Dementia with Lewy Bodies (DLB)
Lewy Body Dementia (LBD) is a form of neurodegenerative dementia characterized by the presence of pathological intracytoplasmic inclusions called Lewy bodies, primarily composed of alpha-synuclein aggregates. It is the second most common cause of degenerative dementia after Alzheimer’s disease. It mainly affects individuals over the age of 60, with a slightly higher prevalence in men. It is characterized by a complex clinical picture, featuring cognitive, motor, and psychiatric symptoms that often overlap with Parkinson’s disease and Alzheimer’s disease.
The exact cause of Lewy Body Dementia is still unknown, but the pathological accumulation of alpha-synuclein in the brain represents the primary neuropathological event. This deposition mainly affects the cerebral cortex, the basal ganglia, and the brainstem. Genetic factors appear to play a smaller role compared to other dementias: mutations in the SNCA or GBA genes are only rarely observed. However, advanced age and certain genetic predispositions can increase the risk of developing the pathology.
LBD presents a diverse clinical picture that can make diagnosis difficult, especially in the early stages. The primary symptoms include:
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Marked cognitive fluctuations: daily or even hourly variations in attention and alertness.
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Complex visual hallucinations: often very vivid and recurrent.
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Parkinsonian symptoms: rigidity, bradykinesia, and postural instability, similar to those seen in Parkinson’s disease, with frequent falls.
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REM sleep behavior disorder (RBD): motor behaviors during dreams (aggression, vocalizations).
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Antipsychotic hypersensitivity: many patients show extreme sensitivity to neuroleptics, with a risk of severe clinical worsening.
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Memory may be less impaired than in Alzheimer’s disease during the early stages, but visuospatial abilities and attention are frequently affected.
The diagnosis is clinical and is based on the DLB Consortium diagnostic criteria. Magnetic Resonance Imaging (MRI) may show mild cortical atrophy, while FDG-PET highlights a typical occipital hypometabolism. Ioflupane scintigraphy (DaTSCAN) and myocardial scintigraphy are useful for documenting dopaminergic degeneration in the basal ganglia and at the cardiac level, respectively. Cerebrospinal fluid (CSF) analysis may show beta-amyloid deposition, similar to what occurs in Alzheimer’s disease. Finally, in cases with REM sleep behavior disorder, polysomnography can be useful.
Available therapies
There is no definitive cure for LBD; treatment is multidisciplinary and aimed at symptom management. Acetylcholinesterase inhibitors (such as donepezil and rivastigmine) are often effective in improving attention and cognition and reducing hallucinations, while dopaminergic drugs, used with caution, can help control motor symptoms. The use of antipsychotics is very limited due to the well-known hypersensitivity of these patients. Physical therapy, occupational therapy, and psychological support are essential to improve the quality of life for the patient and their family members.
Research in progress
Lewy Body Dementia represents a diagnostic and therapeutic challenge, but the growing understanding of its mechanisms opens new perspectives for the future.
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Identification of specific biomarkers for early diagnosis and differentiation from Alzheimer’s and Parkinson’s disease.
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New preclinical models for studying the molecular mechanisms of LBD.
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Evaluation of non-pharmacological strategies to improve behavioral and cognitive disturbances.
Reference laboratory
Contacts and informations
Contact: Marco Milianti
Mail: segreteria.neurodeg@policlinico.mi.it 0255038508
Links to scientific publications or useful resources:
Centro per disturbi cognitivi e demenze (CDCD)