New Orleans—Mood and memory deteriorate along with motor function in neurological disorders that disrupt basal ganglia–cortical circuits, critical pathways to the limbic system. Depression, trouble concentrating, and other cognitive problems often precede loss of motor function. Psychiatric symptoms thus may distress patients and their families before Parkinson disease (PD), Huntington disease (HD), multiple sclerosis (MS), and other neurological illnesses are diagnosed.
Lamberg L. Psychiatric Symptoms Common in Neurological Disorders. JAMA. 2001;286(2):154-156. doi:10.1001/jama.286.2.154-JMN0711-2-1