Neglect is a condition in which stroke survivors have trouble paying attention to one side of space. It is very important that neglect is successfully diagnosed in stroke survivors, as this condition has a significant impact on patients’ daily lives. Stroke severity is most commonly diagnosed using a neurological observational scale, the National Institute of Health Stroke Scale (NIHSS), which also contains an item for assessors (usually the doctor in charge), to check whether patients look like they have neglect symptoms. This is based on observation, and patients are not required to complete any performance based tests. We suspected that this may not be the most effective way to diagnose neglect.
The purpose of this study was to compare the sensitivity of the NIHSS neglect item and a gold standard neuropsychological screening task for neglect. The task is a simple pen-and-paper cancellation task for diagnosing neglect in stroke survivors. The observational scoring on the NIHSS item was found to miss many cases of neglect which were successfully diagnosed on the cancellation task. The exam was found to be more likely to pick up on left neglect than right neglect even if the severity and extent of neglect impairment was the same. Overall, though, the more severe a patient’s neglect was the more likely they were to be successfully diagnosed by the NIHSS item but this observational method still missed many of the most severe neglect cases. This is shown in Figure 1, where the red parts of the graph show the missed cases. The severity goes from left to right, with more milder cases of neglect towards the very right of the graph.
These findings are important because they show that pen-and-paper neglect tests are more sensitive (and less biased) than observational neglect assessments. It is therefore critically important for all stroke survivors to complete standardised pen-and-paper neglect tests in order to effectively diagnose this condition.