Neuropsychological recovery during the first 12 months after severe traumatic brain injury: A longitudinal study with monthly assessments

ABSTRACT

Neuropsychologists are commonly asked practical questions about cognitive recovery in the first year following moderate-to-severe traumatic brain injury (TBI), however guiding evidence to provide answers is limited. The design of this longitudinal study rectifies methodological problems in the literature by taking serial assessments on a monthly basis from 3- to 12-months post-trauma in a severe TBI sample (n = 23), and using four alternate forms of a brief yet sensitive cognitive assessment battery. Fifteen variables sampling seven cognitive domains were used: orientation, attention, processing speed, executive function, memory, language and visuospatial function. A matched control group (n = 23) was used to establish equivalence of the four alternate forms (no statistically significant differences), document practice effects (no statistically significant differences), and provide a comparison standard of cognitive functioning against which to interpret the TBI recovery curves. Twenty-one of 23 consenting TBI participants continued with the serial assessments. Hierarchical growth model analyses typically revealed linear recovery trajectories over the first 12 months. However, by 12-months post-trauma, a significant proportion (up to 36%) had residual mild to severe impairments in various cognitive domains. These results provide detailed information about patterns of cognitive recovery that also have direct clinical application.

KEYWORDS:

• Traumatic brain injury
• Cognition disorders
• Neuropsychological recovery
• Practice effects
• Psychometric tests

Acknowledgements

The authors acknowledge the enormous commitment of the participants who completed monthly assessments over a 1-year period contributing data of immense value. We thank Bronwyn Coward and Kali Godbee for their assistance with data collection and data preparation.

Disclosure statement

No potential conflict of interest was reported by the author(s).