Nrump,jch,,k,gx,. Vol 27. I*io Prmled ,n Great Brircirn IO. pp 1301-1307. 0028-3932,89 53.00+000 c~’ 1989 Pergamon Press plc 1989 NOTE LATERALITY OF MOTOR RESPONSE IN VISUO-SPATIAL STUDY * NEGLECT: A CASE PETER W. HALLIC;ANP and JOHN C. MAKSHALI Rivermead Rehabilitation Centre, Oxford, Clinical Neurology, (Receioed U.K.; and Neuropsychology Unit, University The Radcliffe Infirmary, Oxford, U.K. 29 December 1988; accepted Department of 10 July 1989) Abstract-We report a case of severe visuo-spatial neglect consequent upon right hemisphere stroke. At time of testing, the patient had a left visual field deficit and a very mild left hemiparesis. Star cancellation and line bisection performed with the right hand revealed profound left neglect; tested with the left hand, performance was only slightly impaired. The results are compatible with recent accounts of differential hemispheric activation provoked by lateralized pre-motor programming. INTRODUCTION SEVERELEFT visuo-spatial neglect is usually consequent upon large lesions of the right hemisphere; most patients accordingly have both left visual field deficits and left hemiparesis [S]. The motor loss thus results in the patient only being tested on traditional neglect tasks with his or her ipsilesional (right) hand. Because the anatomic relationship between cerebral hemispheres and limb control is primarily contralateral, a possible conclusion from most studies of neglect is that much of the observed symptomatology is programmed from the left hemisphere. Interesting issues of attentional control thereby arise. How. for example, do the (damaged) right hemisphere and the (intact) left hemisphere interact to produce the classical “neglect” patterns of impaired and preserved performance as a function of spatial position? We are aware of only one study, that by JOANETE et al. [4], in which patients with manifest left neglect have been systematically tested with both the ipsilesional and the contralesional hand. Three right-handed patients were diagnosed as showing neglect by virtue of their performance (with the right hand) on a modified version of Albert’s line cancellation task [I]; left hand performance on this test was not reported. However, all the patients were capable of pointing with either hand. In the experimental task, six light-emitting diodes were situated 50 cm in front of the subject and 10 cm below eye level; stimulus eccentricities were 20’., 40‘ and 55 in the left and right fields, respectively. Patients were required to “touch as quickly as possible, with the index finger of a given hand” the diode that lit up on that trial; the order in which the diodes were illuminated was random. In the primary experiment, the patients (two of whom did not have visual field deficits) fixated a central diode; detection, as assessed by manual pointing, was significantly better when the patients used the left (contralesional) hand than when the right was used. In a follow-up study (with one of the patients), the same result was obtained in a “free gaze” condition. These findings suggest that it may be informative to study performance on more traditional neglect tasks in a patient who is able, like those of JoANETTE et al. [4] to use both the right and left arm and hand. The results of such testmg should throw light on the two hemispheres’ respective contributions to overt performance in neglect tasks. *This work was supported by the Chest, Heart, and Stroke Association (P.W.H.) and by the Medical Research Council (J.C.M.). tcorrespondence to be addressed to P. W. Halligan, Rivermead Rehabilitation Centre, Abingdon Road, Oxford OX1 4XD. U.K. 1301 1302 NOTE METHOD Subject C.M., a 54-year-old, right-handed, laboratory technician was admitted to Wexham Park Hospital on 23 June 1988. His presumptive diagnosis was right hemisphere stroke. CT scan, performed at Charing Cross Hospital on 27.6.1988, showed an extensive lesion of the right parietal and upper temporal regions, consistent with a recent middle cerebral artery infarct. Lacunar infarcts in the right lentiform nucleus and internal capsule were also Table 1. Transection displacements on the line bisection task (Patient displacement, ~ =leftward displacement. Signed displacement Line length 279 mm (1 I in.) 254 mm (10 in.) 228 mm (9 in.) 203 mm (8 in.) 178 mm (7 in.) 152 mm (6 in.) 127 mm (5 in) 102 mm (4 in) 77 mm (3 in) 51 mm (2 in) 25 mm (I in) Left hand Right hand Left hand Right hand Left hand Right hand Left hand Right hand Left hand Right hand Left hand Right hand Left hand Right hand Left hand Right hand Left hand Right hand Absolute displacement (SD) + =rightward Range -7.0 (11.92) 9.6 (9.69) -33+ +8 +21.5 (9.3) 21.5 (9.3) +9- +33 +4.3 (10.7) 8.3 (7.7) -12++26 + 16.7 (10.9) 16.7 (10.9) +6++37 + 1.3 (13.6) 9.9 (9.9) -32++20 +17.9 17.9 (11.3) +3++44 10.6 (5.6) -17++12 9.3 (5.6) +I++20 11.o (I 1.9) -21++40 + 14.9 (12.4) 16.9 (9.14) -lo++36 -1.1 (9.4) 6.7 (6.3) -10++22 + 7.2 (9.04) 9.8 (5.7) -10++20 - 5.3 (8.4) 8.7 (4.3) -154 - 0.4 (X.41) 7.0 (4.1) -124+12 ~ 9.5 (5.8) 9.5 (5.8) -18-- -2 ~ IO.0 (2.0) 10.0 (2.0) -13- -6 - 10.2 (4.7) 10.2 (4.7) - 7.6 (3.78) 7.6 (3.78) 8.6 (4.6) 8.6 (4.6) -16- -2 - 10.5 (3.03) 10.5 (3.03) -14- -5 ~ 3.5 (1.27) 3.5 (1.3) -5- -I - 5.4 (0.84) 5.4 (0.84) -7+ -4 Left hand Right hand Left hand Right hand (SD) C.M.). (11.3) ~ 6.2 (10.6) ~ +9.3 (5.6) +4.8 (15.8) +2 1303 NOTE Fig. 1. CT-scan of patient CM., showing infarction of the right middle cerebral artery territory NOTE 1305 observed. In addition, evidence of diminished density in the left occipital lobe suggested the appearance of old infarcts. The CT scan is shown in Fig. 1. On admission to Rivermead Rehabilitation Centre (19.9.1988), C.M. was found to have a mild left hemiparesis, left homonvmous hemianopia, and left-sided visuo-spatial neglect. Over the next 8 weeks, the motor deficit improved, although visual neglect persisted. At 8 weeks post-admission to Rivermead, perimetric visual field testing revealed a left homonymous inferior quadrantanopia. Examined at this time on the Behavioural Inattention Test [IO] C.M. obtained a score of 96/146. This BIT aggregate is based upon performance on: line crossing; letter and star cancellation; figure copying; line bisection; and representational drawing. The cut-off score for normality is 130/146. C.M. also showed neglect on reading, writing, and picture-scanning tasks. Procedure Two of the six screening tasks were then employed in further experimental investigations. (1) The star cancellation test (from the BIT) was performed six times. Over a 3-day period, C.M. undertook the task three times with the right hand and three times with the left in alternate order. The test comprises 56 small stars (the targets), pseudo-randomly interspersed with distracters (large stars, letters, and words). The overall dimensions of the stimulus sheet are 298 x 208 mm (A4). The task is simply to cancel (that is, cross-out) with a fine pen or pencil all the small stars. The two central stars are crossed out by the examiner while explaining the nature of the test to the patient. C.M. was seated at a comfortable distance from the test sheet displayed on the desk top; the stimulus sheet was centred on the sagittal midplane of the patient’s head and trunk. Head and eye movements were in no way constrained, but moving the stimulus sheet was not allowed. The distance from the patient’s eyes to the midpoint of the stimulus sheet was approx. 400 mm. No knowledge of results was fed-back to the patient and no time pressure was imposed. The patient stopped when satisfied with his performance. Further details of the test, and results from a representative sample of neglect patients can be found in MARSHALL and HALLSAN 171. (2) The Line Bisection Test was performed with 11 lines (1 mm in width) that varied in length from 1 in. (25 mm) to 11 in. (279 mm) in steps of 1 in. Each black line was presented individually and centred both horizontally and vertically on a sheet of white A4 (298 x 208 mm); the stimulus sheet was always centred on the midsagittal plane of the subject’s head and trunk. All stimulus lengths were presented ten times in one session; order of presentation was pseudo-randomized across lengths, C. M. bisected two sets of 110 lines (11 lengths x 10 trials), one set with the right hand and one with the left. All stimuli were presented in free vision, without restraint on head and eye movements. Knowledge of results was not provided. RESULTS For scoring purposes, the star cancellation stimulus sheet was divided into six columns. Reading from left-toright, the 54 target stars are distributed as follows: columns: 1 (width 51 mm) = 8 stars; 2 (width 40 mm)=8 stars; 3 (width 50 mm) = 11 stars; 4 (width 48 mm) = 8 stars; 5 (width 48 mm) = 8 stars; and 6 (width 49 mm) = 8 stars. The visual angle subtended in left field (from the midpoint of the array to the far boundary of column 1) was approximately 20”, and likewise approx. 20” in right field. The data are reported in terms of percentage cancellations across the six columns so defined. The results (means of three trials) are shown in Fig. 2, for performance with the right (RH) and left (LH) hands, respectively. It is clear that left hand performance is dramatically better than right hand performance. With the right hand, targets are never detected in the two left-most columns, and detection then improves from left-to-right until, at the right-most column, performance reaches ceiling. With the left hand, detection is relatively good at all eccentricities, although there is again a discernible, if very slight, improvement from left to right. Results from the second task, line bisection, are given in Table 1, where we show the mean and absolute displacements (and their respective standard deviations and ranges) for all line lengths. For 10 out of 11 line lengths, mean left hand performance is closer to true centre than is right hand performance (P