What is it?

USN is typically associated with right hemisphere lesions, particularly parietal lobe lesions and sometimes frontal lobe lesions, causing neglect of the left side of space. It is possible to have right neglect after left brain damage but this is usually less severe and does not last as long.  

Stone et al (1993) looking at stroke survivors, found that at three days post stroke neglect is equally likely after left (62%) and right hemisphere (72%) stroke, while by 3 months the figures dropped to 33% of left hemisphere strokes versus 75% of right hemisphere strokes.

It is also possible to have neglect for any part of space, not just the left (or right) side. Indeed, one can have bilateral neglect as can be seen, for example, in patients with apperceptive agnosia (Wilson 1999). The prognosis for patients with neglect after several months is poor (Tunnard and Wilson 2014). In everyday life, such patients are likely to have accidents and bang into things on the left; in severe cases, men may only shave on one side of the face and women only make up on one side.  All may fail to see food on one side of the plate, and have grooming problems. 

How should one assess UN? 

In clinical practice there are two main types of assessment: the first using standardised tests, the second using more functional or behavioural measures.

Both are useful when determining whether or not someone has USN. It is necessary to be cautious when assessing, however, with many standardised tests because the USN means the patient is unable to attend to all parts of the stimulus material There are, of course, a number of standardised tests to measure neglect, including cancellation tests, bisection tasks and copying or drawing tasks.

There is also the Fluff Test (Cocchini, Breschin and Mehkonen 2001). This test requires participants to explore body parts with their eyes closed. Other functional measures include behavioural observations such as watching someone preparing food, using a cooker, moving though doorways, trapping the left hand in the wheelchair spokes and so forth. 

The Behavioural Inattention Test, (BIT; Wilson, Cockburn and Halligan 1987). Perhaps the most comprehensive test battery of USN is the BIT. It is an objective test of everyday skills relevant to visual neglect. 
The BIT is in two parts, the first is comprised of six conventional subtests, namely: three cancellation subtests (line crossing; letter cancellation and star cancellation), line bisection; copying figures and copying shapes. The behavioural subtests reflect aspects of daily life such as dialling a telephone, telling and setting the time, menu reading, coin sorting and map navigation. The BIT has been used to evaluate the effects of treatment for USN (Tunnard and Wilson 2014). 

Personal Neglect, Near Neglect and Far Neglect

Although neuropsychologists tend to assess near neglect, that is neglect as measured by subtests in the BIT, there are other types of neglect and we should consider these as part of any assessment. 

Halligan and Marshall (1991) describe a man who had USN when tested on paper and pencil tests but, nevertheless, played darts for his pub team. This lead them to consider a distinction between peri-personal neglect (neglect for things within grasping or walking distance) and extra personal neglect  (neglect for things within throwing distance). Williams et al (2017) tested a man with severe neglect for near tasks (traditional USN tests). He was also assessed for personal neglect (the Fluff Test) and far neglect.
For this last measure the star cancellation test was projected on a distant wall and a torch given to the man to cancel the small stars; the number of omissions were counted. He showed no personal neglect, severe near neglect and mild far neglect.

In conclusion, any neuropsychological assessment should include measures of neglect. 

References  

Bisiach E & Luzzati C (1978)  Unilateral neglect of representational space. Corte 14 129-33.  

Halligan, P., Marshall, J. Left neglect for near but not far space in man. Nature 350, 498–500 (1991).  

Stone S. Halligan P and Greenwood R.J (1993) The incidence of neglect phenomena and related disorders in patients with an acute right or left hemisphere stroke. Age and Ageing 22  46-52 

Tunnard C & Wilson B.A  (20014) Comparison of neuropsychological rehabilitation techniques for unilateral neglect: An ABACADAEAF single-case experimental design Neuropsychological Rehabilitation 24 382-399  

Williams A, Rose A, Wilson B and Florschutz G (2017) Adapting assessment procedures for a man with unilateral neglect. Poster presented at the meeting of  15th international meeting of the SIG NR-WFNR group in Prague.  

Wilson, B.A. (1999). Case Studies in Neuropsychological Rehabilitation. New York: Oxford University Press. 

Wilson, B.A., Cockburn, J., & Halligan, P.W. (1987). The Behavioural Inattention Test. Bury St Edmunds: Thames Valley Test Company.  

About the author

Barbara Wilson qualified as a clinical psychologist in 1977 and since 1979 she has worked in Brain Injury Rehabilitation, first at Rivermead Rehabilitation Centre in Oxford, then at Charing Cross Hospital, London and at The University of Southampton Medical School. Since 1990 she has been employed as a Senior Scientist at The Medical Research Council’s Cognition and Brain Sciences Unit, Cambridge.