuits of the parietal lobe.
Peña
Alonso
A
Academic Neurosurgery Unit, Wolfson Brain Imaging Centre, Addenbrooke's Hospital, Department of Engineering, University of Cambridge, United Kingdom. ap10007@wbic.cam.ac.uk
Owler
Brian K
BK
Fryer
Tim D
TD
Minhas
Pawan
P
Czosnyka
Marek
M
Crawford
Peter J
PJ
Pickard
John D
JD
D000368:Aged; D016080:Arachnoid Cysts / Q000150:complications / Q000601:surgery; D001931:Brain Mapping; D002560:Cerebrovascular Circulation; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D010468:Perceptual Disorders / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D014055:Tomography, Emission-Computed