| 1. |
- Andersson, Nina, et al.
(författare)
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Dependency of cerebrospinal fluid outflow resistance on intracranial pressure
- 2008
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Ingår i: Journal of Neurosurgery. - 0022-3085 .- 1933-0693. ; 109:5, s. 918-922
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Tidskriftsartikel (refereegranskat)abstract
- OBJECT: The outflow resistance (Rout) of the cerebrospinal fluid (CSF) system has generally been accepted by most investigators as independent of intracranial pressure (ICP), but there are also those claiming that it is not. The general belief is that this question has been investigated numerous times in the past, but few studies have actually been specifically aimed at looking at this relationship, and no study has been able to provide scientific evidence to elucidate fully this fundamental and important issue. The objective of this study was to investigate the relationship between ICP and CSF outflow in 30 patients investigated for idiopathic normal-pressure hydrocephalus. METHODS: Lumbar infusion tests with constant pressure levels were performed, and ICP and corresponding flow were measured on 6 pressure levels for each patient. All data were standardized for comparison. RESULTS: In the range of moderate increases from baseline pressure (approximately 5-12 mm Hg, mean baseline pressure 11.7 mm Hg), the assumption of a pressure-independent Rout was confirmed (p = 0.5). However, when the pressure increment from baseline pressure was larger (approximately 15-22 mm Hg), the relationship had a nonlinear tendency (p < 0.05). CONCLUSIONS: The results of this study support the classic textbook theory of a pressure-independent Rout in the normal ICP range, where the CSF system is commonly operating. However, the theory might have to be questioned in regions where ICP exceeds baseline pressure by too much.
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| 2. |
- Behrens, Anders, et al.
(författare)
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The Computerized General Neuropsychological INPH Test revealed improvement in idiopathic normal pressure hydrocephalus after shunt surgery
- 2020
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Ingår i: Journal of Neurosurgery. - : AMER ASSOC NEUROLOGICAL SURGEONS. - 0022-3085 .- 1933-0693. ; 132:3, s. 733-740
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE The Computerized General Neuropsychological INPH Test (CoGNIT) provides the clinician and the researcher with standardized and accessible cognitive assessments in patients with idiopathic normal pressure hydrocephalus (INPH). CoGNIT includes tests of memory, executive functions, attention, manual dexterity, and psychomotor speed. Investigations of the validity and reliability of CoGNIT have been published previously. The aim of this study was to evaluate CoGNIT's sensitivity to cognitive change after shunt surgery in patients with INPH.METHODS Forty-one patients with INPH (median Mini-Mental State Examination score 26) were given CoGNIT preoperatively and at a postoperative follow-up 4 months after shunt surgery. Scores were compared to those of 44 healthy elderly control volunteers. CoGNIT was administered by either a nurse or an occupational therapist.RESULTS Improvement after shunt surgery was seen in all cognitive domains: memory (10-word list test, p < 0.01); executive functions (Stroop incongruent color and word test, p < 0.01); attention (2-choice reaction test, p < 0.01); psychomotor speed (Stroop congruent color and word test, p < 0.01); and manual dexterity (4-finger tapping, p < 0.01). No improvement was seen in the Mini-Mental State Examination score. Preoperative INPH test scores were significantly impaired compared to healthy control subjects (p < 0.001 for all tests).CONCLUSIONS In this study the feasibility for CoGNIT to detect a preoperative impairment and postoperative improvement in INPH was demonstrated. CoGNIT has the potential to become a valuable tool in clinical and research work.
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| 3. |
- Eklund, Sanna A., et al.
(författare)
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Vascular risk profiles for predicting outcome and long-term mortality in patients with idiopathic normal pressure hydrocephalus : comparison of clinical decision support tools
- 2023
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Ingår i: Journal of Neurosurgery. - : Journal of Neurosurgery Publishing Group (JNSPG). - 0022-3085 .- 1933-0693. ; 138:2, s. 476-482
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Vascular risk factors (VRFs) may act synergistically, and clinical decision support tools (CDSTs) have been developed that present vascular risk as a summarized score. Because VRFs are a major issue in patients with idiopathic normal pressure hydrocephalus (INPH), a CDST may be useful in the diagnostic workup. The objective was to compare 4 CDSTs to determine which one most accurately predicts short-term outcome and 10-year mortality after CSF shunt surgery in INPH patients.METHODS: One-hundred forty INPH patients who underwent CSF shunt surgery were included. For each patient, 4 CDST scores (Systematic Coronary Risk Evaluation–Older Persons [SCORE-OP], Framingham Risk Score [FRS], Revised Framingham Stroke Risk Profile, and Kiefer’s Comorbidity Index [KCI]) were estimated. Short-term outcome (3 months after CSF shunt surgery) was defined on the basis of improvements in gait, Mini-Mental State Examination score, and modified Rankin Scale score. The 10-year mortality rate after surgery was noted. The CDSTs were compared by using Cox regression analysis, receiver operating characteristic curve analysis, and the chi-square test.RESULTS: For 3 CDSTs, increased score was associated with increased risk of 10-year mortality. A 1-point increase in the FRS indicated a 2% higher risk of death within 10 years (HR 1.02, 95% CI 1.003–1.035, p = 0.021); SCORE-OP, 5% (HR 1.05, 95% CI 1.019–1.087, p = 0.002); and KCI, 12% (HR 1.12, 95% CI 1.03–1.219, p = 0.008). FRS predicted short-term outcome of surgery (p = 0.024). When the cutoff value was set to 32.5%, the positive predictive value was 80% and the negative predictive value was 48% (p = 0.012).CONCLUSIONS: The authors recommend using FRS to predict short-term outcome and 10-year risk of mortality in INPH patients. The study indicated that extensive treatment of the risk factors of INPH may decrease risk of mortality.
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| 4. |
- Eklund, Sanna A., et al.
(författare)
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Vascular risk profiles for predicting outcome and long-term mortality in patients with idiopathic normal pressure hydrocephalus: comparison of clinical decision support tools
- 2023
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Ingår i: Journal of Neurosurgery. - : AMER ASSOC NEUROLOGICAL SURGEONS. - 0022-3085 .- 1933-0693. ; 138:2, s. 476-482
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE Vascular risk factors (VRFs) may act synergistically, and clinical decision support tools (CDSTs) have been developed that present vascular risk as a summarized score. Because VRFs are a major issue in patients with idiopathic normal pressure hydrocephalus (INPH), a CDST may be useful in the diagnostic workup. The objective was to compare 4 CDSTs to determine which one most accurately predicts short-term outcome and 10-year mortality after CSF shunt surgery in INPH patients. METHODS One-hundred forty INPH patients who underwent CSF shunt surgery were included. For each patient, 4 CDST scores (Systematic Coronary Risk Evaluation-Older Persons [SCORE-OP], Framingham Risk Score [FRS], Revised Framingham Stroke Risk Profile, and Kiefers Comorbidity Index [KCI]) were estimated. Short-term outcome (3 months after CSF shunt surgery) was defined on the basis of improvements in gait, Mini-Mental State Examination score, and modified Rankin Scale score. The 10-year mortality rate after surgery was noted. The CDSTs were compared by using Cox regression analysis, receiver operating characteristic curve analysis, and the chi-square test. RESULTS For 3 CDSTs, increased score was associated with increased risk of 10-year mortality. A 1-point increase in the FRS indicated a 2% higher risk of death within 10 years (HR 1.02, 95% CI 1.003-1.035, p = 0.021); SCORE-OP, 5% (HR 1.05, 95% CI 1.019-1.087, p = 0.002); and KCI, 12% (HR 1.12, 95% CI 1.03-1.219, p = 0.008). FRS predicted short-term outcome of surgery (p = 0.024). When the cutoff value was set to 32.5%, the positive predictive value was 80% and the negative predictive value was 48% (p = 0.012). CONCLUSIONS The authors recommend using FRS to predict short-term outcome and 10-year risk of mortality in INPH patients. The study indicated that extensive treatment of the risk factors of INPH may decrease risk of mortality. Clinical trial registration no.: NCT01850914 (ClinicalTrials.gov)
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| 5. |
- Gasslander, Johan, et al.
(författare)
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Risk factors for developing subdural hematoma : a registry-based study in 1457 patients with shunted idiopathic normal pressure hydrocephalus
- 2021
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Ingår i: Journal of Neurosurgery. - : American Association of Neurological Surgeons. - 0022-3085 .- 1933-0693. ; 134:2, s. 668-677
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Subdural hematomas and hygromas (SDHs) are common complications in idiopathic normal pressure hydrocephalus (iNPH) patients with shunts. In this registry-based study, patients with shunted iNPH were screened nationwide to identify perioperative variables that may increase the risk of SDH.METHODS: The Swedish Hydrocephalus Quality Registry was reviewed for iNPH patients who had undergone shunt surgery in Sweden in 2004-2014. Potential risk factors for SDH were recorded preoperatively and 3 months after surgery. Drug prescriptions were identified from a national pharmacy database. Patients who developed SDHs were compared with those without SDHs.RESULTS: The study population consisted of 1457 patients, 152 (10.4%) of whom developed an SDH. Men developed an SDH more often than women (OR 2.084, 95% CI 1.421-3.058, p < 0.001). Patients on platelet aggregation inhibitors developed an SDH more often than those who were not (OR 1.733, 95% CI 1.236-2.431, p = 0.001). At surgery, shunt opening pressures had been set 5.9 mm H2O lower in the SDH group than in the no-SDH group (109.6 ± 24.1 vs 115.5 ± 25.4 mm H2O, respectively, p = 0.009). Antisiphoning devices (ASDs) were used in 892 patients but did not prevent SDH. Mean opening pressures at surgery and the follow-up were lower with shunts with an ASD, without causing more SDHs. No other differences were seen between the groups.CONCLUSIONS: iNPH patients in this study were diagnosed and operated on in routine practice; thus, the results represent everyday care. Male sex, antiplatelet medication, and a lower opening pressure at surgery were risk factors for SDH. Physical status and comorbidity were not. ASD did not prevent SDH, but a shunt with an ASD allowed a lower opening pressure without causing more SDHs.
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| 6. |
- Jacobsson, Johan, et al.
(författare)
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Comparison of the CSF dynamics between patients with idiopathic normal pressure hydrocephalus and healthy volunteers
- 2019
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Ingår i: Journal of Neurosurgery. - : American Association of Neurological Surgeons. - 0022-3085 .- 1933-0693. ; 131:4, s. 1018-1023
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Intracranial pressure (ICP), outflow resistance (Rout), and amplitude of cardiac-related ICP pulsations (AMPs) are established parameters to describe the CSF hydrodynamic system and are assumed, but not confirmed, to be disturbed in idiopathic normal pressure hydrocephalus (INPH). The aim of this study was to compare the CSF hydrodynamic profile between patients with INPH and healthy volunteers.METHODS: Sixty-two consecutive INPH patients (mean age 74 years) and 40 healthy volunteers (mean age 70 years) were included. Diagnosis was made by two independent neurologists who assessed patients’ history, neurological status, and MRI studies. A CSF dynamic investigation through the lumbar route was performed: ICP and other CSF dynamic variables were blinded to the neurologists during the diagnostic process and were not used for establishing the diagnosis of INPH.RESULTS: Rout was significantly higher in INPH (Rout 17.1 vs 11.1; p < 0.001), though a substantial number of INPH subjects had normal Rout. There were no differences between INPH patients and controls regarding ICP (mean 11.5 mm Hg). At resting pressure, there was a trend that AMP in INPH was increased (2.4 vs 2.0 mm Hg; p = 0.109). The relationship between AMP and ICP was that they shared the same slope, but the curve was significantly shifted to the left for INPH (reduced P0 [p < 0.05]; i.e., higher AMP for the same ICP).CONCLUSIONS: This study established that the CSF dynamic profile of INPH deviates from that of healthy volunteers and that INPH should thus be regarded as a disease in which intracranial hydrodynamics are part of the pathophysiology.Clinical trial registration no.: NCT01188382 (clinicaltrials.gov)
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| 7. |
- Larsson, Jenny, et al.
(författare)
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Epilepsy, headache, and abdominal pain after shunt surgery for idiopathic normal pressure hydrocephalus : the INPH-CRasH study
- 2018
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Ingår i: Journal of Neurosurgery. - Rolling Meadows : American association of neurological surgeons. - 0022-3085 .- 1933-0693. ; 128:6, s. 1674-1683
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE Adverse events related to shunt surgery are common and might have a negative effect on outcome in patients with idiopathic normal pressure hydrocephalus (INPH). The authors' objectives were to establish the frequencies of epilepsy, headache, and abdominal pain and determine their impact on patient quality of life (QOL), in long-term follow-up after shunt surgery for INPH.METHODS One hundred seventy-six shunt-treated patients with INPH (mean age 74 years) and 368 age- and sex-matched controls from the population were included. The mean follow-up time after surgery was 21 months (range 6-45 months). Each participant answered a questionnaire regarding present frequency and severity of headache and abdominal pain. Confirmed diagnoses of epilepsy and all prescriptions for antiepileptic drugs (AEDs) before and after shunt surgery for INPH were gathered from national registries. Equivalent presurgical and postsurgical time periods were constructed for the controls based on the date of surgery (the division date for controls is referred to as virtual surgery). All registry data covered a mean period of 6 years (range 3-8 years) before surgery/virtual surgery and 4 years (range 2-6 years) after surgery/virtual surgery. Provoked epileptic seizures were excluded. Patient QOL was assessed with the EuroQoL 5-dimension 5-level instrument.RESULTS Epilepsy was more common in shunt-treated patients with INPH than in controls (4.5% vs 1.1%, respectively; p = 0.023), as was treatment with AEDs (14.8% vs 7.3%, respectively; p = 0.010). No difference was found between the populations before surgery/virtual surgery (epilepsy, 2.3% [INPH] vs 1.1% [control], p = 0.280; AED treatment, 8.5% [INPH] vs 5.4% [control], p = 0.235). New-onset epilepsy and new AED treatment after surgery/virtual surgery were more common in INPH (epilepsy, 2.3% [INPH] vs 0.0% [control], p = 0.011; AED, 8.5% [INPH] vs 3.3% [control], p = 0.015). At follow-up, more patients with INPH than controls experienced headache several times per month or more often (36.1% vs 11.6%, respectively; p < 0.001). Patients with INPH and unilateral headache had more right-sided headaches than controls (p = 0.038). Postural headache was experienced by 16% (n = 27 of 169) of the patients with INPH. Twenty percent (n = 35) of the patients with INPH had persistent abdominal pain. Headache was not correlated to lower QOL. The study was underpowered to draw conclusions regarding QOL in patients with INPH who had epilepsy and abdominal pain, but the finding of no net difference in mean QOL indicates that no correlation between them existed.CONCLUSIONS Epilepsy, headache, and abdominal pain are common in long-term follow-up in patients after shunt surgery for INPH and are more common among patients with INPH than in the general population. All adverse events, including mild and moderate ones, should be considered during postoperative follow-ups and in the development of new methods for shunt placement.
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| 8. |
- Lenfeldt, Niklas, et al.
(författare)
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Cerebrospinal fluid pulse pressure method: a possible substitute for the examination of B waves
- 2004
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Ingår i: Journal of Neurosurgery. - : American Association of Neurological Surgeons. - 0022-3085 .- 1933-0693. ; 101:6, s. 944-950
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Tidskriftsartikel (refereegranskat)abstract
- Object. The appearance of numerous B waves during intracranial pressure (ICP) registration in patients with idiopathic adult hydrocephalus syndrome (IAHS) is considered to predict good outcome after shunt surgery. The aim of this study was to describe which physical parameters of the cerebrospinal fluid (CSF) system B-waves reflect and to find a method that could replace long-term B-wave analysis.Methods. Ten patients with IAHS were subjected to long-term registration of ICP and a lumbar constant-pressure infusion test. The B-wave presence, CSF outflow resistance (Rout), and relative pulse pressure coefficient (RPPC) were assessed using computerized analysis. The RPPC was introduced as a parameter reflecting the joint effect of elastance and pulsatory volume changes on ICP and was determined by relating ICP pulse amplitudes to mean ICP.Conclusions. The B-wave presence on ICP registration correlates strongly with RPPC (r = 0.91, p < 0.001, 10 patients) but not with CSF Rout. This correlation indicates that B waves—like RPPC—primarily reflect the ability of the CSF system to reallocate and store liquid rather than absorb it. The RPPC-assessing lumbar short-term CSF pulse pressure method could replace the intracranial long-term B-wave analysis.
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| 9. |
- Sundström, Nina, et al.
(författare)
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Comparison between 3 infusion methods to measure cerebrospinal fluid outflow conductance
- 2010
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Ingår i: Journal of Neurosurgery. - : American Association of Neurological Surgeons. - 0022-3085 .- 1933-0693. ; 113:6, s. 1294-1303
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Tidskriftsartikel (refereegranskat)abstract
- Object There are several infusion methods available to estimate the outflow conductance (Cout) or outflow resistance (Rout = 1/Cout) of the CSF system. It has been stated that for unknown reasons, the bolus infusion method estimates a higher Cout than steady-state infusion methods. The aim of this study was to compare different infusion methods for estimation of Cout.Methods The following 3 different infusion methods were used: the bolus infusion method (Cout bol); the constant flow infusion method, both static (Cout stat) and dynamic (Cout dyn) analyses; and the constant pressure infusion method (Cout cpi). Repeated investigations were performed on an experimental model with well-known characteristics, with and without physiological pressure variations (B-waves, breathing, and so on). All 3 methods were also performed in a randomized order during the same investigation in 20 patients with probable or possible idiopathic normal-pressure hydrocephalus; 6 of these patients had a shunt and 14 did not.Results Without the presence of physiological pressure variations, the concordance in the experimental model was good between all methods. When they were added, the repeatability was better for the steady-state methods and a significantly higher Cout was found with the bolus method in the region of clinically relevant Cout (p < 0.05). The visual fit for the bolus infusion was dependent on subjective assessment by the operator. This experimental finding was confirmed by the clinical results, where significant differences were found in the investigations in patients without shunts between Cout of the visual bolus method and Cout stat, Cout dyn, and Cout cpi (4.58, 4.18, and 6.12 μl/[second × kPa], respectively).Conclusions This study emphasized the necessity for standardization of Cout measurements. An experienced operator could partly compensate for difficulties in correctly estimating the pressure parameters for the bolus infusion method, but for the general user this study suggests a steady-state method for estimating Cout.
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| 10. |
- Sundström, Nina, et al.
(författare)
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Subdural hematomas in 1846 patients with shunted idiopathic normal pressure hydrocephalus : treatment and long-term survival
- 2018
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Ingår i: Journal of Neurosurgery. - : American Association of Neurological Surgeons. - 0022-3085 .- 1933-0693. ; 129:3, s. 797-804
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE Subdural hematoma (SDH) is the most common serious adverse event in patients with shunts. Adjustable shunts are used with increasing frequency and make it possible to noninvasively treat postoperative SDH. The objective of this study was to describe the prevalence and treatment preferences of SDHs, based on fixed or adjustable shunt valves, in a national cohort of patients with shunted idiopathic normal pressure hydrocephalus (iNPH), as well as to evaluate the effect of SDH and treatment on long-term survival.METHODS Patients with iNPH who received a CSF shunt in Sweden from 2004 to 2015 were included in a prospective quality registry (n = 1846) and followed regarding SDH, its treatment, and mortality. The treatment of SDH was categorized into surgery, opening pressure adjustments, or no treatment.RESULTS During the study period, the proportion of adjustable shunts increased from 75% to 95%. Ten percent (n = 184) of the patients developed an SDH. In 103 patients, treatment was solely opening pressure adjustment. Surgical treatment was used in 66 cases (36%), and 15 (8%) received no treatment. In patients with fixed shunt valves, 90% (n = 17) of SDHs were treated surgically compared with 30% (n = 49) in patients with adjustable shunts (p < 0.001). There was no difference in long-term patient survival between the SDH and non-SDH groups or between different treatments.CONCLUSIONS SDH remains a common complication after shunt surgery, but adjustable shunts reduced the need for surgical interventions. SDH and treatment did not significantly affect survival in this patient group, thus the noninvasive treatment offered by adjustable shunts considerably reduces the level of severity for this common adverse event.
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