ABSTRACT
OBJECTIVE: The aim of this study was to investigate the diagnostic accuracy of the pulsatility curve to predict shunt response in patients with idiopathic normal pressure hydrocephalus (iNPH). METHODS: Lumbar cerebrospinal fluid dynamics were derived from an automatic lumbar infusion test (LIT) protocol. All patients were treated with ventriculoperitoneal shunting and re-examined 6 months after shunting. Patient demographics and outcomes were gathered in a prospective, electronic database that spanned from January 2012 to January 2020. A validated iNPH scale was used to assess patients preoperatively and 6 months postoperatively. The relationship of the relative pulse pressure coefficient (RPPC), delta amplitude, successful lowering of amplitude, and the pressure-value at a hypothetical amplitude of zero (P0), resistance to outflow (Rout), and outcome, were assessed using receiver operating characteristic (ROC) curves. RESULTS: We included 38 patients. The RPPC, delta amplitude, successful lowering of amplitude, and P0 parameters did not predict shunt response. Mean P0 was 0.5 (IQR 0.4-0.9) in improved patients and 0.4 (IQR 0-1.2) in non-improved patients. The delta amplitude was 0.16 kPa (IQR 0.10-0.23) in improved patients and 0.18 kPa (IQR 0.11-0.24) in non-improved patients. Furthermore, we found a technical failure rate of pulsatility curve measurements of 32%. CONCLUSION: Pulsatility curve results were not suitable in predicting shunt response in our cohort. The diagnostic value of LIT in case of normal pressure hydrocephalus should be subject to more rigorous research.
Subject(s)
Hydrocephalus, Normal Pressure , Cerebrospinal Fluid Shunts/methods , Humans , Hydrocephalus, Normal Pressure/cerebrospinal fluid , Hydrocephalus, Normal Pressure/diagnosis , Hydrocephalus, Normal Pressure/surgery , Neurosurgical Procedures , Prospective Studies , Ventriculoperitoneal ShuntABSTRACT
A detailed protocol is presented for the targeted enrichment of whole mitochondrial genomes based on an in-solution hybridization strategy. Bait is produced in-house by sonication of two long-range PCR amplicons and ligation of biotinylated double-stranded adapters. Indexed target DNA is hybridized with the bait in a multiplex enrichment reaction and pulled down using magnetic streptavidin beads followed by subsequent post-enrichment PCR and sequencing on an Illumina MiSeq. This strategy removes the need for expensive commercial bait probes while allowing enrichment of multiple samples in a single hybridization reaction. The method is particularly suitable for degraded DNA as it is able to enrich short DNA fragments and is not susceptible to polymerase artifacts introduced during PCR-based assays.
