Spinal dopamine mechanisms and primary sensory symptoms in Parkinson's disease

Primary sensory symptoms occur in approximately 40% of patients with Parkinson's disease. Although the pathophysiology of these symptoms is poorly understood, the recent discovery of diencephalospinal dopaminergic neuronal pathways potentially implicates this system in the etiology of these symptoms. The possible contribution of the hypothalamus with its connections to descending midbrain structures and the spinal cord to the etiology of primary sensory symptoms in Parkinson's disease are discussed.