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- Farahmand, Dan, et al.
(author)
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Intracranial pressure in hydrocephalus: impact of shunt adjustments and body positions
- 2015
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In: Journal of Neurology Neurosurgery and Psychiatry. - : BMJ. - 0022-3050 .- 1468-330X. ; 86:2, s. 222-228
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Journal article (peer-reviewed)abstract
- Background The association between intracranial pressure (ICP) and different shunt valve opening pressures in relation to body positions is fundamental for understanding the physiological function of the shunt. Objective To analyse the ICP and ICP wave amplitude (AMP) at different shunt settings and body positions in patients with hydrocephalus. Methods In this prospective study 15 patients with communicating hydrocephalus were implanted with a ligated adjustable ventriculoperitoneal shunt. They also received a portable intraparenchymatous ICP-monitoring device. Postoperative ICP and AMP were recorded with the patients in three different body positions (supine, sitting and walking) and with the shunt ligated and open at high, medium and low valve settings. In each patient 12 10 min segments were coded, blinded and analysed for mean ICP and mean AMP using an automated computer algorithm. Results Mean ICP and mean AMP were lower at all three valve settings compared with the ligated shunt state (p<0.001). Overall, when compared with the supine position, mean ICP was 11.5 +/- 1.1 (mean +/- SD) mm Hg lower when sitting and 10.5 +/- 1.1 mm Hg lower when walking (p<0.001). Mean ICP was overall 1.1 mm Hg higher (p=0.042) when walking compared with sitting. The maximal adjustability difference (highest vs lowest valve setting) was 4.4 mm Hg. Conclusions Changing from a supine to an upright position reduced ICP while AMP only increased at trend level. Lowering of the shunt valve opening pressure decreased ICP and AMP but the difference in mean ICP in vivo between the highest and lowest opening pressures was less than half that previously observed in vitro.
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| 2. |
- Jeppsson, Anna, et al.
(author)
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CSF biomarkers distinguish idiopathic normal pressure hydrocephalus from its mimics
- 2019
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In: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ. - 0022-3050 .- 1468-330X. ; 90:10, s. 1117-1123
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Journal article (peer-reviewed)abstract
- Objective: To examine the differential diagnostic significance of cerebrospinal fluid (CSF) biomarkers reflecting Alzheimer's disease-related amyloid β (Aβ) production and aggregation, cortical neuronal damage, tau pathology, damage to long myelinated axons and astrocyte activation, which hypothetically separates patients with idiopathic normal pressure hydrocephalus (iNPH) from patients with other neurodegenerative disorders. Methods: The study included lumbar CSF samples from 82 patients with iNPH, 75 with vascular dementia, 70 with Parkinson's disease, 34 with multiple system atrophy, 34 with progressive supranuclear palsy, 15 with corticobasal degeneration, 50 with Alzheimer's disease, 19 with frontotemporal lobar degeneration and 54 healthy individuals (HIs). We analysed soluble amyloid precursor protein alpha (sAPPα) and beta (sAPPβ), Aβ species (Aβ38, Aβ40 and Aβ42), total tau (T-tau), phosphorylated tau, neurofilament light and monocyte chemoattractant protein 1 (MCP-1). Results: Patients with iNPH had lower concentrations of tau and APP-derived proteins in combination with elevated MCP-1 compared with HI and the non-iNPH disorders. T-tau, Aβ40 and MCP-1 together yielded an area under the curve of 0.86, differentiating iNPH from the other disorders. A prediction algorithm consisting of T-tau, Aβ40 and MCP-1 was designed as a diagnostic tool using CSF biomarkers. Conclusions: The combination of the CSF biomarkers T-tau, Aβ40 and MCP-1 separates iNPH from cognitive and movement disorders with good diagnostic sensitivity and specificity. This may have important implications for diagnosis and clinical research on disease mechanisms for iNPH. © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
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