Wednesday, November 20, 2013

Response to Levadopa not proof of Parkinson's

An old article (2006), but it makes an interesting point or two about PD diagnosis.

Highlights: If movement problems don't lessen significantly with doses of the drug levodopa, sold under the brand name Sinemet or apomorphine, other neurologic disorders should be strongly considered. However, 30 percent of patients who do respond well to levodopa actually have a disorder other than Parkinson's. Levodopa restores levels of dopamine in an area of the brain that controls movement.

Parkinson's often misdiagnosed 


Neurologists submit guidelines to identify movement disorder

By Cheryl Clark

April 3, 2006

As many as 200,000 of the estimated 1 million people in North America who learn they have Parkinson's disease, a progressive disorder marked by tremors and slow movement, may be misdiagnosed because the condition requires special expertise to recognize and treat.

They instead may have ailments with a far better prognosis, such as actress Katharine Hepburn's head tremor, or recurring strokes that may be treatable. But typically, they have diseases much more serious and aggressive than Parkinson's, such as supranuclear palsy or multiple system atrophy.

NANCEE E. LEWIS / Union-Tribune
Dr. David Song conducted tests on Parkinson's patient Ann Maier last week at UCSD's ThorntonHospital. Maier frequently monitors the disease's progression.

Likewise, the academy said 5 percent to 10 percent of people who complain of tremors and stiffness have Parkinson's, but are told they have something else, such as arthritis.

"From my experience, (these) patients are often told they have tendinitis, frozen shoulder, or 'you're just getting older, dear,' (or) 'You slept on your arm wrong,'" said Dr. Janis Miyasaki. "I've heard the most amazing things."

This key message about misdiagnosis was issued today by theAmerican Academy of Neurology as part of its first comprehensive set of recommendations to doctors and patients on how to detect and treat Parkinson's disease. Miyasaki was one of 20 movement-disorder neurologists who wrote the guidelines.

The recommendations, published as four reports in the journalNeurology, were released as 10,000 neurologists and others attended the academy's annual meeting at the San DiegoConvention Center. The conference will last through Saturday.

"It's important for patients who have these symptoms to see a neurologist, and, if possible, a movement disorder specialist, because we have more experience in diagnosing these problems," said Dr. Oksana Suchowersky, lead researcher for two of the papers and director of movement disorders at the University of Calgary in Canada.

Parkinson's disease

Movement problems occur because of reduced levels of dopamine,a neurotransmitter that enables smooth and coordinated musclemovement. Signs that such a deficit is causing Parkinson's include:

Patient improves after taking the drugs levodopa or apomorphine.

Shaking or tremors affect limbs on only one side of the body.

Walking turns into a shuffle.

Movements are slow.

Patients experience problems with balance.

Handwriting becomes small and cramped.

Ability to show facial expression is diminished.

Speech becomes soft andmuffled.

Symptoms progress steadily, not rapidly.

Source: American Academy of Neurology

Far too many people are being wrongly diagnosed by family practice physicians or other doctors who don't see Parkinson's disease that often, said Suchowersky and the other reports' authors.

Ann Maier, 60, ofEscondido is an example of how Parkinson's can sometimes be misdiagnosed. Maier, a high school gym teacher for many years, told her primary care doctor that her right arm had gradually started to shake.

"It wouldn't swing properly," she said, "and my handwriting changed so much. I couldn't read my own hen-scratch grocery list. And I was walking differently. But one side of my body was affected more than the other."

During several visits over 18 months, she said, the doctor blamed her problems on a condition known as benign essential tremor.

It took two years before she was referred to a neurologist, who diagnosed her with Parkinson's. Now, her disease is well managed with appropriate drugs, and she sees a neurologist to frequently monitor Parkinson's progression.

Parkinson's symptoms

While the guidelines might raise suspicion among patients that they won't be properly diagnosed, there is probably no need to switch doctors as long as the one providing treatment is a neurologist, Miyasaki and Suchowersky said.

"But you can ask your neurologist if he or she is sure of the diagnosis. And any doctor who treats Parkinson patients should re-review their patients' histories as they follow them every year or two," Suchowersky said.

About 50,000 people are diagnosed with Parkinson's each year based on clinical symptoms, whether they respond to drugs or show signs of the disease's progression.

"Baby boomers are aging, and with that, we're going to see more Parkinson disease," said the academy's guidelines director Dr. William Weiner, chairman of neurology at the University of Maryland School of Medicine in Baltimore.

Because a large percentage of patients with diseases that mimic aspects of Parkinson's have a more dire prognosis, he said, it's important that people be diagnosed correctly so they can make appropriate social and financial plans. For example, they may need a wheelchair or a nursing home sooner.

"It's important for people to have some notion of what lies ahead," Weiner said.

There is no blood, imaging or spinal fluid test that can detect the disease, which can only be identified definitively by an autopsy. The condition can occur in people as young as 30, such as actor Michael J. Fox, but usually appears after age 60. It is marked by loss of dopamine-producing neurons in an area of the brain called the substantia nigra, which shows up as pale instead of dark in an autopsy.

Degeneration of brain cells manifests first with trembling on one side of the body, such as the hand or leg when it's at rest. Attempts to move appear hesitant because limbs feel rigid. Gradually, the disease progresses to create a stooped posture and normal walking becomes a shuffle. Facial expressiveness eventually disappears and patients begin speaking in a voice that is much softer than before.

Parkinson's disease is not considered terminal, but its progression can result in pneumonia or urinary tract infections, which can be fatal.

Latest research

The academy's four-part guidelines emphasized these points:

If movement problems don't lessen significantly with doses of the drug levodopa, sold under the brand name Sinemet or apomorphine, other neurologic disorders should be strongly considered. However, 30 percent of patients who do respond well to levodopa actually have a disorder other than Parkinson's. Levodopa restores levels of dopamine in an area of the brain that controls movement.

Levodopa does not increase progression of Parkinson's disease, as many people have feared.

Unlike many mimic disorders, Parkinson's can impair a person's ability to smell. The problem can be measured with olfaction testing.

Falling as an early symptom and slowness or stiffness on both sides of the body suggest a condition other than Parkinson's.

There are no data showing that nutritional supplements such as vitamin E protect against Parkinson's progression.

Some clinical trials to test promising Parkinson's drugs require that patients not use any other medications or supplements that might confuse the studies' results. But many patients don't want to stop taking them, and that has made recruitment for clinical trials especially difficult.

Anxiety and depression often are interwoven with Parkinson's as a result of changes in levels of certain neurotransmitters like dopamine.

"Patients very often do not bring this up to the doctor, and doctors often don't bring it up," Weiner said.

Treatments such as anti-depressant drugs do not interfere with other therapies used for the disease. The guidelines said that for some patients, the surgical strategy known as deep brain stimulation may have benefit.

Movement difficulties may be improved with regular exercise and physical and speech therapy, which often aren't considered for Parkinson's patients.

Many drugs besides levodopa can improve symptoms.

It's important that physicians monitor their patients' illness over the years to make sure their Parkinson's symptoms don't change.

Hoping for change

The extensive guidelines are controversial because some doctors might view them as an attempt to write a cookbook that dictates how they should practice, Weiner acknowledged. But the guidelines are not a doctrine, he stressed.

"We've looked at all the research in a systematic way to give order to the chaos that exists in the neurologic literature about Parkinson," he said.

Robin Elliott, executive director of the Parkinson's Disease Foundation in New York City, touted the guidelines' emphasis on recognition of depression, sleep and memory problems in dealing with Parkinson's patients.

"If you ask a group of patients what upsets them most about this disease, it's the fatigue, depression, sleeplessness – that's disproportionate in Parkinson patients," Elliott said.

At the UCSD Medical Center's clinic for movement disorders, director Dr. David Song said he hopes the guidelines will encourage doctors to change certain practice patterns. The recommendations "promote better awareness about what Parkinson is and is not, and how to treat it with proven therapeutic strategies," he said.

Unfortunately, he said, there are very few neurologists with expertise in movement disorders nationwide, so many other brain-disease specialists will have to step up.

"Most of the time, diagnoses are made by general practitioners and primary care doctors," Song said. "All have a general knowledge of Parkinson but there is variability, and for that reason misdiagnosis can occur."

Dr. Wendy Galpern, clinical trials program director for the National Institute of Neurological Disorders and Stroke, the federal government's funding arm for neurology research, characterized the guidelines as "the most rigorous and extensive summary of the status of the field." But, she said, it also "highlights lots of questions that aren't answered and points to many other avenues for research."

Cheryl Clark: (619) 542-4573;



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