- 60 to 75% = Alzheimer’s and mixed (Alzheimer’s and vascular dementia) type
- 10 to 15% are Lewy body type
- Remaining types being of an entire spectrum of dementias including frontotemporal lobar degeneration, alcoholic dementia, pure vascular dementia, etc
Presenting symptoms / signs:
- Fluctuating cognition with great variations in attention and alertness from day to day and hour to hour
- Recurrent visual hallucinations (observed in 75% of people with DLB)
- Motor features of Parkinson’s. Suggestive symptoms are rapid eye movement, (REM)-sleep behavior disorder and abnormalities detected in PET or SPECT scans
- Additional features may include = Parkinson’s features, tremors are less common in DLB than in Parkinson’s disease, problems with orthostasis, transient loss of consciousness, hypersensitivity to neuroleptic and antiemetic medications that affect dopaminergic and cholinergic systems.
- Possibly – PARK11 gene, APOE.
DLB = the loss of cholinergic (acetylcholine-producing) neurons is thought to account for the degradation of cognitive functioning, as in Alzheimer’s disease; while the loss of dopaminergic (dopamine-producing) neurons is thought to account for the degradation of motor control, as in Parkinson’s disease
- Treatment of the movement portion of the disease can worsen hallucinations and psychosis, while treatment of hallucinations and psychosis can worsen parkinsonian symptoms
- Cholinesterase inhibitors, donepezil (Aricept), rivastigmine (Exelon) and galantamine – tx cognitive problems
- Memantine, sinemet, clonazepam
- Botulinum toxin injections in the parotid glands may help with sialorrhea. Other medications, such as methylphenidate and modafinil, may improve daytime alertness.
- Palliative – no tx can stop disease progression.. thus caregiving is very important and incredibly demanding – always explore how the caregiver is feeling and coping with this task.