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MENTAL SYMPTOMS 16 MENTAL SYMPTOMS: It is becoming clear that PD affects many parts of the brain other than centers of motor control. Specific aspects such as memory, sleep disturbance, hallucinations and psychoses have been thoroughly studied, but since PD is age- related, it's hard to know whether such symptoms are due to the disease or merely to normal aging deterioration. ATTENTION DEFICIT: Many patients (and caregivers) report difficulty concentrating on a mental task. To be sure it's a cognitive effect, one must rule out such causes as reading and eye problems. Tests do confirm that PWP are less able than normal controls to handle multiple simultaneous tasks. MEMORY: It was recently discovered that there are at least two distinct kinds of memory, which occupy different locations in the brain. That supports the idea that loss of one or another comes from localized degeneration that is typical of PD. Long-term memory of facts, such as dates, places, and events, seems to be spared in PD, but other kinds are not. Short-Term Memory: In my own lexicon, there is a sort of scratch-pad memory, which we depend on after deciding to go to the next room for some article, or for avoiding some obstacle that appears in view while walking. PWP seem more likely than usual to forget the object of a very short errand, or to bump into something which they had seen was in the way. Habit And Rote Learning: Everyone has to learn how to deal with stochastic situations without memorizing specific facts; for instance how to navigate on foot through a crowd, how to play a game of chance, habits of hygiene, and so forth. In a fascinating study, PWP were found deficient in ability to learn what amounted to new habits. Some PWP, and a group of people with confirmed amnesia, were given a short training course in a simple guessing game of chance, where the sequence of clues gave not the precise outcome but only a statistical hint. The amnesiacs forgot taking the training but did learn to play as well as normal subjects. The PWP recalled taking the training but they didn't learn from it how to play. Pattern Recognition: Learning a set of numbers or other parameters is different from learning a pattern, such as a face. In one study, PWP were not only less able to assume specified emotional expressions, but also less able to recognize such expressions on the faces of others. MENTAL SYMPTOMS (cont.) 17 SLEEP DISTURBANCE Interruption: Sleep of PWP may be interrupted in many ways. Some of the drugs commonly taken, such as Sinemet, cause insomnia because of their stimulating effect. Also, the dosage schedule may require waking up two or three times each night. Because of the brief "lift" from dopaminergic drugs, patients may report that they stay up for a half hour or so after a dose, to read or otherwise occupy themselves before returning to bed. If the dopaminergic regimen is frugal, the sleeper may be awakened by painful dystonia, usually in the leg or foot, as a reminder that the time for the next dose has arrived. Vivid Dreams: Neither PD itself nor its drugs seem to interfere with the soundness of sleep, as shown by frequent reports of vivid dreams, often with a complex plot. The dreams may result from some psychological state, but I suspect that medication drugs are the root. Violence: Researchers have collected many reports that PWP punch, kick, or shove their bed partners while in deep sleep. It may come from the medications, as do the dreams. HALLUCINATIONS: These are a mild form of delusions, reminding that some PD drugs may cause genuine psychosis in certain patients. It is also noted that dementia of many forms may occur in advanced stages of PD, particularly in elderly patients who are more susceptible. Visual: Visual hallucinations are a common side effect of some PD medications, and can be troublesome enough to force discontinuance of a drug. The effect seems to vary widely, with patients having different susceptibility to different drugs. Therefore the recourse is to try various drugs until one having similar therapeutic benefit is found to be tolerable. Auditory: Not all hallucinations are visual; auditory hallucinations are often reported, but seldom by patients who don't also have visual hallucinations. At one time during the course of my own loss of smell sensitivity, I had olfactory hallucinations- unfamiliar odors that I could not identify and no one else could detect. MENTAL SYMPTOMS (cont.) 18 DEPRESSION: When a patient has PD, there is no guarantee of immunity from any other neurological dysfunction. Depression is very often diagnosed along with PD, and when found is considered to place the subject in a different category, for such purposes as a research program. I perceive two basic kinds of depression: so-called clinical depression, which is even more common in absence of PD, and the short-term mood swings that are exclusively related to PD. Clinical Depression: This illness is beyond the scope of the present discussion, except to say that it is now treatable very effectively in many cases by drugs alone. Unfortunately for PWP who also suffer clinical depression, some of those drugs have serious, potentially fatal, interaction with certain drugs used to treat PD. Clinical depression may be distinguished from the mood swings of PD by its very long development time, and of course by its lack of response to drugs used for PD. Mood swings, in contrast, are brief and sudden, and response to the usual antidepressant drugs may be disappointing. Mood Swings: The reason why cocaine, nicotine, and chocolate evoke psychological dependence is that they all contain elements that bind to dopamine receptors related to the sensation of pleasure. No surprise then, that dopamine itself has a similar effect. I'm not clear how the effect can be virtually instantaneous, since dopamine by mouth has to go a long way to enter the brain, but it's true. PWP in the fluctuation stage very often feel depressed as their levodopa dose nears exhaustion, and get a quick lift immediately on taking the next dose. This is so common that the onset of gloomy thoughts may serve as an indicator of the best dosage interval. It seems that many patients and doctors don't recognize the difference between this short-lived depression and true "clinical" depression, and therefore choose antidepressants such as Prozac or Zoloft, which may not be really needed. In contrast to clinical depression, the mood swings from fluctuating dopamine supply are not nearly so severe, and are quick to come and go. The depression may arrive within seconds, like a big wave on the seashore, and recede within a few more seconds, after taking the next scheduled dopamine-enhancing medication. BRADYPHRENIA (Slow Or Impaired Reasoning): Another phenomenon that has generated much research and debate, on whether it is a true symptom of PD, or (since most PWP are middle-aged or older) merely the result of "normal" aging. Scientific opinion presently is about evenly divided. It's easy to test thinking speed, the hard part is to prove where any such effect originates. (This completes the file) Cheers, JOe -- J. R. Bruman (818) 789-3694 3527 Cody Road Sherman Oaks, CA 91403-5013