The time in the mid to late stages of Parkinson’s disease when anti-parkinson’s medications are at peak effectiveness and are keeping the symptoms of Parkinson’s disease under control. In the early to mid stages of Parkinson’s when Levodopa is most effective, most people do not experience a differentiation between on-state and off-state because anti-Parkinson’s medications can maintain a fairly constant level of symptom control during which symptoms are barely, if at all, perceptible.
As dopaminergic neurons (dopamine-produc-ing brain cells) continue to die and the brain’s supply of endogenous dopamine (dopamine that the brain’s dopamine-producing neurons manufacture) diminishes, so does the capacity of anti-Parkinson’s medications to maintain adequate neurotransmitter function. Higher dosages of medications begin to cause more severe side effects, such as dyskinesias (involuntary movements) and dystonia (severe muscle rigidity), that are as debilitating as the symptoms of Parkinson’s.
Strategic manipulation of medications and dosages can help to extend on-state times or to structure them to occur when they are needed or desired, such as during times of activity. off-state episodes are most pronounced in the early morning, when medication levels are at their lowest. on-state time becomes both shorter per episode and less frequent as the disease advances, however, and eventually anti-Parkinson’s medications have limited effect in mitigating symptoms. Nonpharma-cotherapeutic methods such as physical therapy and occupational therapy can help to maintain
MUSCLE TONE, MUSCLE STRENGTH, and MOTOR FUNCTION for as long as possible. Planning activities to take place during on-state times as much as this is predictable eases frustration. During on-state times, the person with Parkinson’s can appear fairly normal in motor function, movement, and cognitive function even in later stages of the disease.
