Actor Patrick Stewart, known for playing Professor Xavier in the X-Men franchise, passed away on Wednesday, October 28th, at the age of 86. Although family members have not disclosed the exact cause of death, it was revealed that the actor was simultaneously dealing with two neurodegenerative pathologies: Alzheimer's disease and Lewy body dementia.
Both are classified as some of the most prevalent neurodegenerative diseases and are characterized by cognitive deterioration, behavioral problems, and memory loss. However, despite the similarities, each condition has its distinct mechanisms and clinical manifestations.
Alzheimer's disease results from a defect in protein processing in the central nervous system. Abnormal and toxic proteins, notably beta-amyloids and tau, accumulate irregularly in the brain, both inside and outside neurons. This leads to the progressive death of neurons in areas crucial for memory and processing, such as the hippocampus and cortex, compromising cognition and causing changes in behavior. A common initial sign is forgetting recent events, and its origin is multifactorial, involving genetic and hereditary aspects.
Lewy body dementia, on the other hand, also involves protein accumulation, but in a different manner. In this condition, the alpha-synuclein protein deposits inside the neurons and in the cerebral cortex, forming aggregates called Lewy bodies. These deposits also serve as indicators of other illnesses, such as Parkinson's, and are named after the physician Frederic Lewy, who discovered the phenomenon. These deposits can affect various parts of the brain, interfering with communication and neuronal function, potentially leading to cell death in the long term, similar to what occurs in Alzheimer's.
Primary signs of Lewy body dementia include motor changes, such as tremors, muscle rigidity, and slowness, which often lead to confusion with Parkinson's, as happened with Robin Williams. The correct diagnosis was only established after his passing. Other recurring symptoms include sleep disorders, mental confusion, difficulty reasoning, and paranoia. The condition can also cause autonomic dysfunction, affecting involuntary bodily processes such as blood pressure regulation, digestion, and bladder control.
A distinctive symptom is the occurrence of visual hallucinations, which can affect up to 80% of patients. Although memory is affected over time, it is generally not the first symptom presented. While Alzheimer's tends to be more common in women, Lewy body dementia shows a higher incidence in men. Both diseases have no definitive cure, but treatments are available to manage symptoms and improve quality of life, including medications aimed at inhibiting neurotransmitter degradation or increasing cerebral dopamine.
