What is Lewy Body Dementia? – Causes and Symptoms

Lewy Body Dementia (LBD) is a progressive neurological disorder that affects cognitive abilities, movement, and behaviour.

It is the second most common type of dementia after Alzheimer’s disease and is caused by abnormal protein deposits in the brain known as Lewy bodies. These deposits disrupt normal brain function, leading to a decline in memory, reasoning, and motor control.

Despite its prevalence, LBD is often misdiagnosed, as its symptoms overlap with other neurological conditions such as Parkinson’s disease and Alzheimer’s.

Causes of Lewy Body Dementia

The exact cause of Lewy Body Dementia is not fully understood, but it is linked to the presence of Lewy bodies, which are abnormal clumps of a protein called alpha-synuclein. These deposits accumulate in areas of the brain responsible for cognitive functions, motor control, and behaviour. Although the precise reason for their formation is unknown, researchers believe several factors may contribute to the development of LBD:

1. Genetic Factors

While LBD is not typically inherited, certain genetic mutations may increase the risk. Studies suggest that individuals with a family history of Parkinson’s disease or dementia may have a slightly higher likelihood of developing LBD.

2. Age and Gender

LBD primarily affects older adults, typically over the age of 60. Men are more likely to develop the condition than women, although the reasons for this gender difference are still being studied.

3. Neurological Conditions

People with Parkinson’s disease are at a higher risk of developing LBD, as both conditions share similar characteristics, including the presence of Lewy bodies in the brain.

4. Environmental and Lifestyle Factors

Exposure to toxins, head injuries, and lifestyle habits such as poor diet and lack of physical activity may contribute to the risk of developing LBD, although more research is needed to establish a definitive connection.

Symptoms of Lewy Body Dementia

The symptoms of LBD vary from person to person and often progress over time. The condition is characterised by a combination of cognitive, motor, and behavioural symptoms, making diagnosis challenging.

1. Cognitive Decline

Memory loss in LBD may not be as severe in the early stages as in Alzheimer’s disease, but individuals experience difficulties with attention, problem-solving, and decision-making. Fluctuations in cognitive abilities are a key feature, with some days appearing normal while others are marked by severe confusion.

2. Hallucinations and Delusions

Visual hallucinations—seeing things that are not there—are one of the early symptoms of LBD. These hallucinations can be vivid and detailed, often involving people or animals. Delusions, such as paranoia or false beliefs, may also occur.

3. Motor Symptoms

LBD shares many symptoms with Parkinson’s disease, including muscle stiffness, tremors, slow movement (bradykinesia), and balance problems. These symptoms can lead to frequent falls and mobility issues.

4. Sleep Disorders

People with LBD often experience REM sleep behaviour disorder (RBD), which causes them to act out dreams, sometimes violently. Insomnia and excessive daytime sleepiness are also common.

5. Autonomic Nervous System Dysfunction

LBD can affect the autonomic nervous system, leading to symptoms such as low blood pressure (causing dizziness or fainting), digestive problems, urinary incontinence, and irregular heart rate.

6. Mood and Behavioural Changes

Depression, anxiety, aggression, and apathy are frequent in individuals with LBD. Mood swings and changes in personality can make caregiving challenging for families.

Conclusion

Lewy Body Dementia is a complex and progressive disorder that affects cognitive, motor, and behavioural functions. While its exact cause remains unclear, factors such as genetics, age, and neurological conditions may contribute to its development. Early symptoms, including cognitive fluctuations, hallucinations, and motor impairments, often lead to misdiagnosis. Understanding these symptoms can help in seeking timely medical intervention, improving quality of life for both patients and caregivers.