PET Studies of Transplantation Therapy

The assessment of the effect of transplant therapy for neurological disease in humans is complex. This is particularly the case for the neurodegenerative conditions that are candidates for transplant therapy including Parkinson’s disease, Huntington’s disease, and Alzheimer’s disease. These diseasees are characterized by disturbances of higher order neurologic function, which are complex and often not easily reduced to numerical values. Most rating scales for these conditions are not linear. They also often rely on the subjective judgment of the examiner. The neurologic deficits of neurodegenerative disorders also change with the emotional state of the patient; for example, the enthusiasm and optimism surrounding a transplant procedure may be sufficient to improve the motor performance of a patient with Parkinson’s disease. For the preceding reasons, the use of positron emission tomography (PET) as an objective measure of the degree of neurologic function improves the ability of investigators to determine the effect and measure objectively the results of transplant therapy in humans.