ON-time is the period when your levodopa medication is effective, and your Parkinson’s symptoms are generally under control.
OFF-time is the period when your Parkinson’s symptoms return after your ON-time because the effects of your levodopa don’t last as long. You may become partially or completely immobile. The symptoms experienced during the OFF-time may vary from person to person.
Wearing-off is where you begin to feel that the improvement gained from a dose of levodopa does not last until the next dose of medication begins to take effect. Therefore, you may want to take your next dose sooner.
4. Delayed on
Delayed on is where there is a delay before you begin to feel the benefits after taking your levodopa. This may be more common with controlled-release preparations of levodopa, as the levodopa is released more slowly. Particularly in the later stages of the disease, protein-rich food may inhibit the absorption of levodopa in the intestines, so the effect may be delayed or prevented completely.
5. On-off phenomenon
The on-off phenomenon refers to sudden, sometimes unpredictable, changes in your symptoms, varying between good and poor mobility. The ON-phase is usually associated with involuntary movements (dyskinesia) and the OFF-phase is associated with Parkinson’s symptoms. The phenomenon has no relationship with the timing of the medication.
6. Freezing episodes
Freezing episodes are sudden, brief periods of immobility. You may feel as if your feet are glued to the floor. Freezing episodes tend to occur when you start to move, turn, or go through a doorway.