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Bäckström D, Linder J, Jakobson Mo S, Riklund K, Zetterberg H, Blennow K, Forsgren L, Lenfeldt N. NfL as a biomarker for neurodegeneration and survival in Parkinson disease. Neurology 2020; 95:e827-e838. [PMID: 32680941 PMCID: PMC7605503 DOI: 10.1212/wnl.0000000000010084] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 02/13/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine whether neurofilament light chain protein in CSF (cNfL), a sensitive biomarker of neuroaxonal damage, reflects disease severity or can predict survival in Parkinson disease (PD). METHODS We investigated whether disease severity, phenotype, or survival in patients with new-onset PD correlates with cNfL concentrations around the time of diagnosis in the population-based New Parkinsonism in Umeå (NYPUM) study cohort (n = 99). A second, larger new-onset PD cohort (n = 194) was used for independent validation. Association of brain pathology with the cNfL concentration was examined with striatal dopamine transporter imaging and repeated diffusion tensor imaging at baseline and 1 and 3 years. RESULTS Higher cNfL in the early phase of PD was associated with greater severity of all cardinal motor symptoms except tremor in both cohorts and with shorter survival and impaired olfaction. cNfL concentrations above the median of 903 ng/L conferred an overall 5.8 times increased hazard of death during follow-up. After adjustment for age and sex, higher cNfL correlated with striatal dopamine transporter uptake deficits and lower fractional anisotropy in diffusion tensor imaging of several axonal tracts. CONCLUSIONS cNfL shows usefulness as a biomarker of disease severity and to predict survival in PD. The present results indicate that the cNfL concentration reflects the intensity of the neurodegenerative process, which could be important in future clinical trials. CLASSIFICATION OF EVIDENCE This study provides Class II evidence that in patients with PD, cNfL concentrations are associated with more severe disease and shorter survival.
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Affiliation(s)
- David Bäckström
- From the Department of Clinical Science (D.B., J.L., L.F., N.L.), Neurosciences, and Department of Radiation Sciences (S.J.M., K.R.), Diagnostic Radiology and Umeå Center for Functional Brain Imaging, Umeå University; Department of Psychiatry and Neurochemistry (H.Z., K.B.), Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z., K.B.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), UCL Queen Square Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK.
| | - Jan Linder
- From the Department of Clinical Science (D.B., J.L., L.F., N.L.), Neurosciences, and Department of Radiation Sciences (S.J.M., K.R.), Diagnostic Radiology and Umeå Center for Functional Brain Imaging, Umeå University; Department of Psychiatry and Neurochemistry (H.Z., K.B.), Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z., K.B.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), UCL Queen Square Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK
| | - Susanna Jakobson Mo
- From the Department of Clinical Science (D.B., J.L., L.F., N.L.), Neurosciences, and Department of Radiation Sciences (S.J.M., K.R.), Diagnostic Radiology and Umeå Center for Functional Brain Imaging, Umeå University; Department of Psychiatry and Neurochemistry (H.Z., K.B.), Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z., K.B.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), UCL Queen Square Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK
| | - Katrine Riklund
- From the Department of Clinical Science (D.B., J.L., L.F., N.L.), Neurosciences, and Department of Radiation Sciences (S.J.M., K.R.), Diagnostic Radiology and Umeå Center for Functional Brain Imaging, Umeå University; Department of Psychiatry and Neurochemistry (H.Z., K.B.), Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z., K.B.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), UCL Queen Square Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK
| | - Henrik Zetterberg
- From the Department of Clinical Science (D.B., J.L., L.F., N.L.), Neurosciences, and Department of Radiation Sciences (S.J.M., K.R.), Diagnostic Radiology and Umeå Center for Functional Brain Imaging, Umeå University; Department of Psychiatry and Neurochemistry (H.Z., K.B.), Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z., K.B.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), UCL Queen Square Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK
| | - Kaj Blennow
- From the Department of Clinical Science (D.B., J.L., L.F., N.L.), Neurosciences, and Department of Radiation Sciences (S.J.M., K.R.), Diagnostic Radiology and Umeå Center for Functional Brain Imaging, Umeå University; Department of Psychiatry and Neurochemistry (H.Z., K.B.), Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z., K.B.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), UCL Queen Square Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK
| | - Lars Forsgren
- From the Department of Clinical Science (D.B., J.L., L.F., N.L.), Neurosciences, and Department of Radiation Sciences (S.J.M., K.R.), Diagnostic Radiology and Umeå Center for Functional Brain Imaging, Umeå University; Department of Psychiatry and Neurochemistry (H.Z., K.B.), Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z., K.B.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), UCL Queen Square Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK
| | - Niklas Lenfeldt
- From the Department of Clinical Science (D.B., J.L., L.F., N.L.), Neurosciences, and Department of Radiation Sciences (S.J.M., K.R.), Diagnostic Radiology and Umeå Center for Functional Brain Imaging, Umeå University; Department of Psychiatry and Neurochemistry (H.Z., K.B.), Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg; Clinical Neurochemistry Laboratory (H.Z., K.B.), Sahlgrenska University Hospital, Mölndal, Sweden; Department of Neurodegenerative Disease (H.Z.), UCL Queen Square Institute of Neurology; and UK Dementia Research Institute at UCL (H.Z.), London, UK
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Wåhlin A, Fordell H, Ekman U, Lenfeldt N, Malm J. Rehabilitation in chronic spatial neglect strengthens resting-state connectivity. Acta Neurol Scand 2019; 139:254-259. [PMID: 30427058 DOI: 10.1111/ane.13048] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Rehabilitation of patients with chronic visuospatial neglect is underexplored, and little is known about neural mechanisms that can be exploited to promote recovery. In this study, we present data on resting-state functional connectivity within the dorsal attention network (DAN) in chronic neglect patients as they underwent training in a virtual reality (VR) environment that improved left-side awareness. METHODS The study included 13 patients with visuospatial neglect persisting more than six months after a right-sided stroke. The patients underwent resting-state functional magnetic resonance imaging (fMRI). Scans were collected at baseline and after five weeks of intense training. We specifically examined resting-state functional connectivity within the DAN. In addition, using spatial concordance correlation, we compared changes in the spatial topology of the DAN with that of other networks. RESULTS We found a longitudinal increase in interhemispheric functional connectivity between the right frontal eye field and the left intraparietal sulcus following training (before: 0.33 ± 0.17 [mean ± SD]; after: 0.45 ± 0.13; P = 0.004). The spatial concordance analyses indicated that training influenced the DAN connectivity more than any of the other networks. CONCLUSION Intense VR training that improved left-sided awareness in chronic stroke patients also increased sporadic interhemispheric functional connectivity within the DAN. Specifically, a region responsible for saccadic eye movement to the left became more integrated with the left posterior parietal cortex. These results highlight a mechanism that should be exploited in the training of patients with chronic visuospatial neglect.
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Affiliation(s)
- Anders Wåhlin
- Department of Radiation Sciences, Biomedical Engineering; Umeå University; Umeå Sweden
- Umeå Center for Functional Brain Imaging; Umeå University; Umeå Sweden
| | - Helena Fordell
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - Urban Ekman
- Umeå Center for Functional Brain Imaging; Umeå University; Umeå Sweden
- Department of Integrative Medical Biology; Umeå University; Umeå Sweden
- Department of Neurobiology, Care Sciences and Society; Karolinska Institutet; Stockholm Sweden
| | - Niklas Lenfeldt
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - Jan Malm
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
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Ekman U, Fordell H, Eriksson J, Lenfeldt N, Wåhlin A, Eklund A, Malm J. Increase of frontal neuronal activity in chronic neglect after training in virtual reality. Acta Neurol Scand 2018; 138:284-292. [PMID: 29770439 DOI: 10.1111/ane.12955] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2018] [Indexed: 10/16/2022]
Abstract
OBJECTIVES A third of patients with stroke acquire spatial neglect associated with poor rehabilitation outcome. New effective rehabilitation interventions are needed. Scanning training combined with multisensory stimulation to enhance the rehabilitation effect is suggested. In accordance, we have designed a virtual-reality based scanning training that combines visual, audio and sensori-motor stimulation called RehAtt® . Effects were shown in behavioural tests and activity of daily living. Here, we use fMRI to evaluate the change in brain activity during Posner's Cuing Task (attention task) after RehAtt® intervention, in patients with chronic neglect. METHODS Twelve patients (mean age = 72.7 years, SD = 6.1) with chronic neglect (persistent symptoms >6 months) performed the interventions 3 times/wk during 5 weeks, in total 15 hours. Training effects on brain activity were evaluated using fMRI task-evoked responses during the Posner's cuing task before and after the intervention. RESULTS Patients improved their performance in the Posner fMRI task. In addition, patients increased their task-evoked brain activity after the VR interventions in an extended network including pre-frontal and temporal cortex during attentional cueing, but showed no training effects during target presentations. CONCLUSIONS The current pilot study demonstrates that a novel multisensory VR intervention has the potential to benefit patients with chronic neglect in respect of behaviour and brain changes. Specifically, the fMRI results show that strategic processes (top-down control during attentional cuing) were enhanced by the intervention. The findings increase knowledge of the plasticity processes underlying positive rehabilitation effects from RehAtt® in chronic neglect.
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Affiliation(s)
- U. Ekman
- Department of Integrative Medical Biology; Umeå University; Umeå Sweden
- Umeå Center for Functional Brain Imaging; Umeå University; Umeå Sweden
- Department of Neurobiology, Care Sciences and Society; Karolinska Institutet; Stockholm Sweden
| | - H. Fordell
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - J. Eriksson
- Department of Integrative Medical Biology; Umeå University; Umeå Sweden
- Umeå Center for Functional Brain Imaging; Umeå University; Umeå Sweden
| | - N. Lenfeldt
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - A. Wåhlin
- Department of Radiation Sciences; Biomedical Engineering; Umeå University; Umeå Sweden
| | - A. Eklund
- Umeå Center for Functional Brain Imaging; Umeå University; Umeå Sweden
- Department of Radiation Sciences; Biomedical Engineering; Umeå University; Umeå Sweden
| | - J. Malm
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
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Lenfeldt N, Johansson AM, Domellöf E, Riklund K, Rönnqvist L. Alterations in white matter microstructure are associated with goal-directed upper-limb movement segmentation in children born extremely preterm. Hum Brain Mapp 2017; 38:5051-5068. [PMID: 28685893 DOI: 10.1002/hbm.23714] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/19/2017] [Accepted: 06/19/2017] [Indexed: 12/14/2022] Open
Abstract
Altered white matter microstructure is commonly found in children born preterm (PT), especially those born at an extremely low gestational age (GA). These children also commonly show disturbed motor function. This study explores the relation between white matter alterations and upper-limb movement segmentation in 41 children born PT (19 girls), and 41 children born at term (18 girls) at 8 years. The PT group was subdivided into extremely PT (E-PT; GA = 25-27 weeks, N = 10), very PT (V-PT; GA = 28-32 weeks, N = 13), and moderately PT (M-PT; GA = 33-35 weeks, N = 18). Arm/hand preference (preferred/non-preferred) was determined through object interactions and the brain hemispheres were designated accordingly. White matter alterations were assessed using diffusion tensor imaging in nine areas, and movement segmentation of the body-parts head, shoulder, elbow, and wrist were registered during a unimanual goal-directed task. Increased movement segmentation was demonstrated consistently on the preferred side in the E-PT group compared with the term born group. Also compared with the term born peers, the E-PT group demonstrated reduced fractional anisotropy (FA) in the cerebral peduncle (targeting the corticospinal tract) in the hemisphere on the non-preferred side and in the splenium of corpus callosum. In contrast, in the anterior internal capsule on the preferred side, the E-PT group had increased FA. Lower FA in the cerebral peduncle, but higher FA in the anterior internal capsule, was associated with increased movement segmentation across body-parts in a contralateral manner. The results suggest that impaired development of sensorimotor tracts in E-PT children could explain a sub-optimal spatiotemporal organization of upper-limb movements. Hum Brain Mapp 38:5051-5068, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Niklas Lenfeldt
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Anna-Maria Johansson
- Department of Psychology, , Umeå University, Umeå, Sweden.,Department of Community Medicine and Rehabilitation, Physiotheraphy, Umeå University, Umeå, Sweden
| | - Erik Domellöf
- Department of Psychology, , Umeå University, Umeå, Sweden
| | - Katrine Riklund
- Department of Radiation Sciences, Diagnostic Radiology, Umeå University, Umeå, Sweden
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Lenfeldt N, Eriksson J, Åström B, Forsgren L, Mo SJ. Fractional Anisotropy and Mean Diffusion as Measures of Dopaminergic Function in Parkinson’s Disease: Challenging Results. JPD 2017; 7:129-142. [DOI: 10.3233/jpd-161011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Niklas Lenfeldt
- Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Johan Eriksson
- Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Björn Åström
- Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Lars Forsgren
- Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
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Lenfeldt N, Holmlund H, Larsson A, Birgander R, Forsgren L. Frontal white matter injuries predestine gait difficulties in Parkinson's disease. Acta Neurol Scand 2016; 134:210-8. [PMID: 27465659 DOI: 10.1111/ane.12532] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This study applies diffusion tensor imaging (DTI) to determine differences in neuronal integrity between motor phenotypes in Parkinson's disease. MATERIAL AND METHODS One hundred and twenty-two patients (47 females, mean age = 70.3 years) were included at baseline. Forty patients were tremor dominant (TD), 64 had postural imbalance and gait difficulty (PIGD), and 18 patients were indeterminate. The DTI was repeated after one, three and 5 years, including reassessment of phenotype. DTI was quantified using fractional anisotropy (FA), and mean, radial and axial diffusion. Targeted white matter involved six regions of interests (ROIs) in prefrontal cortex (PFC), the entrance to the external capsule (EEC) and lateral to the horn of the anterior ventricle (LVAH). Grey matter involved the basal ganglia. Data were analysed using mixed linear models with P < 0.05 (Bonferroni corrected) as significance threshold. RESULTS PIGD and Indeterminate had reduced FA and axial diffusion in PFC, EEC and LVAH compared to Tremor dominant (P < 0.05). Basal ganglia showed no differences. Post hoc analysis showed that FA correlated negatively, and mean and radial diffusion positively, to PIGD symptoms in EEC, LVAH and four ROIs in PFC (P < 0.05). Tremor symptoms showed no correlations. Patients converting to PIGD and Indeterminate had lower FA, and higher mean and radial diffusion, at baseline in EEC, LVAH and four areas in PFC compared to non-converting patients (P < 0.05). CONCLUSION Degeneration in frontal white matter is connected to PIGD symptoms in Parkinson's disease and if present at an early stage, the risk for conversion to the PIGD phenotype increases.
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Affiliation(s)
- N. Lenfeldt
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - H. Holmlund
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
| | - A. Larsson
- Department of Radiation Sciences; Umeå University; Umeå Sweden
| | - R. Birgander
- Department of Radiation Sciences; Umeå University; Umeå Sweden
| | - L. Forsgren
- Department of Pharmacology and Clinical Neuroscience; Umeå University; Umeå Sweden
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Lenfeldt N, Larsson A, Nyberg L, Birgander R, Forsgren L. Fractional anisotropy in the substantia nigra in Parkinson's disease: a complex picture. Eur J Neurol 2015; 22:1408-14. [PMID: 26118635 DOI: 10.1111/ene.12760] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 04/27/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE This study employs magnetic resonance imaging (MRI) diffusion tensor imaging to compare diffusion measures in the brains of patients with Parkinson's disease (PD) with healthy controls using longitudinal data. METHODS One-hundred and twenty-two patients and 34 controls were included at baseline. The MRI investigations were repeated after 1, 3 and 5 years. The diffusion measures were quantified using fractional anisotropy and mean, radial and axial diffusion (FA, MD, RD, AD). Regions of interest included the anterior, middle and posterior substantia nigra (SN), but also other areas. Linear models were used to test for the effect of disease and hemispheric lateralization. The P value was set at 0.05 (Bonferroni corrected). RESULTS Fractional anisotropy and AD were increased in the three nigral subareas in PD (P < 0.01), but MD and RD were unaltered. The right SN had higher FA than the left in all subareas (P < 0.01). MD and AD were increased in the right anterior part (P < 0.04), whereas MD and RD were decreased in the right middle and posterior parts (P < 0.001). The left middle cerebellar peduncle had increased FA and AD (P < 0.001) and decreased MD and RD (P < 0.01) compared to the right. Diffusion measures did not progress over time and side differences were not related to disease or lateralization of symptoms. CONCLUSIONS Increased FA in the SN in PD indicates gliosis and inflammation in the nuclei, but possibly also intrusion of surrounding fibres into the shrinking structure. The hemispheric side differences of diffusion might reflect natural lateralization of connectivity, but their relation to PD must be studied further.
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Affiliation(s)
- N Lenfeldt
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - A Larsson
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - L Nyberg
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | - R Birgander
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - L Forsgren
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
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Behrens A, Lenfeldt N, Qvarlander S, Koskinen LO, Malm J, Eklund A. Are intracranial pressure wave amplitudes measurable through lumbar puncture? Acta Neurol Scand 2013; 127:233-41. [PMID: 22784234 DOI: 10.1111/j.1600-0404.2012.01701.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2012] [Indexed: 12/01/2022]
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 45 mmHg 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 0.9 mmHg. At the highest ICP, the difference changed to -0.2 mmHg. 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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Affiliation(s)
| | | | - S. Qvarlander
- Department of Radiation Sciences - Biomedical Enigneering; Umeå University; Umeå; Sweden
| | - L.-O. Koskinen
- Department of Clinical Neuroscience; Umeå University; Umeå; Sweden
| | - J. Malm
- Department of Clinical Neuroscience; Umeå University; Umeå; Sweden
| | - A. Eklund
- Centre for Biomedical Engineering and Physics; Umeå University; Umeå; Sweden
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Lenfeldt N, Larsson A, Nyberg L, Birgander R, Forsgren L. Diffusion measures in early stage parkinsonism: controversial findings including hemispheric lateralisation. Parkinsonism Relat Disord 2012; 19:469-71. [PMID: 23142335 DOI: 10.1016/j.parkreldis.2012.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 09/24/2012] [Accepted: 10/01/2012] [Indexed: 10/27/2022]
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Lenfeldt N, Hansson W, Larsson A, Birgander R, Eklund A, Malm J. Three-day CSF drainage barely reduces ventricular size in normal pressure hydrocephalus. Neurology 2012; 79:237-42. [PMID: 22764254 DOI: 10.1212/wnl.0b013e31825fdf8a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE External lumbar drainage (ELD) of CSF is a test to determine the suitability of a shunt for patients with normal pressure hydrocephalus (NPH), but its effect on ventricular volume is not known. This study investigates the effect of 3-day ELD of 500 mL on ventricular size and clinical features in patients with idiopathic NPH. METHODS Fifteen patients were investigated in a 1.5-T MRI scanner before and after ELD. Ventricular volume was measured manually. Clinical features involved motor and cognitive functions, testing primarily gait and attention. Reduction in ventricular volume was correlated to total drain volume and clinical parameters. Statistical tests were nonparametric, and p < 0.05 was required for significance. RESULTS Drain volume was 415 mL (median 470 mL, range 160-510 mL). Ventricular size was reduced in all patients, averaging 3.7 mL (SD 2.2 mL, p < 0.001), which corresponded to a 4.2% contraction. The ratio of volume contraction to drain volume was only 0.9%. Seven patients improved in gait and 6 in attention. Ventricular reduction and total drain volume correlated neither with improvement nor with each other. The 7 patients with the largest drain volumes (close to 500 mL), had ventricular changes varying from 1.3 to 7.5 mL. CONCLUSIONS Clinical improvement occurs in patients with NPH after ELD despite unaltered ventricles, suggesting that ventricular size is of little relevance for postshunt improvement or determining shunt function. The clinical effect provided by ELD, mimicking shunting, is probably related to the recurring CSF extractions rather than to the cumulative effect of the drainage on ventricular volume.
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Affiliation(s)
- Niklas Lenfeldt
- Department of Clinical Neuroscience, Centre for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden.
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Lenfeldt N, Larsson A, Nyberg L, Birgander R, Eklund A, Malm J. Diffusion tensor imaging reveals supplementary lesions to frontal white matter in idiopathic normal pressure hydrocephalus. Neurosurgery 2011; 68:1586-93; discussion 1593. [PMID: 21336219 DOI: 10.1227/neu.0b013e31820f3401] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Idiopathic normal-pressure hydrocephalus (INPH) is associated with white matter lesions, but the extent and severity of the lesions do not cohere with symptoms or improvement after shunting, implying the presence of further, yet undisclosed, injuries to white matter in INPH. OBJECTIVE To apply diffusion tensor imaging (DTI) to explore white matter lesions in patients with INPH before and after drainage of cerebrospinal fluid (CSF). METHODS Eighteen patients and 10 controls were included. DTI was performed in a 1.5T MRI scanner before and after 3-day drainage of 400 mL of CSF. Regions of interest included corpus callosum, capsula interna, frontal and lateral periventricular white matter, and centrum semiovale. White matter integrity was quantified by assessing fractional anisotropies (FA) and apparent diffusion coefficients (ADC), comparing them between patients and controls and between patients before and after drainage. The significance level corresponded to .05 (Bonferroni corrected). RESULTS Decreased FA in patients was found in 3 regions (P<.002, P<.001, and P<.001) in anterior frontal white matter, whereas elevated ADC was found in genu corpus callosum (P<.001) and areas of centrum semiovale associated with the precentral gyri (P<.002). Diffusion patterns in these areas did not change after drainage. CONCLUSION DTI reveals subtle injuries-interpreted as axonal loss and gliosis-to anterior frontal white matter where high-order motor systems between frontal cortex and basal ganglia travel, further supporting the notion that motor symptoms in INPH are caused by a chronic ischemia to the neuronal systems involved in the planning processes of movements.
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Affiliation(s)
- Niklas Lenfeldt
- Department of Clinical Neuroscience, Umeå University, Umeå, Sweden.
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Behrens A, Lenfeldt N, Ambarki K, Malm J, Eklund A, Koskinen LO. Intracranial Pressure and Pulsatility Index. Neurosurgery 2011; 69:E1033-4; author reply E1034. [DOI: 10.1227/neu.0b013e31822999b7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Behrens A, Lenfeldt N, Ambarki K, Malm J, Eklund A, Koskinen LO. Transcranial Doppler pulsatility index: not an accurate method to assess intracranial pressure. Neurosurgery 2010; 66:1050-7. [PMID: 20495421 DOI: 10.1227/01.neu.0000369519.35932.f2] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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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Affiliation(s)
- Anders Behrens
- Department of Clinical Neuroscience, Umeå University, Umeå, Sweden.
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Behrens A, Lenfeldt N, Ambarki K, Malm J, Eklund A, Koskinen LO. In Reply. Neurosurgery 2010; 67:E1864. [PMID: 27759663 DOI: 10.1227/neu.0b013e3181fdbf39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Lenfeldt N, Larsson A, Nyberg L, Andersson M, Birgander R, Eklund A, Malm J. Idiopathic normal pressure hydrocephalus: increased supplementary motor activity accounts for improvement after CSF drainage. Brain 2008; 131:2904-12. [PMID: 18931387 DOI: 10.1093/brain/awn232] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In patients with idiopathic normal pressure hydrocephalus (INPH), the changes in brain function that take place in conjunction with improved behavioural performance after CSF drainage is still unknown. In this study, we use functional MRI (fMRI) to investigate the changes in cortical activity that accompany improved motor and cognitive performance after long-term external lumbar drainage (ELD) of CSF in patients with INPH. Eighteen INPH patients were initially included together with age- and sex-matched controls. Data from 11 INPH patients were analysed both before and after ELD. The average drain volume for these 11 patients was 400 ml/3 days. Brain activation was investigated by fMRI before and after the procedure on a 1.5T Philips scanner using protocols taxing motor performance (finger tapping and reaction time) and cognitive functioning (memory and attention). Behavioural data were compared using non-parametric tests at a significance level of 0.05, whereas fMRI data were analysed by statistical parametric mapping including conjunction analysis of areas with enhanced activity after drainage in patients and areas activated in controls (P < 0.005, uncorrected). Improved regions were defined as areas in the INPH brain that increased in activity after ELD with the requirement that the same areas were activated in control subjects. Following ELD, right-hand finger tapping improved from 104 +/- 38 to 117 +/- 25 (mean +/- SD) (P = 0.02). Left-hand finger tapping showed a tendency to improve, the number of keystrokes increasing from 91 +/- 40 to 105 +/- 20 (P = 0.12). Right-hand reaction time improved from 1630 +/- 566 ms to 1409 +/- 442 ms, whereas left-hand reaction time improved from 1760 +/- 600 ms to 1467 +/- 420 ms (both P-values = 0.01). Significant improvements in motor performance were accompanied by bilateral increased activation in the supplementary motor area. No improvement was found in cognitive functioning. The results suggest that motor function recovery in INPH patients after CSF removal is related to enhanced activity in medial parts of frontal motor areas considered crucial for motor planning; a finding consistent with INPH being a syndrome related to a reversible suppression of frontal periventricular cortico-basal ganglia-thalamo-cortical pathways.
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Affiliation(s)
- Niklas Lenfeldt
- Department of Clinical Neuroscience, Umeå University, Umeå, Sweden.
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Lenfeldt N, Hauksson J, Birgander R, Eklund A, Malm J. Improvement after cerebrospinal fluid drainage is related to levels of N-acetyl-aspartate in idiopathic normal pressure hydrocephalus. Neurosurgery 2008; 62:135-41, discussion 141-2. [PMID: 18300900 DOI: 10.1227/01.neu.0000311070.25992.05] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE This study uses proton magnetic resonance spectroscopy to investigate whether or not idiopathic normal pressure hydrocephalus is associated with neuronal dysfunction or ischemia in the brain. We evaluate whether or not proton magnetic resonance spectroscopy is useful for predicting improvement after long-term external lumbar drainage (ELD) of cerebrospinal fluid. METHODS Eighteen patients (mean age, 73 yr; six women) and 10 matching controls participated. Participants were characterized by clinical features, cognitive and motor function tests, and cerebrospinal fluid hydrodynamics (patients only). Signals from N-acetyl-aspartate (NAA), choline, lactate, and creatine (Cr) (reference) were sampled once in controls and twice in patients (before and after a 3-day ELD of approximately 135 mL/24 h) by proton magnetic resonance spectroscopy (1.5 T) from a 7.2-mL volume in the frontal white matter. Improvement was defined by video recordings of the patients' gait. RESULTS Sixteen patients finished the ELD (one patient had meningitis, and one patient had catheter insertion failure) with a mean drain volume of 395 mL. NAA/Cr ratios were lower in patients than in controls (1.60 versus 1.84, P = 0.02), but no difference was found for choline/Cr ratios. No lactate signals were detected. Fifty percent of patients improved after ELD. They had higher NAA/Cr ratios than nonimproved patients (1.70 versus 1.51, P = 0.01), but no differences were found in choline/Cr ratios or drain volume. CONCLUSION NAA/Cr ratios were decreased in patients with idiopathic normal pressure hydrocephalus, which is consistent with neuronal dysfunction in the frontal white matter. Improved patients had NAA/Cr ratios close to normal, indicating that enough functional neurons are a prerequisite for the cerebrospinal fluid drainage to have an effect.
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Affiliation(s)
- Niklas Lenfeldt
- Department of Clinical Neuroscience, Center for Biomedical Engineering and Physics, Umeå University, Umeå, Sweden.
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Abstract
The accuracy of estimating intracranial pressure in brain tissue (ICP(BT)) via lumbar space was investigated using preset pressure levels in the interval 0 to 600 mm H(2)O in patients with communicating hydrocephalus. Lumbar space ICP correlated excellently to ICP(BT), demonstrated by a measured mean difference of 10 mm H(2)O (0.75 mm Hg) and a regression coefficient of 0.98. The concurrence supports the lumbar puncture as an accurate technique to determine ICP in patients with communicating CSF systems.
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Affiliation(s)
- N Lenfeldt
- Department of Clinical Neuroscience, Umeå University, S-901 85 Umeå, Sweden.
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Lenfeldt N, Andersson N, Agren-Wilsson A, Bergenheim AT, Koskinen LOD, Eklund A, Malm J. Cerebrospinal fluid pulse pressure method: a possible substitute for the examination of B waves. J Neurosurg 2005; 101:944-50. [PMID: 15597755 DOI: 10.3171/jns.2004.101.6.0944] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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 (R(out)), 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 R(out). 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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Affiliation(s)
- Niklas Lenfeldt
- Department of Clinical Neuroscience, Umeå University Hospital, University of Umeå, Sweden.
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