Functional Imaging

What is it?

  • qEEG
  • Heart Rate Variability (HRV)
  • fMRI
  • MRI
  • Structural MRI

qEEG

Quantitative Electroencephalography (qEEG) or 'Brain Mapping' with source localisation is a technique where the electrical brain activity is measured digitally. Using this technique, researchers are able to interpret how and which areas of the brain work together. The qEEG procedure involves the use of a 19 or more electrode EEG cap. Electrode gel is used to ensure that each electrode has optimal contact with the skin. The placement of the cap and electrode takes approximately 10 minutes followed by a 5 minutes recording. Before the procedure, patients are asked not to use hair gel, spray or conditioner. They are also asked not to consume alcohol, coffee or other stimulants.

The qEEG provides critical information about the electrical activity and connectivity in the brain and can be compared to a normative database, i.e it can tell whether the activity and connectivity of your brain is normal or abnormal. The qEEG is essential to determine where to stimulate and what technique to use. Therefore everybody presenting at BRAI3N will undergo a qEEG before treatments are initialised and also after some treatment session so we can evaluate whether the treatment delivers what it should do, i.e. normalise brain activity.

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qEEG showing brain activity in the parahippocampus in people who respond better to auditory cortex stimulation as a treatment for tinnitus

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qEEG showing brain activity in the parahippocampus in people who respond better to auditory cortex stimulation as a treatment for tinnitus

Heart Rate Variability (HRV)

HRV is a measurement of the heart rhythm by means of 2 electrodes that are placed on the chest. This happens during the qEEG recording allowing researchers to track the influence of brain activity on the autonomic nervous system.
The autonomic nervous system is responsible for control of a large number of unconsciously directed functions such as breathing, digestion and heart rate.
When someone is stressed, his/her sympathetic nervous system are activated. The body is getting ready to "fight or flee".

The breathing and the heart rate are faster, the pupils dilate. This is an evolutionary system and it protects us from danger. For example how you would react when you are being chased by a hungry bear? The chance that you will encounter a bear today is quite small, but our body does not distinguish between seeing a bear or be overloaded with work, and noise.
Sometimes we are unable to 'relaxed' because the stress 'network' in our brain is hyperactivated. A HRV measurement gives us an idea about the relationship between the sympathetic and parasympathetic activity at rest.

 

fMRI

Functional Magnetic Resonance Imaging (fMRI) is an imaging method for brain activity based on oxygen levels in the brain (BOLD activity). There are two forms of fMRI, evoked fMRI and resting state fMRI.
During the evoked fMRI procedure the researcher may ask you to complete a task, such as counting, listening to sound, music or watching a show or stimulating a painful area. This allows the researchers to associate brain activity with a related task or sensory stimulus.

During resting state fMRI no specific task needs to be done. The fMRI will be performed while you are quietly lying in the MRI machine.

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MRI

Magnetic Resonance Imaging (MRI) is an imaging method that is more sensitive than RX or CT scans to take a picture of your brain. The patient lays on a table which partly in a "tube". During the investigation, the MR-unit makes a loud noise but is completely painless and harmless. MR brain research utilises a contrast dye to obtain a better understanding of the region of interest. Depending on the body part, an MR-research session takes approximately 15 to 45 minutes.

Structural MRI

Structural MRI, in contrast to routine MRI, quantifies structure of your brain. The brain consists of grey matter (= cells) and white matter (= fibres). Both grey and white matter can be quantified to see whether they are normal in size and volume. This can correlate with specific brain functions.

The technique is complementary to qEEG and fMRI, both techniques which look at function in contrast to structure.

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VBM (voxel based morphometry) , demonstrating decrease in grey matter in different regions of the brain associated with hearing loss

20a

Tractography showing the white matter bundles