Radio personality and The Partridge Family actor Danny Bonaduce made headlines this week as he announced he would be undergoing brain surgery to treat hydrocephalus, a neurological condition that involves buildup of cerebrospinal fluid in the brain.

Bonaduce, 63, has been dealing with symptoms for about a year, including difficulties walking and balance. Last spring, he posted on his Instagram noting he was taking a temporary medical leave from his radio show, the Danny Bonaduce & Sarah Morning Show.

In the post, which featured a photo of him with a cane, Bonaduce noted that he was working to receive a diagnosis but needed time to focus on his health. 

“Charlie Chaplin, Willy Wonka, Danny Bonaduce,” he wrote. “I’ve joined the club of cool guys with canes.”

Since then, media reports indicated that Bonaduce was suffering from hydrocephalus and that he would be receiving surgery to treat it.

Bonaduce reportedly underwent surgery for the condition on Monday, with his wife Amy Bonaduce tweeting that evening that “it’s been a long day but I just wanted to let you guys know that Danny’s surgery went according to plan and he’s doing well.”

Bonaduce’s diagnosis and surgery made hydrocephalus itself gain traction in the news, but what is it exactly?

Hydrocephalus is marked by the accumulation of cerebrospinal fluid in the ventricles of the brain. This causes the ventricles to increase in size and put pressure on the brain, which can lead to damaged brain tissues and neurological problems like nausea or vomiting, seizures, loss of bladder control, and muscle and coordination issues.

The condition is most commonly identified in infants or in people over the age of 60, according to Mayo Clinic.

When a baby is born with hydrocephalus, the infant will typically have an unusually large head caused by the brain swelling, with a bulging soft spot on the top of the head. If hydrocephalus goes untreated, it can lead to long-term complications including physical and even intellectual disabilities – it can also result in death in severe cases.

Hydrocephalus occurs in about one to two out of every 1,000 births, according to the National Institutes of Health.

Surgery is the typical treatment pathway for hydrocephalus and there are two main types of surgical procedures for it. 

The most common type of surgery involves placing a ventriculoperitoneal shunt into a brain ventricle and redirecting cerebrospinal fluid through to the abdomen. 

Another type, endoscopic third ventriculostomy, involves placing an endoscope into the brain to create a hole at the bottom of a ventricle to drain fluid.

Bonaduce did not clarify what type of brain surgery he received, but on Tuesday he tweeted confirming that the operation had indeed been successful: “I lived, b*tch,” he wrote.