Incidence and Predictors of Implantable Cardioverter-defibrillator Therapies After Generator Replacement-A Pooled Analysis of 31,640 Patients' Data

Among primary prevention implantable cardioverter-defibrillator (ICD) recipients, 75% do not experience any appropriate ICD therapies during their lifetime, and nearly 25% have improvements in their left ventricular ejection fraction (LVEF) during the lifespan of their first generator. The practice guidelines concerning this subgroup's clinical need for generator replacement (GR) remain unclear. We conducted a proportional meta-analysis to determine the incidence and predictors of ICD therapies after GR and compared this to the immediate and long-term complications. A systematic review of existing literature on ICD GR was performed. Selected studies were critically appraised using the Newcastle-Ottawa scale. Outcomes data were analyzed by random-effects modeling using R (R Foundation for Statistical Computing, Vienna, Austria), and covariate analyses were conducted using the restricted maximum likelihood function. A total of 31,640 patients across 20 studies were included in the meta-analysis with a median (range) follow-up of 2.9 (1.2-8.1) years. The incidences of total therapies, appropriate shocks, and anti-tachycardia pacing post-GR were approximately 8, 4, and 5 per 100 patient-years, respectively, corresponding to 22%, 12%, and 12% of patients of the total cohort, with a high level of heterogeneity across the studies. Greater anti-arrhythmic drug use and previous shocks were associated with ICD therapies post-GR. The all-cause mortality was approximately 6 per 100 patient-years, corresponding to 17% of the cohort. Diabetes mellitus, atrial fibrillation, ischemic cardiomyopathy, and the use of digoxin were predictors of all-cause mortality in the univariate analysis; however, none of these were found to be significant predictors in the multivariate analysis. The incidences of inappropriate shocks and other procedural complications were 2 and 2 per 100 patient-years, respectively, which corresponded to 6% and 4% of the entire cohort. Patients undergoing ICD GR continue to require therapy in a significant proportion of cases without any correlation with an improvement in LVEF. Further prospective studies are necessary to risk-stratify ICD patients undergoing GR.

His-bundle Pacing as a Bailout Therapy for a Patient with Subclavian Stenosis and No Suitable Coronary Sinus Branch: A Double Whammy

We present an interesting case of an 88-year-old man who was referred to our arrhythmia service for an upgrade of his dual-chamber pacemaker to a biventricular pacemaker for right ventricular pacing-induced cardiomyopathy. The patient was found to have stenosis of the left subclavian vein. Here, we describe the approach used to perform venoplasty in this patient. After venoplasty of the left subclavian vein, the patient did not have suitable coronary venous anatomy for deployment of the coronary sinus lead. Subsequently, a His lead was implanted. We achieved significant narrowing of the QRS with good thresholds and other lead parameters. Through this case report, we seek to present our approach of venoplasty in patients with occluded venous access for either an upgrade or a de novo implant.

The Role of High-output His-bundle Pacing During Atrioventricular Node Ablation

Atrioventricular (AV) junction ablation (AVJA) is an acceptable strategy to control the heart rate in atrial fibrillation (AF) with a high procedural success rate. However, a small subset of patients pose a technical challenge with the standard right-sided approach. High-output His-bundle pacing has been shown to help localize the His bundle in a difficult-to-ablate AV junction. We report a case series of patients with difficult-to-ablate AVJA and present strategies to troubleshoot them. In this small series of patients, we found that high-output His pacing can be an effective alternative for successfully localizing the AVJA site. In this series, we also observed that an inability to achieve His capture from the right side can predict failure of ablation using the standard right-sided approach and the consequent need for a left-sided approach.

Device-based Optimization of Cardiac Resynchronization-One Size Does Not Fit All

We report on a 72-year-old female patient who was sent to our clinic for evaluation of a biventricular intracardiac defibrillator (BIV-ICD). The patient was diagnosed with ischemic cardiomyopathy and showed a persistently low ejection fraction in the range of 20%-25% with New York Heart Association class III heart failure symptoms despite being on guideline-directed medical therapy, including a β-blocker and a combination of sacubitril and valsartan, for >3 months. In addition, the patient had underlying right bundle branch block (RBBB) with a QRS duration of 160 ms. The device was programmed with a Sync-AV algorithm on with nominal settings (delta of -50 ms). The thresholds and lead impedances were acceptable. Electrocardiography was performed in the postoperative period, showing persistent RBBB similar to the baseline electrocardiogram without much QRS narrowing. In this report, we discuss the mechanism and troubleshooting of this problem.

Fuchs Heterochromic Iridocylitis: Clinical Characteristics and Outcome of Cataract Extraction with Intra Ocular Lens Implantation in a Kashmiri Population- A Hospital Based Study

INTRODUCTION

Fuchs Heterochromic Iridocylitis (FHI) is a rare form of uveitis which is frequently complicated by cataract and glaucoma, but it does not show typical features of uveitis like pain, redness and posterior synechia.

AIM

To study the clinical characteristics and outcome of cataract extraction with Intra Ocular Lens (IOL) implantation in patients with FHI.

MATERIALS AND METHODS

The present prospective study was carried out in the Postgraduate Department of Ophthalmology, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Bemina from March 2012 to January 2015. The study included 33 eyes of 32 patients of FHI who underwent thorough clinical examination and cataract surgery with IOL implantation and were evaluated based on their visual outcome and intra and post-operative complications. Post-operative follow-up was done on 1^st day, one week, one month, two month, six month and at twelve months.

RESULTS

Mean age of our study group was 33.9 years (Range 18 to 65 years). No male or female preponderance was seen. There was bilateral involvement of eyes in only one case. Cataract and stellate keratic precipitates were present in all cases whereas, heterochromia was present in only six eyes (18.75%). Best Corrected Visual Acuity (BCVA) showed a significant improvement following cataract surgery (p<0.001). Post-operatively, 26 eyes (78.78%) showed an improvement of four lines or more (BCVA of > 6/12). Most common causes of decreased vision post-operatively were vitreous opacities in nine eyes (27.27%) followed by glaucoma in eight eyes (24.24%) and posterior capsular opacification in six eyes (18.18%).

CONCLUSION

Cataract extraction with IOL lens implantation in FHI is a safe procedure associated with good visual prognosis and few complications. However, glaucoma is one of the main concerns and should be closely monitored both pre and post-operatively.

Normal-appearing grey and white matter T1 abnormality in early relapsing–remitting multiple sclerosis: a longitudinal study

Objective

To investigate the presence and evolution of T1 relaxation time abnormalities in normal-appearing white matter (NAWM) and grey matter (GM), early in the course of relapsing–remitting multiple sclerosis (MS).

Methods

Twenty-three patients with early relapsing–remitting MS and 14 healthy controls were imaged six monthly for up to three years. Mean follow-up was 26 months for MS patients and 24 months for controls. Dual-echo fast-spin echo and gradient-echo proton-density and T1-weighted data sets (permitting the calculation of a T1 map) were acquired in all subjects. GM and NAWM T1 histograms were produced and a hierarchical regression model was used to investigate changes in T1 over time.

Results

At baseline, significant patient-control differences were seen, both in NAWM (P = 0.001) and in GM (P = 0.01). At follow-up, there was no evidence for a serial change in either mean T1 or peak-location for either NAWM or GM. There was weak evidence for a decline in patient NAWM peak-height and also evidence for a decline in control GM peak-height.

Conclusion

There are significant and persistent abnormalities of NAWM and GM T1 in early relapsing-remitting MS. Further studies should address whether such T1 measures have a role in prognosis or therapeutic monitoring. Multiple Sclerosis 2007; 13:169–177. http://msj.sagepub.com

Relationship of triple dose contrast enhanced lesions with clinical measures and brain atrophy in early relapsing-remitting multiple sclerosis: a two-year longitudinal study

Gadolinium (Gd) enhancement of lesions indicates inflammatory lesion activity in multiple sclerosis (MS). The question arises whether early inflammatory lesion activity – measured sensitively using triple dose Gd – is related to the future clinical course, or to the development of brain atrophy that is thought to reflect the underlying pathological progression of the disease. In this study, 26 patients with early relapsing-remitting (RR) MS (median disease duration: 1.7 years) were followed up over two years. Associations were explored between their levels of Gd-lesion enhancement in the first six months and later clinical (Expanded Disability Status Scale (EDSS) and MS Functional Composite Score (MSFC)) and magnetic resonance imaging (MRI) (brain volume, T2 and T1 lesion volumes) measures. The extent of Gd-enhancement in the first six months correlated weakly with concurrent relapses (P = 0.041), but there was no consistent correlation with clinical and MRI outcomes at two years. More prolonged follow-up is warranted to clarify the relationship between early inflammatory lesions and long-term clinical course. Multiple Sclerosis 2007; 13: 178–185. http://msj.sagepub.com

Cognitive impairment among patients with multiple sclerosis: associations with employment and quality of life

OBJECTIVES

To explore the relationship between cognitive impairment and conventional measures of disability in multiple sclerosis (MS), quality of life (QOL) and employment status using the brief international cognitive assessment for multiple sclerosis (BICAMS) in the routine outpatient clinic.

METHODS

62 patients with MS were assessed on the BICAMS test battery for cognitive impairment. Data were obtained on employment status and a number of questionnaires completed including fatigue severity score, multiple sclerosis neuropsychological questionnaire, hospital anxiety and depression scale, the functional assessment of multiple sclerosis (FAMS) as well as on the EuroQOL five dimension questionnaire (EQ-5D). Other assessments include the patient activation measure and unidimensional self-efficacy scale for multiple sclerosis.

RESULTS

Cognitive assessment revealed 44 subjects (65%) had evidence of cognitive impairment on formal testing. In comparison with patients without evidence of cognitive impairment, cognitively impaired patients exhibited significantly higher rates of unemployment (p=0.009). The symbol digits modalities test was the most significant predictor of unemployment. Cognitive impairment was associated with lower QOL scores on the FAMS (p=0.001) and EQ-5D (p<0.001).

CONCLUSIONS

BICAMS provides a sensitive and easy to administer screening test for cognitive impairment within the outpatient setting. Cognitive impairment is common in our cohort of patients with MS attending outpatients and appears to be associated with increased rates of unemployment and lower measures of QOL.

Diffusion tensor imaging of early relapsing-remitting multiple sclerosis with histogram analysis using automated segmentation and brain volume correction

Diffusion tensor magnetic resonance imaging (DTI) reveals measurable abnormalities in normal-appear ing brain tissue (NA BT) in established multiple sclerosis (MS). However, it is unclear how early this occurs. Recent studies have employed whole brain histogram analysis to improve sensitivity, but concern exists regarding reliability of tissue/cerebrospinal fluid segmentation and possible intersubject brain volume differences, which can introduce partial volume error. To address this, 28 early relapsing-remitting MS subjects [median disease duration 1.6 years; median Expanded Disability Status Scale (EDSS) score 1.5] and 20 controls were compared with whole brain histogram analysis using an automated segmentation algorithm to improve reproducibility. Brain parenchymal volumes (BPV) were estimated for each subject in the analysis. The mean, peak height and peak location were calculated for DTI parameters [fractional anisotropy (FA), mean diffusivity and volume ratio]. A n increased FA peak height in MS subject NA BT was observed (P =0.02) accounting for age, gender and BPV. Removing BPV revealed additional abnormalities in NABT. The main conclusions are i) FA peak height is increased in NA BT in early MS, ii) partial volume edge effects may contribute to apparent NA BT histogram abnormalities, and iii) correction for brain volume differences should reduce potential partial volume edge effects.

High altitude pulmonary edema among "Amarnath Yatris"

BACKGROUND

Annual pilgrimage (Yatra) to the cave shrine of Shri Amarnath Ji' is a holy ritual among the Hindu devotees of Lord Shiva. Located in the Himalayan Mountain Range (altitude 13,000 ft) in south Kashmir, the shrine is visited by thousands of devotees and altitude sickness is reportedly common.

MATERIALS AND METHODS

More than 600,000 pilgrims visited the cave shrine in 2011 and 2012 with 239 recorded deaths. Thirty one patients with suspected altitude sickness were referred from medical centers en-route the cave to Sher-i-Kashmir Institute of Medical Sciences, a tertiary-care center in capital Srinagar (5,000 ft). The clinical features and the response to treatment were recorded.

RESULTS

Thirty-one patients (all lowlanders, 19 male; age 18-60 years, median 41) had presented with acute onset breathlessness of 1-4 days (median 1.9 d) starting within 12-24 h of a rapid ascent; accompanied by cough (68%), headache (8%), dizziness and nausea (65%). Sixteen patients had associated encephalopathy. Clinical features on admission included tachypnea (n = 31), tachycardia (n = 23), bilateral chest rales (n = 29), cyanosis (n = 22) and grade 2-4 encephalopathy. Hypoxemia was demonstrable in 24 cases and bilateral infiltrates on radiologic imaging in 29. Ten patients had evidence of high-altitude cerebral edema. All patients were managed with oxygen, steroids, nifedipine, sildenafil and other supportive measures including invasive ventilation (n = 3). Three patients died due to multiorgan dysfunction.

CONCLUSIONS

Altitude sickness is common among Amaranath Yatris from the plains and appropriate educational strategies should be invoked for prevention and prompt treatment.

64-section multiphase CT enterography as a diagnostic tool in the evaluation of obscure gastrointestinal bleeding

BACKGROUND AND AIM

Small bowel follow through (SBFT) and enteroclysis have low sensitivity in picking up lesions in obscure gastrointestinal bleed (OGIB). Computed tomographic enterography (CT-EG), performed with 64-slice multiphase CT system by using large volumes of ingested neutral enteric contrast material, has high spatial and temporal resolution in visualization of the small bowel wall and lumen. The role of 64-slice multiphase CT-EG in the evaluation of OGIB is still evolving, and data on this role are scarce. We evaluated the efficacy of 64-slice multiphase CT-EG using polyethylene glycol (PEG) electrolyte solution as neutral contrast in patients of OGIB.

METHODS

CT-EG was performed with 64-slice multiphase CT system using large volume (2,000 mL) of PEG electrolyte solution as oral contrast in patients of OGIB.

RESULTS

Thirty-five patients (21 men, age 41.4 [13.5] y, range 19-70 year) with OGIB underwent CT-EG; 20 patients had overt OGIB whereas 15 patients had occult OGIB. Among 15 patients with occult OGIB, 10 patients had iron deficiency anemia (IDA) with fecal occult blood test (FOBT) positive and 5 had IDA with FOBT negative. Thirty-two patients (92 %) completed the procedure successfully. The total time taken for the ingestion of 2,000 mL of PEG electrolyte solution was median 64 (range 60-78) minutes. Adequate luminal distension of small bowel was seen in 29 (90.6 %) patients for successful interpretation of radiological images. Fifteen of 32 (46.9 %) patients had positive findings on CT-EG; 12 of them underwent exploratory laparotomy. The surgical findings were in conformity with CT-EG findings in all patients, which included gastrointestinal stromal tumors (GIST; n = 6), carcinoid (1), Meckel's diverticulum (1), small bowel adenocarcinoma (2) and jejunal vascular malformation (2).

CONCLUSION

64-slice multiphase CT-EG is a useful investigation in the evaluation of both occult and overt OGIB.

Voxel-based analysis of grey matter magnetization transfer ratio maps in early relapsing remitting multiple sclerosis

Previous studies using magnetization transfer ratio (MTR) histogram analysis have demonstrated the existence of global grey matter (GM) abnormalities in patients with early relapsing-remitting multiple sclerosis (RRMS). However, MTR histogram analysis does not provide any information on the localization of the morphological changes within the GM. The aim of this study was to investigate the localization of GM injury in early RRMS, performing voxel-based analysis of GM MTR maps. Statistical mapping analysis of GM MTR maps was performed in a group of 38 patients with early RRMS and 45 healthy controls. Between-group comparisons (P<0.05, corrected for multiple comparisons) demonstrated significant GM MTR decrease in patients located in the bilateral lenticular nuclei, the bilateral insula, the left posterior cingulate cortex, and the right orbitofrontal cortex. To limit the potential confounding effect of regional GM atrophy, the percentages of GM were assessed in the regions showing significant MTR decrease, and no GM atrophy was evidenced in these regions. This study demonstrates that several GM regions are commonly affected in patients with early RRMS. Predominant involvement of these structures may be partly related to their vulnerability to anterograde or retrograde degeneration from transected axons in the white matter and/or to the predominant localization of GM demyelinating lesions in such regions.

Cord atrophy separates early primary progressive and relapsing remitting multiple sclerosis

BACKGROUND AND OBJECTIVE

The onset of multiple sclerosis is relapsing remitting or primary progressive. An improved understanding of the causes of early progressive disability in primary progressive multiple sclerosis (PPMS) could provide mechanistic targets for therapeutic intervention.

METHODS

Five magnetic resonance imaging (MRI) parameters that could potentially cause progressive disability were investigated in 43 patients with early PPMS and in 37 patients with early relapsing remitting multiple sclerosis (RRMS): atrophy in brain, both grey matter and white matter; intrinsic abnormality in brain, both grey matter and white matter (measured by the magnetisation transfer ratio (MTR)); and atrophy of the upper cervical spinal cord. Both groups were also compared with controls.

RESULTS

Patients with PPMS were older and more likely to be men. Both patient groups had atrophy of brain grey matter and white matter, and intrinsic abnormality in MTR of normal-appearing grey matter and white matter. Cord atrophy was present only in the PPMS (mean cord area: PPMS, 67.8 mm2; RRMS, 72.7 mm2; controls, 73.4 mm2; p = 0.007). This was confirmed by multivariate analysis of all five MRI parameters, age and sex.

CONCLUSION

Grey matter and white matter of the brain are abnormal in both early RRMS and PPMS, but cord atrophy is present only in PPMS. This is concordant with myelopathy being the usual clinical presentation of PPMS. Measurement of cord atrophy seems to be clinically relevant in PPMS treatment trials.

Increasing cord atrophy in early relapsing-remitting multiple sclerosis: a 3 year study

OBJECTIVES

Previous studies have shown that upper cervical cord atrophy (UCCA) occurs in multiple sclerosis (MS), particularly in those disabled and with primary or secondary progressive disease. It is less clear how early it can be detected in relapsing-remitting (RR) MS, and whether early cord atrophy relates to the concurrent or future clinical course.

METHODS

Twenty seven RR MS patients (median disease duration 1.7 years, in all cases <3 years from onset) were recruited along with 20 controls. They were followed for up to 3 years with a yearly assessment of UCCA and clinical function measured by the Expanded Disability Status Scale (EDSS) and MS Functional Composite Score (MSFC). Clinical and MRI correlations were investigated. Statistical models adjusted for covariates including total intracranial volume.

RESULTS

Longitudinal analysis showed a significant decrease in UCCA in patients both within the patient cohort (p < 0.001) and in comparison with controls (p = 0.001). There was a significant increase in EDSS (p = 0.008) but no significant change in MSFC. The rate of UCCA loss did not correlate with clinical change or with change in brain volume.

CONCLUSIONS

In summary, serial UCCA measurement detects the development of spinal cord atrophy in clinically early RR MS.

Metabolite changes in early relapsing-remitting multiple sclerosis. A two year follow-up study

Previous in vivo proton magnetic resonance spectroscopic imaging ((1)H-MRSI) studies have found reduced levels of N-acetyl-aspartate (NAA) in multiple sclerosis (MS) lesions, the surrounding normal-appearing white matter (NAWM) and cortical grey matter (CGM), suggesting neuronal and axonal dysfunction and loss. Other metabolites, such as myoinositol (Ins), creatine (Cr), choline (Cho), and glutamate plus glutamine (Glx), can also be quantified by (1)H-MRSI, and studies have indicated that concentrations of these metabolites may also be altered in MS. Relatively little is known about the time course of such metabolite changes. This preliminary study aimed to characterise changes in total NAA (tNAA, the sum of NAA and N-acetyl-aspartyl-glutamate), Cr, Cho, Ins and Glx concentrations in NAWM and in CGM, and their relationship with clinical outcome, in subjects with clinically early relapsing-remitting MS (RRMS). Twenty RRMS subjects and 10 healthy control subjects underwent (1)H-MRSI examinations yearly for two years. Using the LCModel, tNAA, Cr, Cho, Ins and Glx concentrations were estimated both in NAWM and CGM. At baseline, the concentration of tNAA was significantly reduced in the NAWM of the MS patients compared to the control group (-7%, p = 0.003), as well as in the CGM (-8.7%, p = 0.009). NAWM tNAA concentrations tended to recover from baseline, but otherwise tissue metabolite profiles did not significantly change in the MS subjects, or relatively between MS and healthy control subjects. While neuronal and axonal damage is apparent from the early clinical stages of MS, this study suggests that initially it may be partly reversible. Compared with other MR imaging measures, serial (1)H-MRSI may be relatively less sensitive to progressive pathological tissue changes in early RRMS.

Emergence of thalamic magnetization transfer ratio abnormality in early relapsing-remitting multiple sclerosis

While there is now evidence for thalamic abnormality in established secondary progressive and relapsing-remitting multiple sclerosis (MS), it remains unclear when such abnormality begins. This study investigated the emergence of thalamic abnormality in relapsing-remitting MS by assessing the thalamic magnetization transfer ratio (MTR) in a cohort with clinically early disease. Twenty-three patients with early relapsing-remitting MS (mean age 37; mean disease duration 1.9 years; Expanded Disability Status Scale (EDSS) range 0-3) and 19 healthy controls (mean age 34) were imaged yearly with a magnetization transfer imaging sequence. Twenty-two MS patients and 14 controls completed two-year follow-up. Regions of interest were placed in both thalami and mean thalamic MTR calculated. At baseline, significant differences between patient and control thalamic MTR were not observed. However, at years one and two, the thalamic MTR in patients was significantly lower than control MTR. Although baseline lesion volume did not correlate with baseline thalamic MTR, at year one, an association between baseline lesion volume and year one thalamic MTR emerged. There was also a significant inverse correlation between EDSS and thalamic MTR (r = -0.47, P = 0.02). The study suggests that thalamic involvement occurs within the first five years of MS onset, when most patients are still minimally disabled.

Increasing normal-appearing grey and white matter magnetisation transfer ratio abnormality in early relapsing-remitting multiple sclerosis

Abnormalities within normal-appearing grey and white matter (NAGM and NAWM) occur early in the clinical course of multiple sclerosis (MS) and can be detected in-vivo using the magnetisation transfer ratio (MTR). To better characterize the rates of change in both tissues and to ascertain when such changes begin, we serially studied a cohort of minimally disabled, early relapsing-remitting MS patients, using NAGM and NAWM MTR histograms. Twenty-three patients with clinically definite early relapsing-remitting MS (mean disease duration at baseline 1.9 years), and 19 healthy controls were studied. A magnetisation transfer imaging sequence was acquired yearly for two years. Twenty-one patients and 10 controls completed followup. NAWM and NAGM MTR histograms were derived and mean MTR calculated. A hierarchical regression analysis, adjusting for brain parenchymal fraction,was used to assess MTR change over time. MS NAWM and NAGM MTR were significantly reduced in comparison with controls at baseline and, in patients, both measures decreased further during follow-up: (-0.10 pu/year, p=0.001 and -0.18 pu/year, p<0.001 respectively). The rate of MTR decrease was significantly greater in NAGM than NAWM (p=0.004). Under the assumption that such changes are linear, backward extrapolation of the observed rates of change suggested that NAWM abnormality began before symptom onset. We conclude that increasing MTR abnormalities in NAWM and NAGM are observed early in the course of relapsing-remitting MS. It is now important to investigate whether these measures are predictive of future disability, and consequently, whether MTR could be used as a surrogate marker in therapeutic trials.

Gray and white matter volume changes in early RRMS: A 2-year longitudinal study

BACKGROUND

Brain atrophy, in excess of that seen with normal aging, has been observed early in the clinical course of relapsing-remitting multiple sclerosis (RRMS). Previous work has suggested that at this stage of the disease, gray matter (GM) atrophy progresses more rapidly than the white matter (WM) atrophy.

OBJECTIVES

To characterize the evolution of GM and WM volumes over 2 years, and their associations with lesion loads in a cohort of patients with clinically early RRMS.

METHODS

Twenty-one patients with RRMS (mean age 37.5 years, mean disease duration from symptom onset 2.1 years) and 10 healthy control subjects (mean age 37.1 years) were studied. Tissue volumes, as fractions of total intracranial volumes, were estimated at baseline and 1- and 2-year follow-up. Brain parenchymal fractions (BPF), GM fractions (GMF), and WM fractions (WMF) were estimated. In subjects with MS, brain lesion loads were determined on conventional T2-weighted along with pre- and post-gadolinium (Gd) enhanced T1-weighted images at each timepoint.

RESULTS

A decrease in GMF was observed in subjects with MS vs normal controls over the 2 years of the study (mean -2.1% vs -1.0%, p = 0.044), while no change was seen in WMF over the same period (mean -0.09% vs +0.09%, p = 0.812). However, when the MS cohort was divided in half, dependent upon change in Gd-enhancing lesion load over 2 years (n = 20), a decrease in WMF was seen in the group (n = 10) with the largest decline in Gd volume, whereas WMF increased in the other half (n = 10) concurrent with a net increase in volume of Gd-enhancing lesions (difference between groups: p = 0.034).

CONCLUSIONS

Increasing gray matter but not white matter (WM) atrophy was observed early in the clinical course of relapsing-remitting multiple sclerosis. Fluctuations in inflammatory WM lesions appear to be related to volume changes in WM over this time period.

Abnormalities of cerebral perfusion in multiple sclerosis

BACKGROUND

Measuring perfusion provides a potential indication of metabolic activity in brain tissue. Studies in multiple sclerosis (MS) have identified areas of decreased perfusion in grey matter (GM) and white matter (WM), but the pattern in clinical subgroups is unclear.

OBJECTIVES

This study investigated perfusion changes in differing MS clinical subgroups on or off beta-interferon therapy using a non-invasive MRI technique (continuous arterial spin labelling) to investigate whether different clinical MS subtypes displayed perfusion changes and whether this could give a further insight into the pathological mechanisms involved.

METHODS

Sixty patients (21 relapsing remitting, 14 secondary progressive, 12 primary progressive, 13 benign) and 34 healthy controls were compared. Statistical parametric mapping (SPM '99) was used to investigate regional variations in perfusion in both GM and WM. Global WM perfusion was derived by segmenting WM from images using T(1) relaxation times.

RESULTS

Regions of lower perfusion in predominantly GM were observed in the primary and secondary progressive cohorts, particularly in the thalamus. Increased WM perfusion was seen in relapsing remitting and secondary progressive cohorts.

CONCLUSIONS

Low GM perfusion could reflect decreased metabolism secondary to neuronal and axonal loss or dysfunction with a predilection for progressive forms of MS. Increased WM perfusion may indicate increased metabolic activity possibly due to increased cellularity and inflammation. Improved methodology and longitudinal studies may enable further investigation of regional and temporal changes, and their relationship with physical and cognitive impairment.

Progressive grey matter atrophy in clinically early relapsing-remitting multiple sclerosis

Brain atrophy appears to occur in patients with multiple sclerosis (MS) in excess of that associated with normal ageing, and may be observed early in the clinical course of the disease. The dynamics and tissue specificity of this process remain unclear This preliminary study explored the evolution of brain grey matter (GM) and white matter (WM) volume loss (as fractions of total intracranial volumes) in 13 subjects with relapsing-remitting MS (mean disease duration 1.9 years at first scan), compared with nine normal control (NC) subjects. Subjects were scanned every six months for 18 months. In MS compared with NC subjects, significant differences in WM fractional volumes were observed at baseline (mean - 5.8%, P = 0.008) but no apparent progressive WM tissue loss was detected. In contrast, while no significant differences in GM fractional volumes were observed at baseline, there was significantly greater time-related volume loss in MS compared with NC subjects over the follow-up period (circa - 0.0086 per year in MS subjects, - 0.0021 per year in the NC subjects, difference P = 0.010). These results suggest that while both GM and WM atrophy are seen early in the clinical course of MS, they may not occur concurrently and may evolve at different rates.

Evidence for grey matter MTR abnormality in minimally disabled patients with early relapsing-remitting multiple sclerosis

OBJECTIVES

To establish whether magnetisation transfer ratio (MTR) histograms are sensitive to change in normal appearing grey matter (NAGM) in early relapsing-remitting multiple sclerosis (RRMS) in the absence of significant disability; and to assess whether grey or white matter MTR measures are associated with clinical measures of impairment in early RRMS METHODS: 38 patients were studied (mean disease duration 1.9 years (range 0.5 to 3.7); median expanded disability status scale (EDSS) 1.5 (0 to 3)), along with 35 healthy controls. MTR was determined from proton density weighted images with and without MT presaturation. SPM99 was used to generate normal appearing white matter (NAWM) and NAGM segments of the MTR map, and partial voxels were minimised with a 10 pu threshold and voxel erosions. Mean MTR was calculated from the tissue segments. Atrophy measures were determined using a 3D fast spoiled gradient recall sequence from 37 patients and 17 controls.

RESULTS

Mean NAGM and NAWM MTR were both reduced in early RRMS (NAGM MTR: 31.9 pu in patients v 32.2 pu in controls; p<0.001; NAWM MTR: 37.9 v 38.3 pu, p = 0.001). Brain parenchymal fraction (BPF) correlated with NAGM MTR, but when BPF was included as a covariate NAGM MTR was still lower in the patients (p = 0.009). EDSS correlated with NAGM MTR (r = 0.446 p = 0.005).

CONCLUSIONS

In early RRMS, grey matter MTR abnormality is apparent. The correlation with mild clinical impairment (in this essentially non-disabled cohort) suggests that NAGM MTR could be a clinically relevant surrogate marker in therapeutic trials.