Neurophysiologic Correlates of Post-stroke Mood and Emotional Control.
OBJECTIVE
Emotional disturbance is a common complication of stroke significantly affecting functional recovery and quality of life. Identifying relevant neurophysiologic markers associated with post-stroke emotional disturbance may lead to a better understanding of this disabling condition, guiding the diagnosis, development of new interventions and the assessments of treatment response.


METHODS
Thirty-five subjects with chronic stroke were enrolled in this study. The emotion sub-domain of Stroke Impact Scale (SIS-Emotion) was used to assess post-stroke mood and emotional control. The relation between SIS-Emotion and neurophysiologic measures was assessed by using covariance mapping and univariate linear regression. Multivariate analyses were conducted to identify and adjust for potential confounders. Neurophysiologic measures included power asymmetry and coherence assessed by electroencephalography (EEG); and motor threshold, intracortical inhibition (ICI) and intracortical facilitation (ICF) measured by transcranial magnetic stimulation (TMS).


RESULTS
Lower scores on SIS-Emotion was associated with (1) frontal EEG power asymmetry in alpha and beta bands, (2) central EEG power asymmetry in alpha and theta bands, and (3) lower inter-hemispheric coherence over frontal and central areas in alpha band. SIS-Emotion also correlated with higher ICF and MT in the unlesioned hemisphere as measured by TMS.


CONCLUSIONS
To our knowledge, this is the first study using EEG and TMS to index neurophysiologic changes associated with post-stroke mood and emotional control. Our results suggest that inter-hemispheric imbalance measured by EEG power and coherence, as well as an increased ICF in the unlesioned hemisphere measured by TMS might be relevant markers associated with post-stroke mood and emotional control which can guide future studies investigating new diagnostic and treatment modalities in stroke rehabilitation.
Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School Boston, MA, USA.
Deniz
D
Doruk
Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical SchoolBoston, MA, USA; Physical and Rehabilitation Medicine Institute of the University of São Paulo, Medical School General HospitalSão Paulo, Brazil.
Marcel
M
Simis
Physical and Rehabilitation Medicine Institute of the University of São Paulo, Medical School General Hospital São Paulo, Brazil.
Marta
M
Imamura
Service of Interdisciplinary Neuromodulation, Laboratory of Neurosciences (LIM-27), Department and Institute of Psychiatry, University of São Paulo São Paulo, Brazil.
André R
AR
Brunoni
Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School Boston, MA, USA.
Leon
L
Morales-Quezada
Physical and Rehabilitation Medicine Institute of the University of São Paulo, Medical School General Hospital São Paulo, Brazil.
Renato
R
Anghinah
Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical SchoolBoston, MA, USA; Physical and Rehabilitation Medicine Institute of the University of São Paulo, Medical School General HospitalSão Paulo, Brazil.
Felipe
F
Fregni
Physical and Rehabilitation Medicine Institute of the University of São Paulo, Medical School General Hospital São Paulo, Brazil.
Linamara R
LR
Battistella
chronic stroke; emotional disturbance; inter-hemispheric connectivity; power asymmetry; qEEG