Information
Editors
Parkinson's Disease Dementia and Dementia with Lewy Bodies
Essentials
- Parkinson's disease dementia is associated with reduced attention and a decline in executive function skills as well as neuropsychiatric symptoms, such as reduced ability to take initiative and changes in mood.
- Dementia with Lewy bodies is characterised, in addition to cognitive symptoms, by recurring visual hallucinations, extrapyramidal symptoms as well as fluctuations in levels of alertness and cognitive function.
Parkinson's disease dementia
- The incidence of a progressive memory disease is 4-6 times higher in patients with Parkinson's disease than in the general population. Follow-up studies report a memory disease in 60-70% of patients with Parkinson's disease.
- Factors predisposing the patient to Parkinson's disease dementia (PDD) are: advanced age, severe and hypokinetic-rigid clinical picture (as compared to tremor-dominant form of the disease), postural instability in an upright position and gait disturbance as well as an early occurrence of memory complaints.
- Criteria for PDD:
- Core features
- Diagnosis of Parkinson's disease according to the clinical criteria (Queen Square Brain Bank)
- Progressive cognitive symptoms
- In more than one domain: e.g. impairment in and slowing down of attention, executive functioning, visual perception and memory functions
- Decline in level as compared to the situation before disease onset
- Possible impairment in coping with daily activities.
- Associated clinical features
- Neuropsychiatric symptoms: reduced initiative (apathy), depressive mood, changes in personality, hallucinations, delusions, excessive daytime tiredness
- Pathology is based on the presence of cortical Lewy bodies, concomitant Alzheimer's disease (AD) changes, disorders of different neurotransmitter systems, or a combination of these processes. The cognitive symptoms are associated with a decline in the cholinergic system.
- Different therapy forms have not been shown to be effective in treating the symptoms of PDD. Supportive treatment involves a safe and calm environment and support from family members.
- Acetylcholinesterase inhibitors are the first-line pharmacotherapy for PDD. Rivastigmine is the only drug in this group that has PDD as an official indication.
Dementia with Lewy bodies (DLB)
- In Parkinson's disease, Lewy bodies are typically found in substantia nigra and in the basal ganglia. In DLB, Lewy bodies are abundant in the cerebral cortex. Half of the patients with DLB also exhibit cerebral changes typical to Alzheimer's disease (AD).
- The onset is slow, and the duration of the disease varies; the average duration is 8 years.
- Core features (two are essential for a diagnosis of DLB) http://www.dynamed.com/condition/dementia-with-lewy-bodies#MAKING_THE_DIAGNOSIS:
- Fluctuating cognition with variations in attention and alertness
- Recurrent detailed visual hallucinations
- REM sleep behaviour disorder
- Extrapyramidal symptoms, i.e. features of parkinsonism (stiffness, slowness, gait disturbance, sometimes tremor).
- Features supportive of the diagnosis of DLB include:
- sensitivity to antipsychotics
- balance difficulties, recurrent falls or fainting
- reduced dopamine transporter binding in the basal ganglia.
- Memory impairment is not typical in the early stages. An early progressive decline in episodic memory with coexisting DLB features is suggestive of concomitant Alzheimer's disease (DLB/AD).
- These patients are sensitive to antipsychotics, and even small doses may cause confusion and inability to walk.
- Combining pharmacological and non-pharmacological treatments offers the best treatment results.
- Acetylcholinesterase inhibitors (donepezil http://www.dynamed.com/condition/dementia-with-lewy-bodies#DONEPEZIL, galantamine http://www.dynamed.com/condition/dementia-with-lewy-bodies#GALANTAMINE, rivastigmine Cholinesterase Inhibitors for Lewy Body Dementia http://www.dynamed.com/condition/dementia-with-lewy-bodies#RIVASTIGMINE) have been shown to be useful for the behavioural symptoms and attention disorders of DLB. Acetylcholinesterase inhibitors are, however, not licensed for use in DLB. On the other hand, AD with features of DLB is an official indication for acetylcholinesterase inhibitors. The diagnosis is in this case DLB/AD.
- If severe visual hallucinations and confusion cannot be controlled by other means, second-generation antipsychotics (clozapine, risperidone, quetiapine) may need to be tried. The starting dose should be as small as possible, and the development of any adverse effects should be monitored closely.
- Physiotherapy and walking exercises must be initiated early to maintain mobility.