Dementia with Lewy bodies (DLB)

Timothy C. Hain, MD Most recent update: August 29, 2009

DLB was first described in 1996, not very long ago. Lewy bodies are accumulations of alpha-synuclein. In this disease, accumulation of Lewy bodies is associated with a slowly progressive neurological deterioration.

DLB was intitially reported as accounting for about 15-25% of all dementia. There may be an incidence of DLB of about 0.1% in the general population.

Entities that can be confused with DLB include

• Progressive supranuclear Palsy (PSP) (overlaps with basal ganglia findings)
• Corticobasal degeneration (CBD)
• Frontotemporal dementia (FTD)
• Multisystem atrophy(overlaps with autonomic failure and ataxia)

Pathophysiology of DLB

Damage is thought to occur due to accumulation of Lewy bodies in the nervous system. A 6-stage system has been suggested beginning with lesions in the medulla and olfactory cortex, and with progression to the cortex. Lewy bodys may also be found in sympathetic and intramural ganglia (i.e. outside the CNS).

Diagnosis of DLB

DLB is characterized by dementia associated with any two of the following three core features:

• 1. Fluctuating cognition
• 2. Visual hallucinations. These often involve children, little people or animals.
• 3. Spontaneous parkinsonian signs. These may include rigidity, bradykinesia, resting tremor and loss of postural reflexes. There are several variants of this including
  • Parkinson disease with dementia (PD)
  • Parkinson disease without dementia (PDD)

Autonomic failure may also accompany DLB ( Akaogi et al, 2009). Olfactory disturbances and autonomic failure may precede the motor symptoms and onset of dementia. Sweating disturbances and orthostatic hypotension are common.

Treatments for DLB

Cholinesterase inhibitors

• Donazepril
• Rivastigmine (Excelon)
• Razadyne

Memantine (Namenda)

Antipsychotic agents

• Quetiapine (Seroquel)
• Risperidone (Risperdol)
• Olanzapine (Zyprexa)
• Anpiprazole (Ablify)
• Clozapine (Clozaril)

References:

Akaogi, Y., M. Asahina, et al. (2009). "Sudomotor, skin vasomotor, and cardiovascular reflexes in 3 clinical forms of Lewy body disease." Neurology 73(1): 59-65.