3. Dementia with Lewy Bodies

Dementia with Lewy Bodies

This PatientPlus article is written for healthcare professionals so the language may be more technical than the condition leaflets. You may find the abbreviations list helpful.

See other related dementia articles.

Dementia with Lewy bodies (DLB) is the second most common form of primary neurodegenerative dementia after Alzheimer's disease.

It is characterised by eosinophilic intracytoplasmic neuronal inclusion bodies (Lewy bodies) in the brainstem and neocortex.

There is a spectrum of Lewy body disorders that includes not only dementia with Lewy bodies (DLB), Parkinson's disease and Parkinson's disease-associated dementia but also Lewy body dysphagia and autonomic failure with Lewy bodies.

It accounts for about 15-20% of patients with dementia,[1] and there are an estimated 100,000 cases in the UK.[2] Approximately 75% of older people with Parkinson's disease will develop dementia after 10 years.[3]

  • Characteristically there are fluctuating levels of awareness, often with signs of mild Parkinsonism (tremor, rigidity, poverty of facial expression, festinating gait). Falls frequently occur.
  • Psychiatric symptoms are more common, especially visual hallucinations or delusions.[1]
  • Attentional deficits and impaired visuospatial skills are often more pronounced than in Alzheimer's disease and recent memory may be better preserved.[4]
  • Intermittent loss of consciousness, rapid eye movement sleep disorder.
Consider DLB in elderly patients presenting with delirium, movement disorders, myoclonus, falls or syncope.[2]

The international consensus criteria should be used.[5] Accurate diagnosis is important as it affects management (see Management section, below).

Two of the three core diagnostic features are required for 'probable' dementia with Lewy bodies (DLB); one for 'possible' DLB:[2]

  • Fluctuating confusion
  • Persistent visual hallucinations
  • Spontaneous Parkinsonism

Standard informant interviews may help improve sensitivity (eg the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE).[6]

  • Diagnosis is usually a clinical one.
  • Dopaminergic iodine-123-radiolabelled 2β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FP-CIT) single photon emission computed tomography (SPECT) can be used to help establish the diagnosis in patients with suspected dementia with Lewy bodies (DLB).[1]
  • Metaiodobenzylguanidine (MIBG) scintigraphy is a valuable diagnostic tool for differentiation between Lewy body disease and Parkinsonian syndromes or other movement disorders with Parkinsonism.[7] This method may also provide a tool for differentiating between DLB and Alzheimer's disease.
  • Refer to a specialist with expertise in differential diagnosis - so that Lewy body dementia can be identified using the appropriate criteria and investigations.
  • Nominate a key worker, and agree a mental health care management plan with the principal carer:
    • Record the key worker in the patient's record.
    • Care plans should address the patient's activities of daily living (ADL), particularly trying to maximise their independence.
    • The aim to keep the patient in as familiar and unchanging an environment as possible, building in exercise and occupational therapy, and some flexibility to cope with fluctuating abilities.
  • Identify and involve all carers as much as possible, and ensure they understand both the diagnosis and prognosis (prepare the spouse for the day when the patient no longer recognises loved ones).
  • Try to involve the psychiatric social worker and carer support workers early. They can help with the initial risk assessment, arrange appropriate financial support (allowances etc.), arrange day care, day centre attendance, relief admissions, etc.
  • Driving is a very complex task and people who have dementia with Lewy bodies (DLB) must not drive. There may be lack of insight and reluctance to lose mobility and freedom.

Medication

Behavioural and psychotic symptoms may need assessment by a psychogeriatrician, who may also assess whether drug treatment is appropriate to prevent deterioration.

  • Avoid neuroleptic drugs for psychiatric and behavioural problems - these commonly induce severe sensitivity reactions in DLB patients - motor and mental impairment is worsened and mortality is increased threefold.[5][8]
  • Anti-Parkinsonian treatment may also worsen psychosis.
  • Cholinesterase inhibitors - eg rivastigmine, at daily doses of 6 mg and above, can be helpful in treating cognitive decline in people with DLB.[1]

Monitor for the emergence of severe untoward reactions, particularly neuroleptic sensitivity reactions - eg worsening extrapyramidal features and/or severe physical deterioration following prescription antipsychotic drugs, for which there is no other apparent cause.[9]

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Further reading & references

  1. Management of patients with dementia, Scottish Intercollegiate Guidelines Network - SIGN (Feb 2006)
  2. McKeith IG, O'Brien JT, Ballard C; McKeith IG, O'Brien JT, Ballard C; Diagnosing dementia with Lewy bodies. Lancet. 1999 Oct 9;354(9186):1227-8.
  3. Aarsland D, Andersen K, Larsen JP, et al; Prevalence and characteristics of dementia in Parkinson disease: an 8-year prospective study. Arch Neurol. 2003 Mar;60(3):387-92.
  4. Crystal HA; Dementia with Lewy Bodies, eMedicine, Dec 2009.
  5. McKeith IG, Galasko D, Kosaka K, et al; Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): report of the consortium on DLB international workshop. Neurology. 1996 Nov;47(5):1113-24.
  6. Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) - Copies downloadable from website (paper format).
  7. Treglia G, Cason E, Gabellini A, et al; Recent developments in innervation imaging using Neurol Sci. 2010 Mar 10.
  8. McKeith I, Fairbairn A, Perry R, et al; Neuroleptic sensitivity in patients with senile dementia of Lewy body type. BMJ. 1992 Sep 19;305(6855):673-8.
  9. Dementia: Supporting people with dementia and their carers in health and social care, NICE Clinical Guideline (2006)
Original Author: Dr Huw Thomas Current Version:
Last Checked: 21/05/2010 Document ID: 2976  Version: 23 © EMIS

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.