Multimodal EEG analysis in man suggests impairment-specific changes in movement-related electric brain activity after stroke

Abstract

Movement-related slow cortical potentials and event-related desynchronization of alpha (alpha-ERD) and beta (beta-ERD) activity after self-paced voluntary triangular finger movements were studied in 13 ischaemic supratentorial stroke patients and 10 age-matched control subjects during movement preparation and actual performance. The stroke patients suffered from central arm paresis (n = 8), somatosensory deficits (n = 3) or ideomotor apraxia (n = 2). The multimodal EEG analysis suggested impairment-specific changes in the movement-related electrical activity of the brain. The readiness potential of paretic subjects was centred more anteriorly and laterally; during movement, they showed increased beta-ERD at left lateral frontal recording sites. Patients with somatosensory deficits showed reduced alpha-ERD and beta-ERD during both movement preparation and actual performance. Patients with ideomotor apraxia showed more lateralized frontal movement-related slow cortical potentials during both movement preparation and performance, and reduced left parietal beta-ERD during movement preparation. We conclude that (i) disturbed motor efference is associated with an increased need for excitatory drive of pyramidal cells in motor and premotor areas or an attempt to drive movements through projections from these areas to brainstem motor systems during movement preparation; (ii) an undisturbed somatosensory afference might contribute to the release of relevant cortical areas from their 'idling' state when movements are prepared and performed; and (iii) apraxic patients have a relative lack of activity of the mesial frontal motor system and the left parietal cortex, which is believed to be part of a network subserving ideomotor praxis.

Altered corticomuscular coherence elicited by paced isotonic contractions in individuals with cerebral palsy: A case-control study

“…Furthermore, it could be that simple hand movements required higher concentration and effort in individuals with CP than in HC, leading to an increased coupling power between beta brain oscillations and muscle motor units, together with an increased delay of muscular contraction. This interpretation seems to be also in accordance with previous studies showing an enhancement of corticomuscular coherence in patients with stroke or pseudochoreothetosis associated with increased excitatory drive of pyramidal cells in motor and premotor areas (Meng et al, 2009;Platz et al, 2000;Timmermann et al, 2001).…”

Efficient neuroplasticity induction in chronic stroke patients by an associative brain-computer interface

“…This is in contrast to other BCIs for neuromodulation in stroke where patients were required to spend several sessions (15 or more, over the duration of months) for learning to produce controllable brain signals (Ang et al 2009;Buch et al 2008). Stroke patients have altered temporal as well as spatial MRCPs (Platz et al 2000;Yilmaz et al 2013), and it is known that a patient's ability to perform a motor task accurately is significantly enhanced when a cue is provided (Heremans et al 2009). This was the case in our intervention and may have led to the enhanced effects in the BCI associative group.…”

Synthetic consciousness: the distributed adaptive control perspective

“…The CVNM comprises a key ingredient of the frontal-parietal network that is disrupted in neglect patients [118]. Stroke gives rise to dynamic reorganization of the thalamo-cortical system as expressed in large increases in delta and decreases in alpha activity [121,214]. Taken together this shows that stroke provides an alternative model to investigate consciousness as opposed to sleep or coma, with the advantage to specifically probe the informational aspects of conscious and unconscious processing and their highly variable spatio-temporal organization.…”