Symptoms of Parkinson's: Men vs. Women

More men than women are diagnosed with Parkinson's disease (PD) by almost a 2 to 1 margin. Several studies support this number, including a large study in the American Journal of Epidemiology.

Usually there is a physiological reason for a difference in disease between men and women. How does being female protect against PD? And do women and men experience PD symptoms differently?

Women develop PD less often than men do. When they do develop PD, the age of onset is two years later than in men.

When women are first diagnosed, tremor is usually the dominant symptom. The initial symptom in men is usually slow or rigid movement (bradykinesia).

The tremor-dominant form of PD is associated with a slower disease progression and higher quality of life.

However, women often report less satisfaction with their quality of life, even with a similar level of symptoms.

PD can affect mental faculties and the senses as well as muscle control.

There is some evidence that men and women are affected differently. For instance, men appear to retain a better ability to understand spatial orientation. Women, on the other hand, retain more verbal fluency.

These types of skills are influenced not only by sex, but also by the 'side' of PD symptoms. Left side or right side motor symptom onset reflects which side of the brain has the largest dopamine deficiency.

For instance, you might have more difficulty with muscle control on the left side of your body if you have a dopamine deficiency on the right side of your brain.

Different skills, such as spatial abilities, are more dominant on a specific side of the brain.

PD rigidity can cause the muscles of the face to 'freeze.' This leads to a mask-like expression. As a result, patients with PD have difficulty expressing emotion with their faces. They also can begin to have difficulty interpreting others' facial expressions.

One study suggests that both men and women with PD can have difficulty interpreting anger and surprise, and that men are more likely to lose the ability to interpret fear.

However, women may be more upset by their inability to interpret emotions. All PD patients may benefit from speech and physical therapy to help with this symptom.

Rapid eye movement behavior disorder (RBD) is a sleep disorder that occurs during the REM sleep cycle.

Normally, a sleeping person has no muscle tone and doesn't move during sleep. In RBD, a person can move limbs and seem to act out their dreams.

RBD occurs rarely, but more often in people with neurodegenerative diseases. About 15 percent of people with PD also have RBD, according to the Internal Review of Psychiatry. Men are much more likely to have this condition than women.

Why are there differences in PD symptoms between men and women? It seems likely that estrogen exposure protects women from some PD progression.

A study published in the Journal of Neurology, Neurosurgery & Psychiatry found that a woman who experiences later menopause, or has more children, is more likely to have delayed onset of PD symptoms. These are both markers of estrogen exposure over her lifetime.

What is not yet fully explained is why estrogen has this effect. A study in the American Journal of Psychiatry has shown that women have more available dopamine in key areas of the brain. Estrogen may serve as a neuroprotectant for dopamine activity.

Women with PD may encounter more problems during treatment of their PD symptoms than men.

Women receive surgery less often than men do, and their symptoms are more severe by the time they get surgery. Also, the improvements gained from surgery may not be as great.

Drugs to treat PD symptoms may also affect women differently. Due to a lower body weight, women often are exposed to higher doses of medications. This has been a problem with levodopa, one of the most common medications for PD.

Higher exposure can lead to an increased rate of negative side effects, like dyskinesia. Dyskinesia is difficulty performing voluntary movement.

Men and women often have different responses to the experience of living with PD.

Women with PD tend to experience a higher rate of depression than men with PD do. They therefore receive antidepressant medication more often.

Men may have more behavioral problems and aggression, such as a greater risk of wandering and inappropriate or abusive behavior. Men are more likely to receive antipsychotic medications to treat this behavior.