Cognitive Problems in Lewy Body Dementia
Diffuse Lewy Body disease (DLBD), also known as dementia with Lewy Bodies (DLB) or Lewy Body Dementia (LBD) is a progressive brain disorder that often presents with dementia and parkinsonian symptoms including stiffness, akinesia, slow shuffling gait. Other early features of DLB can include fluctuating mental status (waxing and waning of mental status during the daytime such that the person appears confused, disoriented, lethargic or drowsy, and staring off into space), visual hallucinations, delusions, and dysautonomia. In DLB there is a diffuse distribution of Lewy bodies throughout the brain. It shares symptoms, and sometimes overlaps, with several diseases, especially Alzheimer’s disease (AD) and Parkinson’s disease (PD). More than 1 million people in the U.S. are affected by Lewy body dementia, according to the Lewy Body Dementia Association.
People who develop DLB can have cognitive (thinking and memory) and behavioral symptoms similar to those of Alzheimer’s disease and, to varying extents, to the motor and non-motor symptoms seen in Parkinson’s disease.
People with Lewy body disease presenting with primarily parkinsonism are thought to have PD or PD-Dementia (with primarily autonomic features have Primary autonomic failure) and those with primarily cognitive deficits are thought to have DLBD/DLB. However, there are some contrasts to these conditions. The cognitive symptoms of a person with DLB might fluctuate from hour to hour or day to day, and attention and alertness may wax and wane. The motor symptoms may be similar to those features seen in Parkinson's but their severity and treatment response may differ. While people with PD may develop dementia, it has traditionally been viewed as occurring late in the disease course. Meanwhile, people with DLBD/DLB tend to develop dementia within the first year of having parkinsonian motor symptoms. Indeed, people diagnosed with DLBD often present first with neuropsychological deficits, and then develop parkinsonian symptoms.
Two of the distinguishing symptoms of DLB from Alzheimer’s disease include vivid visual hallucinations, particularly early in the course of the disorder, and a sleep disorder in which the person physically acts out his/her dreams, called REM sleep behavior disorder (RBD). People with DLBD/DLB exhibit greater deficits in attention/working memory and visuoperceptual functions compared to Alzheimer’s disease.
The neuropsychological deficits in DLBD/DLB tend to result in marked deficits in attention/executive and visuoperceptual/visuoconstructional functions. Impairments in memory are typically mild early in the course of the disease but they can progressively worsen faster than what is classically associated with PD/PD-D. Memory deficits tend to be due to inefficient encoding. Language deficits are not pronounced early in DLB, but impaired fluency and confrontation naming do develop. Phonemic and semantic verbal fluency may be impaired. Mood symptoms of DLBD/DLB can be pronounced early in the course of the disease, with hallucinations and delusions.
A recent study in Neurology examined whether the cognitive profiles in DLB/LBD and Parkinson's disease dementia (PD-D) differ. The results from their study revealed that both DLB and PD-D were more "impaired and declined more rapidly than AD in the visuospatial domain." Patients with PD-D exhibited the most impairment and fastest decline in executive tasks, although patients with DLB also declined faster on executive tasks than AD. The researchers also noted that "memory was more impaired in AD than DLB and in both compared with PD-D; however, all 3 groups declined at comparable rates." In contrast, PD-D declined at a slower rate on language tasks than DLB/LBD or AD. The researchers stated that their power analyses "suggest that visuospatial and executive outcome measures would be most sensitive in PD-D, but memory and language in DLB."
If you are concerned about DLB/LBD please consult with your medical doctor for further evaluation. They can then begin a medical work-up that includes physical and neurological examinations and tests to distinguish DLB/LBD from other disorders. This work-up may include:
Medical history and examination – A review of previous and current illnesses, medications, and current symptoms and tests of movement and memory give the doctor valuable information.
Medical tests – Laboratory studies can help rule out other diseases and hormonal or vitamin deficiencies that can be associated with cognitive changes.
Brain imaging – Computed tomography or magnetic resonance imaging can help detect brain shrinkage or structural abnormalities and help rule out other possible causes of dementia or movement symptoms.
Neuropsychological tests – These tests are used to assess memory and other cognitive functions and can help identify affected brain region
If you live in the New Jersey or New York area and would like to schedule a neuropsychological evaluation for yourself or a family member in order to determine if there have been any potential cognitive changes that would be atypical or unexpected for your age please contact Dr. Corey Burchette at 201-577-8286 to inquire about scheduling an appointment at the New Jersey Memory Center which is located in Verona, New Jersey. Easily accessible from many points in North Jersey (including Montclair, Upper Montclair, Cedar Grove, Bloomfield, Glen Ridge, Caldwell, West Caldwell, North Caldwell, Totowa, Wayne, Little Falls, West Orange, Maplewood, Livingston, and many more).