Objective

Unilateral spatial neglect (USN) and verticality perception biases are frequently associated after right hemispheric cerebral stroke (Pérennou et al., 2006). These troubles in spatial cognition have also in common to present different clinical types, according to the space considered: personal (PN) and extra-personal neglect (EPN), and biases in the visual (VV) or the postural (PV) vertical. Here, we hypothesized that PN is specially related to a biased PV, and that EPN could be more related to a biased VV.

Material/Patients and methods

Forty-six patients (25 females, 41 right-handed, mean age = 62) were submitted to neuropsychological and verticality perception assessment at 30, 60, and/or 90 days after a first right hemispheric stroke. Z-scores on neuropsychological tests were used to compute a composite score for PN (based on Bisiach test, thumb find test, Comb test, Fluff test and 4 items of the Catherine Bergego Scale, CBS) and EPN (based on bells cancellation test, clock drawing test, overlapping figures task, copy of a landscape, text reading, and 4 items of the CBS). A diagnosis of PN or EPN required at least two abnormal tests. Verticality assessment comprised both VV and PV, considered abnormal for a contralesional bias over 2.5°. We tested the link between neglect and verticality perception by conducting linear regression analyses, on NC and NEC, with VV and PV as predictors.

Results

PN and EPN were found in 28 and 32 patients, respectively. A biased verticality perception was found in 24 patients for VV; among them, 5 without NSU, 12 had PN + EPN, 1 PN, 6 EPN and in 17 patients for PV; among them, 1 without NSU, 13 PN + EPN, 3 EPN. Regression analyses showed that PV was significantly associated to PN (F = 15.4; P < 0.001) but also to EPN (F = 9.4; P < 0.01). No significant effect was found for VV.

Discussion – Conclusion

Findings confirm the link between neglect and verticality perception. However, instead of showing specific links VV-EPN and VP-PN, results showed that both EPN and PN severity predict a biased PV (but not a biased VV). The stronger links was found between PV and PN, in relation with the body space.