Burst spinal cord stimulation for pain and motor function in Parkinson's disease: A case series.

INTRODUCTION: Spinal cord stimulation (SCS) is an established strategy for pain reduction used in whole world including Japan to treat chronic intractable pain. Pain is a frequent comorbidity of Parkinson's disease (PD), leading to poorer quality of life. SCS has been reported to effectively reduce pain in PD and may also improve motor function, but most studies have employed the modality of tonic stimulation. As such, the effects of SCS using the newly developed paradigm of burst stimulation in PD remain relatively unexplored. METHODS: This case series reviewed PD patients who underwent SCS using BurstDR stimulation to treat intractable lower back pain (LBP). Pain and motor outcomes were assessed before and at several timepoints after implantation over a 24-week observation period. RESULTS: Pain indices (visual analogue scale [VAS] and short-form McGill Pain Questionnaire 2 [SF-MPQ-2] scores) improved in nearly all patients. Improvements were especially notable in the dimension of affective pain (SF-MPQ-2). Functional motor improvements were evident in the Unified Parkinson's Disease Rating Scale (UPDRS), especially walking-related items, and timed-up-and-go (TUG) test performance, which generally persisted through week 24 of observation. CONCLUSION: Burst SCS improved pain (especially the affective component) in PD patients with LBP, with effects generally lasting for at least 24 weeks. Neither paresthesia nor obvious adverse events were experienced in any case. Motor symptoms as scored of UPDRS Part III had the trends of improvement in lower limb akinesia at week 24 and gait at week 4. These findings suggest that burst SCS may be an effective treatment option for LBP and may be influenced to gait-related motor symptoms in PD.

Comparison between ultrafast fluorescence dynamics of FMN binding protein from Desulfovibrio vulgaris, strain Miyazaki, in solution vs crystal phases.

Ultrafast fluorescence dynamics of FMN binding protein (FBP) from Desulfobivrio vulgaris, strain Miyaxaki F, were compared in solution and crystal phases. Fluorescence lifetimes of FBP were 167 fs (96%) and 1.5 ps (4%) in solution (tau(av) = 220 fs), and 730 fs (60%) and longer than 10 ps (40%) in crystals (tau(av) = 4.44 ps). The quenching of the fluorescence of flavin in the protein was considered to be due to photoinduced electron transfer (ET) from Trp or Tyr to the excited isoalloxazine (Iso) nearby. The average lifetime was 20 times longer in crystal vs in solution. Averaged distances between Iso and nearby Trp-32, Tyr-35, and Trp-106 were 8.42, 7.36, and 8.15 A in solution, respectively (obtained by NMR spectroscopy), and 7.05, 7.72, and 8.49 A in crystal, respectively (obtained by X-ray crystallography). The prolonged lifetime in crystal cannot be elucidated by the change in the distances between the states. It was suggested that the longer lifetime in crystal was ascribed to the absence of water molecules around FBP with rapid motional freedom, which may be the driving force for the ET in flavoproteins.