Transplantation of Embryonic Dopamine Neurons for Severe Parkinson's Disease.

Transplantation of Embryonic Dopamine Neurons for Severe Parkinson's Disease Freed CR, Greene PE, Breeze RE, et al (University of Colorado School of Medicine, Denver, Colo; Columbia University College of Physicians and Surgeons, New York, NY; AT&T Shannon Laboratory, Florham Park, NJ; University of Pennsylvania Medical Center, Philadelphia, Pa; North Shore University Hospital, Manhasset, NY), N Engl J Med. 2001;344:710-719.

A number of small, unblinded studies report that patients with Parkinson disease (PD) have improved clinically after the transplantation of human embryonic dopamine neurons. The researchers conducted a randomized, double-blind, sham-surgery-controlled study to determine if the transplanted embryonic dopamine neurons survived and if the implant improved the symptoms of patients with severe PD. A secondary goal was to determine if the success of the transplant was related to the age of the patient.

Patients with severe PD (mean duration= 14 years) between the ages of 34 and 70 (N=40; 19 women, 21 men; average age=57 [+ or -] 10 years) were randomly assigned to receive either an injection of cultured embryonic mesencephalic neurons in their putamen or a sham surgical procedure. The primary outcome variable was the patient's subjective global rating of clinical improvement or deterioration at 12 months after surgery. Secondary outcome variables were standardized scores measured using the Unified Parkinson's Disease Rating Scale (UPDRS) and the Schwab and England scale and the growth of the transplants as measured by [sup.18]F-fluorodopa positron-emission tomography (PET) scans.

There were no differences between the treatment and control groups in the global rating scale used by the patients (mean score=0.0 [+ or -] 2.1 and--0.4 [+ or -] 1.7 respectively). However, there were improvements in the UPDRS and Schwab and England scores, particularly in the motor components (rigidity and bradykinesia, but not tremor) in the younger ([is less than or equal to] 60 years of age) patients in the treatment group compared with the younger patients in control group 1 year after surgery. The PET scans revealed that the transplants had survived and were growing in almost all of the patients (17 of 20).

The researchers concluded that most transplants survived in patients regardless of age but that the implants provided some clinical benefit only to patients who were 60 years of age or younger.

Anthony E Kincaid, PT, PhD
Creighton University
Omaha, Neb