Long-term follow-up of Parkinsonian patients operated on with deep brain electromodulation without intraoperative microrecording

Abstract

Background: Deep brain electromodulation (DBEM), also known as deep brain stimulation in different intracerebral targets, is the most widely used surgical treatment due to its effects in reducing motor symptoms of Parkinson's disease. The intracerebral microelectrode recording has been considered for decades as a necessary tool for the success of Parkinson's surgery. However, some publications give more importance to intracerebral stimulation as a better predictive test. Since 2002, we initiated a technique of brain implant of electrodes without micro recording and based solely on image-guided stereotaxis followed by intraoperative macrostimulation. In this work, we analyze our long-term results, taking into account motor skills and quality of life (QL) before and after surgery, and we also establish the patient's time of clinical improvement.

Methods: This is a descriptive clinical study in which the motor state of the patients was evaluated with the unified Parkinson's disease scale (UPDRS) and the QL using the Parkinson's disease QL questionnaire 39 questionnaires before surgery, in the "on" state of the medication; and after surgery, under active stimulation and in the "on" state.

Results: Twenty-four patients with ages ranging from 37 to 78 years undergoing surgery DBEM on the subthalamic nucleus were studied. An improvement of 41.4% in motor skills and 41.7% in QL was obtained.

Conclusion: When microrecording is not available, the results that can be obtained, based on preoperative imaging and clinical intraoperative findings, are optimal and beneficial for patients.

Keywords: Brain microrecording; Deep brain electromodulation; Deep brain stimulation; Image-guided implantation; Parkinson’s disease; Parkinson’s surgery; Quality of life.

Graph 1:

Comparison of the mean of unified Parkinson’s disease rating scale (UPDRS) score on motor symptoms before and after surgery. We can observe that all of them were reduced (improved). Preoperatively, the highest scores in motor parameters were as follows: standing up from a chair (“arising from a chair,” mean 3 points; standard deviation [SD]: 0.95), agility in the lower limbs (mean 2.92 points; SD: 0.9), movement (bradykinesia) and finger tapping (both mean 2.75 points; SD: 0.8 and 1.42, respectively), axial rigidity, alternating movements (“pronation/supination arms”), and tremor in the lower limbs (average 2.67 points; SD 0.98, 1.07, 1.15, respectively). Postoperatively, a significant reduction in their score was subsequently achieved between 48.4% and 71.8%. The motor parameters that had the highest percentage of postoperative improvement were as follows: hand tremor (73.0%), alternating movements with the hands (“pronation/supination arms,” 71.8%), and leg (65.6%) and arm (64,5%) tremor. The axial symptoms that were taken into account were Language, standing up from a chair (“arising from a chair”), posture, postural stability (“stability”), and gait. A preoperative score was obtained for these items, with a mean of 11.67 points (SD: 3.7) and a postoperative score of 5.75 points (SD: 5.81), achieving an average reduction (improvement) of 5.92 points (SD: 4.6), which represents a 50.71% improvement in axial symptoms after surgery.

Graph 2:

(a) Patients grouped according to their improvement in quality of life (QL). Regarding the analysis of QL, the preoperative Parkinson’s disease QL questionnaire-39 score ranged from 28 to 58 points (mean 42.75 points), and the postoperative was 3–53 points (mean 19, 91 points); thus, the average improvement was 22.8 points. The results of these patients in terms of improvement in QL were as follows: Excellent improvement in 11 patients (46%), marked improvement in 5 (21%), moderate improvement in 6 (25%), and poor improvement in 2 individuals (8%). (b) Patients were grouped according to their improvement in QL. Comparison of the mean QL aspects before and after surgery (*annoyances: Painful muscles rigidity, pain in joints). The characteristics of the QL that had the greatest improvement were emotionality (in 66.40%), self-sufficiency (in 61.59%), and the performance of daily tasks (in 39.84%).