Hennessy, M.J., Marshman, L.A.G., delle Baite, L., and McLellan, J. (2020) Optimizing and simplifying post-traumatic amnesia testing after moderate-severe traumatic brain injury despite common confounders in routine practice. Journal of Clinical Neuroscience, 81. pp. 37-42.

PDF (Published Version) - Published Version Restricted to Repository staff only

 

5

1

Abstract

The duration of post-traumatic amnesia (PTA) following traumatic brain injury (TBI) is a key diagnostic and outcome indicator. However, concerningly, different PTA paradigms record different PTA durations: some over-estimate, others under-estimate, PTA. Thus, a compromise is implied. The potential effect of in-hospital confounders including opioids is unknown. Three clinical groups were prospectively recruited. Group-1: in-patients with moderate-severe-TBI (MS-TBI), considered likely 'in-PTA'. Group- 2: patients rehabilitating after recent MS-TBI, considered 'out-of-PTA'. Group-3: orthopaedic in- patients without TBI undergoing elective surgery. Only Groups 1813 were taking opioids. All were administered the Westmead Post-traumatic Amnesia Scale (WPTAS) and the Galveston Orientation and Amnesia Test (GOAT). Results were obtained in n = 56 (Group-1:n = 18, Group-2:n = 13 and Group-3: n = 25). On WPTAS, Groups 183 scored similarly, but significantly lower than, Group-2 (chi(2) = 8.2, P = 0.017). Contrariwise, on GOAT, Group-1 scored significantly lower than Groups 2&3 (chi(2) = 23.99, P < 0.001): however, no patient scored GOAT <75. WPTAS showed moderate sensitivity (72%) but poor specificity (40%) in distinguishing Group-1 from Groups 2&3. Contrariwise, GOAT showed 100% specificity but 0% sensitivity. WPTAS 'day of week' and 'pictures' combined with GOAT 'transport medium to hospital', 'anterograde amnesia' and 'retrograde amnesia' maximized sensitivity (100%), specificity (85-88%), PPV (77-83%) and NPV (100%) in distinguishing Group-1 from Groups 2&3.

Conclusions: Confounders including opioids likely affected WPTAS overall, but not GOAT specificity. A merger, whereby WPTAS sensitivity augmented GOAT specificity, was therefore sought. Favourable items from WPTAS (4/12) and GOAT (3/10) together optimized, and yet simplified, PTA testing; despite preva- lent clinical confounders. Less, not more, 'PTA' items would benefit both patients and staff alike. Crown Copyright (C) 2020 Published by Elsevier Ltd. All rights reserved.

Actions (Repository Staff Only)

Item Control Page