Complex sentence: Those who survived sank into a semi-conscious state that lasted for decades until neurologist Oliver Sacks used the Parkinson's drug L-DOPA to revive those still alive in the late 1960s.
Split into simpler sentences: Those who survived sank into a semi-conscious state that lasted for decades. Neurologist Oliver Sacks used the Parkinson's drug L-DOPA to revive those still alive in the late 1960s.