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Updated: Feb 28, 2026

Investigations on Alterations of Hippocampal Circuit Function Following Mild Traumatic Brain Injury
Published on: November 19, 2012
Factors Affecting Recovery from Post-Traumatic Amnesia During Inpatient Brain Injury Rehabilitation: A Retrospective
Rathi Ratha Krishnan1,2,3, Yuhan Yang2,4, Emily Yee1,5
1Institute of Rehabilitation Excellence (IREx), Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore.
Background:
Longer post-traumatic amnesia (PTA) durations in traumatic brain injury (TBI) are associated with worse functional outcomes, poorer cognition, and persistent disability. A retrospective cohort study was conducted to evaluate factors affecting PTA duration and emergence.
Methods:
Data extraction of discharged records of adult TBI was performed between 1 April 2022 and 4 May 2023. Independent variables collected include socio-demographic, acute TBI, and rehabilitation characteristics. Admission/discharge Functional Independence Measure (FIM) was the main rehabilitation outcome measure charted. Dependent variables included PTA duration ≤ 30 days, >30 days, and PTA emergence.
Results:
A total of 189 datasets were analysed. Median age (IQR) 64 years (26), 145 males (76.7%), and 64.6% >55 years. PTA ≥ 30 days were correlated with the following factors: older age (66 years vs. 59.5 years, p = 0.017), presence of ICU admission (75.2% vs. 61.4%, p = 0.029), longer ICU stays (5 days vs. 3 days, p = 0.001), and longer duration of inpatient hospitalization (acute length of stay, ALOS 23 days vs. ALOS 14 days, p < 0.001). Age ≥ 55 years were 5.6 times as likely (p = 0.011) to be in prolonged PTA, an additional day's stay in the acute hospital increased the odds by 1.15 (p < 0.001), and every score lost in the total admission FIM from 40 and below increased the odds of prolonged PTA by 3.35 times (p = 0.014).
Conclusions:
This study demonstrated that older age at TBI onset and longer ALOS significantly increased the risk of prolonged PTA duration. Conversely, higher admission FIM score, lower age at admission, and shorter ALOS were associated with lower PTA duration.
Related Concept Videos
Amnesia
The severity and duration of memory loss vary depending on the type and underlying cause. Amnesia is classified into two main types: retrograde and anterograde.
Retrograde amnesia is marked by the loss of memories formed before the onset of the condition. Patients may recall distant past events but often forget those occurring shortly before the incident.
Anterograde...
Higher Mental Functions of Brain: Learning and Memory

