Hall of Fame baseball pitcher Tom Seaver recently died at the age of 75 because of complications of Lewy body dementia (LBD) and COVID-19.
Seaver, also known as “Tom Terrific,” turned the previously laughable New York Mets into the 1969 “Miracle Mets,” leading his team to its first World Series championship. In addition, he won 311 games and had a 2.86 earned run average over his 20-year career (1967-1986), which also included six seasons with the Cincinnati Reds and late-career stints with other teams.
According to the New York Daily News, in 2013 Seaver was noted to have difficulty remembering things, and his thoughts “tended to wander and become garbled in transmission.” When he didn’t remember a man who had been working with him for 7 years, his wife, Nancy, insisted he see a doctor. After an examination and a battery of tests, the doctor told him that he had Lyme disease (a disease he had been diagnosed with back in November 1991). He was treated with antibiotics and vitamins and seemed to show some improvement.
However, in March 2019, his family announced that he had been diagnosed with dementia and would no longer be making any public appearances.
Major League Baseball Commissioner Rob Manfred said: “I am deeply saddened by the death of Tom Seaver, one of the greatest pitchers of all time. Tom was a gentleman who represented the best of our national pastime. He was synonymous with the New York Mets and their unforgettable 1969 season. After their improbable World Series championship, Tom became a household name to baseball fans — a responsibility he carried out with distinction throughout his life.”
Lewy Body Dementia
LBD is associated with abnormal deposits of a protein called alpha-synuclein in the brain. These deposits, called Lewy bodies, affect chemicals in the brain whose changes, in turn, can lead to problems with thinking, movement, behavior, and mood.
Although lesser known than its “cousins” Alzheimer’s disease and Parkinson’s disease, LBD is not a rare disorder. It affects more than one million individuals in the United States, and typically begins at age 50 or older, although sometimes younger people have it. LBD appears to affect slightly more men than women.
LBD is a progressive disease, with symptoms starting slowly and worsening over time. The disease lasts an average of 5 to 7 years from the time of diagnosis to death, but the time span can range from 2 to 20 years. How quickly symptoms develop and change varies greatly from person to person, depending on overall health, age, and the severity of symptoms.
The precise cause of LBD is unknown, but scientists are learning more about its biology and genetics. For example, an accumulation of Lewy bodies is known to be associated with a loss of certain neurons in the brain that produce two important neurotransmitters: acetylcholine, which is important for memory and learning, and dopamine, which plays an important role in behavior, cognition, movement, motivation, sleep, and mood.
What are Lewy Bodies?
Lewy bodies are named for Friedrich Lewy, a German neurologist. In 1912, he discovered abnormal protein deposits that disrupt the brain’s normal functioning in people with Parkinson’s disease. These abnormal deposits are now called “Lewy bodies.”
Lewy bodies are made of alpha-synuclein. In the healthy brain, this protein plays several important roles in neurons in the brain, especially at synapses. In LBD, alpha-synuclein forms into clumps inside neurons. This process causes neurons to work less effectively and, eventually, to die.
Lewy bodies affect several different brain regions in LBD:
- Cerebral cortex, which controls many functions including information processing, perception, thought, and language
- Limbic cortex, which plays a major role in emotions and behavior
- Hippocampus, which is essential to forming new memories
- Midbrain, including the substantia nigra, which is involved in movement
- Brainstem, which is important in regulating sleep and maintaining alertness
- Olfactory pathways
Types of LBD
The disease includes two related conditions — dementia with Lewy bodies and Parkinson’s disease dementia. The difference lies largely in the timing of cognitive and movement symptoms. In dementia with Lewy bodies, cognitive symptoms are typically noted within a year of parkinsonism, any condition that involves the types of movement changes, such as tremor or muscle stiffness, seen in Parkinson’s disease. In Parkinson’s disease dementia, movement symptoms are pronounced in the early stages, with cognitive symptoms developing years later.
Dementia with Lewy bodies
People with dementia with Lewy bodies have a decline in thinking ability that may look somewhat like Alzheimer’s disease. But over time they also develop movement and other distinctive symptoms that suggest dementia with Lewy bodies. Symptoms that distinguish this form of dementia from others may include:
- Visual hallucinations, especially early in the course of disease
- Fluctuations in cognitive ability, attention, and alertness
- Slowness of movement, difficulty walking, or rigidity (parkinsonism)
- Rapid-eye-movement (REM) sleep behavior disorder (see below)
- Comparatively more trouble with complex mental activities, such as multitasking, problem solving, and analytical thinking, than with memory
Parkinson’s disease dementia
This type of LBD starts as a movement disorder, with symptoms consistent with a diagnosis of Parkinson’s disease, such as slowed movement, muscle stiffness, tremor, and a shuffling walk. Later, cognitive symptoms of dementia and changes in mood and behavior may arise. Not all people with Parkinson’s develop dementia, and it is difficult to predict who will.
Common Symptoms of LBD
People with LBD may not have every LBD symptom, and the severity of symptoms can vary greatly from person to person. The most common symptoms are changes in cognition, movement, sleep, and behavior.
LBD causes changes in thinking abilities. These changes may include:
- Dementia: Severe loss of thinking ability that interferes with a person’s capacity to perform daily activities. Dementia is a primary symptom in LBD and usually includes trouble with visual and spatial abilities (judging distance and depth or misidentifying objects), planning, multi-tasking, problem solving, and reasoning. Memory problems may not be evident at first but often arise as LBD progresses
- Cognitive fluctuations: Unpredictable changes in concentration, attention, alertness, and wakefulness from day to day and sometimes throughout the day. The flow of ideas may be disorganized, unclear, or illogical at times. Cognitive fluctuations are common in LBD: The person may seem better one day, then worse the next
- Hallucinations: Seeing or hearing things that are not present. Visual hallucinations occur in up to 80% of people with LBD, often early on. They are typically realistic and detailed, such as images of children or animals. Auditory hallucinations are less common than visual ones but may also occur
Some people with LBD may not experience significant movement problems for several years. Others may have them early on. At first, signs of movement problems, such as a change in handwriting, may be very mild and thus overlooked. Specific signs of parkinsonism may include:
- Muscle rigidity or stiffness
- Shuffling gait, slow movement, or frozen stance
- Tremor or shaking, most commonly at rest
- Balance problems and falls
- Stooped posture
- Loss of coordination
- Smaller handwriting than had been usual for the person
- Reduced facial expression
- Difficulty swallowing
- Weak voice
Sleep disorders are common in people with LBD but are often undiagnosed. These may include:
- REM sleep behavior disorder: A condition in which a person seems to act out dreams. It may include vivid dreaming, talking in one’s sleep, violent movements, or falling out of bed
- Insomnia: Difficulty falling or staying asleep or waking up too early
- Restless leg syndrome: A condition in which a person, while resting, feels the urge to move his or her legs to stop unpleasant or unusual sensations. Walking or moving usually relieves the discomfort.
Behavioral and mood symptoms
Changes in behavior and mood are possible in LBD. These changes may include:
- Depression: A persistent feeling of sadness, inability to enjoy activities, or trouble with sleeping, eating, and other normal activities
- Apathy: A lack of interest in normal daily activities or events; less social interaction
- Anxiety: Intense apprehension, uncertainty, or fear about a future event or situation
- Agitation: Restlessness, as seen by pacing, hand wringing, an inability to get settled, constant repeating of words or phrases, or irritability
- Delusions: Strongly held false beliefs or opinions not based on evidence. One delusion seen in people with LBD is Capgras syndrome, in which the person believes a relative or friend has been replaced by an imposter
- Paranoia: An extreme, irrational distrust of others, such as suspicion that people are taking or hiding things
Other LBD symptoms
People with LBD can also experience significant changes in the part of the nervous system that regulates autonomic functions such as those of the heart, glands, and muscles, including:
- Changes in body temperature
- Problems with blood pressure
- Dizziness, fainting
- Frequent falls
- Sensitivity to heat and cold
- Sexual dysfunction
- Urinary incontinence
- Poor sense of smell
While LBD currently cannot be prevented or cured, some symptoms may respond to treatment for a period of time. A comprehensive treatment plan may involve medications, physical and/or other types of therapy, and counseling. Changes to make the home safer, equipment to make everyday tasks easier, and social support are also important.
Michele R. Berman, MD, and Mark S. Boguski, MD, PhD, are a wife and husband team of physicians who have trained and taught at some of the top medical schools in the country, including Harvard, Johns Hopkins, and Washington University in St. Louis. Their mission is both a journalistic and educational one: to report on common diseases affecting uncommon people and summarize the evidence-based medicine behind the headlines.