Aqueductal CSF stroke volume is associated with the burden of perivascular space enlargement in chronic adult hydrocephalus.

The inflow of CSF into perivascular spaces (PVS) in the brain is crucial for clearing waste molecules. Inefficiency in PVS flow leads to neurodegeneration. Failure of PVS flushing is associated with CSF flow impairment in the intracranial hydrodynamic condition of CSF hypo-pulsatility. However, enlarged PVS (ePVS), a finding indicative of PVS flow dysfunction, is also present in patients with derangement of CSF dynamics characterized by CSF hyper-pulsatility, which increases CSF flow. Intriguingly, two opposite intracranial hydrodynamic conditions would lead to the same result of impairing the PVS flushing. To investigate this issue, we assessed the subsistence of a dysfunctional interplay between CSF and PVS flows and, if the case, the mechanisms preventing a hyper-pulsatile brain from providing an effective PVS flushing. We analyzed the association between phase contrast MRI aqueductal CSF stroke volume (aqSV), a proxy of CSF pulsatility, and the burden of ePVS in chronic adult hydrocephalus, a disease involving a broad spectrum of intracranial hydrodynamics disturbances. In the 147 (85 males, 62 females) patients, the age at diagnosis ranged between 28 and 88 years (median 73 years). Ninety-seven patients had tri-ventriculomegaly and 50 tetra-ventriculomegaly. According to the extent of ePVS, 113 patients had a high ePVS burden, while 34 had a low ePVS burden. aqSV, which ranged between 0 and 562 µL (median 86 µL), was increased with respect to healthy subjects. Patients presenting with less ePVS burden had higher aqSV (p < 0.002, corrected for the multiple comparisons) than those with higher ePVS burden. The present study confirmed the association between CSF dynamics and PVS flow disturbances and demonstrated this association in intracranial hyper-pulsatility. Further studies should investigate the association between PVS flow failure and CSF hypo- and hyper-pulsatility as responsible/co-responsible for glymphatic failure in other neurodegenerative diseases, particularly in diseases in which CSF disturbances can be corrected, as in chronic adult hydrocephalus.

Percutaneous carbon-PEEK instrumentation for spine tumors: a prospective observational study.

BACKGROUND: Minimally invasive spine surgery (MISS) has been progressively accepted as a useful approach for spine tumors. Recently released carbon-PEEK implants have been already reported as effective in open surgeries for spine tumors. This study aimed to evaluate the feasibility, surgical, clinical and radiological outcomes of a new percutaneous carbon-PEEK instrumentations for spine tumors. METHODS: This is a prospective case-control observational study. Demographical, clinical, surgical, and radiological data were collected from May 2018 to August 2019. Visual Analogue Scale for back pain (VAS), the Oswestry Disability Index (ODI) Questionnaire, EORTC QLQ-C30 questionnaire for quality of life, and ASIA Impairment Scale (AIS) were collected before surgery and at 6 weeks and follow-up (FU) visits. Data were compared with the control group, a retrospective series of 23 metastatic patients that underwent titanium pedicle screw fixation. RESULTS: Twenty-one patients met inclusion criteria. Mean age was 59.2 years (range, 35-78) and mean FU was 14.2 months (7-22). Thoracic spine was involved in 14 (66.7%) cases, lumbar spine in 7 (33.3%). The mean length of surgery was 75 (42-185) minutes, mean blood loss was 90ml (50-215) and every patient was mobilized within 24 hours after surgery. The VAS (8.3±1.1 to 2.9±1.0, P<0.05) and ODI (54.6±11.7 to 25.1±5.4, P<0.05) scores significantly improved over follow-up. AIS improved in 7 (33.3%) patients and remained unchanged in 14 (66.7%). The EORTC QLQ-C30 global health/QoL, functional and symptomatic scales significantly improved postoperatively and at the last follow-up. Only two minor complications (9.5%) were recorded. No statistically significant difference was observed between the two groups related to clinical, radiological outcomes, complications rate and implant failure. CONCLUSIONS: Percutaneous Carbon/PEEK implants could be considered as alternative to standard titanium implants in oncological patients, according to their lower rate of MRI artifacts, facilitating radiological FU and adjuvant radiotherapy. Further clinical trials and biomechanical evaluations are needed to confirm our preliminary results.

Case report: A multiple sclerosis patient with imaging features of glymphatic failure benefitted from CSF flow shunting.

The derangement of CSF circulation impacts the functions of the glymphatic-lymphatic system (G-Ls), which regulates solute trafficking and immune surveillance in the CNS. The G-Ls failure leads to the dysregulation of clearance of waste molecules in the brain and to an altered CNS immune response. The imaging features of dilated perivascular spaces imply the impairment of the G-Ls. We report on the case of a patient with primary progressive multiple sclerosis and dilatation of perivascular spaces, who transiently improved after CSF shunt diversions. The underlying mechanisms remain to be determined and at this stage, it is not possible to link CSF diversion to an effect on MS pathology. However, this observation provides the rationale to incentivize research in the largely unknown area of CSF dynamic disturbances on G-Ls failure and ultimately in neurodegeneration.

Clinical Outcomes of Shunting in Normal Pressure Hydrocephalus: A Multicenter Prospective Observational Study.

Background: Normal pressure hydrocephalus (NPH) is characterized by the triad of dementia, gait disturbance and urinary incontinence, all potentially reversible following a ventriculoperitoneal shunt (VPS). This study aims to evaluate the clinical outcomes of shunting in normal pressure hydrocephalus following a new standardized protocol. Methods: This study is designed according to the STROBE guidelines. Demographical, clinical, surgical and radiological data were collected from May 2015 to November 2019. Gait, balance and incontinence data based on the NPH European scale were collected before and after one, six and twelve months of treatment with a VPS. Clinical symptoms and changes of the stoke volume, measured on phase-contrast MRI, were used to evaluate improvement after VPS surgery. Results: One hundred and eighty-one consecutive patients met the inclusion criteria. The mean age was 73.1 years (59−86) and mean follow-up was 38.3 months (13−50). The gait (58.5 ± 14.3 to 70.1 ± 13.4, p < 0.001), the balance (66.7 ± 21.5 to 71.7 ± 22.1, p = 0.001), continence domain (69.9 ± 20.5 to 76 ± 20, p = 0.002) scores and neuropsychological scales showed a statistically significant improvement over the follow-up. The overall improvement after 12 months was present in 91.2% of patients. An overall complication rate of 8.8% and a reoperation rate of 9.4% were recorded, respectively. Conclusions: Surgical treatment by VPS for NPH improves symptoms in most patients, when accurately selected. A standardized protocol and a multidisciplinary team dedicated to this disorder is needed to achieve an early and correct diagnosis of NPH. Follow-up with stroke volume measurement is a valuable tool for the early diagnosis of shunt malfunction or the need for valve adjustment.

Anterior Corpectomy and Plating with Carbon-PEEK Instrumentation for Cervical Spinal Metastases: Clinical and Radiological Outcomes.

Background: Anterior cervical corpectomy and plating has been recognized as a valuable approach for the surgical treatment of cervical spinal metastases. This study aimed to report the surgical, clinical and radiological outcomes of anterior carbon-PEEK instrumentations for cervical spinal metastases. Methods: Demographical, clinical, surgical and radiological data were collected from 2017 to 2020. The Neck Disability Index (NDI) questionnaire for neck pain, EORTC QLQ-C30 questionnaire for quality of life, Nurick scale for myelopathy and radiological parameters (segmental Cobb angle and cervical lordosis) were collected before surgery, at 6 weeks postoperatively and follow-up. Results: Seventeen patients met inclusion criteria. Mean age was 60.9 ± 7.6 years and mean follow-up was 12.9 ± 4.0 months. The NDI (55.4 ± 11.7 to 25.1 ± 5.4, p < 0.001) scores and the EORTC QLQ-C30 global health/QoL significantly improved postoperatively and at the last follow-up. The segmental Cobb angle (10.7° ± 5.6 to 3.1° ± 2.2, p < 0.001) and cervical lordosis (0.9° ± 6.7 to -6.2 ± 7.8, p = 0.002) significantly improved postoperatively. Only one minor complication (5.9%) was recorded. Conclusions: Carbon/PEEK implants represent a safe alternative to commonly used titanium ones and should be considered in cervical spinal metastases management due to their lower artifacts in postoperative imaging and radiation planning. Further larger comparative and cost-effectiveness studies are needed to confirm these results.

Aqueductal CSF stroke volume measurements may drive management of shunted idiopathic normal pressure hydrocephalus patients.

CSF shunting with adjustable valve is the treatment of idiopathic normal pressure hydrocephalus. The opening pressure valve setting is left to the neurosurgeon's experience. Aqueductal CSF stroke volume by phase-contrast magnetic resonance measures the CSF passing through the Sylvian aqueduct and it changes with intracranial hydrodynamics. We sought to identify a window of stroke volume differences associated with the best clinical outcome and lowest rate of complications. The records of 69 patients were reviewed. At every clinical check, stroke volume, opening pressure valve, clinical outcome, and CSF overdrainage were analyzed. The correlation between stroke volume differences and negative outcome was also analyzed. The median follow-up was 2.3 years (range 0.3-10.4 years). The odds of negative outcome between two consecutive checks significantly increased by 16% (95%CI 4-28%, p = 0.006). Taking the lowest risk group as reference, the odds ratio of negative outcome was 1.16 (95%CI 0.51-2.63, p = 0.726) for SV differences less than - 37.6 µL, while it was 1.96 (95%CI 0.97-3.98, p = 0.062) for stroke volume changes above + 23.1 µL. Maintaining stroke volume values within a definite range might help maximize clinical benefit and avoid the risk of CSF overdrainage.

Fenestration of Peritoneal Catheter to Avoid Abdominal Pseudocyst Formation after Ventriculoperitoneal Shunts: A Technical Note.

Ventriculoperitoneal shunt (VPS) is a well-known procedure in the neurosurgical field. However, it has high complication and reoperation rates. Abdominal pseudocyst (APC) formation is a rare complication of VPS with reports in the literature varying from 4 to 10%. In this article, we report a simple and effective technique, with no additional cost, to avoid APC formation by making small multiple slits along the length of the peritoneal catheter.

Accuracy and safety of 1-day external lumbar drainage of CSF for shunt selection in patients with idiopathic normal pressure hydrocephalus.

OBJECTIVEThree to five days of external lumbar drainage (ELD) of CSF is a test for ventriculoperitoneal shunt (VPS) selection in idiopathic normal pressure hydrocephalus (iNPH). The accuracy and complication rates of a shorter (1-day) ELD procedure were analyzed.METHODSData of patients with iNPH who underwent 1-day ELD to be selected to undergo VPS placement with a programmable valve in the period from 2005 to 2015 were reviewed. Patients experiencing VPS complications, valve malfunctioning, or with less than 1 year of follow-up were excluded. The ability of 1-day ELD to predict VPS outcome at 1- and 12-month follow-up was assessed by calculating sensitivity, specificity, and positive and negative predictive values.RESULTSOf 93 patients who underwent 1-day ELD, 3 did not complete the procedure. Of the remaining 90 patients, 2 experienced transient nerve root irritation. Twenty-four patients had negative test outcomes and 66 had positive test outcomes. Nine negative-outcome patients had intraprocedural headache, which showed 37.5% sensitivity (95% confidence interval [CI] 19.5%-59.2%) and 100% specificity (95% CI 93.1%-100%) as predictors of negative 1-day ELD outcome. Sixty-eight patients (6 with negative and 62 with positive outcomes) underwent VPS insertion, which was successful in 0 and 58 patients, respectively, at 1-month follow-up. Test sensitivity and specificity in predicting surgical outcome at 1-month follow-up were 100% (95% CI 92.3%-100%) and 60% (95% CI 27.4%-86.3%), respectively, with 94.1% accuracy (95% CI 85.6-98.4%). Among the 1-day ELD-positive patients, 2 showed no clinical benefit at 12 months follow-up. Test sensitivity and specificity in predicting surgical outcome at 12-month follow-up was 100% (95% CI 92.5%-100%) and 75.0% (95% CI 35.6%-95.5%), respectively, with 97.1% (95% CI 89.8%-99.6%) accuracy.CONCLUSIONSOne-day ELD is a reliable tool in iNPH management, with low complication risk and short trial duration. The test is very consistent in predicting who will have a positive outcome with VPS placement, given the high chance of successful outcome at 1- and 12-month follow-up; negative-outcome patients have a high risk of unsuccessful surgery. Intraprocedural headache is prognostic of 1-day ELD negative outcome.

Glaucoma in patients with shunt-treated normal pressure hydrocephalus.

OBJECTIVE: Changes in the pressure gradient between intraocular and intracranial compartments at the lamina cribrosa level are a possible explanation of normal tension glaucoma (NTG). Shunt-treated normal pressure hydrocephalus (NPH) is a model for testing whether the increase (time from disease onset to CSF shunt placement, i.e., "protection period") and decrease (time from shunt placement to observation, i.e., "exposure period") in intracranial pressure (ICP) are glaucoma protective or risk factors, respectively. The authors estimated the prevalence of NTG in patients with shunt-treated NPH and calculated the extent of optic nerve exposure to changes in the trans-lamina cribrosa gradient. METHODS: Data obtained in patients with NPH who had undergone ventriculoperitoneal (VP) shunt placement were analyzed. Patients with more than 6 months' follow-up, no pathologies associated with ICP changes or CSF dynamics disturbances, and no surgical or valve-related complications were scheduled for ophthalmic evaluation. RESULTS: Nine of 22 patients had NTG, which is about a 40-fold increase in rate compared with the rate in the general elderly population without hydrocephalus (p < 0.001). The median protection period was 12.0 months in patients with NTG and 18.0 months in those without NTG (p = 0.033). The median ICP decrease multiplied by duration of exposure in months was 76.0 mm Hg × months in the NTG group and 24.1 mm Hg × months in the no-NTG group (p = 0.048). The patients' median adjusted age (adjusted for "protection" and "exposure" times) was 85.1 years in the NTG group and 78.8 years in the no-NTG group (p = 0.001). CONCLUSIONS: A crucial risk factor for development of NTG in patients with shunt-treated NPH is the duration of optic nerve exposure to the lowering of ICP. Patients with NPH who are candidates for CSF shunting should be informed of the risk of incurring glaucoma. Longitudinal studies could provide estimates of tolerated times for a given ICP decrease.

Decompressive craniectomy arrests pulsatile aqueductal CSF flux: An in vivo demonstration using phase-contrast MRI. Case report.

We give a case study demonstration, using aqueductal cerebrospinal fluid (CSF) stroke volume quantification with phase-contrast magnetic resonance imaging, of a large opening in the rigid cranium by a decompressive craniectomy and its subsequent closure by bone flap repositioning resulted in the arrest and subsequent restoration of aqueductal CSF flow.

CSF proteomic analysis in patients with normal pressure hydrocephalus selected for the shunt: CSF biomarkers of response to surgical treatment.

The aim of our pilot study was to investigate, by a proteomic approach, the expressed differences in cerebrospinal fluid (CSF) protein patterns in order to aid in the diagnosis and treatment of normal pressure hydrocephalus (NPH). Seventeen patients with NPH, selected by Intracranial-Pressure monitoring (ICPmo), underwent implantation of a shunt and after 6 months were clinically re-evaluated. Thirteen patients improved, whereas four did not. During ICPmo CSF was collected and its proteoma was analyzed by 2D gel electrophoresis and mass spectrometry. The over-expression of alpha2HS glycoprotein, alpha1 antichimotrypsin and alpha1beta glycoprotein and the under-expression of glial fibrillary acidic protein, apolipoproteins (AIV, J and E), complement C3c, anti-thrombin, alpha2 antiplasmin and albumin seem to be associated with a positive response to surgery. Most of these proteins have been reported to be altered in Alzheimer disease, supporting the hypothesis of a possible link between these two nosological entities.

Restoration of sexual activity in patients with chronic hydrocephalus after shunt placement.

BACKGROUND: Chronic (normotensive or low pressure) hydrocephalus is characterized clinically by gait disturbance, cognitive and urinary impairment, known as Hakim's triad. Nothing has been reported about impairment in sexual function, which could involve both the patient and the patient's partner. METHODS: Out of 97 patients undergoing shunt placement for chronic hydrocephalus, 28 male patients (28.8%) referenced sexual dysfunction before operation. In these cases, we performed a preoperative and postoperative survey of sexual activity. RESULTS: In the preoperative period, all 28 patients reported having no sexual activity or arousal, from 2 to 4 years before the operation. Following shunt placement, 22/28 (78.5%) of patients regained variable sexual desire within a period ranging from 3 to 8 weeks, affording normal sexual activity with their partner. CONCLUSIONS: Sexual dysfunction can be part of the very early clinical background in patients with Hakim's triad and neuroradiological imaging compatible with chronic hydrocephalus. Restoration of sexual ability and arousal should be considered among the postoperative goals in these cases, together with improvements in cognition, gait, and urinary continence.

Tethered cervical spinal cord due to a hamartomatous stalk in a young adult. Case report.

The authors report on an unusual case of a congenital tethered cervical spinal cord in young man who presented with progressive tetraparesis. Neuroradiological evaluation of the spine revealed a discrete exophitic cervical spinal cord mass with a stalk of tissue that extended from the mass and terminated in the muscle tissue. The patient underwent a laminectomy with intradural exploration. A stalklike lesion was discovered and excised. Pathological examination showed that the stalk was formed of hamartomatous tissue. The patient improved following surgery, which suggested that tethering of the cervical spinal cord was responsible for his symptoms.