MRI of trunk muscles and motor and respiratory function in patients with myotonic dystrophy type 1.

BACKGROUND: Myotonic Dystrophy 1 (DM1) causes progressive myopathy of extremity muscles. DM1 may also affect muscles of the trunk. The aim of this study was to investigate fat infiltration and muscle size in trunk muscles in DM1 patients, and in an age and gender matched control group. Further, explore how fat infiltration and degree of atrophy in these muscles are associated with motor and respiratory function in DM1 patients. METHOD: We measured fat infiltration and trunk muscle size by MRI in 20 patients with genetically confirmed classic form of DM1, and compared these cases with 20 healthy, age and gender matched controls. In the DM1 group, we investigated correlations between MRI findings and clinical measures of muscle strength, mobility and respiration. We used sum scores for fat infiltration and muscle size in trunk flexors and trunk extensors in the analysis of group differences and correlations. RESULTS: Significant differences between cases and controls were present for fat infiltration in trunk flexors (p = 0.001) and trunk extensors (p = < 0.001), and for muscle size in trunk flexors (p = 0.002) and trunk extensors (p = 0.030). Fat infiltration in trunk flexors were significant correlated to back extension strength (rho = - 0.523 p = 0.018), while muscle size in trunk flexors was significantly correlated to trunk flexion strength (rho = 0.506 p = 0.023). Fat infiltration in trunk flexors was significantly correlated with lower general mobility (rho = - 0.628, p = 0.003), reduced balance (rho = 0.630, p < 0.003) and forced vital capacity (rho - 0.487 p = 0.040). CONCLUSIONS: Trunk muscles in DM1 patients had significant higher levels of fat infiltration and reduced muscle size compared to age and gender matched controls. In DM1 patients, fat infiltration was associated with reduced muscle strength, mobility, balance and lung function, while muscle size was associated with reduced muscle strength and lung function. These findings are of importance for clinical management of the disease and could be useful additional outcome measures in future intervention studies.

Alpha-tocopherol and MRI outcomes in multiple sclerosis--association and prediction.

OBJECTIVE: Alpha-tocopherol is the main vitamin E compound in humans, and has important antioxidative and immunomodulatory properties. The aim of this study was to study alpha-tocopherol concentrations and their relationship to disease activity in Norwegian multiple sclerosis (MS) patients. METHODS: Prospective cohort study in 88 relapsing-remitting MS (RRMS) patients, originally included in a randomised placebo-controlled trial of omega-3 fatty acids (the OFAMS study), before and during treatment with interferon beta. The patients were followed for two years with repeated 12 magnetic resonance imaging (MRI) scans and nine serum measurements of alpha-tocopherol. RESULTS: During interferon beta (IFNB) treatment, each 10 µmol/L increase in alpha-tocopherol reduced the odds (CI 95%) for simultaneous new T2 lesions by 36.8 (0.5-59.8) %, p = 0.048, and for combined unique activity by 35.4 (1.6-57.7) %, p = 0.042, in a hierarchical regression model. These associations were not significant prior to IFNB treatment, and were not noticeably changed by gender, age, body mass index, HLA-DRB1*15, treatment group, compliance, or the concentrations of 25-hydroxyvitamin D, retinol, neutralising antibodies against IFNB, or the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. The corresponding odds for having new T1 gadolinium enhancing lesions two months later was reduced by 65.4 (16.5-85.7) %, p = 0.019, and for new T2 lesions by 61.0 (12.4-82.6) %, p = 0.023. CONCLUSION: During treatment with IFNB, increasing serum concentrations of alpha-tocopherol were associated with reduced odds for simultaneous and subsequent MRI disease activity in RRMS patients.

Retinol levels are associated with magnetic resonance imaging outcomes in multiple sclerosis.

BACKGROUND: Vitamin A has immunomodulatory properties and may regulate the transcription of genes involved in remyelination. OBJECTIVE: To investigate the association between retinol and disease activity in multiple sclerosis (MS). METHODS: Cohort study of 88 relapsing-remitting MS patients, originally included in a randomised placebo-controlled trial of omega-3 fatty acids in MS (the OFAMS study), followed prospectively for 24 months with repeated assessments of serum-retinol and magnetic resonance imaging (MRI). All patients were initiated on interferon ß-1a after month 6. RESULTS: Each 1 µmol/L increase in serum-retinol reduced the odds (95% confidence interval) for new T1 gadolinium enhanced (Gd(+)) lesions by 49 (8-70)%, new T2 lesions by 42 (2-66)%, and combined unique activity (CUA) by 46 (3-68)% in simultaneous MRI scans, and 63 (25-82)% for new T1Gd(+) lesions, 49 (3-73)% for new T2 lesions and 43 (12-71)% for CUA the subsequent month. Serum-retinol also predicted new T1Gd(+) and T2 lesions six months ahead. The associations were not affected by HLA-DRB1*15, or serum levels of 25-hydroxyvitamin D, eicosapentaenoic acid or docosahexaenoic acid. CONCLUSION: Serum retinol is inversely associated with simultaneous and subsequent MRI outcomes in RRMS.

Vitamin D and disease activity in multiple sclerosis before and during interferon-ß treatment.

OBJECTIVE: Studies based on deseasonalized vitamin D levels suggest that vitamin D may influence the disease activity in multiple sclerosis (MS), and high doses are suggested as add-on treatment to interferon-ß (IFN-ß). Seasonal fluctuation of vitamin D varies between individuals, thus the relationship to disease activity should preferentially be studied by repeated and simultaneous vitamin D and MRI measurements from each patient. METHODS: This was a cohort study comprising 88 patients with relapsing-remitting MS who were followed for 6 months with 7 MRI and 4 25-hydroxyvitamin D measurements before initiation of IFN-ß, and for 18 months with 5 MRI and 5 25-hydroxyvitamin D measurements during IFN-ß treatment. RESULTS: Prior to IFN-ß treatment, each 10 nmol/L increase in 25-hydroxyvitamin D was associated with 12.7% (p = 0.037) reduced odds for new T1 gadolinium-enhancing lesions, 11.7% (p = 0.044) for new T2 lesions, and 14.1% (p = 0.024) for combined unique activity. Patients with the most pronounced fluctuation in 25-hydroxyvitamin D displayed larger proportion of MRI scans with new T1 gadolinium-enhancing lesions (51% vs 23%, p = 0.004), combined unique activity (60% vs 32%, p = 0.003), and a trend for new T2 lesions (49% vs 28%, p = 0.052) at the lowest compared to the highest 25-hydroxyvitamin D level. No association between 25-hydroxyvitamin D and disease activity was detected after initiation of IFN-ß. HLA-DRB1*15 status did not affect the results. CONCLUSION: In untreated patients with MS, increasing levels of 25-hydroxyvitamin D are inversely associated with radiologic disease activity irrespective of their HLA-DRB1*15 status.

ω-3 fatty acid treatment in multiple sclerosis (OFAMS Study): a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To investigate whether ω-3 fatty acids reduce magnetic resonance imaging (MRI) and clinical disease activity in patients with multiple sclerosis, both as monotherapy and in combination with interferon beta-1a treatment. DESIGN: Multicenter, randomized, double-blind, placebo-controlled clinical trial conducted from 2004 to 2008. SETTING: Thirteen public neurology departments in Norway. PARTICIPANTS: Patients aged 18 to 55 years with active relapsing-remitting multiple sclerosis, with a disability score equivalent to 5.0 or less on the Kurtzke Expanded Disability Status Scale. Ninety-two patients were randomized to ω-3 fatty acids (n = 46) or placebo capsules (n = 46). INTERVENTIONS: Administration of 1350 mg of eicosapentaenoic acid and 850 mg of docosahexaenoic acid daily or placebo. After 6 months, all patients in addition received subcutaneously 44 µg of interferon beta-1a 3 times per week for another 18 months. MAIN OUTCOME MEASURE: The primary outcome measure was MRI disease activity as measured by the number of new T1-weighted gadolinium-enhancing lesions during the first 6 months. Secondary outcome measures included MRI disease activity after 9 months and 24 months, relapse rate, disability progression, fatigue, quality of life, and safety. RESULTS: The cumulative number of gadolinium-enhancing MRI lesions during the first 6 months were similar in the ω-3 fatty acids and placebo groups (median difference, 1; 95% CI, 0 to 3; P = .09). No difference in relapse rate was detected after 6 (median difference, 0; 95% CI, 0 to 0; P = .54) or 24 (median difference, 0; 95% CI, 0 to 0; P = .72) months. The proportion of patients without disability progression was 70% in both groups (P > .99). No differences were detected in fatigue or quality-of-life scores, and no safety concerns appeared. Serum analyses of fatty acids showed an increase in ω-3 fatty acids (mean difference, 7.60; 95% CI, 5.57 to 7.91; P < .001) in the patients treated with ω-3 fatty acids compared with the placebo group. CONCLUSION: No beneficial effects on disease activity were detected from ω-3 fatty acids when compared with placebo as monotherapy or in combination with interferon beta-1a. Magnetic resonance imaging disease activity was reduced as expected by interferon beta-1a. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00360906.

Magnetic resonance brain perfusion imaging with voxel-specific arterial input functions.

PURPOSE: To propose an automatic method for estimating voxel-specific arterial input functions (AIFs) in dynamic contrast brain perfusion imaging. MATERIALS AND METHODS: Voxel-specific AIFs were estimated blindly using the theory of homomorphic transformations and complex cepstrum analysis. Wiener filtering was used in the subsequent deconvolution. The method was verified using simulated data and evaluated in 10 healthy adults. RESULTS: Computer simulations accurately estimated differently shaped, normalized AIFs. Simple Wiener filtering resulted in underestimation of flow values. Preliminary in vivo results showed comparable cerebral flow value ratios between gray matter (GM) and white matter (WM) when using blindly estimated voxel-specific AIFs or a single manually selected AIF. Significant differences (P < or = 0.0125) in mean transit time (MTT) and time-to-peak (TTP) in GM compared to WM was seen with the new method. CONCLUSION: Initial results suggest that the proposed method can replace the tedious and difficult task of manually selecting an AIF, while simultaneously providing better differentiation between time-dependent hemodynamic parameters.

Risk of clinical pulmonary embolism after joint surgery in patients receiving low-molecular-weight heparin prophylaxis in hospital: a 10-year prospective register of 3,954 patients.

We studied the incidence of nonfatal, radiologically-confirmed, clinical pulmonary embolism (PE) after major joint surgery during 10 years of observation. The findings are based on a prospective register of all patients undergoing total hip replacement (THR), total knee replacement (TKR), or nailed hip fracture (NHF) in a Scandinavian hospital between 1989 and 1998. All patients received thromboprophylaxis with low-molecular-weight heparin, continued until discharge. Patients with suspected PE underwent ventilation/perfusion scintigraphy and/or spiral CT. Patients with concomitant clinical signs of deep vein thrombosis (DVT) were also subjected to imaging diagnostics. 3,954 patients underwent THR, TKR, or NHF; 122 of them were readmitted on clinical suspicion of PE, and 50 cases were confirmed. Of patients with confirmed PE, 6/50 had DVT. The average time to readmission was 35 (5-94) days after THR, 24 (1-173) days after NHF, and 9 (2-17) days after TKR. Following major hip surgery, the incidence of PE remained high for at least 2-3 months (less following TKR) in those given thromboprophylaxis for about 10 days. The differences in PE incidence and the time when it developed in NHF versus THR and TKR patients suggest that these patients should be considered separately when determining the optimal thromboprophylactic regimen.