Diagnosis of Lewy Body Dementia
No single test can be used to definitively diagnose Lewy Body Dementia. Currently, Lewy bodies can only be identified through autopsy. Therefore, the process of diagnosis is similar to that of diagnosing Alzheimer's Disease and is designed to rule out other possible causes of a person's symptoms.
A thorough diagnostic evaluation will include physical and neurological examinations (with associated laboratory tests), patient and family interviews (including a detailed medical and medication history), and psychological/psychiatric and neuropsychological testing. Click here to return to our previous in-depth discussion of each of these components of a diagnostic workup. In addition, brain imaging (CT, MRI, PET or SPECT) scans may be performed.
The following tests may be used in a psychological/psychiatric evaluation:
- The Geriatric Depression Scale (GDS) - The GDS is a screening instrument used to detect depression among older adults (click here to return to our previous discussion of this instrument). Clinicians may use it to help determine whether depression coexists with Lewy Body Dementia.
- Mental status exam - As described before, mental status exams assess memory, concentration, and other cognitive skills. Interestingly, some people who meet the diagnostic criteria for LBD will score in the "normal" range of some cognitive screening tools such as the MMSE (described previously, click here to return to that discussion). As we mentioned in the discussion on Alzheimer's disease, relying solely on an MMSE score to confirm (or discard) a diagnosis is inappropriate.
- Neuropsychological testing - As described earlier, neuropsychologists adminster tests that allow them to better understand a person's particular pattern of cognitive impairment and preserved abilities. Neuropsychologists assessing someone for LBD will give particular consideration to attention, concentration, and visuospatial skills, particularly in the early stages of the illness when memory problems may not be detected.
Treatment for Lewy Body Dementia
Lewy Body Dementia is very difficult to treat. Unfortunately, people with this illness often cannot tolerate antipsychotic medications, which might otherwise be helpful in treating symptoms like delusions and hallucinations. Negative reactions to antipsychotic medications can include a worsening of symptoms, extreme muscle rigidity, or even catatonia - which can take the form of apathy and complete motionlessness or constant overexcitement. In addition, as discussed before, people with LBD who use antipsychotic medications may develop a serious and potentially life threatening condition called Neuroleptic Malignant Syndrome.
Medications: No drugs have been approved by the FDA to specifically treat Lewy Body Dementia, but Alzheimer's medications are sometimes helpful. In fact, some researchers assert that people with Lewy Body Dementia respond better to cholinesterase inhibitors (drugs that increase the level of acetylcholine in the brain, such as donepezil, rivastigmine, or galantamine; click here to return to our discussion of these medications) than individuals with any other type of dementia.
Because Parkinsonian symptoms are prevalent in Lewy body dementia, medications used for Parkinson's Disease (e.g., Sinemet) which boost the production and effectiveness of the neurotransmitter dopamine (click here to return to our discussion of how this brain chemical plays a role in LBD) are often used to treat movement symptoms. However, they can also increase confusion, delusions, and hallucinations.
Antidepressants (medications typically used to treat mood disorders such as depression and problems with anxiety) and anticonvulsants (medications typically used to treat seizure disorders) are sometimes used to treat the sleep and mood problems associated with Lewy Body Dementia, but they can also increase a person's level of confusion and motor problems.
Other treatments: Behavior management strategies - which are discussed in more detail later - are also useful for managing the difficult behavioral symptoms of Lewy Body Dementia.
Specific lifestyle changes may also help manage symptoms of LBD. Reducing caffeine intake, increasing physical activity during the day, and providing relaxing activities in the evening can improve sleep patterns and reduce the incidence of violent outbursts during the night while a person is sleeping.
Prognosis for Lewy Body Dementia
Unfortunately, there is currently no cure for Lewy Body Dementia. The average life expectancy for people with LBD after the onset of symptoms is 5 to 8 years. However, individuals with Lewy Body Dementia have lived anywhere between 2 and 20 years depending on their age, the severity of their symptoms, and their other medical conditions.
The course of Lewy Body Dementia can vary across people, but is usually "progressive but vacillating." In other words, across time, people decline, but there may be periods of return to a higher functioning level. This decline may be exacerbated by medications and/or infections/diseases.