Joined: Fri Aug 11, 2006 1:46 pm
Location: SF Bay Area (Northern CA)
Cognition and PD - Webinar Notes (from 3/22/11)
The Parkinson's Disease Foundation hosted a webinar on Tuesday on "Cognition and PD."
You might skim the notes that I took below, starting with a section called "Treating Cognitive Dysfunction in Parkinson's Disease." There's a useful list of things that can be done in "Helping the Parkinsonian with Cognitive Changes." (In this context, "Parkinsonian" means person with Parkinson's Disease.) The Q&A may be of interest.
I imagine the archive of this webinar will be posted to the Parkinson's Disease Foundation website (pdf.org) in a couple of weeks. You can listen to it then.
Parkinson's Disease Foundation Webinar
Cognition and PD: What You've Always Wanted to Know But Were Too Afraid to Ask
Presented by Alexander Troster, PhD, Neuropsychologist
University of North Carolina, Chapel Hill, NC
"I Thought Parkinson's Disease is a Movement Disorder"
* PD is a movement disorder BUT
* PD can also produce non-motor problems -- cognition, emotion, sleep, speech, dysautonomia (constipation, blood pressure, sweating)
What is Cognition?
* Processes by which we "know" about, and apply knowledge to the world around us
* Memory and association or learning
* "Executive functions": concept formation and problem solving, planning, and monitoring of actions. Analogous to the functions of an executive in a company.
* Imagery and spatial processes
What is Dementia?
* Dementia is a very broad label
* Does NOT necessarily mean the person has Alzheimer's Disease
* Involves decline in multiple mental abilities leads to decline in functioning (home and work), and changes in social function
How Common are Problems with Mental Abilities in PD?
* Early changes neglected until recently
* About 25-40% of persons with PD have cognitive changes detectable *by careful testing* at time of diagnosis
* Mild changes may not be noticeable to self or others
* The best studies suggest about 30% of persons with PD have more severe problems or dementia
Changes in Cognition and Mild Cognitive Impairment
Cognitive Problems Sometimes Seen in Early Parkinson's Disease
* Coming up with words
* Slowness in thinking. (Some with YOPD who are still working mention this problem.)
* Remembering: learning and retrieving information [getting something into the filing cabinet, organizing it well, and getting it out of the filing cabinet], and forgetting intentions
* "Executive functions": planning; anticipating consequences; making decisions; problem-solving
A Transition in Thinking about PD Cognitive Impairment (from Troster, 2011) - a diagram
* We used to think of PD without dementia and PD with dementia.
* Now we think of PD without cognitive impairment, PD with mild cognitive impairment, and PD with dementia
* We are considering whether there is PD with cognitive prodrome before PD with mild cognitive impairment.
Possible Advantages of MCI Diagnosis in PD
* Early detection and treatment of cognitive decline and consequent enhancement of functioning
* Evaluation of dementia with Lewy bodies (DLB)/Parkinson's disease with dementia (PDD) distinction. Are these the same thing? If we study MCI early on, it might help answer this question.
* Greater precision in identifying course of cognitive decline, risk factors for these declines, and underlying mechanisms
Evaluation and MC Subtypes - a diagram
If there is cognitive impairment given the relative age of the person, they are often given a detailed neuropsychological evaluation. If there the cognitive impairment unrelated to the relative age of the person, then we ask if there's functional decline. If there is functional decline, then a dementia workup is done. If there is no functional decline, neuropsychological evaluation is done.
MCI Criteria for PD
* Unclear how MCI should be defined in PD
* Movement Disorder Society has Task Force to define diagnostic criteria. Will likely be published later this year or next year.
* Troster has proposed research criteria: subjective report or observation by health professional of cognitive problem; cognitive decline occurs at time of or after motor symptom onset; intact, perhaps more effortful, day-to-day function (eg, with balancing the checkbook and other financial management); deficit or decline on cognitive testing
Mild Cognitive Impairment in PD
* MCI is present in 15% to 62% of PD, with most reports in the 20-30% range
* In PD, MCI in a single domain is more common than multiple domains
* Executive function or attention seems to be the most common domain affected in PD
* Executive/attention, perceptual, and to a lesser extent, memory impairments are associated with higher risk of dementia
Causes of Cognitive Changes in Early Parkinson's Disease
* Changes in brain chemicals: dopamine (working memory, executive functions); acetylcholine (episodic memory, executive functions); norepinepherine (attention and arousal)
Acetylcholinesterase Activity Reduction: PD, PDD, DLB (from Klein et al, Neurology, 2010) - images
Significant reduction of cholinergic transmission in PDD as compared to PD or DLB
Causes of Cognitive Changes in Early Parkinson's Disease - continued
* Medical illness or other brain disease
* Depression and nervousness
* Medication and surgery. (It doesn't have to be brain surgery.)
Medications and Cognition
* Dopamine replacement: little effect on cognitive functions except perhaps a mild, transient benefit on working memory and planning early in the disease. There is something called the "overdose hypothesis."
* Anticholinergic drugs, eg, trihexyphenidyl (used to treat tremor) can affect cognition
* MAO-B inhibitor selegiline's protective effect against mental decline is questioned. There is no convincing evidence of a major cognitive impact of rasagiline in humans.
Effects of Surgical Treatment
* Bilateral ablation (eg, pallidotomy) can negative affect executive function, language and memory
* Deep brain stimulation appears to be relatively safe, but changes in word production are common, and occasionally changes in memory and executive function occur. These changes are mild.
Treating Cognitive Dysfunction in Parkinson's Disease
Cholinesterase Inhibitors and Other Agents
* Can slow progression of cognitive decline and improve psychosis
* Donepezil and Galantamine are used in Alzheimer's Disease
* Rivastigmine is the only FDA-approved medication for use in Parkinson's Disease
* Recent study of Namenda, a glutamate NMDA antagonist. It was found to be more helpful in those with DLB than in those with PDD.
* Other agents: there is limited evidence that methylphenidate and modafinil are helpful
Helping the Parkinsonian with Cognitive Changes
* Prompt recognition rather than expecting recall
* Cue attention by calling their name. Make eye contact.
* Cue word with initial sound of word. Example: "the word you are looking for probably begins with the sound du-" when you know the person is thinking of the word dictionary.
* Medication dispenser
* Alarm or personal digital assistant
* Verbalize sequence of actions -- write the sequence down
* Do NOT finish sentences for the person with PD
* If the person has trouble conversing, pace conversations by asking questions
* Photos on cell phones for face-name association
* Practice new memory strategies, such as bizarre images. (Example: imagine a grocery store with a huge chicken, dropping an egg with a tomato on top when you need to buy chicken, eggs, and tomatoes.)
* Write lists
* Put things in a routine place
* Reminder notes in prominent places such as the refrigerator door and bathroom mirror
* Use memory manuals
When and How to Seek Help for Cognitive Problems
What to Do When One Notices Mental (or Emotional) Problems
* Discuss with your doctor
* Seek referrals, if needed to psychiatrist, neuropsychologist, speech therapist, occupational therapist
* Try not to tell yourself "I will get over it," "It's too mild to worry about," "It must be Alzheimer's," or "I must be crazy"
When to Seek Professional Help
* If changes are bothersome to the patient
* If they distress the family. Arguing is a sign of distress to the family.
* Changes in ability to carry out day-to-day tasks
* Problems at work keeping up with tasks
* Sudden change in mental functions. These are not related to PD, usually, but are related to medication or illness.
* Certain treatments (for example, deep brain stimulation) are being considered
* If the person is depressed or withdraws
* If a person experiences hallucinations
Question & Answer
Q: Do word recovery problems occur in both speaking and writing?
A: Word retrieval problems usually occur in both speaking and writing. Small exception - sometimes people develop motor-speech problems, which are not word retrieval problems; these are only seen in speech, of course.
Sometimes word recovery problems are milder in writing, but they are qualitatively similar to those in speaking.
Q: Any connection between cognitive problems in PD and sleep problems in PD?
A: Sleep disorders, since they impact sleep, can lead to the feeling of being less rested and less alert.
RBD (REM sleep behavior disorder) is where dreams are acted out. There may be an association between RBD and cognitive problems.
Sleep apnea can affect cognitive functioning. Reversible if one treats the sleep apnea with CPAP.
Q: Any connection between B12 deficiency and cognitive problems?
A: B6 and B12 are important to cognition. This isn't specific to PD. If you have cognitive problems, one of the first thing an MD will check is your vitamin B level.
Q: Does mild cognitive impairment always progress to dementia, and how fast?
A: We don't have an answer yet in PD. We are only now coming out with formal diagnostic criteria for MCI in PD.
For amnestic MCI, 30-40% of people develop dementia. Whether this same percentage will hold true in PD, we don't know.
In 10% of PD patients, people progress in 3-4 years to having dementia.
Q: Does exercise help cognition?
A: No trial has been done so far. From studies in normal aging, we see that aerobic exercise is protective against cognitive decline. Patients who get aerobic exercise decline less. This likely also holds true in PD.
Q: Any association between cognitive decline and hallucinations?
A: Those with hallucinations are more likely to develop dementia. These people are more likely to have greater susceptibility to dopaminergic medications. Medications must be ruled out as a cause of hallucinations before medications are added to treat hallucinations.
Q: Any association between depression and cognitive decline?
A: Depression can be well-treated. The most potent predictor of quality of life is depression. It is a far better predictor of QoL than movement symptoms in Parkinson's Disease. So treatment is important due to the quality of life issue. Depression increases the risk for dementia and disability down the road. Depression can lead to faster disability and dementia.
Q: What about cognitive problems and DBS (deep brain stimulation)?
A: If you have dementia, most centers will not do DBS. An issue is that the person cannot properly operate the device.
No agreement on DBS for those with MCI. Verbal fluency declines post-surgery are probably more likely to happen in those with more severe MCI. Most centers don't exclude those with mild MCI from getting DBS.
1-2% of DBS patients have moderate or severe cognitive changes. These changes made be related to the placement of electrodes in brain, complications during the operation (eg, brain bleed), or complications after the operation.
Very common for DBS patients to have word finding inefficiency. Most patients are willing to trade improved motor abilities with word finding inefficiency. In his career, only one or two patients have wanted better word finding ability and worse motor abilities.
Q: Do computer games help?
A: Some computer games are usual especially if they are visually demanding, and if time to complete a game is tracked. This can improve attention.
Q: [Didn't hear the question.}
A: Common issue: MD is almost as afraid to address cognitive decline as the patient is to ask. "Physician collusion" is where the MD colludes with the patient to ignore the problem.
Most MDs wait until cognitive problems are obvious. It's best if patients bring up the topic and ask for a referral to a specialist.
Q: Does one need to have a special sequence of tests?
A: There doesn't need to be a special sequence of neuropsychological tests. These tests are demanding. Many people find them stimulating. It's best to have these tests early on so that we have a baseline. Subtle changes are easier to detect if there's a baseline test.
We may wonder if cognitive changes are due to PD or medications. It's easier to answer this question if there's a baseline test.
Q: Is there new research going on in this crucial area?
A: The hope is one day that we'll have an agent (gene therapy, etc) for cognitive function or a good test to detect cognitive function. A more immediate hope is about increased funding. Funding is critical. There's been a dearth of funding on the cognitive aspects of PD.