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Symptoms & Causes of DLB

What are the Symptoms?

Dementia with Lewy Bodies (DLB) affects many areas of the nervous system. DLB is categorized by cognitive, psychiatric/behavioral and physical symptoms a person experiences. These symptoms are similar to what a person with Parkinson Disease Dementia (PDD) may experience as well. In DLB motor symptoms start about a year after cognitive symptoms. In Parkinson’s disease patients, if cognitive symptoms start after one year from motor symptoms the condition is called Parkinson Disease Dementia (PDD). DLB and PDD are collectively called Lewy body dementias.

  • Cognitive symptoms: Individuals may experience a decline in ability to perform daily activities, difficulty with visual processing and navigation. Memory problems occur later in DLB and PDD. 
  • Psychiatric symptoms: Persons may experience recurrent visual hallucinations and delusions, as well as agitation, depression, and anxiety. An individual with hallucinations may see things that aren't really there, and somone with delusions may think that they are in danger or that other people are stealing from them — it may present like paranoia. 
  • Physical symptoms: Persons might experience REM sleep behavior disorder (RBD). RBD is a disorder of sleep and can include new onset of talking a lot during sleep. They may also act out their dreams, which can cause injuries for them or their bed partners. RBD can happen years before the onset of cognitive symptoms.
  • Additional physical symptoms: Patients with DLB and PDD have associated motor difficulties known as Parkinsonism. Patients may have rigidity and slowing in their limb movements, they may have balance problems and sometimes may develop shaking in their extremities. Other physical symptoms of DLB and PDD include decrease sense of smell, constipation, and low blood pressure and fainting which may happen years before cognitive symptoms.

What Causes DLB?

Lewy body disease is what causes Dementia with Lewy Bodies and Parkinson Disease Dementia, two dementia syndromes. Lewy body disease is caused by accumulation of abnormal synuclein-based protein (Lewy bodies) in brain cells. Injury to brain cells follows.  

When Lewy bodies affect the brain stem, they cause Parkinson disease. However, when the disease affects main brain regions, it can cause dementia, known as Dementia with Lewy Bodies (DLB).  


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