 Their dysfunction results in a wide range of neurological conditions including disorders of behaviour control and movement, as well as cognitive deficits that are similar to those that result from damage to the prefrontal cortex.Those of behaviour include Tourette syndrome, obsessive–compulsive disorder, and addiction.Movement disorders include, most notably Parkinson's disease, which involves degeneration of the dopamine-producing cells in the substantia nigra, Huntington's disease, which primarily involves damage to the striatum, dystonia, and more rarely hemiballismus.