Slope until reaching the plateau: a new predictor of valve response obtained by lumbar infusion test for idiopathic normal pressure hydrocephalus.

BACKGROUND: Diagnosis of idiopathic normal pressure hydrocephalus (iNPH) is based on clinical, radiological, and hydrodynamic data of cerebrospinal fluid (CSF) obtained by invasive methods such as lumbar infusion test, which is used to determine the resistance to CSF outflow (Rout). However, Rout has limitations, and its value as predictor of valve response is questioned. Other variables can be obtained by lumbar infusion test, such as the time to reach the plateau (TRP) and the slope until reaching the plateau (SRP). The objectives were to determine if SRP could be a predictor of response to ventriculoperitoneal shunt (VPS) and what variable (Rout versus SRP) would have greater predictive value. METHOD: Patients with probable iNPH who underwent a lumbar infusion test and were indicated for a VPS were retrospectively studied. Two groups were established, responders and non-responders. Rout, TRP (period between the start of infusion until reaching the plateau measured in seconds) and SRP ((plateau pressure-opening pressure)/TRP) were obtained. For Rout and SRP, the receiver operating curves (ROC) with its areas under the curve (AUC) were calculated. RESULTS: One hundred ten patients were included, being 86 responders (78.20%). Shunt responders had a significantly greater Rout (17.02 (14.45-20.23) versus 13.34 (12.10-16.28) mmHg/ml/min, p = 0.002) and SRP (0.049 (0.043-0.054) versus 0.031 (0.026-0.036) mmHg/sec, p < 0.001) and smaller TRP (641.28 (584.83-697.73) versus 777.65 (654.03-901.27) sec, p = 0.028) than non-responders. The AUC for SRP was greater than the AUC for Rout (0.763 (95 % CI 0.655-0.871, p < 0.001) versus 0.673 (95 % CI 0.595-0.801, p = 0.008), respectively), but the differences were not significant (p = 0.180). CONCLUSIONS: SRP could be considered predictor of response to VPS, and its accuracy tends to be better than Rout. So, this variable may be a useful tool to select shunt candidates among patients with probable iNPH.

[Utility of the intraoperative neurophysiological monitoring as a prognostic value of postoperative facial paresis in vestibular schwannomas]. / Utilidad de la monitorización neurofisiológica intraoperatoria como valor pronóstico de la parálisis facial posquirúrgica en schwannomas vestibulares.

BACKGROUND AND OBJECTIVE: Intraoperative neurophysiological monitoring allows us to predict the functional status of the facial nerve after vestibular schwannoma surgery. Due to the great variability of the neurophysiological protocols used for it, the goal of this study is to determine the prognostic ability of our neurophysiological protocol. MATERIAL AND METHODS: We have performed a statistical analysis of the neurophysiological monitoring data collected from patients operated between March 2009 and July 2021 at the Neurosurgery Service of Salamanca according to their functional status, both in the immediate post-surgical period and one year after surgery. RESULTS: A number of 51 patients between 46 and 63 years old (median: 54) were analyzed. We have found significant differences studying the threshold value of the stimulation intensity of the facial nerve and the variation of the Cortico-bulbar Evoked Motor Potentials (P=0.043 and P=0.011, respectively) between the patients with good and bad clinical situation after surgery. The most discriminating intensity threshold value was 0.35mA (Sensitivity: 85%; Specificity: 48%). No statistical relationship was found in the study group one year after surgery. CONCLUSIONS: Our intraoperative monitoring protocol allows us to predict the clinical situation of patients in the immediate postoperative period and improve information for the patient and her relatives after surgery. We cannot, however, use these parameters to predict the functional situation one year after surgery and make clinical decisions in this regard.

Cerebellar Hemangioblastoma with Leptomeningeal Spread and a Fatal Outcome: A Rare Case Report with MDM2 and EGFR Alterations.

Hemangioblastoma (HB) is a Central Nervous System (CNS) tumor with a generally favorable behavior and prognosis, classified as WHO grade 1. Sporadic HB is not related to any inherited disease, and it usually appears in a single location. Sporadic or VHL-related HBs show variable patterns of growth velocity. Cases of growing HB can cause mild symptoms such as headache, but some cases develop serious complications such as accumulation of cerebrospinal fluid in the brain with secondary neurological damage sometimes being irreversible when early treatment is not started. Our case showed some clinical characteristics more frequently observed in VHL-related HB rather than sporadic HB, and the presence of alterations in MDM2 and EGFR that could be related to the oncogenesis of these tumors. Even when the treatment of choice for HB is surgery, the presence of these genetic alterations could open a new window for research aimed at assessing the possibility of new therapies with TKIs-EGFR and anti-MDM2 inhibitors in those HB cases with multifocal recurrences or cases with an adverse clinical behavior.

Prognostic value of the pulse pressure amplitudes, time to reach the plateau and the slope obtained in the lumbar infusion test for the study of idiophatic normal pressure hydrocephalus.

BACKGROUND AND OBJECTIVE: To study the prognostic value of the resistance to the cerebrospinal fluid outflow (Rout) obtained in the lumbar infusion test in idiopathic normal pressure hydrocephalus (iNPH), as well as the pulse pressure amplitudes in the different periods of the test and other new variables extracted by Neuropicture® software. MATERIAL AND METHODS: Patients with 'probable iNPH' who underwent a lumbar infusion test were retrospectively revised. The positive predictive values (PPV) of the cutoff point of the best prognostic accuracy of the Rout, the basal pulse pressure amplitude (AMPo), the pulse pressure amplitude during the first 10 min (AMP10min), the plateau pulse pressure amplitude (AMPmes), the Rout pulse pressure amplitude (AMPRout), the time to reach the plateau (T), and the slope until reaching the plateau were determined. Patients were categorized either as responders or non-responders. RESULTS: The study included 64 responders patients and 16 non-responders patients. The PPV of Rout > 15 mmHg/mL/min was 91.7%; AMPo > 2.34 mmHg: 91.3%; AMP10 min > 4.34 mmHg: 83.3%; AMPmes > 12.44 mmHg: 84.6%; AMPRout > 6.34 mmHg: 85%; T < 634 s: 86.7%; p > 0.040 mmHg/s: 96.3%. CONCLUSIONS: Rout is a valid criterion to indicate a ventricular shunt. Pulse pressure amplitudes in the different periods of the lumbar infusion test, in addition to T and P, are other variables whose positivity is indicative of shunt response and should be considered in the diagnostic protocol of the iNPH.

Abdominal pseudocysts, an unusual complication of ventriculoperitoneal shunt systems: Literature systematic review. / Pseudoquistes abdominales, una complicación rara de los sistemas de derivación ventrículo-peritoneal: revisión sistemática de la literatura.

Since the first report in 1954, abdominal pseudocysts have been recognized as a particularly uncommon complication of ventriculoperitoneal shunts of CSF, so their etiology, diagnosis, and therapeutic management remain very controversial. Our objective is to offer a critical and updated systematic review of those controversial points, using a thorough search and review of the most relevant literature available. The clinical presentation of pseudocysts is normally through non-specific abdominal symptoms. The most validated etiology consists on the existence of a concomitant infection of the CSF shunt system, and so, treatment needs of antibiotherapy and total or partial substitution of the system. However, the pseudocyst itself doesn't need an active treatment, except for some specific cases. This management, algorithmically presented in the present work, achieves a lower recurrence rate than other options, but this one is still important, and is also associated with other complications of those shunts related with several other factors which need to be taken in account.

Prognostic value of the pulse pressure amplitudes, time to reach the plateau and the slope obtained in the lumbar infusion test for the study of idiophatic normal pressure hydrocephalus. / Validez pronóstica de las amplitudes de presión, tiempo en alcanzar la meseta y la pendiente obtenidas en el test de infusión para el estudio de la hidrocefalia idiopática de presión normal.

BACKGROUND AND OBJECTIVE: To study the prognostic value of the resistance to the cerebrospinal fluid outflow (Rout) obtained in the lumbar infusion test in idiopathic normal pressure hydrocephalus (iNPH), as well as the pulse pressure amplitudes in the different periods of the test and other new variables extracted by Neuropicture® software. MATERIAL AND METHODS: Patients with ́probable iNPH́ who underwent a lumbar infusion test were retrospectively revised. The positive predictive values (PPV) of the cutoff point of the best prognostic accuracy of the Rout, the basal pulse pressure amplitude (AMP0), the pulse pressure amplitude during the first 10minutes (AMP10min), the plateau pulse pressure amplitude (AMPmes), the Rout pulse pressure amplitude (AMPRout), the time to reach the plateau (T), and the slope until reaching the plateau were determined. Patients were categorized either as responders or non-responders. RESULTS: The study included 64 responders patients and 16 non-responders patients. The PPV of Rout> 15mmHg/ml/min was 91.7%; AMP0> 2.34mmHg: 91.3%; AMP10min>4.34mmHg: 83.3%; AMPmes>12.44mmHg: 84.6%; AMPRout>6.34mmHg: 85%; T <634seconds: 86.7%; P>0.040mmHg/sec: 96.3%. CONCLUSIONS: Rout is a valid criterion to indicate a ventricular shunt. Pulse pressure amplitudes in the different periods of the lumbar infusion test, in addition to T and P, are other variables whose positivity is indicative of shunt response and should be considered in the diagnostic protocol of the iNPH.

Utility of Radiologic Variables to Predict the Result of Lumbar Infusion Test in the Diagnosis of Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND: Diagnosis of idiopathic normal pressure hydrocephalus is based in clinical data, radiologic variables, and invasive cerebrospinal fluid (CSF) testing, such as the lumbar infusion test. Several neuroimaging findings are inconclusively related to improvement after CSF shunt surgery. CSF tests are invasive and have complications. The aim of this study was to select radiologic variables related to a positive lumbar infusion test so as to avoid this test in patients. METHODS: Patients with possible idiopathic normal pressure hydrocephalus were reviewed. The collected radiologic data were cingulate sulcus sign, disproportionately enlarged subarachnoid space, callosal angle, and width of temporal horns. Two groups were established: group 1, comprising patients with resistance to CSF outflow <12 mm Hg/mL/minute, and group 2, comprising patients with resistance to CSF outflow >12 mm Hg/mL/minute. Negative and positive predictive values were determined. RESULTS: The study included 43 patients in group 1 and 64 patients in group 2. Group 2 significantly showed more acute callosal angle with higher accuracy cutoff value of 90.6°, lower width of temporal horns with higher accuracy cutoff value of 8 mm, and higher percentage of cingulate sulcus sign and disproportionately enlarged subarachnoid space. Matching the radiologic variables, positive predictive values were >80%; however, negative predictive values were low. CONCLUSIONS: Owing to high positive predictive values of matched radiological variables, the lumbar infusion test could be avoided in the diagnosis of idiopathic normal pressure hydrocephalus. However, when 1 or 2 of the variables are negative, this invasive test should be performed.

Re-Evaluating Simpson Grade I, II, and III Resections in Neurosurgical Treatment of World Health Organization Grade I Meningiomas.

BACKGROUND: Since 1957, the Simpson grading system has been considered a predictive system for meningioma recurrence. However, since then, surgical equipment and neurosurgical technique have developed extensively, so this grading system should be re-evaluated. This study aims to assess if the recurrence rate and recurrence-free survival (RFS) are different after Simpson grade I, II, and III resections in World Health Organization (WHO) grade I meningiomas. METHODS: We retrospectively reviewed the data of patients who underwent surgical treatment of WHO grade I meningiomas located in the convexity (group 1), falx/parasagittal (group 2), skull base, and tentorium (group 3) between June 1991 and December 2011. We compared the recurrence rates and RFSs between Simpson grade I, II, and III resections in both overall cases and tumor subsets according to their localization. RESULTS: A total of 224 meningiomas were included in this study. There were no significant differences in recurrence rates and RFSs between Simpson grades I, II, and III. In each of the location groups, no significant differences were noted between the different degrees of Simpson. CONCLUSIONS: We have shown that complete resection of WHO grade I meningiomas achieves excellent tumor control, regardless of Simpson grades. More aggressive attempts at tumor resection (ie, Simpson grade I) must be balanced against the risks of removing dura or damaging critical neurovascular structures.