What is Dementia with Lewy Bodies?

Dementia with Lewy Bodies (DLB) is a progressive brain condition that affects thinking, movement, behavior, and the autonomic nervous system. It is characterized by abnormal protein deposits in the brain, known as Lewy bodies, which disrupt normal brain function.

Why Dizziness Occurs in DLB

Dizziness is a frequent and often distressing symptom in Dementia with Lewy Bodies. It can arise from several mechanisms, including:

• Autonomic dysfunction, which impairs the body's ability to regulate blood pressure and heart rate
• Orthostatic hypotension, a sudden drop in blood pressure caused by standing up or changing position
• Parkinsonism-related stiffness and postural instability, which can make balance feel precarious
• Side effects of medications used to treat hallucinations, movement symptoms, or cognitive decline
• Sleep disturbances and fatigue, which may contribute to a general sense of light-headedness

Orthostatic Hypotension and DLB

Among the most common causes of dizziness in DLB is orthostatic hypotension. In this condition, the autonomic nervous system fails to adequately constrict blood vessels when a person stands. Blood pools in the lower limbs, leading to reduced blood flow to the brain. Symptoms may include light-headedness, blurry vision, weakness, a feeling of faintness, or even fainting. These symptoms typically appear within seconds or minutes of rising from sitting or lying down.

The Impact of Falls

Dizziness in DLB significantly increases the risk of falls. Because DLB already affects balance and coordination, episodes of dizziness can make falls more likely and more dangerous. Falls can lead to fractures, head injury, hospital admission, and a loss of independence. Recognizing dizziness as a serious and treatable symptom is an important part of DLB care.

Medication and Autonomic Worsening

Certain medications can make dizziness worse in DLB. Antipsychotic drugs, sometimes prescribed for visual hallucinations, may exacerbate autonomic dysfunction and orthostatic hypotension. Similarly, antiparkinsonian agents can lower blood pressure in some individuals. A careful and gradual medication review is often necessary to balance the benefits for cognition and behavior against the risk of worsening dizziness.

Diagnostic Clues in DLB-Related Dizziness

Dizziness in DLB is often accompanied by other distinctive features, including:

• Recurrent visual hallucinations, typically well-formed and detailed
• Fluctuating attention, alertness, or cognition
• Parkinsonism, such as slow movements, tremor, or rigidity without tremor at rest
• Rapid eye movement (REM) sleep behavior disorder, in which individuals act out vivid dreams
• Severe sensitivity to antipsychotic medications

When dizziness appears together with these changes, it adds weight to the clinical diagnosis of DLB, particularly if other causes have been excluded.

Evaluation of Dizziness

Many underlying causes of dizziness are reversible or manageable. A structured assessment may include blood pressure measurements while lying, sitting, and standing; heart rhythm monitoring; blood tests; and review of all prescribed and over-the-counter drugs. The evaluation also helps to rule out stroke, cardiac disease, dehydration, or inner ear disorders, which may coexist with DLB.

Management and Prevention Strategies

Although DLB is a progressive condition, dizziness can often be improved. Practical strategies include:

• Rising slowly from a sitting or lying position and pausing before walking
• Maintaining adequate hydration and, if tolerated, increasing daily fluid intake
• Using compression stockings to prevent blood pooling in the legs
• Elevating the head of the bed slightly to reduce morning dizziness
• Eating smaller, more frequent meals to limit postprandial hypotension
• Avoiding alcohol and hot environments, which are known triggers
• Performing physical therapy or structured exercise to improve strength and balance
• Reviewing the timing and dosage of medications with a healthcare professional

In some cases, medication may be prescribed to raise blood pressure or to support autonomic function. However, such treatment must be tailored carefully to the individual, given the complex nature of DLB.

When to Seek Urgent Medical Attention

Not every dizzy spell is an emergency, but attention is needed if dizziness is accompanied by chest pain, palpitations, shortness of breath, severe headache, sudden weakness, difficulty speaking, or a change in vision. A sudden loss of consciousness also warrants immediate medical assessment. For people with DLB, a fall can be the first sign of an underlying cardiac or neurological issue that requires prompt investigation.

Living with DLB and Dizziness

A diagnosis of dementia with Lewy bodies poses many challenges, and dizziness adds an extra layer of difficulty for the person and their family. It is helpful to make the home safer by removing trip hazards, improving lighting, and installing grab bars near the toilet and shower. Educating caregivers about orthostatic hypotension is equally important, so they can assist the person in standing gradually and recognize warning signs of an imminent fall.