RESUMO
Objective: This study sought to characterize postoperative day one MRI findings in deep brain stimulation (DBS) patients. Methods: DBS patients were identified by CPT and had their reviewed by a trained neuroradiologist and neurosurgeon blinded to MR sequence and patient information. The radiographic abnormalities of interest were track microhemorrhage, pneumocephalus, hematomas, and edema, and the occurrence of these findings in compare the detection of these complications between T1/T2 gradient-echo (GRE) and T1/T2 fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) sequences was compared. The presence, size, and association of susceptibility artifact with other radiographic abnormalities was also described. Lastly, the association of multiple microelectrode cannula passes with each radiographic finding was evaluated. Ad-hoc investigation evaluated hemisphere-specific associations. Multiple logistic regression with Bonferroni correction (corrected p = 0.006) was used for all analysis. Results: Out of 198 DBS patients reviewed, 115 (58%) patients showed entry microhemorrhage; 77 (39%) track microhemorrhage; 44 (22%) edema; 69 (35%) pneumocephalus; and 12 (6%) intracranial hematoma. T2 GRE was better for detecting microhemorrhage (OR = 14.82, p < 0.0001 for entry site and OR = 4.03, p < 0.0001 for track) and pneumocephalus (OR = 11.86, p < 0.0001), while T2 FLAIR was better at detecting edema (OR = 123.6, p < 0.0001). The relatively common findings of microhemorrhage and edema were best visualized by T2 GRE and T2 FLAIR sequences, respectively. More passes intraoperatively was associated with detection of ipsilateral track microhemorrhage (OR = 7.151, p < 0.0001 left; OR = 8.953, p < 0.0001 right). Susceptibility artifact surrounding electrodes possibly interfered with further detection of ipsilateral edema (OR = 4.323, p = 0.0025 left hemisphere only). Discussion: Day one postoperative magnetic resonance imaging (MRI) for DBS patients can be used to detect numerous radiographic abnormalities not identifiable on a computed tomographic (CT) scan. For this cohort, multiple stimulating cannula passes intraoperatively was associated with increased microhemorrhage along the electrode track. Further studies should be performed to evaluate the clinical relevance of these observations.
RESUMO
OBJECTIVE: The aim of the study was to retrospectively evaluate the effect of directional deep brain stimulation (DBS) on ataxia in an essential tremor patient population. MATERIALS AND METHODS: A retrospective chart review of documented Scale for Assessment and Rating of Ataxia (SARA) scores were analyzed using a case-control design. All subjects we evaluated were treated at a single, tertiary care academic center. We reviewed 14 patients who underwent bilateral ventral intermediate nucleus of the thalamus (VIM) implantation with microelectrode recording, with electrodeposition and segmented contact orientation confirmed via postoperative computed tomography. The main outcome was to determine change in ataxia scores between directional versus monopolar circumferential stimulation. RESULTS: Fourteen patients (9 males, median age at implantation 69 [range 63-82]) underwent surgery between October 2017 and July 2020 at the UNC Movement Disorders Center. SARA scores between directional stimulation and monopolar circumferential stimulation demonstrated a significant reduction in total scores with best possible segmented stimulation (n = 13, p < 0.0001, 95% confidence interval [CI] -3.496 to -6.789). This difference remained statistically significant even after removing the SARA tremor subscore (n = 13, p < 0.0001, 95% CI -3.155 to -6.274). In line with prior reports, SARA score changes from the preoperative state were generally worsened when applying monopolar circumferential stimulation bilaterally (n = 13, p = 0.655; 95% CI -2.836 to 4.359), but improved with directional stimulation (n = 13, p = 0.010; 95% CI -1.216 to -7.547). CONCLUSION: This retrospective analysis appears to show evidence for improved outcomes through directional stimulation in bilateral VIM DBS implantation with reduction of ataxic side effects that have traditionally plagued postoperative results, all while providing optimized tremor reduction via stimulation.
