Recharn Implants

A fungus found deep within northreach caverns has a peculiar property that makes it an excellent tool for treating neurological damage and or diseases. The fungus is called recharn and it grows by attaching itself to the body of a host creature, and simulating one of its organs. Typically, this takes the place of skin on moles or other creatures dwelling within the caverns. However, it was found that the recharn had the ability to replicate internal organs as well. The vast majority of organs it attempted to replicate worked too hard for it to be able to hold itself together, but it received electrical impulses impressively well.
Due to this discovery, further experiments have led us to see that recharn is very compatible with brain tissue, and has no issues holding itself together when functioning as part of a brain, due to the low physical effort required to function. Patients who have had their brains deteriorate, or been damaged due to an injury are able to return to full cognitive function through implants of recharn directly into the brain.
The patients are not unscathed however, as any memories, motor skills, or other functions impaired by the missing portion are not perfectly preserved. They have simply build new neuro pathways where the old ones were missing. This does mean that they can rebuild, or relearn their old skills though. So it's a much better position than they were in before.
This is a rather new treatment, so we are not sure if there will be any other long term effects to this treatment. Some doctors have hypothesized that there will be negative effects to allow a fungus that simulates functions of the brain and has rapid growth capabilities, but currently we have no reason to believe there will be anything to worry about.