Actress Nathalie Baye has died at the age of 77 from Lewy body disease. This disease affects around 200,000 people in France but many patients are unaware of it because it can be confused with Alzheimer’s or Parkinson’s.
Lewy body disease is a neurodegenerative disease like Alzheimer’s or Parkinson’s. We also speak of “dementia with Lewy bodies”. The actress Nathalie Baye, who died on April 17, 2026, suffered from it, as did the former weather presenter Catherine Laborde and the American actor Robin Williams. It is a disease that is still poorly diagnosed because, unlike Alzheimer’s or Parkinson’s, there is no obvious symptom that immediately alerts (memory loss or tremors). It’s harder to spot. Explanations with Professor Mathieu Ceccaldi, professor in the Department of Neurology and Neuropsychology at La Timone University Hospital in Marseille.
What is Lewy body disease? It is a disease linked to the abnormal accumulation of deposits called “Lewy bodies” in certain areas of the brain. The German neurologist Friedrich Lewy first described these deposits at the beginning of the 20th century and gave the disease its name. Lewy bodies are made primarily of a protein, alpha-synuclein, which disrupts the functioning of nerve cells and causes their gradual death. “Lewy body is a lesion that is also found in Parkinson’s disease but it then affects the structures involved in motor skills. In Lewy body disease, it is found mainly in the cerebral cortex and causes cognitive disorders.Professor Ceccaldi explains to us. In Alzheimer’s disease, other abnormal deposits form in neurons (beta-amyloid protein and tau protein).
Lewy body disease usually begins after age 50. It can be confused with Alzheimer’s or Parkinson’s since it shares certain characteristics but four types of symptoms allow it to be distinguished, as explained by the Association of Caregivers and Patients with Lewy Bodies. First, attention and information processing disorders. These are the first cognitive disorders described. The person has difficulty following a conversation, staying focused or organizing a simple task. Everyday actions become less fluid, not through forgetting, but through difficulty processing information.
Added to this are variations in the state. The person may seem perfectly lucid at one moment, then disoriented a few hours later: “This is what particularly characterizes this disease. Patients alternate between phases where they are well and phases where they are confused” the neurologist explains to us. And this, in the same day or in just a few hours. This is a major difference from Alzheimer’s disease. Third typical symptom: hallucinations. About 80% of sick people experience visual, sometimes auditory, hallucinations, often in the early stages. They are generally detailed (silhouettes, animals, very realistic scenes, etc.).
Finally, sleep problems. They are very common and can appear years before other symptoms start. Some people start moving, talking or screaming during the night, as if they are living their dreams. Taken in isolation, these signs may go unnoticed, but together they form a very specific picture that should prompt you to consult a doctor. It is the neurologist who makes the final diagnosis and implements treatments to manage the symptoms. Lewy body disease cannot be cured.
