Doctors get to the task, dropping a floppy, hair-thin wire into the left side of Acosta's brain. They quiz him periodically, because if he doesn't talk, they'll know they've hit the wrong spot.
"Can you open and close your right hand, Bill?"
Acosta does so.
"Great. Say 'The rain in Spain falls mainly in the plain.' "
Acosta pulls that off, too, mumbling a little.
The wire is moved yet again. "OK, now tell us your phone number."
Acosta's jaw suddenly locks; he's unable to answer.
They've hit the wrong spot.
This therapy, called deep-brain stimulation, is a promising alternative for patients with neurodegenerative diseases when their medication loses its effectiveness. Electricity travels from a battery implanted beneath the chest, up through wires hidden behind the skull, and into leads placed in the damaged area of the brain.
At 7 a.m. the day of his surgery, Acosta winces as doctors screw a head frame onto his skull to hold his body still. His bald head is streaked yellow with iodine, a disinfectant for an injection of local anesthetic, and it matches the color of his skid-free socks.
"I looked up Dr. Frankenstein to see if he was available," Acosta jokes. "He doesn't work on Fridays."
His wife of 16 years, Kathleen, says the pleasantries are a way of deflecting anxiety. She tempers his boyish confidence with concern that prompted her to take 30 questions to a doctor for a second opinion.
"I won't let your head explode, and if it does, I can fix it," responds Ashwini Sharan, neurosurgeon in charge.
He shakes the frame to ascertain that it is secure, then walks out to scarf an egg-and-sausage sandwich.
Before the onset of Parkinson's 11 years ago, Acosta led a gritty, blue-collar life. He grew up in Brooklyn; even with the tremors in his jaw, you can still make out the accent.
His gang disbanded after a policeman introduced them to boxing. He then aspired to the heroism of actors such as George Reeves, the early TV Superman, and Guy Williams of Lost in Space.
Acosta worked in law enforcement and as a martial arts instructor before becoming a security guard at Jefferson. He now works in heating and air conditioning repair
In the briefcase by his hospital bed is a reminder of headier days: Prince of the City, a novel about a policeman who exposes corruption in New York.
"I've been a fighter all my life, but with Parkinson's, it's the first time I've been afraid," Acosta said.
Parkinson's affects 1 percent of people over 60. The current number afflicted, 1 million Americans, will double in the next 20 years as the population ages.
The disease destroys brain cells that make the neurotransmitter dopamine. That, in turn, causes symptoms such as resting tremors, rigidity, slow movement, and imbalance.
"My grandkids look at me and say, 'Papa's always saying yes,' " Acosta said of his involuntary head-bobbing.
Medication can control the symptoms for several years before losing its effectiveness. Acosta increased his dosage and pill intake as his disease progressed, taking up to 30 pills a day. Drugs can cost up to $6,000 a year.
For Acosta, the side effects of medication became too much. He would wake up at 4 a.m. every day to start taking pills and wait till 6:30 a.m. to leave for work, after the nausea subsided.
He also developed impulsive behavior, a known side effect of the drugs, spending more than $100 a week to buy tools for hobbies like stained glass.
"We were really running out of medical options," said Daniel Kremens, Acosta's Jefferson neurologist.
Deep-brain stimulation can improve quality of life and motor function, according to patient surveys and clinical trials. In a 2009 study of 255 Parkinson's patients, those with neurostimulation like Acosta's experienced 4.6 more hours of "on" time each day, meaning the time when their medication continued to work.
Exactly how deep-brain stimulation works is unknown, but Sharan offers an analogy. "Imagine you're at a U2 concert," he said, "and there's a lot of noise because everyone's yelling and screaming. Then Bono comes on stage and starts playing a song. Everyone's still yelling and screaming, but you can now focus on the song. The brain has an equivalent mechanism. When an area of the brain is degenerating, it's making noise, and deep-brain stimulation overrides that noise."
Just before surgery, a CT scan of Acosta's head reveals major blood vessels and provides a reference on which a machine can overlay more detailed MRI images. The information is encoded on a compact disc.
But then the CD drive breaks down.
The medical team lugs in a replacement, only to discover that the team has damaged the CD by trying to shove it into the drive.
"Get every CD burner on this campus burning that CD," Sharan thunders.
Thirty minutes tick by before a resident darts into the room with one in hand.
Back in the OR, the staff is squirting saline solution from a turkey baster to clean and irrigate the hole in Acosta's head, causing a pink stream to cascade down the back of his head.
Acosta, still awake, points to his left cheek to ask if someone could scratch it.
The thin wire going into his brain carries a microphone that leads back to a computer. The system, an innovation of recent years, enables parts of the brain to project distinctive sounds so surgeons know where they are. The gray matter, for example, sounds like chips or Doritos crunching, while the substantia nigra, which fails to produce sufficient dopamine in Parkinson's disease, makes a zipperlike sound.
The team stares blankly at the floor, listening for the sound that indicates the wire is nearing its target.
Only on the third attempt do they hear a scratching like that of a vinyl record, indicating that the wire has arrived at the subthalamic nucleus, where the electric leads will go.
Targeting specific brain structures via surgery began in 1947, when the stereotactic head frame was invented at Temple University. Early uses involved removing whole parts of the brain for psychiatric problems, pain, and epilepsy.
In 1998, actor Michael J. Fox had his thalamus removed to treat Parkinson's.
But surgeries that remove parts of the brain began falling out of favor in 1987 when French doctors developed the reversible option of deep-brain stimulation.
The FDA approved neurostimulation of the subthalamic nucleus for Parkinson's in 2002.
"It's not perfect. It's not a cure," said Casey Halpern, a neurosurgery resident at the University of Pennsylvania who published a study in April showing that neurostimulation led to weight loss in obese mice.
Halpern cautions that not all symptoms improve with deep-brain stimulation, and that some, especially verbal fluency, may worsen.
Only a few Parkinson's patients are eligible for the treatment. They must have late-stage disease, respond well to drugs, and show good cognition because depression and suicidal thoughts may arise after surgery. A study in February found improvements in early-stage patients.
Cost of surgery is another barrier, ranging up to $50,000. Potential complications include infection and brain hemorrhages, which occur in 5 to 15 percent of patients.
Hardware issues are not uncommon. While neurostimulation works for at least 10 years, not much is known about effects over a longer period.
Back at the hospital, when the misplaced wire paralyzes Acosta's jaw, his doctors reposition it.
Suddenly, Acosta can dictate his phone number.
They ramp up the voltage, and his right leg thrashes in the repetitive, jerky movements of dyskinesia, a complication of care. It's more evidence they are in the right place.
The doctors leave the wire in the subthalamic nucleus, protect the other end with plastic covering, suture Acosta's scalp, and repeat the procedure on the right side of his brain. The entire operation takes seven hours.
The next morning, before going home, Acosta recalled far more than doctors expected, including a visiting neurosurgeon's dapper shoes.
The sci-fi quality was not lost on him. "It reminds me of a Lost in Space episode," he said.
Two weeks later, Acosta returns to the OR for Sharan to implant the battery on the left side of his chest, to send electricity to his brain.
"I'm hurting like hell," Acosta said days after his second operation. The wiring beneath his scalp has left a permanent "speed bump," causing discomfort in his sleep.
Walking to a clinical appointment last week, Acosta freezes repeatedly. He has been off his medications since the previous afternoon so his neurologist can assess his normal behavior.
The battery is turned on. But Acosta doesn't feel any different.
After three increases to the electricity going to his brain, the right side of his body begins shaking: The therapy works, just as it did in the OR.
With the juice flowing, Acosta now strides confidently down the hall, arms swinging, no falter in his gait. Back in the exam room, he leaps into his wife's embrace, and breaks into tears. "It's a miracle," his wife said.
Acosta will have monthly appointments to adjust his medications, which will be decreased as more electricity runs through his brain. At least one more month of recovery will pass before he returns to work. In five years, he will have to undergo surgery to replace the battery.
Patients like Acosta "risk so much of themselves," said Sharan, who is writing a book to inspire others in a similar situation. "The brain is an intimate part of your body; it's your soul.
"That's why these guys are heroes."
Leila Haghighat can be reached at firstname.lastname@example.org or 408-355-4468.