Akathisia

Akathisia, or acathisia, is a syndrome characterized by unpleasant sensations of inner restlessness that manifests itself with an inability to sit still or remain motionless (hence the word's origin in Ancient Greek: from καθίζειν - kathízein - "to sit" with a privative a as prefix expressing negation or absence; literally meaning inability to sit). It can be a side effect of medications, or it can, to a lesser extent, be caused by Parkinson's disease and related syndromes, and likely other neurological diseases. However, this may be due more to the drugs used in treatment such as sinemet (l-dopa) and less with the Parkinson's disease itself. Another major cause is withdrawal from almost any physical addiction, for example, in benzodiazepine withdrawal syndrome. It was discovered that akathisia involves increased levels of the neurotransmitter norepinephrine, which is associated with mechanisms that regulate aggression, alertness, and arousal. Though no further research has been done as of yet, it may also be involved with disrupted NMDA channels in the brain, which have both synergistic and regulatory effects on norepinephrine.