There are some general properties shared by all forms of electromagnetic radiation: 1  It can travel through empty space. 2  The speed of light is constant in space. 3  A wavelength of light is defined similarly to that of water waves---distance between crests or between troughs.
The Parkinson Handbook Fatigue and Parkinsonâs Disease. Fatigue due to Depression-Depression is common in people with Parkinson's disease. It occurs in about 40% of the patients. Fatigue is a typical symptom of depression and is often reported as a lack of motivation or a loss of energy.
There are numerous causes of fatigue symptoms. Examples of some treatable causes of fatigue include anemia, diabetes,thyroid disease, heart disease, COPD and sleep disorders (Table). Long lasting complaints of fatigue do not equate to chronic fatigue syndrome.