Can DBS help advanced Parkinson’s with hallucinations at 69?

Hi doctor,

My father is 69 years old and has been living with Parkinson's disease for six years. We feel like we are slowly losing him to this illness. Initially, he was prescribed Levodopa-Carbidopa, which helped a lot, but now the wearing-off effect is very pronounced. He experiences only two to three hours of good mobility after each dose before the stiffness and tremors return intensely.

His neurologist added Ropinirole, but it has caused him to fall asleep suddenly during the day, which is dangerous. He often experiences freezing of gait, especially at doorways, and he had two falls last month, one of which resulted in a wrist fracture. Swallowing has become difficult for him, and a speech therapist has indicated that he is at high risk for aspiration.

Additionally, his blood pressure drops suddenly when he stands, going from 135 systolic while sitting to 88 while standing. The Parkinson's disease specialist explained that this is due to autonomic involvement. My father has also started experiencing visual hallucinations, such as seeing children in the room, which is distressing for the entire family. His sleep is very disturbed, and he has acted out his dreams violently, injuring my mother twice.

We consulted a psychiatrist, who is hesitant to prescribe antipsychotics because of his Parkinson's disease. His cognitive testing score on the MMSE was 22. I am wondering if deep brain stimulation is still an option at this stage of Parkinson's disease and what can be done safely to address his hallucinations.

Please guide.