Recently, we had a very interesting refining request here at MGS: an intracranial platinum-electrode grid for electrocorticography (ECoG).
ECoG is a vital preliminary step for brain surgeons. During an ECoG, a network of electrodes is placed over an exposed brain and used to map the cortex or detect epileptogenic zones – regions of the cortex that generate epileptic seizures. This procedure is similar to an electroencephalogram or EEG. An EEG is non-invasive and uses electrodes placed on the scalp. Doctors will often use an EEG to do some preliminary mapping and determine the most effective electrode layout for the invasive ECoG.
Using information gathered during the ECoG, a surgeon removes epileptogenic zones and resections the cortex while avoiding areas of the cortex the ECoG has mapped as vital. After surgery, another ECoG is performed to detect any remaining epileptic activity and to determine the success of the surgery.
Like its other medical applications, platinum is the perfect material for this type of procedure. Platinum has good electrical conductivity and can be fabricated into small, complex components. Also, like gold, platinum is inert and does not corrode or react inside the body. This makes it ideal electrode material for ECoG grids, pacemakers, and more.