4D * EEG: a new tool to investigate the spatial and temporal activity patterns in the brain during stroke rehabilitation

Stroke is a major cause of disability in the developed world. Up to 80% of the
stroke patients suffer an upper limb paresis. Only one one-third of those
patients regain some dexterity, leaving the majority with disabilities in
activities of daily living. (Dobkin et al. 2005; Kwakkel 2003). Little is known
of the mechanisms behind functional recovery. Much of our knowledge on
neuroplasticity and its mechanisms is derived from animal studies. Ways to
assess neuroplasticity in humans are in an early developmental phase. In order
to make true progress, the next step is to assess the dynamics of cortical
activity in a larger cohort of patients, covering the entire possible phenotype
from patients with an initial good to poor prognosis and longitudinal in time.
In order to develop additional evidence based therapies, a better understanding
of underlying brain dynamics is essential. To this end, accurate mapping of
brain network connectivity and localization is needed.

The 4D-EEG study aims to elucidate the underlying mechanisms of upper limb
functional recovery using high density portable
EEG (electroencephalography) methodology as well as clinical measures of motor
function. The following questions are addressed:
How do true neurological restitution and substitution contribute to upper limb
recovery? What changes occur in the brain when
patients show recovery of upper limb capacity? Do these changes contribute to
better function or do they result from decreased
cortical inhibition? Does early EEG provide additional value in prediction
algorithms of functional outcome of upper limb
dexterity? And finally, how does the cortical spinal tract integrity affect the
functional outcome?

Projects:
A1. Cross-sectional study: Relate our EEG methodology to fMRI (functional
magnetic resonance imaging).
A2. Cross-sectional study: Assess the construct validity of the NeuroFlexor
A3. Cross-sectional study: Development of an EEG amplitude calibration
procedure
B1. Prospective cohort study: Repeated application of our EEG method in the
first six month post stroke.
B2. Prospective cohort study: Longitudinal changes in neuromechanic parameters
in the first six months post stroke.
C. Cross-sectional study: Cortical spinal tract (CST) integrity and its
relation with functional recovery. Using trans cranial magnetic stimulation
(TMS) & diffusion tensor imaging (DTI) measurements
D) Prospective cohort study: Longitudinal changes in neuroanatomical parameters
in the first six months post stroke.

Stroke is a major cause of disability in the developed world. Up to 80% of the
stroke patients suffer an upper limb paresis. Only one one-third of those
patients regain some dexterity, leaving the majority with disabilities in
activities of daily living. Little is known of the mechanisms behind functional
recovery. Much of our knowledge on neuroplasticity and its mechanisms is
derived from animal studies. In order to make true progress, the next step is
to assess the dynamics of cortical activity in a larger cohort of patientsAll
the proposed experiments are no-invasive and safe.