ABSTRACT
BACKGROUND: Spinal cord stimulation is a well-established method for the management of several types of chronic and intractable pain. This form of stimulation elicits a tingling sensation (paresthesia) in the corresponding dermatomes. The goal of this study was to establish a correlation between the spinal levels of the implanted epidural electrodes and the paresthesia elicited due to stimulation of the neural structures. METHODS: Thirty five patients, who received trial spinal cord stimulation, were evaluated. After the insertion of the lead to the selected position, the areas of paresthesia evoked by stimulation were evaluated. RESULTS: Seventy-one percent of cases showed paresthesia in the shoulder area when the tip of the electrode was located between the C2 C4 levels. At the upper extremities, paresthesia was evoked in 86 93% of cases, regardless of the location of the electrode tip within the cervical spinal segments. The most common tip placement of the leads eliciting hand stimulation was at the C5 level. The most common level of electrode tip placement eliciting paresthesia of the anterior and posterior thigh and the foot were at the T7 T12, T10 L1 and T11 L1 vertebral segments, respectively. CONCLUSIONS: Detailed knowledge of the patterns of stimulation induced paresthesia in relation to the spine level of the implanted electrodes has allowed the more consistent and successful placement of epidural electrodes at the desired spine level.