What Is Lewy Body Dementia? Frank Bonner of 'WKRP in Cincinnati' Dies of Complications

Actor and director Frank Bonner has died aged 79 from complications relating to Lewy body dementia, his wife has told The Hollywood Reporter.

Bonner was best known for playing Herb Tarlek in the CBS sitcom WKRP in Cincinnati. He also appeared in Saved by the Bell: The New Class and Murder, She Wrote, as well as working as a TV director for more than 20 years.

His death appears to have sparked search queries for Lewy body dementia, Google Trends data has shown.

According to the National Institute on Aging, Lewy body dementia (LBD) is "a disease associated with abnormal deposits of a protein called alpha-synuclein in the brain."

The deposits are known as Lewy bodies—named after Friederich Lewy, the neurologist who first identified them. It is unclear why they appear, according to U.K. charity the Alzheimer's Society.

Lewy bodies can affect chemicals in the brain, leading to problems with thinking, movement and behavior. The deposits are a common cause of dementia.

Symptoms of LBD can vary widely from person to person and it can be confused with Alzheimer's disease. A person with LBD may also show symptoms of Parkinson's disease.

Dr Ian McKeith, professor of old age psychiatry at the Newcastle University Institute for Ageing, U.K., told Newsweek that the possibility of measuring alpha-synuclein, the key protein implicated in Lewy body disease, "seems to be coming close" with certain techniques.

He said: "Since intervention is most likely to be effective if applied early, research efforts are being directed towards prodromal (early symptomatic) diagnosis supported by the development and validation of sensitive and specific biomarker tests.

"Clinical trials have also started in [LBD] with pharma and biotech companies expressing their interest in [LBD] as a potentially tractable and relatively common disorder for which we currently have only limited symptomatic treatments."

The National Institute on Aging says diagnosing LBD is "challenging" and adds: "Early Lewy body dementia symptoms are often confused with similar symptoms found in other brain diseases like Alzheimer's or in psychiatric disorders like schizophrenia."

The primary symptom associated with LBD is dementia—a severe loss of thinking abilities, which can include problems with attention and multitasking as well as changes in mood and behavior.

Some people with LBD also experience hallucinations. The National Institute on Aging states that up to 80 percent of LBD patients may be affected. The hallucinations tend to be visual—seeing things that are not present—but can also affect a person's hearing or sense of smell.

Another LBD symptom may be Parkinsonism—problems with body movement.

Signs of Parkinsonism include muscle stiffness, slow movement, shaking, difficulty swallowing and smaller handwriting than usual.

Lewy body dementia is described by the National Institute on Aging as a progressive disease, with symptoms getting worse over time. The speed of this process can vary greatly.

The disease cannot currently be prevented or cured, but treatment by physical therapists, occupational therapists and counselors can help patients to manage their symptoms.

Although the exact cause of LBD is still unknown, scientists think the appearance of Lewy bodies is linked to the loss of connections between nerve cells in the brain and low levels of chemicals that carry messages between nerve cells, according to the Alzheimer's Society.

This article has been updated to include a quote from Dr. Ian McKeith.

Nurse holding hands
Stock photo of a medical professional holding the hands of an elderly patient. Physical and occupational therapies can improve the lives of people with Lewy body dementia. Piksel/Getty