120 Prospective study determining the predictive value of inattention in the evaluation of suspected acute stroke; a territory wide study

Introduction 25%-30% of patients admitted with acute stroke are stroke mimics. Clinical assessment plays a major role in diagnosis in the hyperacute clinical setting. Identifying physical signs that correctly identify stroke is therefore important. A retrospective study1 suggested that the presence of sensory inattention (or neglect) was seen exclusively in stroke patients, suggesting that inattention might be a reliable discriminator between stroke and mimics. This study aimed to test that hypothesis. Methods Prospective assessment of suspected stroke patients for the presence of neglect (NIHSS definition). Neglect could be visual and/or somatosensory. The presence of neglect was then correlated with eventual diagnosis at 48 hours. Sensitivity, specificity and predictive values were calculated. A post-hoc analysis evaluated the correlation of neglect with large vessel occlusion in patients who underwent angiography. Results 115 patients were recruited, 70 ultimately with stroke and 45 with other diagnoses. Neglect was present in 27 patients (of whom 23 had stroke) and absent in 88. This yielded: sensitivity 32.9%, specificity 91.1%, positive predictive value 85.2%, and negative predictive value 41.9%. Two patients with neglect had a diagnosis of functional illness, one a seizure, and one a brain tumour. Neglect was present in 7 out of 8 patients with large vessel occlusion (sensitivity 87.5%) and was absent in all patients who did not have large vessel occlusion on angiogram. Conclusion When present, neglect is a strong predictor of organic pathology and large vessel occlusion. However, it is not 100% specific and can be seen in functional presentations. Reference Gargalas S, Weeks R, Khan-Bourne N, Shotbolt P, Simblett S, Ashraf L, Doyle C, Bancroft V, David AS: Incidence and outcome of functional stroke mimics admitted to a hyperacute stroke unit. J Neurol Neurosurg Psychiatry 2017, 88:2–6.