neurological

Its exact neurological cause is unknown, and patients on average take up to 5.5 years to receive a correct diagnosis.

LD, a neurological problem where the vocal cords spasm, has drawn more attention since US President-elect Donald Trump appointed Robert F Kennedy Jr - who has the condition - to his new team.

Parkinson's disease, a neurological disorder best known for causing tremors, stiffness, slow movement and poor balance, also causes cognitive symptoms that can progress to Parkinson's dementia.

They can, however, also infect other organs and cause neurological disorders.

It is the first demonstration that optogenetics can be used to control seizure activity in living human brain tissue, and it opens the door to new treatments for other neurological diseases and conditions.