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QuestionChoice
Normal pressure hydrocephalus is a cause of secondary dementia and presents with a triad of urinary incontinence, dementia, and falls. It is treatable by shunting away the excess CSF from the ventricles. This patient does not have these clinical features, but is instead presenting with the characteristic features as associated with Dementia with Lewy Bodies.
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Normal pressure hydrocephalus
QuestionChoice
Vascular dementia is the second commonest cause cause of dementia after Alzheimer's and presents with a step-wise decline in cognitive function due to accumulation of ischaemic infarcts over time (or small vessel disease.) Risk factors such as hypertension, hypercholesterolaemia, and diabetes should be managed. This patient has none of these risk factors, and the characteristic features are that of Lewy Body Dementia and not vascular dementia.
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Vascular dementia
QuestionChoice
Parkinson's Disease Dementia and Dementia with Lewy Bodies are on a spectrum with one another, presenting with similar clinical features due to a common pathophysiological basis (alpha synucleinopathy.) If the dementia precedes or begins at the same time as the movement disorder (Parkinsonism), then the diagnosis is Dementia with Lewy Bodies (also known as Lewy Body Dementia), but if the dementia occurs a year or more after the movement disorder/diagnosis of Parkinson's Disease, then the diagnosis is referred to as Parkinson's Disease Dementia.
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Parkinson's Disease Dementia
QuestionChoice
Alzheimer's disease is the commonest cause of dementia but does not present with movement issues or hallucinations.
Patients present with gradual loss of memory, difficulty with word-finding, poor recognition of objects and people, and an inability to carry out tasks which require fine motor function.
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Alzheimer's disease
QuestionChoice
Dementia with Lewy Bodies is a progressive neurodegenerative disorder caused by deposits of alpha-synuclein within the brain. Patients develop cognitive decline, hallucinations (typically of little people or animals, 'Lilliputian bodies'), and Parkinsonism. If the dementia precedes or begins at the same time as the movement disorder (Parkinsonism), then the diagnosis is Dementia with Lewy Bodies (also known as Lewy Body Dementia), but if the dementia occurs a year or more after the movement disorder/diagnosis of Parkinson's Disease, then the diagnosis is referred to as Parkinson's Disease Dementia.
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Dementia with Lewy bodies
QuestionComment
De mention started 2 years ago and Parkinson’s movements last month. Isn’t this F least a year apart?
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Z-line Gallbladder
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# Summary

Dementia with Lewy bodies (DLB) is a progressive, complex condition, accounting for approximately 10-15% of dementia cases. DLB is characterised by the presence of Lewy bodies, abnormal protein deposits, within brain cells, particularly in the substantia nigra, paralimbic, and neocortical areas. The clinical picture is often characterised by fluctuating cognition, Parkinsonism, and visual hallucinations. A diagnosis is primarily clinical, although dopamine uptake scanning can provide supplementary data. Patients with DLB are highly sensitive to neuroleptics, potentially exacerbating Parkinsonism.  

# Definition

Dementia with Lewy bodies (DLB) is a type of progressive dementia caused by deposits of an abnormal protein, alpha-synuclein, forming cytoplasmic inclusions known as Lewy bodies within brain cells. These aggregates disrupt normal cell functioning and eventually lead to neuronal death.

# Epidemiology

DLB is the third most common type of dementia, following Alzheimer's disease and vascular dementia. It represents around 10-15% of all dementia cases.

# Aetiology

The primary pathological feature of DLB is the presence of Lewy bodies in the brain's substantia nigra, paralimbic, and neocortical areas. However, the exact cause of this accumulation remains unknown. An association with Parkinson's disease has been noted, with many patients exhibiting overlapping symptoms. 

New research suggests that LBD and Parkinson’s disease have much more overlap than originally thought. Parkinson’s disease starts in the basal ganglia/brainstem and then progresses upwards towards cerebral cortex (hence dementia is late), whereas in LBD the process progresses downwards from the cerebral cortex.

# Clinical Features

The clinical features of DLB include:

- Fluctuating cognition: Changes in attention and alertness may occur
- Parkinsonism: Rigidity, bradykinesia, and postural instability are common
- Visual hallucinations: Patients often experience complex and recurrent visual hallucinations
	- Classically, patients complain of seeing small mammals around them 
- High sensitivity to neuroleptics: These drugs can induce or worsen parkinsonism

A general rule of thumb that can help with distinguishing LBD form Parkinson's disease (PD) is if cognitive impairment and parkinsonism develop <1 year of each other, it is likely LBD. If diagnosed with PD and dementia develops >1 year later this is Parkinson’s disease.

# Differential Diagnosis

Differential diagnoses for DLB include:

- Alzheimer's disease: Characterised by gradual memory loss, difficulties with problem-solving, and changes in mood or behaviour. However, Alzheimer's patients do not typically exhibit the severe sensitivity to neuroleptics seen in DLB.
- Parkinson's disease dementia: While it shares many symptoms with DLB, Parkinson's disease dementia typically starts with motor symptoms before cognitive decline. 
- Vascular dementia: This condition features stepwise cognitive decline and evidence of cerebrovascular disease. Parkinsonism and hallucinations are less common.

# Investigations

Diagnosis is primarily clinical, involving a careful medical history and physical examination. However, some additional investigations may be useful, such as:

- Dopamine transporter (DaT) scan: This can help distinguish DLB from other types of dementia.
- Neuropsychological testing: To assess cognitive functioning and fluctuations.
- Electroencephalography (EEG): Although not diagnostic, a slowing background rhythm may be seen in DLB.


# Management

Management of DLB includes should follow the biopsychosocial model - please see our Dementia section for holistic management principles.

- Non-pharmacological interventions: These include cognitive stimulation, physical therapy, and occupational therapy.
- Supportive care: As DLB is a progressive disorder, palliative and end-of-life care considerations are essential.
- Medications: Cholinesterase inhibitors can help manage cognitive symptoms. However, caution is required with antipsychotic medications due to neuroleptic sensitivity.


# NICE Guidelines

[Click here to see information on NICE CKS on dementia](https://cks.nice.org.uk/topics/dementia/)
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Dementia with Lewy bodies
Topic
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Psychiatry
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A 63-year-old woman presents to the GP with her daughter. Her daughter reports a gradual deterioration of her mother's memory over the last two years, which is concerning her. During this time period, her mother has frequently been found to be talking to small children sitting by the foot of the bed, who her daughter cannot see. Over the last month, she has also noticed that her mother's movement has slowed down significantly, which is limiting her mobility, as well as a new resting tremor in her mother's hands. She has no past medical history.

Which of the following is the most likely diagnosis?
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