| 151. |
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| 152. |
- van Westen, Danielle
(författare)
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MRI at 3 T of brain functions and fibre tracts adjacent to intracranial tumors
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aims of the studies were: to evaluate the spatial resolution of fMRI at 3 T by studying fingersomatotopy in area 3 b of the primary sensory area (Paper 1); to investigate the potential of fMRI at 3T as a clinical tool for preoperative evaluation of patients with intracranial tumors (Paper 2); to investigate the effect of glioma resection on the spatial extent of fMRI activation as compared to the normal within-subject variability (Paper 3); to determine whether the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) can distinguish tumor-infiltrated edema of gliomas from pure edema of meningiomas and metastases (Paper 4). Results: Strict somatotopic organisation in the primary sensory cortex was shown in the group average; at the subject level the thumb was located laterally, anteriorly and inferiorly to the little finger in 94 % of subjects (Paper 1). The sensorimotor and language areas close to intracranial tumors were identified in 95 % of patients. Paradigm effectiveness ranged from 79 to 95 %. The median quality of the activation maps was high. fMRI contributed to the decision to operate, the surgical approach and the extent of the resection in 9, 13 and 12 patients, respectively (Paper 2). BOLD activation obtained from fMRI with motor, sensory and language stimulation pre- and postoperatively in glioma patients yielded differences in the spatial extent similar to those obtained from repeated examinations in healthy controls (Paper 3). Values and lesion-to-brain ratios of ADC and FA in peritumoral edema did not differ between high grade gliomas, meningiomas and metastases (Paper 4). Conclusions: Our results suggest that the spatial resolution of fMRI using a clinical protocol is adequate for localisation of the sensory representation of a finger (Paper 1). Preoperative fMRI for mapping of motor, sensory and language functions at 3 T is feasible and contributes to neurosurgical decision making (Paper 2). Longitudinal pre- and postoperative fMRI studies may be performed in patients with gliomas without concerns for potential effects of the decreased tumor volume on the BOLD effect as a possible source of error (Paper 3). Values and lesion-to-brain ratios of ADC and FA may not be useful to distinguish pure edema from tumor-infiltrated edema in peritumoral areas with T2-signal changes (Paper 4).
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| 153. |
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| 154. |
- van Westen, Danielle, et al.
(författare)
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Solid bolus swallowing in the radiologic evaluation of dysphagia
- 1993
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Ingår i: Acta Radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 34:4, s. 372-375
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Tidskriftsartikel (refereegranskat)abstract
- Patients with dysphagia, heartburn and chest pain are regularly referred for radiologic evaluation of swallowing. The liquid barium swallow has been of great value for the biphasic evaluation of the pharynx and esophagus. Though many patients complain of dysphagia specifically for solids, solid bolus swallow is usually not part of the evaluation. For the present study we therefore included the use of a solid bolus with a diameter of 13 mm and interviewed the patients carefully for any symptoms during this tablet swallow. Of 200 patients examined, the tablet passed through the esophagus without delay in 102. In the 98 patients with delayed passage, the solid bolus arrest occurred in the pharynx in 5 and in the esophagus in 93. Arrest in the esophagus was due to esophageal dysmotility in 48 patients. Twenty of these were symptomatic during the tablet swallow. A narrowing was the cause in 45, of whom 9 had symptoms. In 18 patients (9%) the solid bolus added key information to the radiologic evaluation. We therefore recommend that the solid bolus is included in the routine radiologic work-up of patients with dysphagia. Careful attention to symptoms during the tablet swallow is important.
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| 155. |
- van Westen, Danielle, et al.
(författare)
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Tumor extension in high-grade gliomas assessed with diffusion magnetic resonance imaging: values and lesion-to-brain ratios of apparent diffusion coefficient and fractional anisotropy.
- 2006
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Ingår i: Acta Radiologica. - : SAGE Publications. - 1600-0455 .- 0284-1851. ; 47:3, s. 311-319
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To determine whether the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) can distinguish tumor-infiltrated edema in gliomas from pure edema in meningiomas and metastases. Material and Methods: Thirty patients were studied: 18 WHO grade III or IV gliomas, 7 meningiomas, and 5 metastatic lesions. ADC and FA were determined from ROIs placed in peritumoral areas with T2-signal changes, adjacent normal appearing white matter (NAWM), and corresponding areas in the contralateral healthy brain. Values and lesion-to-brain ratios from gliomas were compared to those from meningiomas and metastases. Results: Values and lesion-to-brain ratios of ADC and FA in peritumoral areas with T2-signal changes did not differ between gliomas, meningiomas, and metastases (P = 0.40, P = 0.40, P = 0.61, P = 0.34). Values of ADC and FA and the lesion-to-brain ratio of FA in the adjacent NAWM did not differ between tumor types (P = 0.74, P = 0.25, and P = 0.31). The lesion-to-brain ratio of ADC in the adjacent NAWM was higher in gliomas than in meningiomas and metastases (P = 0.004), but overlapped between tumor types. Conclusion: Values and lesion-to-brain ratios of ADC and FA in areas with T2-signal changes surrounding intracranial tumors and adjacent NAWM were not helpful for distinguishing pure edema from tumor-infiltrated edema when data from gliomas, meningiomas, and metastases were compared.
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| 156. |
- Vang, Fredrik, et al.
(författare)
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Size of basal ganglia in suicide attempters, and its association with temperament and serotonin transporter density.
- 2010
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Ingår i: Psychiatry Research. - : Elsevier BV. - 1872-7123 .- 0925-4927. ; 183:2, s. 177-179
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Tidskriftsartikel (refereegranskat)abstract
- Magnetic resonance imaging was used to compare subcortical volumes of seven suicide attempters with those of six healthy controls. Suicide attempters had 10% smaller right caudate nucleus and 19% bilaterally smaller globus pallidus. In suicide attempters, volumes of the globus pallidus correlated negatively with previously reported measures of solidity (non-impulsive temperament) and serotonin transporter binding potential.
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| 157. |
- Ventorp, Filip, et al.
(författare)
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Preliminary Evidence of Efficacy and Target Engagement of Pramipexole in Anhedonic Depression
- 2022
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Ingår i: Psychiatric Research and Clinical Practice. - : John Wiley and Sons Inc.. - 2575-5609. ; 4:2, s. 42-47
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Tidskriftsartikel (refereegranskat)abstract
- Objective : To investigate feasibility and target engagement of high-dose, add-on pramipexole treatment in anhedonic depression. Method : In this open-label pilot study, we included 12 patients with unipolar or bipolar, moderate-to-severe depression and with significant anhedonia symptoms. All patients were on a stable dose of one or a combination of antidepressants and/or mood stabilizers and received 10 weeks of adjunctive pramipexole titrated to a maximum dose of 4.5 mg salt/day. All patients were rated with the Dimensional Anhedonia Rating Scale (DARS), the Montgomery Åsberg Depression Rating (MADRS) and the Snaith Hamilton Pleasure Scale (SHAPS). Serum high-sensitivity C-reactive protein (hs-CRP) was analyzed pre- and post-treatment. Eight patients underwent fMRI pre- and post-treatment and a simplified version of the monetary incentive delay task was used to investigate the effect of treatment on striatal activity during reward anticipation. Results : DARS, MADRS and SHAPS scores all improved significantly over 10 weeks of pramipexole treatment (p<0.01). Mean levels of hs-CRP decreased significantly over the course of treatment from mean 3.8 mg/L at baseline to 2.6 mg/L at endpoint (p<0.01). There were significant treatment-associated increases in reward related activity in several brain areas including the right lateral putamen, anterior left caudate, left posterior putamen, right dorsal caudate, left anterior putamen, and the right nucleus accumbens. Conclusions : This is the first study to suggest efficacy and target engagement of pramipexole in anhedonic depression. Larger randomized controlled trials are needed to confirm or refute these preliminary findings.
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| 158. |
- Voevodskaya, Olga, et al.
(författare)
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Altered structural network organization in cognitively normal individuals with amyloid pathology
- 2018
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Ingår i: Neurobiology of Aging. - : Elsevier BV. - 0197-4580 .- 1558-1497. ; 64, s. 15-24
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Tidskriftsartikel (refereegranskat)abstract
- Recent findings show that structural network topology is disrupted in Alzheimer’s disease (AD), with changes occurring already at the prodromal disease stages. Amyloid accumulation, a hallmark of AD, begins several decades before symptom onset and its effects on brain connectivity at the earliest disease stages is not fully known. We studied global and local network changes in a large cohort of cognitively healthy individuals (N=299, Swedish BioFINDER study) with and without β-amyloid (Aβ) pathology (based on cerebrospinal fluid Aβ42/Aβ40 levels). Structural correlation matrices were constructed based on MRI cortical thickness data. Despite the fact that no significant regional cortical atrophy was found in the Aβ-positive group, this group exhibited an altered global network organization, including decreased global efficiency and modularity. At the local level, Aβ-positive individuals displayed fewer and more disorganized modules as well as a loss of hubs. Our findings suggest that changes in network topology occur already at the presymptomatic (preclinical) stage of AD and may precede detectable cortical thinning.
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| 159. |
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| 160. |
- Vogel, Jacob W., et al.
(författare)
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Spread of pathological tau proteins through communicating neurons in human Alzheimer's disease
- 2020
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Tau is a hallmark pathology of Alzheimer's disease, and animal models have suggested that tau spreads from cell to cell through neuronal connections, facilitated by β-amyloid (Aβ). We test this hypothesis in humans using an epidemic spreading model (ESM) to simulate tau spread, and compare these simulations to observed patterns measured using tau-PET in 312 individuals along Alzheimer's disease continuum. Up to 70% of the variance in the overall spatial pattern of tau can be explained by our model. Surprisingly, the ESM predicts the spatial patterns of tau irrespective of whether brain Aβ is present, but regions with greater Aβ burden show greater tau than predicted by connectivity patterns, suggesting a role of Aβ in accelerating tau spread. Altogether, our results provide evidence in humans that tau spreads through neuronal communication pathways even in normal aging, and that this process is accelerated by the presence of brain Aβ.
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