Delta–alpha ratio correlates with level of recovery after neurorehabilitation in patients with acquired brain injury

• Published in: Clinical neurophysiology 2009-06, Vol.120 (6), p.1039-1045
• Main Authors: Leon-Carrion, Jose, Martin-Rodriguez, Juan Francisco, Damas-Lopez, Jesus, Barroso y Martin, Juan Manuel, Dominguez-Morales, Maria Rosario
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Alpha Rhythm; Biological and medical sciences; Brain Injuries - physiopathology; Brain Injuries - rehabilitation; Delta Rhythm; Electrodiagnosis. Electric activity recording; Electroencephalography; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Longitudinal Studies; Male; Medical sciences; Middle Aged; Monitoring, Physiologic; Nervous system; Neurology; Outcome Assessment (Health Care); Predictive Value of Tests; Recovery of Function - physiology; Stroke - physiopathology; Stroke Rehabilitation; Vascular diseases and vascular malformations of the nervous system; Young Adult
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2009.01.021

Abstract Objective To explore the relationship between three QEEG global indexes and their association with functional outcome after neurorehabilitation in non-acute acquired brain injury (ABI) patients (traumatic brain injury and stroke). Methods Twenty-one adult ABI patients in post-acute phase were studied. Delta–alpha ratio (DAR), Power Ratio Index (PRI) and Mean Brain Symmetry Index (mBSI) were calculated from resting-state EEG taken at admission. These indexes and other clinical variables were correlated with functional recovery achieved after six months of neurorehabilitation. Results DAR showed the highest strength of association with the functional outcome measure ( ρ = −0.65, P = 0.002). The other QEEG indexes and clinical variables showed modest non-significant correlations. A posteriori group analysis showed higher DAR in patients with poor recovery as compared to good recovery patients. Conclusions Functional recovery after neurorehabilitation appears to be associated with a number of clinical and neurophysiological variables. Among the latter, the ratio between delta and alpha may play a significant role in predicting and monitoring functional rehabilitation outcome. Significance Neurophysiological assessment of ABI patients may be an important tool in monitoring and predicting outcomes after neurorehabilitation.