Neurocognitive functioning and brain plasticity in high-grade glioma patients: a magnetoencephalography pilot

Patients with localized brain tumors, such as glioblastoma multiforme,
often suffer from diffuse cognitive deficits. It is difficult to understand how
such a local brain lesion gives rise to non-specific, diffuse cognitive
deficits. Evidence has accumulated that higher cognitive functions require
functional interactions, or connectivity, between multiple distinct neural
networks. An optimal neuronal network architecture is probably
characterized by so-called 'small-world' characteristics, combining high
local connectivity with efficient overall integration.
By using magnetoencephalography (MEG), which has proven to be an
excellent way to capture the dynamics of the electromagnetic fields of the
brain, we recently found that brain tumor patients not only have altered
levels of synchronization throughout the brain, but also that these
alterations correlate with neurocognitive functioning. It is unknown,
however, to what extent remodeling of the neurosynaptic networks (i.e:
cerebral plasticity), varies as a function of treatment (i.e., surgery,
radiotherapy, chemotherapy) and tumor recurrence.
Using prospective cognitive data and MEG recordings of ten newly
diagnosed glioblastoma multiforme patients and ten glioblastoma
multiforme patients with tumor recurrence we will investigate 1) the
impact of tumor- and treatment-related factors on functional connectivity
and neural network features, and 2) the correlation between changes in
these measures and cognitive function.
If such treatment- and/or tumor-related cerebral plasticity and its
correlation with cognition can be established in this pilot, future
prospective studies will focus in more detail on 1) the effects of different
treatment modalities (e.g. less or more extensive surgery, radiotherapy)
and 2) the contribution of tumor-related symptoms (e.g. epilepsy) and
their treatment (e.g. anti-epileptic drugs) on neural network function and
cognition. This knowledge will eventually assist in the guidance of clinical
decision-making in these patients.

We hypothesize that a relationship is present between functional connectivity, network features and neurocognitive performance in GBM patients. We also expect treatment and recurrence of the tumor to lead to remodeling of the neuronosynaptic maps and network features (i.e. plasticity), and hypothesize that these dynamic changes correlate with improvements of cognition.

Not applicable.