The effects of levodopa and deep brain stimulation on subthalamic local field low-frequency oscillations in Parkinson's disease.

New adaptive systems for deep brain stimulation (DBS) could in the near future optimize stimulation settings online so as to achieve better control over the clinical fluctuations in Parkinson's disease (PD). Local field potentials (LFPs) recorded from the subthalamic nucleus (STN) in PD patients show that levodopa and DBS modulate STN oscillations. Because previous research has shown that levodopa and DBS variably influence beta LFP activity (8-20 Hz), we designed this study to find out how they affect low-frequency (LF) oscillations (2-7 Hz). STN LFPs were recorded in 19 patients with PD during DBS, after levodopa medication, and during DBS and levodopa intake combined. We investigated the relationship between LF modulations, DBS duration and levodopa intake. We also studied whether LF power depended on disease severity, the patient's clinical condition and whether LF modulations were related to electrode impedances. LF power increased during DBS, after levodopa intake and under both experimental conditions combined. The LF power increase correlated with the levodopa-induced clinical improvement and the higher the electrode impedance, the greater was the LF power change. These data suggest that the LF band could be useful as a control neurosignal for developing novel adaptive DBS systems for patients with PD.

Safety in the use of dexmedetomidine (precedex) for deep brain stimulation surgery: our experience in 23 randomized patients.

OBJECTIVE: Evaluation of safety and efficacy of dexmedetomidine in deep brain stimulation (DBS) surgery. MATERIALS AND METHODS: A cohort of 23 patients, candidates for DBS for Parkinson's disease, Tourette syndrome, or obsessive-compulsive disorder, was randomized in two groups: dexmedetomidine group and control group. Standard anesthesiologic parameters were recorded and analyzed, together with the need for other medications. A ten-degree scale (visual analog scale) assessing patient discomfort during DBS also was recorded at the end of surgery. RESULTS: The results demonstrated good stability of intraoperative monitoring: no respiratory depression and good overall cooperation with the neurologist, while no side-effects were recorded. CONCLUSIONS: Our conclusion is that dexmedetomidine should be considered as a valuable option for sedation in poorly collaborating patients undergoing DBS surgery.

A cervical solitary fibrous tumor with intramedullary invasion.

Solitary fibrous tumor is a tumor originating from the mesenchymal cells, which occurrence in the central nervous system is extremely rare and was described in few patients as to yet. We report on a 53-years old male patient presenting with right upper limb radicular pain and ipsilateral limbs paresis, who was diagnosed with a cervical spinal lesion which, after surgical resection, resulted to be a solitary fibrous tumor (SFT). We discuss imaging, clinical and histopathological findings to allow considering this tumor early in the differential diagnosis.

Degenerative Lumbar Stenosis Surgery: Predictive Factors of Clinical Outcome-Experience with 1001 Patients.

BACKGROUND: Degenerative lumbar spinal stenosis (DLSS) carries a high risk of morbidity and represents a financial burden to society. A late diagnosis can lead to severe disability. Although lumbar decompressive surgery has been widely used worldwide, the proper preoperative factors to define the ideal candidates for decompression are missing. METHODS: A total of 1001 patients who had undergone decompressive surgery from 2012 to 2019 for DLSS were screened for the presence of 9 clinical and radiological parameters. For all cases, the differences between the baseline and postoperative Oswestry disability index were calculated and the results categorized as 5 different classes (ranging from very poor outcomes to excellent outcomes) according to the specific scores. Generalized ordinal logistic regression was then used to analyze the significance of the 9 parameters (coded as dummy variables) in predicting the outcome as measured by Oswestry disability index improvement after surgery. RESULTS: Of the 9 parameters, 8 were found to be significant predictors. The radiological grade of compression was the strongest, followed by polyneuropathy, obesity, symptom duration, gait autonomy, radicular deficits, American Society of Anesthesiologists score, and level of surgery. In contrast, previous back surgery was not predictive of the outcome. CONCLUSIONS: Our findings have indicated that the ideal candidate for surgery will have the following preoperative characteristics: Schizas grade D, no signs of peripheral polyneuropathy, body mass index <30 kg/m2, symptom duration of <2 years, gait autonomy <100 m, no radicular deficits, 1 level of stenosis, and an American Society of Anesthesiologists score of 1, 2, or 3.

Cervical synovial cyst: case report and review of literature.

Synovial cysts, typically observed in the lumbar spine eventually associated with degenerative changes of the facet joints, only rarely present in the cervical spine. Up to now, only 28 symptomatic cases are described in literature. Typically, the treatment of these cases is a decompressive laminectomy followed by complete surgical removal of the lesion. The authors present the case of an 84-year-old man with a symptomatic synovial cyst involving the space between C7 and T1.

Contralateral interlaminar approach for intraforaminal lumbar degenerative disease with special emphasis on L5-S1 level: A technical note.

BACKGROUND: Intraforaminal disc herniations at the L5-S1 level are extremely surgically challenging lesions. Intracanal approaches frequently require partial or total facetectomy, which may lead to instability. Solely extraforaminal approaches may offer limited visualization of the more medial superiorly exiting and inferiorly exiting nerve roots; this approach is also more complicated at L5-S1 due to the often large L5 transverse process and the iliac wing. METHODS: Nine patients with intraforaminal L5-S1 disc herniations, foraminal stenosis, or synovial cysts underwent contralateral interlaminar approaches for lesion resection. Preoperative and postoperative visual analog scale scores were evaluated, and complications were reviewed. RESULTS: All 9 patients demonstrated immediate postoperative clinical improvement. None of the patients exhibited complications and none developed instability or neuropathic disorders. CONCLUSIONS: Although the number of cases in our sample was very small (9 in total), the contralateral interlaminar approach appeared to effectively address multiple degenerative L5-S1 foraminal pathologies. Large studies are needed to further evaluate the pros and cons of this approach.

Long-term follow-up of deep brain stimulation of peduncolopontine nucleus in progressive supranuclear palsy: Report of three cases.

BACKGROUND: Progressive supranuclear palsy (PSP) is a neurodegenerative disease due to mitochondrial dysfunction. The PSP syndrome presents generally with gait disorder, Parkinsonism, ophthalmoparesis and cognitive alteration. Few reports exist on deep brain stimulation (DBS) in patients with atypical Parkinsonism. The aim of our study was to evaluate further the potential role of DBS in PSP. CASE DESCRIPTION: We report three patients with PSP with long-term follow up undergoing DBS. Two patients had right peripedunculopontine nucleus (PPN) stimulation and one patient had simultaneous right PPN and bilateral globus pallidus internus DBS. DBS of the PPN alone or combined with globus pallidus internus (GPi) determined an improvement in gait and a reduction in falls sustained over time. Combined target stimulation (GPi-PPN) was correlated with better clinical outcome than single target (PPN) DBS for PSP. CONCLUSIONS: Although few data on DBS for PSP exist, reported clinical results are encouraging. DBS might be considered as an alternative therapeutic option for patients with PSP presenting with relevant gait imbalance and frequent falls, who fail to respond to pharmacological treatment. Larger cohorts with longer follow-ups are needed to evaluate more exhaustively the efficacy of DBS in PSP.

Continuous tamoxifen and dose-dense temozolomide in recurrent glioblastoma.

BACKGROUND: The current standard-of-care for glioblastoma (GBM) is represented by concomitant radiotherapy (RT) and temozolomide (TMZ), according to Stupp's protocol. Second-line treatments for GBM have not been yet defined. Tamoxifen is an anti-estrogen molecule with anti-neoplastic effects whose role is under investigation. tamoxifen is generally well tolerated but thromboembolic complications have been reported. In this study, we report our experience on the administration of tamoxifen plus dose-dense TMZ in patients with recurrent GBM. PATIENTS AND METHODS: All patients underwent surgical resection of GBM and completed concomitant RT and TMZ. Eligibility criteria also included evidence of GBM recurrence and good general conditions [Karnofsky Performance Score (KPS) >70] at recurrence. Patients with rapidly progressive disease, clearly unfavorable prognosis, or history of deep-venous thrombosis were excluded. The second-line treatment consisted of dose-dense TMZ (75-150 mg/m(2) one week on/ one week off) plus daily tamoxifen (80 mg/m(2)). Follow-up was performed with contrast-enhanced brain Magnetic Resonance Imaging (MRI) every three months. RESULTS: Thirty-two patients (18 males, 14 females; median age 57 years) with GBM relapse were included. Median overall survival time (OS) and time to tumor progression after recurrence (TTP-2) were 17.5 and 7 months, respectively. Interestingly, no differences in OS and TTP-2 were noted in GBM between those with methylated and unmethylated MGMT. None of the patients had complications related to TMZ plus tamoxifen administration. CONCLUSION: The combinatorial administration of tamoxifen and TMZ appeared to be well-tolerated, and potentially effective in increasing the efficacy of dose-dense TMZ schedule as a second-line therapeutic strategy.

Subthalamic local field potentials after seven-year deep brain stimulation in Parkinson's disease.

Studies describing subthalamic (STN) local field potentials (LFPs) recorded during deep brain stimulation (DBS) in patients with Parkinson's disease (PD), within the first month after DBS electrode implant, show that DBS modulates specific STN oscillations: whereas low-frequency (LF) oscillations (2-7 Hz) increase, beta oscillations (8-30 Hz) variably decrease. No data show whether LFPs remain stable for longer than one month after DBS surgery. Having long-term information is essential especially for use as a long-term feedback control signal for adaptive DBS systems. To evaluate how STN activity behaves years after prolonged chronic stimulation in PD we studied STN LFPs at rest without DBS and during ongoing DBS, in 11 parkinsonian patients 7 years (7.54±1.04) after STN electrode implantation for DBS (hyperchronic group) and in 16 patients 3 days after STN electrode implantation (acute group). STN LF and beta-band LFPs recorded at rest at 7 years contained almost the same information as those recorded at 3 days. STN recordings showed similar LFP responses to DBS in the acute and hyperchronic stages: whereas during ongoing DBS the LF power band increased for the whole population, beta activity decreased only in nuclei with significant beta activity at baseline. The LF/beta power ratio in all nuclei changed in both study groups, suggesting that this variable might be an even more informative marker of PD than the single LF and beta bands. Because STN LFP activity patterns and STN LFP responses to DBS stay almost unchanged for years after DBS electrode implantation they should provide a consistent feedback control signal for adaptive DBS.