To the Editor:
I have read with great interest the paper of Ali et al1 regarding the usefulness of spinal cord stimulation (SCS) in the treatment of central pain after stroke (CPSP), also well known as thalamic pain.
Patients with focal CPSP instead of generalized pain were considered for treatment by Ali et al.1 Two cases with complete hemibody pain had circumscribed areas of more severe pain.
Percutaneous tetrapolar epidural electrodes were implanted and held for a 2- to 7-day trial period in 30 patients. Then, the electrode was removed. The analgesic results of the trial period were discussed with the patient. Ten patients received a new tetrapolar electrode. After a second trial period (whose duration is not specified), the internal pulse generator was implanted.
In their discussion the authors claim to be the first to describe good results with the SCS for the treatment of CPSP. The work published by our group2 shows that this statement is not true. Our series is shorter than the one by Ali et al.1 Follow-up is longer. They have a 28-month follow-up (range, 6-62), while that ours is longer: 81.6 months (range, 36-149).
I assume with Ali et al1 that SCS is a much less aggressive surgical method than deep brain stimulation or motor prefrontal cortex. I also agree that better results can be attained in cases of focal pain rather than generalized pain.
I disagree with Ali et al1 on the appropriateness of a short trial period of 2 to 7 days. I disagree very much with the removal of the electrode test and the return to implant it in the case of the definite implant. It is possible that the second electrode failed to obtain the same paresthesia as did the first. In addition, the rate of local complications could be increased.
Congratulations to Ali et al1 for his excellent work, which confirms the good results that were previously shown by our work.2
Jose Antonio Lopez Lopez
1. Ali M, Saitoh Y, Hosomi K, Oshino S, Kishima H, Yoshimiro T. Spinal cord stimulation for central poststroke pain. Neurosurgery. 2010;67(3):ONS206-ONS212.
2. Lopez JA, Torres LM, Gala F, Iglesias I. Spinal cord stimulation and thalamic pain: long-term results of eight cases. Neuromodulation. 2009;12(3):240-243.