Unlike Alzheimer’s, the symptoms of LBD cannot be classified into concrete stages as it manifests differently in each person. One person might show one combination of symptoms while another person might display a different combination of symptoms. They may even fluctuate between normal and abnormal conditions from day to day, hour to hour, or even moment to moment. Overall, the symptoms of LBD can be classified into initial, core, suggestive, and supportive features. However, the central feature is the same as other dementias: progressive dementia, where memory, attention, and executive function deteriorate over time.
During the initial stages, symptoms of Lewy Body Dementia can be very similar to that of Alzheimer’s or Vascular Dementia where it involves a decline in the person’s cognition. This includes confusion, loss of memory, and poor judgment. For others, they may first show neuromuscular signs of Parkinsonism such as loss of spontaneous movement, muscle rigidity, and shuffling gait. On rare occasions, some may even experience hallucinations, delusions, or depression.
The main symptoms, or core features, of LBD include fluctuating cognition, hallucinations, and Parkinsonism. When a person has fluctuating cognition, it typically involves variations in their attention and alertness level as well as difficulty with learning new skills and impaired decision making. Often, to an outside observer it may seem like a person is ‘faking’ it, but close family and friends should be able to detect these as symptoms.
While they are not necessarily frightening, the hallucinations are usually well-formed and very detailed. It is often more pronounced when the person is most confused. There are also other modalities of hallucination including sound, taste, smell, and touch. Parkinsonism takes the form of changes in gait, where the person might shuffle or walk stiffly. They may also frequently fall. Stiffness of limbs and tremors may also occur. Other signs include Parkinson’s mask—blank stares and emotionless expression—, stooped posture, drooling, and runny nose.
The suggestive features are symptoms that could point to LBD, once other possible causes of the symptoms have been ruled out. One such feature is REM sleep behavior disorder (RBD), which can appear years before the onset of dementia and Parkinsonism itself. It is common in individuals with LBD. A person with RBD will move, gesture and even speak while in their REM sleep, leading to confusion between dreams and waking reality. Some recent studies suggest that RBD could be a significant risk factor for developing LBD.
Another suggestive feature for LBD is severe sensitivity to neuroleptic drugs, or anti-psychotics, which occurs in up to 50% of LBD patients who take them. These medications can worsen Parkinsonism, cognitive decline, and hallucinations. Lastly, low dopamine transporter uptake in the brain’s basal ganglia is also considered to be a suggestive feature.
Supportive features are those symptoms that may support the clinical diagnosis of LBD, but lack diagnostic specificity. They can also be present in other neurodegenerative disorders. Warning signs in this category includes fainting spells, unexplained loss of consciousness, severe autonomic dysfunction, hallucinations in other sensory modes, visuospatial abnormalities, and other psychiatric disturbances.
In terms of visuospatial difficulties, a person may experience difficulties with depth perception, object orientation, or lack a sense of direction. As for autonomic dysfunction, it is when a person’s autonomic system and its functioning go out of order. It can be anything from blood pressure fluctuations and heart rate variability to urinary problems, constipation, and impotence. Delusions, aggression, and depression on the other hand, are possible types of psychiatric disturbances that a person could display if suffering from LBD.
While as mentioned above, Lewy Body Dementia does not have defined stages, this infographic attempts to summarize symptoms experienced at general progressions of LBD. Symptoms in bold are more common in LBD than in other types of dementia: