To the best of my knowledge you can not regrow dead brain cells.

The treatment for Parkinsons involves injecting into the brain, cells which produce Dopamine. Hoping that they will multiply.

It is possible that constitutional/miasmatic treatment may stimulate the body/life force to use the resources left to it , in a more efficient way. Thus regaining many of the lost facilities . This only happens if all the internal pressures are negated.

An interesting project , but doubt if Conium has a part to play.