Na Young Jung, Chang Kyu Park, Won Seok Chang, Hyun Ho Jung and Jin Woo Chang
Although neurosurgical procedures are effective treatments for controlling involuntary tremor in patients with essential tremor (ET), they can cause cognitive decline, which can affect quality of life (QOL). The purpose of this study is to assess the changes in the neuropsychological profile and QOL of patients following MR-guided focused ultrasound (MRgFUS) thalamotomy for ET.
The authors prospectively analyzed 20 patients with ET who underwent unilateral MRgFUS thalamotomy at their institute in the period from March 2012 to September 2014. Patients were regularly evaluated with the Clinical Rating Scale for Tremor (CRST), neuroimaging, and cognition and QOL measures. The Seoul Neuropsychological Screening Battery was used to assess cognitive function, and the Quality of Life in Essential Tremor Questionnaire (QUEST) was used to evaluate the postoperative change in QOL.
The total CRST score improved by 67.3% (from 44.75 ± 9.57 to 14.65 ± 9.19, p < 0.001) at 1 year following MRgFUS thalamotomy. Mean tremor scores improved by 68% in the hand contralateral to the thalamotomy, but there was no significant improvement in the ipsilateral hand. Although minimal cognitive decline was observed without statistical significance, memory function was much improved (p = 0.031). The total QUEST score also showed the same trend of improving (64.16 ± 17.75 vs 27.38 ± 13.96, p < 0.001).
The authors report that MRgFUS thalamotomy had beneficial effects in terms of not only tremor control but also safety for cognitive function and QOL. Acceptable postoperative changes in cognition and much-improved QOL positively support the clinical significance of MRgFUS thalamotomy as a new, favorable surgical treatment in patients with ET.
Young-Soo Kim, Ho-Yeol Zhang, Byung-Jin Moon, Kyung-Woo Park, Kyu-Yeul Ji, Won-Chang Lee, Kyu-Sung Oh, Gwon-Ui Ryu and Daniel H. Kim
The purpose of this study was to analyze the usefulness of the BioFlex, a Nitinol spring rod dynamic stabilization system, and the Nitinol shape memory loop (KIMPF-DI Fixing System) as a posterior dynamic stabilization system in surgery for low-back pain.
The 103 patients who underwent treatment with the BioFlex system were divided into two groups: Group 1, dynamic stabilization with or without posterior lumbar interbody fusion (PLIF); and Group 2, rigid fixation (PLIF + BioFlex system only). A total of 66 segments were treated with only the BioFlex system; in these the preoperative range of motion (ROM) was 10.0 ± 4.3°, which changed to 4.1 ± 1.9° after surgery. Adjacent-segment ROM changed from 8.4 ± 3.4° to 10.7 ± 3.2° in Group 1 and from 6.5 ± 3.2° to 10.5 ± 4.6° in Group 2 postoperatively. A total of 110 segments received both BioFlex and PLIF, with a fusion rate of 90.0%. The visual analog scale score for back pain improved from 7.3 ± 3.1 to 1.4 ± 1.8 in Group 1 and from 7.4 ± 2.4 to 2.1 ± 2.3 in Group 2. The Oswestry Disability Index improved from 35.2 ± 6.4 to 12.1 ± 4.5 in Group 1 and from 37.8 ± 5.7 to 13.6 ± 4.2 in Group 2. (The ROM and assessment scores expressed are the mean ± standard deviation.)
The 194 patients in whom Nitinol memory loops were implanted were analyzed based on the preoperative and 1-year postoperative ROM of each lumbar segment. The change of ROM in looped segments treated with PLIF was significantly reduced, but the change of ROM in looped segments without PLIF was not significant. The change of ROM at the segment adjacent to the loop was not significant, and the change of kyphosis reflected a slight recovery.
The Nitinol BioFlex dynamic stabilization system can achieve stabilization and simultaneously allow physiological movement, which can in turn decrease the degeneration of adjacent segments. When used with PLIF, the fusion rate can be expected to increase. The flexible Nitinol shape memory loop, a posterior dynamic stabilization device, is an adequate tension band that displays strength similar to the posterior ligamentous structures. In combination with PLIF at the main lesion, the BioFlex system or the Nitinol memory loop can provide posterior dynamic stabilization to the transitional upper or lower segments, enhance the fusion rate, reduce the adjacent-segment degeneration, and provide dynamic stabilization of the spine.