Stress & ET

By: Arif Dalvi, MD, MBA

A stressful situation such as writing a check while in line at a grocery store or using a pointer during a presentation can worsen essential tremor (ET). Observers may believe the tremor is due to nervousness, but in reality the increased tremor is caused by the additional mental and physical stress in such situations. What many people, including people with ET, are not aware of is that good stress, such as watching a favorite team win at a sport, can also increase tremor.

Hans Selye, a pioneer in studying the mechanisms of stress, understood stress to include a wide range of strong external factors, both physical and mental, that can cause a physical response called general adaptation syndrome (GAS).

The three stages of GAS, as defined by Selye, are alarm reaction, adaption, and exhaustion. During an alarm reaction, adrenaline is released to create the fight-or-flight response. Muscles tense, the heart beats faster, breathing becomes deeper, pupils dilate, and perspiration increases. If the stress is removed, the body returns to normal. If the stress continues, the body moves into the adaption stage.

Adaption is the body’s response to long-term stress. Remaining in the adaption stage too long can cause fatigue, concentration lapses, and irritability. If the stress is not relieved, it leads to exhaustion, the third stage. The body’s defenses begin to deplete in the exhaustion stage. Depression can also occur in this final stage of GAS.

A part of the brain called the limbic system, which processes emotion and memory, is greatly involved in this stress reaction. With any situation (stressor), the limbic system searches its memory for a similar situation from the past. Based on that memory, the limbic system determines how much of which neurotransmitter to release. Far from being something in the mind, stress causes a real physical and chemical change in the body. This can help explain why someone with ET in the checkout line at a grocery store can experience severe tremor.

The limbic system processes the emotional memory of having had difficulty signing one’s name in the past and causes the initial alarm reaction of GAS. The associated emotional response of embarrassment at being unable to smoothly perform a relatively simple task increases the tremor. The guilt of holding people up in line also feeds the stress reaction. This causes the limbic system to release adrenaline, which increases tremor.

Understanding how stress affects the body—and the severity of tremor—and finding ways to cope with stress can have a significant effect on the severity and management of ET.

For tips on coping with stress visit the National Mental Health Association website at www.nmha.org.