After being diagnosed with Parkinson's disease five years ago, comedy writer Paul Mayhew-Archer decided to find out what was being done to develop treatments.

He witnessed a new procedure which counteracts tremors, a main symptom of the disease, and went to meet one of its beneficiaries.

Patients undergoing Deep Brain Stimulation (DBS) have small wires inserted into their brains.

A constant electrical pulse is then administered to the organ - which changes brain activity and can reduce the symptoms of Parkinson's disease.