Difference Between Dementia with Lewy Bodies and Parkinson’s

What is Dementia with Lewy bodies and Parkinson’s?

Both conditions relate to decline in cognitive thinking and reasoning, loss of brain cells and abnormal alpha-synuclein protein clusters termed as Lewy bodies.

Both disorders have very similar symptoms, but the symptoms usually happen in a different order dependant on where the Lewy bodies first form. 

Major similarities between Parkinson’s and Lewy Body Dementia include;

  • Both disorders affect approximately one million people in the United States
  • They both cause an impact to the brain nerve cells
  • There is no cure for both of these conditions
  • Symptoms that impact the body include stiffness, weakness and slowness in movements
  • Symptoms that affect brain include: memory loss, attention span and impaired executive functioning

The protein – alpha-synuclein (protein of unknown function found in neural tissue) unusually builds up in the brain in aggregates, or clumps, called Lewy bodies. The location of those clumps makes a difference. 

Also, people who have Lewy bodies dementia tend to exhibit greater variation in brain function ability than those with PD dementia.

Dementia with Lewy Bodies

It is a degenerative neurologic disease in which dementia (cognitive decline) advances early on in the course of this health problem.

It is not a single medical condition but rather a spectrum of closely-associated medical conditions involving disturbances of sleep, autonomic function, cognition, behaviour, and movement.

Symptoms include;

  • Alterations in reasoning and thinking
  • Delusions
  • Well-formed visual hallucinations
  • Slowness in movement and gait imbalance 
  • Poor regulation of body functions (autonomic nervous system)
  • Fluctuating attention and depression
  • Cognitive problems
  • Sleeping difficulties

It represents 15%-25% of all dementias.

Parkinson’s

It is a neurologic disease characterized by progressive deterioration of organs or tissues. The first symptom is problem with the movement. Other symptoms include tremors in the hand, loss of balance, stiffness, slowed movement (bradykinesia), dementia etc. It predominately affects dopamine-producing neurons in a particular area of the central nervous system (brain) termed as substantia nigra. 

Parkinson’s disease (PD) patients experience no or only elusive cognitive decline, and their primary limitation is their motor disorder. However, some people with PD develop dementia as a result of this disease. When dementia (various symptoms of cognitive decline) develops after a confirmed motor disorder (malfunctions of the nervous system), we call the disease PDD – Parkinson’s disease with dementia.

There is no cure for this disease. However, there are medications and treatments available to control the symptoms. It is a chronic disorder and could affect for life long.

Difference between Dementia with Lewy bodies and Parkinson’s

Definition

Dementia with Lewy bodies 

Lewy body dementia, also termed as dementia (cognitive decline) with Lewy bodies (abnormal aggregations of protein that develop in the interior of the nerve cells), is the second most common type of progressive dementia (cognitive decline). Abnormal deposits of alpha-synuclein in the brain – called Lewy bodies, develop in nerve cells in the brain areas responsible for movement, thinking, and memory (motor control).

Parkinson’s

Parkinson’s disease is a disorder of central nervous system that affects movement. Symptoms start gradually, sometimes beginning with a hardly detectable tremor (shaking) in just one hand. Tremors (shaking) are common, but the medical condition also commonly results in stiff muscles, slow shuffling gait or slow movement.

Symptoms

Dementia with Lewy bodies 

Dementia

Parkinson’s

Movement problems

Onset of symptoms

Dementia with Lewy bodies 

Dementia with Lewy bodies is diagnosed if the decline in brain function – cognitive decline and symptoms in movement and muscle weakness happen at the same time, if the cognitive symptoms take place before the motor symptoms, or if a brain function decline develops less than 1 year after the motor symptoms start.

Parkinson’s

To diagnose PD’s dementia, the motor and movement symptoms, including tremors, weakness, and rigidity, need to be present at least 1 year before brain function i.e., cognitive declines develop.

Location in the brain

Dementia with Lewy bodies 

Cerebral cortex (outer layer of the brain)

Parkinson’s

Substantia nigra (located in the mid brain)

Course of disease

Dementia with Lewy bodies 

In this, the course of disease is fluctuating

Parkinson’s

In this, the course of disease is gradual

Treatment

Dementia with Lewy bodies 

  • Cholinesterase inhibitors 
  • Memantine 
  • Other medications and drugs may be prescribed to treat other associated conditions, such as depression, sleep disorders, or agitation.

Parkinson’s

Medications 

  • Carbidopa-levodopa
  • Dopamine agonists
  • Catechol-O-methyltransferase (COMT) inhibitors
  • Amantadine
  1. Physiotherapy
  2. Brain surgery

Sleep Habits

Dementia with Lewy bodies 

Dementia with Lewy Bodies often impacts sleep more significantly because Rapid Eye Movement (REM) sleep disorder, a medical condition where people physically act out their dreams as they go into slumber, is more common in the initial stages of Dementia with Lewy Bodies.

Parkinson’s

This is not the case with Parkinson’s disease.

Summary

The points of difference between Dementia with Lewy bodies and Parkinson’s have been summarized as below: