| 1. |
- Aalto-Setälä, Katriina, et al.
(författare)
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Genetic risk factors and ischemic cerebrovascular disease : role of common variation of the genes encoding apolipoproteins and angiotensin-converting enzyme
- 1998
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Ingår i: Annals of Medicine. - 0785-3890 .- 1365-2060. ; 30:2, s. 224-33
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Tidskriftsartikel (refereegranskat)abstract
- DNA polymorphisms in genes encoding apolipoproteins (apo) A-I, C-III, B and E and angiotensin-converting enzyme (ACE) have been proposed to be associated with the risk of coronary artery disease (CAD). We studied whether the same genetic markers would also be associated with the occurrence and extent of atherosclerosis in cervical arteries. DNA samples from 234 survivors of stroke or a transient ischaemic attack aged 60 years or less were examined. The presence of atherosclerosis was assessed using aortic arch angiograms. The SstI polymorphism of apoA-I/C-III gene locus, the XbaI polymorphism of apoB gene, common apoE phenotypes and the insertion/deletion polymorphism of the ACE gene were analysed. The allele frequencies of the apoA-I/C-III, apoB, apoE or ACE gene did not differ between the groups with (n = 148) or without (n = 85) cervical atherosclerosis. However, when patients with at least one apoE4 allele and one X2 allele of apoB were combined and compared with those without either of them (E2E3 or E3E3 and X1X1), a significant association with the presence of cervical atherosclerosis was found (P = 0.03). The patients having the E2E3 phenotype had a significantly elevated serum triglyceride level compared with those with the E3E3 phenotype (P = 0.03). Serum high-density lipoprotein (HDL) cholesterol was lower in the patients with the E2E3 phenotype than in those with the E3E3 and E3E4 (P = 0.01 and P = 0.06, respectively). The apoB or ACE genotypes were not significantly associated with serum lipid or lipoprotein levels. There was no association between the ACE gene polymorphism and the occurrence of hypertension. In conclusion, the interaction of common apoB and apoE alleles may increase the risk of atherosclerosis in cervical arteries.
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| 2. |
- Abu Hamdeh, Sami, et al.
(författare)
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Extended anatomical grading in diffuse axonal injury using MRI : Hemorrhagic lesions in the substantia nigra and mesencephalic tegmentum indicate poor long-term outcome
- 2017
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 5:34, s. 341-352
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Tidskriftsartikel (refereegranskat)abstract
- Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. In this study, three magnetic resonance imaging (MRI) sequences were used to quantify the anatomical distribution of lesions, to grade DAI according to the Adams grading system, and to evaluate the value of lesion localization in combination with clinical prognostic factors to improve outcome prediction. Thirty patients (mean 31.2 years ±14.3 standard deviation) with severe DAI (Glasgow Motor Score [GMS] <6) examined with MRI within 1 week post-injury were included. Diffusion-weighted (DW), T2*-weighted gradient echo and susceptibility-weighted (SWI) sequences were used. Extended Glasgow outcome score was assessed after 6 months. Number of DW lesions in the thalamus, basal ganglia, and internal capsule and number of SWI lesions in the mesencephalon correlated significantly with outcome in univariate analysis. Age, GMS at admission, GMS at discharge, and low proportion of good monitoring time with cerebral perfusion pressure <60 mm Hg correlated significantly with outcome in univariate analysis. Multivariate analysis revealed an independent relation with poor outcome for age (p = 0.005) and lesions in the mesencephalic region corresponding to substantia nigra and tegmentum on SWI (p = 0.008). We conclude that higher age and lesions in substantia nigra and mesencephalic tegmentum indicate poor long-term outcome in DAI. We propose an extended MRI classification system based on four stages (stage I—hemispheric lesions, stage II—corpus callosum lesions, stage III—brainstem lesions, and stage IV—substantia nigra or mesencephalic tegmentum lesions); all are subdivided by age (≥/<30 years).
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| 3. |
- Abu Hamdeh, Sami, et al.
(författare)
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Intracranial pressure elevations in diffuse axonal injury : association with nonhemorrhagic MR lesions in central mesencephalic structures
- 2019
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Ingår i: Journal of Neurosurgery. - 0022-3085 .- 1933-0693. ; 131:2, s. 604-611
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI.Methods: Fifty-two patients with severe TBI (median age 24 years, range 9–61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression.Results: All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%–13%, p = 0.004) and young age (−0.2% of GMT with ICP > 20 mm Hg, 95% CI −0.07% to −0.3%, p = 0.002) were associated with increased ICP.Conclusions: Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.Abbreviations: ADC = apparent diffusion coefficient; CPP = cerebral perfusion pressure; DAI = diffuse axonal injury; DWI = diffusion-weighted imaging; EVD = external ventricular drain; GCS = Glasgow Coma Scale; GMT = good monitoring time; GOSE = Glasgow Outcome Scale–Extended; ICC = intraclass correlation coefficient; ICP = intracranial pressure; MAP = mean arterial blood pressure; NICU = neurointensive care unit; SN-T = substantia nigra and mesencephalic tegmentum; SWI = susceptibility-weighted imaging; TBI = traumatic brain injury; T2*GRE = T2*-weighted gradient echo.
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| 4. |
- Abu Hamdeh, Sami, et al.
(författare)
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Intracranial pressure elevations in diffuse axonal injury are associated with non-hemorrhagic MR lesions in central mesencephalic structures
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Objective: Increased intracranial pressure (ICP) in severe traumatic brain injury (TBI) patients with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in DAI patients.Methods: Fifty-two severe TBI patients (median 24, range 9-61 years), with ICP-monitoring and DAI on MRI, using T2*-weighted gradient echo, susceptibility-weighted and diffusion-weighted (DW) sequences, were enrolled. Proportion of good monitoring time (GMT) with ICP>20 mmHg during the first 120 hours post-injury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression. Results: All patients had episodes of ICP>20 mmHg. The mean proportion of GMT with ICP>20 mmHg was 5% and 27% of the patients (14/52) had more than 5% of GMT with ICP>20 mmHg. Glasgow Coma Scale motor score at admission (P=0.04) and lesions on DW images in the substantia nigra and mesencephalic tegmentum (SN-T, P=0.001) were associated with the proportion of GMT with ICP>20 mmHg. In multivariate linear regression, lesions on DW images in SN-T (8% of GMT with ICP>20 mmHg, 95% CI 3–13%, P=0.004) and young age (-0.2% of GMT with ICP>20 mmHg, 95% CI -0.07–-0.3%, P=0.0008) were associated with increased ICP. Conclusions: Increased ICP occurs in ~1/3 of severe TBI patients with DAI. Age and lesions on DW images in the central mesencephalon (SN-T) associate with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in DAI patients.
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| 5. |
- Abu Hamdeh, Sami, et al.
(författare)
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MRI analysis of diffuse axonal injury - Hemorrhagic lesions in the mesencephalon idicate poor long-term outcome
- 2016
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Ingår i: MRI analysis of diffuse axonal injury - Hemorrhagic lesions in the mesencephalon idicate poor long-term outcome. - : Springer.
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Konferensbidrag (refereegranskat)abstract
- Purpose: Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. Three MRI techniques were compared in demonstrating acute brain lesions. Relationship of the anatomical distribution of the lesions in combination with clinical prognostic factors to outcome after 6 months was evaluated. Methods and Materials: Thirty patients, aged 16-60 years (mean 31.2 years) with severe DAI (Glasgow Motor Score = GMS < 6) were examined with MRI at 1.5T within one week after the injury. A diffusion-weighted (DW) sequence (SE-EPI, b value 1000 s/mm2), a T2*-weighted gradient echo (T2*GRE) sequence and a susceptibility-weighted (SWI) sequence were evaluated by two independent reviewers with short and long neuroradiological experiences. Clinical outcome was assessed with Extended Glasgow Outcome Score (GOSE) after ≥ 6 months.Results: Interreviewer agreement for DAI classification was very good (ҡ 0.82 – 0.91) with all three sequences. SWI visualized more lesions than the T2*GRE or DW sequence. In univariate analysis, number of DW lesions in the deep gray matter area including the internal capsules, number of SWI lesions in the mesencephalon, age, and GMS at admission and discharge correlated significantly with poor outcome. Multivariate analysis only revealed an independent relation with poor outcome for age (p = 0.011) and lesions in the mesencephalic region including crura cerebri, substantia nigra and tegmentum on SWI (p = 0.032).Conclusion: SWI is the most sensitive technique to visualize lesions in DAI. Age over 30 years and hemorrhagic mesencephalic lesions anterior to the tectum are indicators of poor long-term outcome in DAI.
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| 6. |
- Alemany, Montserrat, et al.
(författare)
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Coexistence of microhemorrhages and acute spontaneous brain hemorrhage : correlation with signs of microangiopathy and clinical data
- 2006
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Ingår i: Radiology. - : Radiological Society of North America (RSNA). - 0033-8419 .- 1527-1315. ; 238:1, s. 240-7
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To evaluate prospectively with magnetic resonance (MR) imaging the coexistence of microhemorrhages (MHs) in white patients with acute spontaneous intraparenchymal hemorrhage (IPH) and acute ischemic stroke and to study the association with imaging findings of microangiopathy and various clinical data. MATERIALS AND METHODS: Before examinations, informed consents were signed by either the patient or a relative. The study was carried out with the approval of the local ethics committee. MR imaging was performed in 90 patients with acute stroke: 45 with acute spontaneous IPHs (24 men and 21 women; median age, 65 and 68 years, respectively) and 45 age-matched control subjects without intracranial hemorrhages (26 men and 19 women; median age for both, 67 years), as determined at computed tomography. MR imaging included transverse T1- and T2-weighted spin-echo, transverse fluid-attenuated inversion recovery, transverse and coronal T2*-weighted gradient-echo, and, in 50 patients, diffusion-weighted sequences. Presence of MHs and signs of microangiopathy, such as T2 hyperintensities or lacunae, were recorded in the white and deep gray matter. The relationships between MH and IPH and between MH and T2 hyperintensities were analyzed by means of regression analysis. Different clinical features, such as arterial hypertension or diabetes, were registered and correlated with the image findings by means of regression analysis. RESULTS: MHs were found in 64% of patients with IPH (29 of 45) and 18% of control subjects (eight of 45). A statistically significant relationship between MH and IPH was determined (P < .001). Among the 29 patients with IPH and MH, 24 (83%) had T2 hyperintensities and 13 (45%) had lacunae; among the 16 patients without MH, seven (44%) had T2 hyperintensities and three (19%) had lacunae. A relationship between MH and occurrence and extent of T2 hyperintensities was also identified (P < .001). There was no clear relationship with the clinical data studied. CONCLUSION: The results support a correlation between the presence of imaging signs of cerebral microangiopathy, clinically silent MHs, and acute IPHs. RSNA, 2006.
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| 7. |
- Alemany Ripoll, Montserrat, et al.
(författare)
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Detection and appearance of intraparenchymal haematomas of the brain at 1.5 T with spin-echo, FLAIR and GE sequences : poor relationship to the age of the haematoma
- 2004
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Ingår i: Neuroradiology. - : Springer Science and Business Media LLC. - 0028-3940 .- 1432-1920. ; 46:6, s. 435-43
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Tidskriftsartikel (refereegranskat)abstract
- The specific appearance of blood related to time at T1- and T2-weighted spin-echo (SE) sequences is generally accepted; thus, these sequences are classically used for estimating the age of haematomas. Magnetic resonance imaging at 1.5 T, including T1- and T2-weighted SE fluid-attenuated inversion recovery (FLAIR) and T2*-weighted gradient-echo (GE) sequences, was performed on 82 intraparenchymal haematomas (IPHs) and 15 haemorrhagic infarcts (HIs) in order to analyse the appearance at different stages and with different sequences, and to investigate how reliably the age of hematomas can be estimated. The IPHs had been previously detected by CT, were spontaneous ( n=72) or traumatic ( n=10) in origin and were of different sizes (2 mm to 7 cm) and ages (from 7.5 h to 4 years after acute haemorrhagic event). The age of the lesion was calculated from the moment when clinical symptoms started or the traumatic event occurred. The 15 patients with HIs were patients with ischaemic stroke in whom there was either a suspicion of haemorrhagic transformation on CT, or haemorrhage was detected as an additional finding on MR performed for other indications. Patients with conditions that could affect the SI of blood, such as anticoagulant therapy or severe anaemia, were excluded. The signal intensity pattern of the lesions was analysed and related to their ages without prior knowledge of the clinical data. All lesions were detected with T2*-weighted GE. T1-weighted SE missed 13 haematomas and T2-weighted SE and FLAIR sequences missed five. Haemorrhagic transformation was missed in three infarcts by T1-, T2-weighted SE and FLAIR. The signal pattern on FLAIR was identical to that on T2-weighted SE. For all sequences, a wide variety of signal patterns, without a clear relationship to the age of the haematomas, was observed. There was a poor relationship between the real MR appearance of IPHs and the theoretical appearance on SE sequences. T2*-weighted GE was effective for detecting small bleedings but was not useful for estimating the age of a lesion. The FLAIR does not provide any more information than T2-weighted SE.
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| 8. |
- Alemany Ripoll, Montserrat, et al.
(författare)
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Experimental intracerebral and subarachnoid/intraventricular haemorrhages
- 2002
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Ingår i: Acta Radiologica. - 0284-1851 .- 1600-0455. ; 43:5, s. 464-73
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To compare the detectability of small experimental intracranial haemorrhages on MR imaging at 0.5 T and 1.5 T, from hyperacute to subacute stages. MATERIAL AND METHODS: 1 ml of autologous blood was injected into the brain of 15 rabbits to create intraparenchymal haematomas. Since the blood partially escaped into the cerebrospinal fluid (CSF) spaces, detectability of subarachnoid and intraventricular blood was also evaluated. MR imaging at 0.5 T and at 1.5 T was repeated up to 14 days, including T1-, proton density- and T2-weighted (w) spin-echo (SE), FLAIR and T2*-w gradient echo (GE) pulse sequences. The last MR investigation was compared to the formalin-fixed brain sections in 7 animals. RESULTS: The intraparenchymal haematomas were best revealed with T2*-w GE sequences, with 100% of sensitivity at 1.5 T and 90-95% at 0.5 T. Blood in the CSF spaces was significantly (p < 0.05) better detected at 1.5 T with T2*-w GE sequences and detected best during the first 2 days. The next most sensitive sequence for intracranial blood was FLAIR. SE sequences were rather insensitive. CONCLUSION: 1.5 T equipment is superior to 0.5 T in the detection of intracranial haemorrhages from acute to subacute stages. T2*-w GE sequences account for this result but other sequences are also needed for a complete examination.
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| 9. |
- Alemany Ripoll, Montserrat, et al.
(författare)
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MR follow-up of small experimental intracranial haemorrhages from hyperacute to subacute phase
- 2002
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Ingår i: Acta Radiologica. - 0284-1851 .- 1600-0455. ; 43:1, s. 2-9
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To compare pulse sequences in revealing intracranial bleeding from the hyperacute to subacute phase. MATERIAL AND METHODS: We injected 0.3-1 ml of autologous blood into the brain of 8 rabbits. MR imaging was performed immediately after haematoma creation and then at determined intervals up to 9-12 days. All images were analysed by two observers. After the last MR investigation, the brain was fixed in formalin. The last MR images were compared to the fixed brain sections and to the histologic findings. RESULTS: T2*-weighted GE sequences, both conventional spoiled and echoplanar sequences, revealed the intraparenchymal haematomas as hypointensities in all but 1 case, which was negative from the second day onward (a rabbit with 0.3 ml blood injected). The signal patterns remained unchanged during the follow-up. The haematoma sizes and shapes corresponded well to gross pathology. Blood in the cerebrospinal fluid (CSF) space was detected with T2*-weighted GE sequences in a great majority of the examinations during the first 2 days. The cases with the smallest injected volume of blood were negative. SE sequences were rather insensitive. The FLAIR sequence often revealed blood in CSF spaces but not in the brain. CONCLUSION: T2*-weighted GE sequences are capable of revealing very small intraparenchymal haemorrhages from the hyperacute to the subacute phase, and blood in CSF spaces during at least the first 2 days.
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| 10. |
- Ali, Zafar, et al.
(författare)
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Novel SACS mutations associated with intellectual disability, epilepsy and widespread supratentorial abnormalities
- 2016
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Ingår i: Journal of the Neurological Sciences. - : Elsevier BV. - 0022-510X .- 1878-5883. ; 371, s. 105-111
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Tidskriftsartikel (refereegranskat)abstract
- We describe eight subjects from two consanguineous families segregating with autosomal recessive childhood onset spastic ataxia, peripheral neuropathy and intellectual disability. The degree of intellectual disability varied from mild to severe and all four affected individuals in one family developed aggressive behavior and epilepsy. Using exome sequencing, we identified two novel truncating mutations (c.2656C>T (p.Gln886*)) and (c.4756_4760delAATCA (p.Asn1586Tyrfs*3)) in the SACS gene responsible for autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). MRI revealed typical cerebellar and pontine changes associated with ARSACS as well as multiple supratentorial changes in both families as likely contributing factors to the cognitive symptoms. Intellectual disability and behavioral abnormalities have been reported in some cases of ARSACS but are not a part of the characteristic triad of symptoms that includes cerebellar ataxia, spasticity and peripheral neuropathy. Our combined findings bring further knowledge to the phenotypic spectrum, neurodegenerative changes and genetic variability associated with the SACS gene of clinical and diagnostic importance.
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