Less Common Symptoms of Lewy Body Dementia

Some of the less common symptoms of Lewy body dementia (LBD) can cause significant concerns for the person with the disease, as well as their caregivers. Knowing the possible symptoms of LBD can help alleviate stress and provide a better treatment plan when they do develop.

First, we'll review the more typical symptoms of LBD and then we'll identify the less common symptoms.

Common Symptoms

Cognitive Changes

Unlike Alzheimer's disease where memory challenges are one of the hallmark features, LBD more commonly presents with difficulties in attention and executive functioning.

Hallucinations and Delusions

Visual hallucinations are the most common type of hallucinations in LBD, and can often be one of the earlier symptoms of the disease. Other kinds of hallucinations, such as auditory, in addition to delusions, are also common in LBD.

Physical Difficulties

Physical symptoms in Lewy body dementia may involve difficulty moving the limbs or a feeling of stiffness in the limbs, which is very similar to what someone with Parkinson's disease may experience. Other features which might also be seen are stooped posture, a lack of facial expression, and a change in walking pace and gait (how the legs function and walk).

Fluctuations in Cognitive Ability

This is one of the classic symptoms of LBD—the differences in functioning from day to day or even from minute to minute. One day the person with this disease might recognize you and greet you by name; the next day, you may appear only vaguely familiar to them.

Reactions to Antipsychotic Medications

Hallucinations are common in LBD; however, some of the medicines that are classified as antipsychotic medications typically prescribed to treat hallucinations can trigger severe and sometimes life-threatening reactions in people who have LBD.

According to the Lewy Body Dementia Association, approximately 25-50% of people with LBD may respond negatively to these medicines. Thus, early diagnosis and appropriate treatment are both critically important in LBD.

Less Common Symptoms

Episodes of Fainting or Loss of Consciousness

Episodes of fainting or loss of consciousness is due to dysautonomia (dysfunction in the autonomic nervous system). Someone affected by this can have very low blood pressure, which leads to dizziness, fainting spells and loss of consciousness when they stand up quickly. They can also develop supine hypertension, meaning that when they are lying down, the blood pressure will increase significantly. 

Visuospatial Changes

Sometimes, people with LBD experience changes in how they see or interpret their surroundings. Things may appear distorted, they may have difficulty in judging distance or location of objects or they may get disoriented and lost easily in familiar locations.

REM Sleep Disorder

During normal REM sleep, an individual develops paralysis of muscles which prevents the body from acting out during the dream stage. People with LBD lose this ability and they "act out" during dreams. This can produce sounds and abnormal movements to the point that they can fall out of bed.

Autonomic System Disorders

Autonomic dysfunctions can include significant changes in blood pressure, heart issues, erectile dysfunction, dizziness, falls, incontinence, constipation, temperature regulations, and swallowing difficulties.

For example, one reason people with LBD may fall more frequently is a drop in blood pressure when they go from a sitting to a standing position. This is called orthostatic hypotension and it can be helped by being aware of this potential condition and asking the person with LBD to sit on the edge of the bed for a few seconds before slowly and cautiously rising to a standing position.

Capgras Syndrome

Experts estimate that about 17% of people with LBD experience Capgras syndrome, a condition where they believe that their caregiver or family member is an imposter. This symptom, along with other delusions, can be a challenging one for both the person with LBD and their loved ones.

A Word From Verywell

When you're coping with Lewy body dementia, it can be very helpful to educate yourself on the various symptoms that go along with the disease. This can help prepare you ahead of time and also reduce worries when new symptoms develop. Knowledge of these less common symptoms could also help point to a diagnosis of Lewy body dementia if there's a question about what's causing your challenges in functioning and you have not yet been diagnosed.