| 1. |
- Sandling, Johanna K., et al.
(författare)
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A candidate gene study of the type I interferon pathway implicates IKBKE and IL8 as risk loci for SLE
- 2011
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Ingår i: European Journal of Human Genetics. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 19:4, s. 479-484
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Tidskriftsartikel (refereegranskat)abstract
- Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease in which the type I interferon pathway has a crucial role. We have previously shown that three genes in this pathway, IRF5, TYK2 and STAT4, are strongly associated with risk for SLE. Here, we investigated 78 genes involved in the type I interferon pathway to identify additional SLE susceptibility loci. First, we genotyped 896 single-nucleotide polymorphisms in these 78 genes and 14 other candidate genes in 482 Swedish SLE patients and 536 controls. Genes with P<0.01 in the initial screen were then followed up in 344 additional Swedish patients and 1299 controls. SNPs in the IKBKE, TANK, STAT1, IL8 and TRAF6 genes gave nominal signals of association with SLE in this extended Swedish cohort. To replicate these findings we extracted data from a genomewide association study on SLE performed in a US cohort. Combined analysis of the Swedish and US data, comprising a total of 2136 cases and 9694 controls, implicates IKBKE and IL8 as SLE susceptibility loci (P(meta)=0.00010 and P(meta)=0.00040, respectively). STAT1 was also associated with SLE in this cohort (P(meta)=3.3 × 10(-5)), but this association signal appears to be dependent of that previously reported for the neighbouring STAT4 gene. Our study suggests additional genes from the type I interferon system in SLE, and highlights genes in this pathway for further functional analysis.
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| 2. |
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| 3. |
- Behrens, Anders, et al.
(författare)
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A computerized neuropsychological test battery designed for idiopathic normal pressure hydrocephalus
- 2014
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Ingår i: Fluids and Barriers of the CNS. - : Springer Science and Business Media LLC. - 2045-8118. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A tool for standardized and repeated neuropsychological assessments in patients with idiopathic normal pressure hydrocephalus (INPH) is needed. The objective of this study was to develop a computerized neuropsychological test battery designed for INPH and to evaluate its reliability, validity and patient's ability to complete the tests.METHODS: Based on a structured review of the literature on neuropsychological testing in INPH, the eight tests most sensitive to the INPH cognitive profile were implemented in a computerized format. The Geriatric Depression Scale (GDS) was also included. Tests were presented on a touch-screen monitor, with animated instructions and speaker sound. The battery was evaluated with the following cohorts: A. Test-retest reliability, 44 healthy elderly; B. Validity against standard pen and pencil testing, 28 patients with various cognitive impairments; C. Ability to complete test battery, defined as completion of at least seven of the eight tests, 40 investigated for INPH.RESULTS: A. All except the figure copy test showed good test-retest reliability, r = 0.67-0.90; B. A high correlation was seen between conventional and computerized tests (r = 0.66-0.85) except for delayed recognition and figure copy task; C. Seventy-eight percent completed the computerized battery; Patients diagnosed with INPH (n = 26) performed worse on all tests, including depression score, compared to healthy controls.CONCLUSIONS: A new computerized neuropsychological test battery designed for patients with communicating hydrocephalus and INPH was introduced. Its reliability, validity for general cognitive impairment and completion rate for INPH was promising. After exclusion of the figure copy task, the battery is ready for clinical evaluation and as a next step we suggest validation for INPH and a comparison before and after shunt surgery.TRIAL REGISTRATION: ClinicalTrials.org NCT01265251.
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| 4. |
- Behrens, Anders, et al.
(författare)
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Are intracranial pressure wave amplitudes measurable through lumbar puncture?
- 2013
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Ingår i: Acta Neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 127:4, s. 233-241
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Tidskriftsartikel (refereegranskat)abstract
- Objective The aim of this study was to investigate whether pulsations measured in the brain correspond to those measured in lumbar space, and subsequently whether lumbar punctures could replace invasive recordings. Methods In ten patients with normal pressure hydrocephalus, simultaneous recordings of the intracranial pressure (ICP; intraparenchymal) and lumbar pressure (LP; cerebrospinal fluid pressure) were performed. During registration, pressure was altered between resting pressure and 45mmHg using an infusion test. Data were analyzed regarding pulsations (i.e., amplitudes). Also, the pressure sensors were compared in a bench test. Results The correlation between intracranial and lumbar amplitudes was 0.98. At resting pressure, and moderately elevated ICP, intracranial pulse amplitudes exceeded that of lumbar space with about 0.9mmHg. At the highest ICP, the difference changed to 0.2mmHg. The bench test showed that the agreement of sensor readings was good at resting pressure, but reduced at higher amplitudes. Conclusions Compared to intracranial registrations, amplitudes measured through lumbar puncture were slightly attenuated. The bench test showed that differences were not attributable to dissimilarities of the sensor systems. A lumbar pressure amplitude measurement is an alternative to ICP recording, but the thresholds for what should be interpreted as elevated amplitudes need to be adjusted.
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| 5. |
- Behrens, Anders, et al.
(författare)
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In Reply
- 2010
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 67:6, s. 1864-
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Tidskriftsartikel (populärvet., debatt m.m.)
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| 6. |
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| 7. |
- Behrens, Anders, 1979-
(författare)
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Measurements in Idiopathic Normal Pressure Hydrocephalus : Computerized neuropsychological test battery and intracranial pulse waves
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Idiopathic Normal Pressure Hydrocephalus (INPH) is a condition affecting gait, cognition and continence. Radiological examination reveals enlarged ventricles of the brain. A shunt that drains CSF from the ventricles to the abdomen often improves the symptoms. Much research on INPH has been focused on identifying tests that predict the outcome after shunt surgery. As part of this quest, there are attempts to find measurement methods of intracranial parameters that are valid, reliable, tolerable and safe for patients.Today's technologies for intracranial pressure (ICP) measurement are invasive, often requiring a burr-hole in the skull. Recently, a method for non-invasive ICP measurements was suggested: the Pulsatile Index (PI) calculated from transcranial Doppler data assessed from the middle cerebral artery. In this thesis the relation between PI and ICP was explored in INPH patients during controlled ICP regulation by lumbar infusion. The confidence interval for predicted ICP, based on measured PI was too large for the method to be of clinical utility.In the quest for better predictive tests for shunt success in INPH, recent studies have shown promising results with criteria based on cardiac related ICP wave amplitudes. The brain ventricular system, and the fluid surrounding the spinal cord are in contact. In this thesis it was shown that ICP waves could be measured via lumbar subarachnoid space, with a slight underestimation.One of the cardinal symptoms of hydrocephalus is cognitive impairment. Neuropsychological studies have demonstrated cognitive tests that are impaired and improve after shunt surgery in INPH patients. However, there is currently no standardized test battery and different studies use different tests. In response, in this thesis a fully automated computerized neuropsychological test battery was developed. The validity, reliability, responsiveness to improvement after shunt surgery and feasibility for testing INPH patients was demonstrated. It was also demonstrated that INPH patients were impaired in all subtests, compared to healthy elderly.
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| 8. |
- Behrens, Anders, et al.
(författare)
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The Computerized General Neuropsychological INPH Test (CoGNIT) revealed improvement in Idiopathic Normal Pressure Hydrocephalus (INPH) after shunt surgery
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundWe have developed the COmputerized General Neuropsychological INPH Test (CoGNIT) dedicated for patients with idiopathic normal pressure hydrocephalus (INPH). Previously, validity and reliability of included tests have been established. The aim was to evaluate the battery’s sensitivity to detect cognitive changes after shunt surgery in INPH patients.MethodsPreoperatively, thirty-one INPH patients were given CoGNIT, which includes tests assessing memory, executive functions, attention, manual dexterity and psychomotor speed. CoGNIT also includes the Geriatric Depression Scale (GDS). Re-examination was done four months after shunt surgery. Scores and test completion were examined and compared to healthy elderly (n=44).ResultsPreoperative INPH test results were significantly lower in all tests compared to healthy. Improvements after shunt surgery were seen in all cognitive domains: memory (Ten-word list test, p<0,01), executive functions (Stroop incongruent, (p<0.05), attention (Two choice reaction test, p<0.01), psychomotor speed (Stroop congruent, p<0.05) and manual dexterity (Four- finger tapping, p<0.01). No ceiling effects were observed. Depressive symptoms were more common in INPH versus healthy and did not change postoperatively. Preoperatively 81 % of INPH patients completed at least eight of the nine included test.ConclusionsCoGNIT is sensitive to cognitive impairment and to investigate changes after shunt surgery in INPH. Completion rates are good. CoGNIT has a potential to be useful in the cognitive assessment of INPH.
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| 9. |
- 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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| 10. |
- Behrens, Anders, et al.
(författare)
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Transcranial Doppler pulsatility index: not an accurate method to assess intracranial pressure.
- 2010
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Ingår i: Neurosurgery. - 0148-396X .- 1524-4040. ; 66:6, s. 1050-1057
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Transcranial Doppler sonography (TCD) assessment of intracranial blood flow velocity has been suggested to accurately determine intracranial pressure (ICP). OBJECTIVE: We attempted to validate this method in patients with communicating cerebrospinal fluid systems using predetermined pressure levels. METHODS: Ten patients underwent a lumbar infusion test, applying 4 to 5 preset ICP levels. On each level, the pulsatility index (PI) in the middle cerebral artery was determined by measuring the blood flow velocity using TCD. ICP was simultaneously measured with an intraparenchymal sensor. ICP and PI were compared using correlation analysis. For further understanding of the ICP-PI relationship, a mathematical model of the intracranial dynamics was simulated using a computer. RESULTS: The ICP-PI regression equation was based on data from 8 patients. For 2 patients, no audible Doppler signal was obtained. The equation was ICP = 23*PI + 14 (R = 0.22, P < .01, N = 35). The 95% confidence interval for a mean ICP of 20 mm Hg was -3.8 to 43.8 mm Hg. Individually, the regression coefficients varied from 42 to 90 and the offsets from -32 to +3. The mathematical simulations suggest that variations in vessel compliance, autoregulation, and arterial pressure have a serious effect on the ICP-PI relationship. CONCLUSIONS: The in vivo results show that PI is not a reliable predictor of ICP. Mathematical simulations indicate that this is caused by variations in physiological parameters.
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