Parkinson’s Disease Is More Than a Tremor

by Karen D. Sullivan, PhD, ABPP

Parkinson’s disease (PD) is a progressive neuropsychological disorder in which the brain does not make enough of a specific chemical, the neurotransmitter dopamine. Dopamine is released by the nerve cells in one part of the brain to communicate with nerve cells in many other parts of the brain. Commonly, PD is characterized only by tremor and slowness of movement; however, other symptoms, including those involved in cognition and mood, are increasingly recognized as a fundamental part of the disorder. These symptoms are important to address and treat as they can reduce quality of life and everyday functioning.

Motor symptoms: People living with PD have both primary and secondary symptoms that affect movement of the body called motor symptoms. Primary symptoms include:

  • a resting tremor, with about 70 percent experiencing a slight tremor in the hand or foot on one side of the body, usually when the muscles are relaxed;
  • bradykinesia, a decrease of spontaneous movement causing short, shuffling steps;
  • rigidity, stiffness and inflexibility of the limbs, neck and trunk; and
  • postural instability, a loss of some reflexes needed for maintaining an upright posture, resulting in a tendency to fall.

Secondary motor symptoms include:

  • freezing, feeling as if the feet are glued to the floor when starting to move;
  • micrographia, a decrease in the size of handwriting that gets worse the more a person writes; and
  • masked facies, a decrease in facial expressions.

Cognitive symptoms: Cognitive change is common in PD and can range from mildly frustrating symptoms to those that interfere with remembering to take one’s medications or pay the bills. These symptoms primarily occur in executive functioning (decreased initiation, multi-tasking, problem-solving, planning/organization), slowed processing and difficulty with new learning. The rapid retrieval of information, i.e, recall is especially affected in PD often making it aggravating to find the right word “on the spot” or participate quickly in a group discussion.

Understanding the cause of cognitive changes in PD is a work in progress, although the same brain changes that result in motor symptoms are likely related. Other factors are thought to be sleep disturbance and medication effect, whether for PD or other conditions. It is critical to address and treat any other medical conditions that may be worsening the cognitive symptoms in PD, such as untreated sleep apnea, diabetes and high blood pressure.

Mood symptoms: Between 40-50 percent of people living with PD experience depression, anxiety or apathy. These symptoms can occur at any stage of the disease, and in many individuals, may occur before motor symptoms.

Scientists believe these symptoms are more related to changes in the brain. A focus of current research is the link between reduced dopamine in the emotional center of the brain-known as the limbic system-and another neurotransmitter, serotonin, known to be essential in maintaining a positive mood.

Treatment: Before any treatment can be successful, an individual evaluation is needed to understand each person’s unique issues. Neuropsychologists guide patients, families and other medical providers to the best treatment options and aim to reduce the severity of the symptoms and improve daily life. Recommendations include:

  • the use of increased coping strategies;
  • memory enhancing medications such as Exelon;
  • skills training;
  • improved sleep;
  • exercise;
  • attending a PD support group;
  • supportive counseling;
  • social interaction; and
  • stimulating leisure activities.

An excellent resource to find out more on this topic is


Dr. Sullivan, a clinical neuropsychologist at Pinehurst Neuropsychology, can be reached at 910-420-8041 or