Articular arthrodesis with the facet wedge technique for the treatment of unstable lumbar degenerative disease and associated conditions: A retrospective study of 96 patients.

Background: Lumbar articular fusion with the facet wedge (FW) technique is gaining increasing interest among surgeons for the treatment of vertebral instability due to its limited invasiveness and ease of use. Studies on cadavers have reported biomechanical properties similar to pedicle screws. Yet, the evidence supporting their use is still limited and moreover focused only on spinal degenerative disease. Methods: 96 cases of lumbar articular fusion with the FW techniques performed at 3 different centers between 2014 and 2022 were retrospectively analyzed based on the specific surgical indications: 1) degenerative spondylolisthesis/unstable lumbar stenosis; 2) synovial cysts; 3) adjacent segment disease (ASD). Medical records were reviewed to identify rates of complications and measures of functional outcome (ODI, low back pain VAS and modified Macnab scale) were collected both at baseline and at the follow-up visits. Wilcoxon signed-rank test was adopted to test for significant functional improvements. Results: Significative clinical improvements were observed from baseline to follow-up regarding ODI and VAS scores. Overall rate of moderate and severe complications (according to Landriel-Ibañez scale) was 7.9%. Only 3.4% of patients with degenerative disease developed ASD requiring reoperations. Only one case of radicular deficit and one of device mobilization were reported. 2/4 cases of synovial cysts treated with unilateral fusions developed contralateral complications. 9 out of 16 (56.25%) patients who underwent long-term postoperative CT scans presented adequate degree of articular fusion. Conclusion: FW technique is easy, safe, and effective. Its low rate of complications justifies its use for cases of mild lumbar instability.

Towards a common language in neurosurgical outcome evaluation: the NEON (NEurosurgical Outcome Network) proposal.

BACKGROUND: The aim of this study was to achieve a consensus on the minimum set of outcome measures and predictors to be used in the neurosurgical practice and on the timing of outcome assessment. METHODS: A consensus building approach was employed. All neurosurgical departments in Lombardy (Italy) were invited to participate by the Carlo Besta Neurologic Institute IRCCS Foundation. Three workshops were organized during which a multidisciplinary group called Neurosurgical Outcome Network (NEON) was created and the methodology to select outcome measures, predictors, and timing of outcome assessment was established. Eight working groups were created for the different neurosurgical diseases (neuro-oncological, skull base, vascular, traumatic, spinal, peripheral nervous system, malformation, functional) and 8 workshops were organized to identify the outcome measures and predictors specific for each of the neurosurgical diseases based on the experts' clinical practice and the existing literature. RESULTS: A total of 20 neurosurgical departments participated in this study. Specific outcome measures, predictors and the timing of outcome assessment were identified for each of the 8 neurosurgical diseases. Moreover, a list of variables common to all pathologies were identified by the NEON group as further data to be collected. CONCLUSIONS: A consensus on the minimum set of outcome measures and predictors and the timing of outcome assessments for 8 neurosurgical diseases was achieved by a group of neurosurgeons of the Lombardy region, called NEON. These sets could be used in future studies for a more homogeneous data collection and as a starting point to reach further agreement also at national and international level.

The interlaminar contralateral approach to far-lateral lumbar disc herniations: a single-center comparison with traditional techniques.

BACKGROUND: The interlaminar contralateral approach (ICA) is a promising surgical alternative for the treatment of far-lateral lumbar disc herniations (FLLDH). To date no study has compared ICA and FLLDH conventional surgical treatments, namely the intertransverse, the transmuscular and the intermuscular approaches, in terms of safety and outcome. METHODS: Patients who underwent FLLDH surgery at our Institution between January 2015 and September 2018 were reviewed. ICA complications and clinical outcomes were compared with those of conventional approaches at 1-month postoperatively and at the last follow-up available. Improvement was defined as reduction of at least two point in the Visual Analogue Scale (VAS) or increase of at least 1 point in the Medical Research Council (MRC) scale of muscle strength. Patient-reported outcome was assessed with the Oswestry Disability Index (ODI). RESULTS: Among 38 patients, 18 underwent ICA and 20 a conventional approach (intertransverse in 16, transmuscular in two, intermuscular in two). Median follow-up was 21 months (range, 2-47). At 1 month, no differences between the two groups were noticed in terms of clinical outcome and symptoms relief (P> 0.05). The median postoperative ODI score was significantly lower in the Conventional approach group at 1 month (P<0.05), but this difference was no longer significant at the last follow-up evaluation (P>0.05). No differences were found between the two groups in surgical complication and recurrence rates. CONCLUSIONS: Our data suggest that the ICA is a safe and effective alternative to conventional approaches in FLLDH surgery. Larger prospective studies are needed to confirm our results.

Aneurismal subarachnoid hemorrhage during the COVID-19 outbreak in a Hub and Spoke system: observational multicenter cohort study in Lombardy, Italy.

BACKGROUND: Lombardy was the most affected Italian region by the first phase of the COVID-19 pandemic and underwent urgent reorganization for the management of emergencies, including subarachnoid hemorrhage from a ruptured cerebral aneurysm (aSAH). The aim of the study was to define demographics, clinical, and therapeutic features of aSAH during the COVID-19 outbreak and compare these with a historical cohort. METHODS: In this observational multicenter cohort study, patients aged 18 years or older, who were diagnosed with aSAH at the participating centers in Lombardy from March 9 to May 10, 2020, were included (COVID-19 group). In order to minimize bias related to possible SAH seasonality, the control group was composed of patients diagnosed with aSAH from March 9 to May 10 of the three previous years, 2017-2018-2019 (pre-pandemic group). Twenty-three demographic, clinical, and therapeutic features were collected. Statistical analysis was performed. RESULTS: Seventy-two patients during the COVID-19 period and 179 in the control group were enrolled at 14 centers. Only 4 patients were positive for SARS-CoV-2. The "diagnostic delay" was significantly increased (+ 68%) in the COVID-19 group vs. pre-pandemic (1.06 vs. 0.63 days, respectively, p-value = 0.030), while "therapeutic delay" did not differ significantly between the two periods (0.89 vs. 0.74 days, p-value = 0.183). Patients with poor outcome (GOS at discharge from 1 to 3) were higher during the COVID-19 period (54.2%) compared to pre-pandemic (40.2%, p = 0.044). In logistic regression analysis, in which outcome was the dichotomized Glasgow Outcome Scale (GOS), five variables showed p-values < 0.05: age at admission, WFNS grade, treatment (none), days in ICU, and ischemia. CONCLUSIONS: We documented a significantly increased "diagnostic delay" for subarachnoid hemorrhages during the first COVID-19 outbreak in Lombardy. However, despite the dramatic situation that the healthcare system was experiencing, the Lombardy regional reorganization model, which allowed centralization of neurosurgical emergencies such as SAHs, avoided a "therapeutic delay" and led to results overall comparable to the control period.

Extracellular spike microrecordings from the subthalamic area in Parkinson's disease.

Intraoperative neuronal microrecordings can help in localizing the subthalamic nucleus (STN) during stereotactic neurosurgery for deep-brain stimulation (DBS) in Parkinson's disease. To obtain quantitative information on neuronal spike descriptors, we systematically analysed neuronal spikes in the STN and substantia nigra pars reticulata (SNr) in 31 sides of the brain in awake patients undergoing stereotactic neurosurgery for DBS electrode implantation. In these two structures we evaluated spike amplitude, area, duration, rise time and mean total firing rate. The recording spike density was higher in the STN than in the SNr (94% vs. 28%). Microelectrode recordings showed a larger spike area and amplitude in the SNr than in the STN ([mean+/-SD] amplitude: 46.7+/-31.1 vs. 36.3+/-29.6 microV; area: 25.6+/-24.2 vs. 36.7+/-21.4 microVmsec), a higher total firing rate at rest in the SNr than in the STN (78.6+/-53.5 vs. 61.9+/-40.8 Hz), and a longer duration and rise time in the SNr than in the STN (duration: 2.0+/-1 vs. 1.3+/-0.6 ms; rise time: 0.95+/-0.6 vs. 0.67+/-0.3 ms). Our analysis also revealed sex-related differences in the studied spike descriptors, paralleling recent findings from deep electroencephalography recordings. In the STN, males had larger spike area and amplitude (amplitude: 41.97+/-32.57 vs. 26.2+/-19.7 microV; area: 31.8+/-26.4 vs. 13.0+/-10.6 microVmsec), whereas females had higher mean total firing rate (66.7+/-53.4 vs. 82.8+/-50.8 Hz). Our results have implications for clinical practice and the development of algorithms for the neurophysiological identification of the STN during stereotactic neurosurgery for Parkinson's disease, based on the on-line automated computation of multiple spike-variables.

Gender differences in patients with Parkinson's disease treated with subthalamic deep brain stimulation.

We investigated gender-differences in clinical phenomenology and response to deep brain stimulation (DBS) of the subthalamic nucleus (STN) in a group of patients with advanced Parkinson's disease (PD). Thirty-eight consecutive patients with PD (22 men and 16 women), bilaterally implanted for DBS of the STN, were evaluated 1 month before and 11 to 14 months after surgery. Gender differences in severity of the disease (HY and UPDRS), ability in the activities of daily living (ADL, UPDRS II), tremor and rigidity (UPDRS III), bradykinesia (UPDRS III and hand tapping test), levodopa-induced dyskinesias (LIDs, UPDRS IV), and levodopa equivalent daily dosage (LEDD) were analyzed before and after intervention. We found a predominantly male population, with no gender-related differences in age at onset, disease progression rate, or severity of disease. Nevertheless, women had more severe LIDs than men, only before the intervention. Bradykinesia was significantly less responsive to any kind of treatment (pharmacologic and neurosurgical) in women than in men. Finally, although STN-DBS induced similar total benefits in both genders, postoperative assessment suggested that the ADL improved more in women than in men. Women and men with advanced PD appear to differ in some clinical features and in response to dopaminergic and STN-DBS treatment.

Subthalamic somatosensory evoked potentials in Parkinson's disease.

Deep brain stimulation (DBS) of subthalamic nucleus (STN) is an effective treatment for advanced Parkinson's disease. It also provides an opportunity to record neural activity from the human basal ganglia. In this study, to investigate the involvement of the human STN in sensory functions, we recorded somatosensory evoked potentials (SEPs) elicited by contralateral median-nerve stimulation, from STN electrodes implanted for DBS in patients with Parkinson's disease. We suggest that the STN N18 component of SEPs in Parkinson's disease is a mainly local field potential elicited by muscle afferent input to the nucleus.