Ultrasound guided versus CT-controlled pararadicular injections in the lumbar spine: a prospective randomized clinical trial.

BACKGROUND AND PURPOSE: Injection therapies play a major role in the treatment of lower back pain and are to date performed mainly under CT- or fluoroscopic guidance. We conducted this study to evaluate the accuracy, time savings, radiation doses, and pain relief of US-guided pararadicular injections versus CT-controlled interventions in the lumbar spine in a prospective randomized clinical trial. MATERIALS AND METHODS: Forty adult patients were consecutively enrolled and assigned to a US or CT group. US-guided pararadicular injections were performed on a standard US device by using a broadband curved-array transducer (9-4 or 5-1 MHz). In the in-plane technique, the needle was advanced through the respective segmental intertransverse ligament. The needle tip position was verified by CT. The CT-guided approaches were performed under standardized procedures by using the CT-positioning laser function. RESULTS: The accuracy of US-guided interventions was 90%. The mean time to final needle placement in the US group was 4.0 ± 1.8 minutes, and in the CT group, 7.6 ± 2.1 minutes. The mean radiation doses, including CT confirmation for study purposes only, were 20.3 ± 9.0 mGy cm for the US group and 42.6 ± 36.1 mGy cm for the CT group. Both groups showed the same significant pain relief (P < .05) without relevant "intermethodic" differences of pain relief (P > .05). CONCLUSIONS: US-guided pararadicular injections show a therapeutic effect similar to that in the time-consuming, expensive, ionizing CT or fluoroscopically guided pararadicular injections and result in a significant reduction of procedure time expenditure and avoidance of radiation.

A new simplified sonographic approach for pararadicular injections in the lumbar spine: a CT-controlled cadaver study.

BACKGROUND AND PURPOSE: Injection therapies play a major role in the treatment of lower back pain and are to date performed mainly under CT or fluoroscopic guidance. The benefits of US-guided instillation procedures have been shown in many studies. We conducted this study to simplify an US-guided approach to the lumbar spinal nerves and to assess the feasibility and preliminary accuracy by means of CT and anatomic dissection. MATERIALS AND METHODS: Ten US-guided injections at 5 different levels (L1-L5) were performed on 1 embalmed cadaver. Images in 3 sagittal/parasagittal scanning planes were obtained at each lumbar level: 1) the plane of the spinous processes, 2) the plane of the lumbar arches/zygapophyseal-joints, and 3) the plane of the transverse processes. The PAP was then defined by positioning the transducer perpendicularly over the medial part of the respective transverse processes, depicting the hyperechoic intertransverse ligament. In the "in-plane technique," spinal needles were advanced through the respective segmental intertransverse ligament. A solution consisting of a contrast agent and a pigmented dispersion was subsequently injected into the pararadicular compartment. An anatomic dissection of the specimen and CT scans were performed to verify the exact placement of the needle tips and to evaluate fluid dispersion in the punctured compartment. RESULTS: CT examination confirmed that each needle tip was correctly placed within the intended compartment with sufficient contrast accumulation around the respective proximal segment of the spinal nerve. On each anatomic section, dye was identified in the correct compartment and directly around each targeted spinal nerve with needles shown in the correct position. CONCLUSIONS: This modified US approach for therapeutic root injections in the lumbar spine by using the intertransverse ligament as a new anatomic landmark allows an easy and correct needle placement within the pararadicular compartment.

Correlation of outcome to neurosurgical lesions: confirmation of a new method using data after microelectrode-guided pallidotomy.

The purpose of this study was the development of a new method to correlate functional surgery with outcome measures. Lesions following microelectrode guided globus pallidus internus (GPi) pallidotomy for Parkinson's disease are presented to demonstrate this new method in regard to clinical outcome. A clinical series of 26 patients with extensive neurological and neuropsychological data were studied. Three-month postoperative MRI lesion borders at the AC-PC plane were scaled to a standard size, and the lesions were stored in a virtual array with a cell size of one voxel. The average outcome measure for each voxel is presented graphically. Unified Parkinson's disease rating scale (UPDRS) motor scores improved more with posterolateral and centrally located GPi lesions than with anteromedial lesions. A correlation of lesion location to outcome was also visible for subscales of the UPDRS. The distributions were similar for the left and right sides, as well as for ipsi- and contralateral measurements. In general, verbal fluency decreased after lesioning the dominant hemisphere, and posterolateral lesions caused less impairment. This method enables associative analyses between brain area and outcome down to the size of a few voxels. This may be particularly helpful for planning and validating neurosurgical targets for various disorders.