Control of abscisic acid synthesis

The abscisic acid (ABA) biosynthetic pathway involves the formation of a 9-cis-epoxycarotenoid precursor. Oxidative cleavage then results in the formation of xanthoxin, which is subsequently converted to ABA. A number of steps in the pathway may control ABA synthesis, but particular attention has been given to the enzyme involved in the oxidative cleavage reaction, i.e. 9-cis-epoxycarotenoid dioxygenase (NCED). Cloning of a gene encoding this enzyme in maize was first reported in 1997. Mapping and DNA sequencing studies indicated that a wilty tomato mutant was due to a deletion in the gene encoding an enzyme with a very similar amino acid sequence to this maize NCED. The potential use of this gene in altering ABA content will be discussed together with other genes encoding ABA biosynthetic enzymes.

The pathogenesis of lesions and normal-appearing white matter changes in multiple sclerosis: a serial diffusion MRI study

The idea that the initiating event in the formation of all new multiple sclerosis lesions is a focal blood-brain barrier (BBB) leakage associated with perivascular inflammation has been challenged recently by the observation of subtle abnormalities in some quantitative magnetic resonance (MR) parameters (including the magnetization transfer ratio) prior to lesion enhancement. MR diffusion imaging can non-invasively quantify the average apparent diffusion coefficient (ADC(av)), a measure of water molecule random motion that is sensitive to pathological change in multiple sclerosis lesions and to abnormalities in the normal-appearing white matter (NAWM). We therefore used MR diffusion imaging to investigate the dynamic evolution of water diffusion measurements in new enhancing multiple sclerosis lesions, in the NAWM from which they arise, and in anatomically matched contralateral NAWM regions from which no visible lesions develop. Gadolinium diethylenetriaminepentaacetic acid (Gd)-enhanced MRI and MR diffusion studies were performed monthly for 1 year in five multiple sclerosis patients with clinically and radiologically active disease. The ADC(av) was calculated at each time point of the study (before, during and after lesion appearance on Gd-enhanced scans) for each new enhancing lesion, and for regions matched for size and position in the contralateral NAWM. A steady and moderate increase in ADC(av) in prelesion NAWM was observed, which was followed by a rapid and marked increase at the time of Gd enhancement and a slower decay after the cessation of enhancement. In matched contralateral NAWM regions there was a significant but milder increase in ADC(av) at the time of the first noted lesion enhancement. These findings indicate that new focal lesions associated with frank BBB leakage are preceded by subtle, progressive alterations in tissue integrity beyond the resolution of conventional MRI. The increases in ADC(av) in anatomically matched contralateral regions after lesions have appeared supports the concept that structural damage in lesions causes damage or dysfunction in connected areas of NAWM.

Diffusion tensor imaging can detect and quantify corticospinal tract degeneration after stroke

Diffusion tensor imaging (DTI) fully characterises water molecule mobility in vivo, allowing an exploration of fibre tract integrity and orientation in the human brain. Using DTI this study demonstrates reduced fibre coherence (anisotropy) associated with cerebral infarction and in the corticospinal tract remote from the lesion, in five patients 2 to 6 months after ischaemic stroke. The study highlights the potential of DTI to detect and monitor the structural degeneration of fibre pathways, which may provide a better understanding of the pattern of clinical evolution after stroke.

Neuropsychological impairment in multiple sclerosis patients: the role of (juxta)cortical lesion on FLAIR

In this study we evaluated the correlation between neuropsychological impairment (measured with the Brief Repeatable Battery Neuropsychological Tests) and (juxta)cortical lesions detected with FLAIR and the relative sensitivity of the FLAIR sequence compared to spin-echo MRI sequences in detecting (juxta)cortical MS lesions. A total of 39 patients with definite MS were evaluated by MRI with a conventional and fast spin echo sequence and fast FLAIR sequence, and neuropsychological tests of the Brief Repeatable Battery Neuropsychological tests were performed. The Z-score of all subtests were used to calculate a Cognitive Impairment Index. The results show that a high number of (juxta)cortical lesions is detected with thin slice FLAIR (30% of all lesions seen). This percentage was not superior to spin-echo, reflecting the thin slice thickness (3 mm) we used. The lesions detected with FLAIR were to a certain degree different ones than the lesions detected with the other techniques. While the number of non-cortical lesions correlated with the expanded disability status scale (r=0.32, P=0.045), the number of (juxta)cortical lesions detected with the FLAIR showed a correlation (r=0.34, P=0.035) with the Cognitive Impairment Index. Our study underlines the high number of (juxta)cortical lesions in MS and the value of thin slice FLAIR sequence to detect such lesions with MRI. It also stresses the importance of (juxta)cortical lesions on determining neuropsychological impairment. Multiple Sclerosis (2000) 6 280 - 285

Ectopic expression of a tomato 9-cis-epoxycarotenoid dioxygenase gene causes over-production of abscisic acid

The tomato mutant notabilis has a wilty phenotype as a result of abscisic acid (ABA) deficiency. The wild-type allele of notabilis, LeNCED1, encodes a putative 9-cis-epoxycarotenoid dioxygenase (NCED) with a potential regulatory role in ABA biosynthesis. We have created transgenic tobacco plants in which expression of the LeNCED1 coding region is under tetracycline-inducible control. When leaf explants from these plants were treated with tetracycline, NCED mRNA was induced and bulk leaf ABA content increased by up to 10-fold. Transgenic tomato plants were also produced containing the LeNCED1 coding region under the control of one of two strong constitutive promoters, either the doubly enhanced CaMV 35S promoter or the chimaeric 'Super-Promoter'. Many of these plants were wilty, suggesting co-suppression of endogenous gene activity; however three transformants displayed a common, heritable phenotype that could be due to enhanced ABA biosynthesis, showing increased guttation and seed dormancy. Progeny from two of these transformants were further characterized, and it was shown that they also exhibited reduced stomatal conductance, increased NCED mRNA and elevated seed ABA content. Progeny of one transformant had significantly higher bulk leaf ABA content compared to the wild type. The increased seed dormancy was reversed by addition of the carotenoid biosynthesis inhibitor norflurazon. These data provide strong evidence that NCED is indeed a key regulatory enzyme in ABA biosynthesis in leaves, and demonstrate for the first time that plant ABA content can be increased through manipulating NCED.

A retrospective analysis of outcome in severe Guillain-Barre syndrome following combined neurological and rehabilitation management

PURPOSE

To determine the outcome in severe Guillain-Barre syndrome following combined neurological and rehabilitation management using standardized disability and handicap measures and to identify the factors which affect this outcome.

METHODS

A retrospective study was performed of 24 patients with Guillain-Barre Syndrome admitted over a 3 year period to the neurological rehabilitation unit of the National Hospital for Neurology and Neurosurgery. Queen Square, London. Disability and handicap on admission and discharge were measured using the modified Barthel Index (BI), Functional Independence Measure (FIM). Environmental Status Scale (ESS) and Handicap Assessment Scale (HAS). Data was collected to identify any factors affecting outcome; age at onset, time to nadir, duration of ventilation, total in-patient stay, duration of stay at the neurological rehabilitation unit, symptoms, signs and electrophysiological findings.

RESULTS

The majority of patients had multiple problems. Outcome was related to the duration of rehabilitation. The mean modified BI score and the FIM score increased whereas ESS scores and HAS scores decreased, these changes were compatible with a reduction in disability and handicap.

CONCLUSIONS

Significant improvement in function occurred during rehabilitation. These changes can be demonstrated using standardized outcome measures.

The effectiveness of neurological rehabilitation in multiple sclerosis

The difficulties inherent in demonstrating the effectiveness of an intervention that is as all-inclusive and poorly defined as neurorehabilitation, especially in a condition as unpredictable and variable as Multiple Sclerosis (MS), are not to be underestimated. They require strict adherence to rigorous methodology and, in particular, the consistent use of a range of clinically appropriate and scientifically sound measures of outcome. Incorporating this approach, it is possible to evaluate rehabilitation at four different levels, including (1) the broadest concept of service delivery; (2) packages of comprehensive care; (3) individual components of the package; and finally, (4) the intrinsic elements of the rehabilitation process. Most recent studies have focused on in-patient rehabilitation and have demonstrated benefits across disability, handicap, and quality of life in patients with mild to severe disability. Such benefits persist following discharge into the community. Studies evaluating service delivery and components of the rehabilitation package are in progress, but few investigators have taken on the intrinsic elements or 'black box' of rehabilitation. These recent studies underline the fact that the evaluation of rehabilitation is feasible. Such studies are important, not simply to justify funding but to ensure continuing improvement of the way in which MS is managed.

Diagnostic criteria for primary progressive multiple sclerosis: a position paper

The unique clinical characteristics of primary progressive multiple sclerosis (PPMS) pose particular diagnostic difficulties, both in excluding other causes of progressive syndromes and in confirming the diagnosis of MS, which is not adequately addressed by current diagnostic criteria. This article presents new diagnostic criteria developed by a group of investigators on the basis of a review of their considerable experience with PPMS. (We conclude that at least 1 year of clinical progression must be documented before a diagnosis of PPMS is made.) Three levels of diagnostic certainty have been defined-definite, probable, and possible--based on clinical findings, abnormal cerebrospinal fluid, abnormalities on magnetic resonance imaging (MRI) of the brain and spinal cord, and evoked potentials. In definite PPMS, evidence of intrathecal synthesis of immunoglobulin G together with one of the following three MRI criteria is required: (1) nine brain lesions, (2) two spinal cord lesions, or (3) four to eight brain lesions and one spinal cord lesion. Preliminary testing of these criteria was carried out on a cohort of 156 patients participating in a European natural history study of PPMS: 64% fulfilled the criteria for definite PPMS, 35% for probable PPMS, and only 1% for possible PPMS. These criteria now require prospective validation in a cohort of newly diagnosed patients and by postmortem examination.

One year follow up study of primary and transitional progressive multiple sclerosis

OBJECTIVE

To document clinical and magnetic resonance imaging (MRI) characteristics of a large cohort of primary and transitional progressive multiple sclerosis (PP and TP MS) patients over one year.

INTRODUCTION

Patients with PP or TP MS have been shown to have low brain T2 and T1 lesion loads and slow rates of new lesion formation with minimal gadolinium enhancement, despite their accumulating disability. Serial evaluation of these patients is needed to elucidate the pathological processes responsible for disease progression and to identify clinical and MRI measures which can monitor these processes in treatment trials.

METHOD

Patients, recruited from six European centres, underwent two assessments on the expanded disability status scale (EDSS) and MRI of the brain and spinal cord, 1 year apart.

RESULTS

Of the 167 patients studied (137 with PP MS and 30 with TP MS), 41 (25%; 35 PP and six TP) showed a one step increase in the EDSS. The mean number of new brain lesions seen was 0.88 in the PP group and 0.47 in the TP MS group. Both groups demonstrated change in T2 lesion load over the year (p< or =0.002), with median percentage changes of 7.3% in the PP group and 10. 8% in the TP MS group. The PP group also showed a significant change in T1 load (p< 0.001, median change 12.6%). The number of new cord lesions seen was small (mean of 0.14 in the PP group and no new cord lesions in the TP group). Both groups demonstrated a decrease in cord cross sectional area (p< 0.001, median changes; PP 3.8%, TP 4. 9%), but only the PP group showed evidence of significant brain atrophy (p<0.001, 0.95%).

CONCLUSION

Although the monitoring of disease progression in this patient group is difficult, this study demonstrates changes in both lesion load and atrophy, which, if shown to correlate with clinical change over a longer time will facilitate therapeutic trial design.

Relation of impairment to everyday competence in visual disorientation syndrome: evidence from a single case study

OBJECTIVE

To determine the relation of neurology and neuropsychology to everyday competence.

DESIGN

The association of these three domains was investigated using a single case multiple baseline design with two phases. Phase A comprised 6 weeks that coincided with an inpatient admission. Phase B comprised 3 months spent at home. A battery of visual spatial tests was completed every fortnight during the A phase and at the end of the B phase. Two new tests of relevant neurologic function with control data were developed and used weekly during the A phase and at the end of the B phase. The first test recorded the speed, accuracy, and efficiency of her walking, and the second test recorded her depth perception.

SETTING

Tertiary care center.

PARTICIPANT

A 35-year-old woman who suffered a venous sinus thrombosis with visual disorientation syndrome.

RESULTS

During Phase A, she achieved significant functional gains in mobility, dressing, bathing, and domestic tasks, in the context of unchanging psychometric test scores and static relevant neurologic function. During Phase B, she achieved few functional gains, despite improvements in neurologic status, demonstrated by depth perception.

CONCLUSIONS

Everyday function can progress without improvement in neurologic and cognitive status.

The incidence and significance of testicular microlithiasis in a subfertile population

The objective of this study was to assess the frequency of testicular microlithiasis (TM) in infertile men who underwent testicular ultrasound and to determine any causative or associated factors. The case notes of 159 consecutive patients who were referred for testicular ultrasound in the investigation of male factor infertility were reviewed. Microcalcification was found in 10 cases (6.2%). This was unilateral in all cases and six patients had clinical evidence of a varicocele. Five cases had minimal calcification and five had marked TM. On patient had a past history of testicular maldescent and another of testicular torsion. Sperm function (as assessed by sperm count, motility and the sperm migration test) was variable within the 10 patients and there was no correlation with hormone profiles or testicular size. There was a statistical difference between a number of investigations in those patients with minimal degrees of calcification and those with TM (sperm migration test (SMT), namely sperm migration and sperm motility (p < 0.05, Mann-Whitney U test)). The results showed a higher than expected incidence of TM. Patients with marked TM seemed to have poorer sperm function than those with minimal calcification. There was a high incidence of co-existing pathology, for instance scrotal varicocele and cryptorchidism, although the numbers in this study were small and further studies need to be carried out to determine the exact nature and significance of this condition.

A (1)H magnetic resonance spectroscopy study of aging in parietal white matter: implications for trials in multiple sclerosis

1H magnetic resonance spectroscopy (MRS) provides a unique tool to detect and quantify brain metabolites. In multiple sclerosis it can be used to investigate axonal loss or dysfunction through measurement of N-acetyl aspartate (NAA), a neuronal marker. Previous studies in adults have reported variable effects of aging on metabolite concentrations but have predominantly focused on changes in the elderly. This study has examined a younger adult age group to provide a reference database more applicable to the multiple sclerosis population. Single voxel (1)H MRS was carried out in 44 subjects between 22 and 62 years of age. Sixteen subjects underwent repeat examination after one year. Absolute concentrations of NA (the sum of NAA and N-acetyl aspartate glutamate), NAA, creatine/phosphocreatine (Cr), choline containing compounds (Cho) and myo-inositol (mI) were measured. NA, NAA and mI concentrations did not correlate with age but there were significant correlations between age and Cr (r = 0.43, p = 0.004) and Cho (r = 0.38, p = 0. 011) concentrations. No significant differences in metabolite concentrations were seen over one year. This study provides evidence that age-related changes of metabolite concentrations occur even in a young to middle aged adult population. This emphasizes the need to perform absolute quantification of metabolite concentrations rather than ratios and the importance of age-matching in (1)H MRS studies of multiple sclerosis.

Lesion heterogeneity in multiple sclerosis: a study of the relations between appearances on T1 weighted images, T1 relaxation times, and metabolite concentrations

OBJECTIVES

Multiple sclerosis lesions appear as areas of high signal on T2 weighted MRI. A proportion of these lesions, when viewed on T1 weighted MRI, appear hypointense compared with surrounding white matter. These hypointense T1 lesions are thought to represent areas of greater tissue damage compared with the more non-specific, total T2 lesion load. This study aimed to better characterise the properties of high signal T2 lesions with differing appearances on T1 weighted MRI using quantitative MR techniques.

METHODS

Eleven patients with secondary progressive multiple sclerosis were studied. Two high signal T2 lesions were selected from each patient-one of which appeared hypointense and one isointense on a T1 weighted image. A voxel was positioned around each lesion and for this volume of brain the metabolite concentrations were estimated using proton MR spectroscopy ((1)H-MRS) and the T1 relaxation time within each voxel calculated from a T1 map generated using a multislice technique.

RESULTS

Compared with isointense T1 lesions, hypointense T1 lesions exhibited a significantly lower absolute concentration of N-acetyl derived metabolites (tNAA) and a significantly higher absolute concentration of myo-inositol (Ins). T1 relaxation time correlated significantly with both tNAA (r=-0.8, p < 0.001) and Ins (r=0.5, p=0. 012). There was no correlation between T1 relaxation times and creatine/phosphocreatine or choline containing compounds.

CONCLUSIONS

Prolonged T1 relaxation times seem to reflect the severity of axonal damage or dysfunction (inferred by a low tNAA) and possibly also gliosis (inferred by a high Ins) in chronic multiple sclerosis lesions.

The incidence of cardiac lesions in infants born with major gastrointestinal malformations in Northern Ireland

There is a recognised association between major gastrointestinal (GI) malformations and congenital heart disease (CHD). A retrospective study over 10 years involving 240 infants born with gastrointestinal malformations was conducted in the Royal Belfast Hospital For Sick Children (RBHSC). We felt it was important to look at the incidence of CHD diagnosed in the infants presenting to the tertiary referral centre in Belfast. Comparable figures for the incidence of CHD associated with major GI malformations was found in the literature.

Recovery from optic neuritis is associated with a change in the distribution of cerebral response to visual stimulation: a functional magnetic resonance imaging study

OBJECTIVES

Recovery to normal or near normal visual acuity is usual after acute demyelinating optic neuritis, despite the frequent persistence of conduction abnormalities as evidenced by the visual evoked potential (VEP). This raises the possibility that cortical adaptation to a persistently abnormal input contributes to the recovery process. The objective of this study was to investigate the pattern of cerebral response to a simple visual stimulus in recovered patients in comparison to normal subjects.

METHODS

Functional magnetic resonance imaging (fMRI) was used to study the brain activation pattern induced by a periodic monocular 8Hz photic stimulus in seven patients who had recovered from a single episode of acute unilateral optic neuritis, and in seven normal controls. VEPs and structural optic nerve MRI were performed on patients.

RESULTS

Stimulation of either eye in controls activated only the occipital visual cortex. However, in patients, stimulation of the recovered eye also induced extensive activation in other areas including the insula-claustrum, lateral temporal and posterior parietal cortices, and thalamus; stimulation of the clinically unaffected eye activated visual cortex and right insula-claustrum only. The volume of extraoccipital activation in patients was strongly correlated with VEP latency (r = 0.71, p = 0.005).

CONCLUSIONS

The extraoccipital areas that were activated in patients all have extensive visual connections, and some have been proposed as sites of multimodal sensory integration. The results indicate a functional reorganisation of the cerebral response to simple visual stimuli after optic neuritis that may represent an adaptive response to a persistently abnormal input. Whether this is a necessary part of the recovery process remains to be determined.

Current management of multiple sclerosis

Multiple sclerosis is a complex disease which presents a unique challenge in clinical management. This decade has seen the advent of new therapies which are partially effective in modifying the disease course. However, current therapies have no impact on existing neurological deficits and so supportive measures, symptomatic treatment and comprehensive rehabilitation remain at the core of management. Historically clinical practice has often been empirical but management should now be evidence-based and guided by consensus opinion if improvements in care are to be made.

Abscisic acid biosynthesis in tomato: regulation of zeaxanthin epoxidase and 9-cis-epoxycarotenoid dioxygenase mRNAs by light/dark cycles, water stress and abscisic acid

Two genes encoding enzymes in the abscisic acid (ABA) biosynthesis pathway, zeaxanthin epoxidase (ZEP) and 9-cis-epoxycarotenoid dioxygenase (NCED), have previously been cloned by transposon tagging in Nicotiana plumbaginifolia and maize respectively. We demonstrate that antisense down-regulation of the tomato gene LeZEP1 causes accumulation of zeaxanthin in leaves, suggesting that this gene also encodes ZEP. LeNCED1 is known to encode NCED from characterization of a null mutation (notabilis) in tomato. We have used LeZEP1 and LeNCED1 as probes to study gene expression in leaves and roots of whole plants given drought treatments, during light/dark cycles, and during dehydration of detached leaves. During drought stress, NCED mRNA increased in both leaves and roots, whereas ZEP mRNA increased in roots but not leaves. When detached leaves were dehydrated, NCED mRNA responded rapidly to small reductions in water content. Using a detached leaf system with ABA-deficient mutants and ABA feeding, we investigated the possibility that NCED mRNA is regulated by the end product of the pathway, ABA, but found no evidence that this is the case. We also describe strong diurnal expression patterns for both ZEP and NCED, with the two genes displaying distinctly different patterns. ZEP mRNA oscillated with a phase very similar to light-harvesting complex II (LHCII) mRNA, and oscillations continued in a 48 h dark period. NCED mRNA oscillated with a different phase and remained low during a 48 h dark period. Implications for regulation of water stress-induced ABA biosynthesis are discussed.

Progressive cerebral atrophy in MS: a serial study using registered, volumetric MRI

OBJECTIVE

To assess the potential of registered volumetric MRI in measuring rates of atrophy in MS.

BACKGROUND

Pathologic and imaging studies suggest that the development of permanent neurologic impairment in MS is associated with progressive brain and spinal cord atrophy. Atrophy has been suggested as a potential marker of disease progression. Conventional atrophy measurements requiring manual outlining are time-consuming and subject to reproducibility problems. Registration of serial MRI may offer a useful alternative in that cerebral losses may be measured directly from automated subtraction of brain volumes.

METHODS

Twenty-six patients with MS and 26 age- and gender-matched controls had two volumetric brain MR studies 1 year apart. Baseline brain and ventricular volumes were measured using semiautomated techniques, and follow-up scans were registered to baseline. Rates of cerebral atrophy were calculated directly from the registered scans.

RESULTS

Baseline brain volumes in the MS group were smaller (mean difference 78 mL [95% CI 13 to 143; p = 0.02]) and ventricular volumes greater (mean difference 12 mL [95% CI 6 to 18; p < 0.001]) than controls. The rate of cerebral atrophy in the MS group (0.8% per year) was over twice that of controls (0.3%), and the rate of ventricular enlargement was five times greater than the controls (1.6 versus 0.3 mL/year).

CONCLUSION

Progressive cerebral atrophy is an important feature of MS. Registration-based measurements are sensitive and reproducible, allowing progressive atrophy to be detected within 1 year and may have potential as a marker of progression in monitoring therapeutic trials.

Clinical appropriateness: a key factor in outcome measure selection: the 36 item short form health survey in multiple sclerosis

OBJECTIVES

Understanding the properties of an outcome measure is essential in choosing the appropriate instrument and interpreting the information it generates. The MOS 36 item short form health survey questionnaire (SF-36) is widely acknowledged as the gold standard generic measure of health status; few studies however have evaluated its use for clinical trials in multiple sclerosis. Its clinical appropriateness, internal consistency reliability, validity, and responsiveness was investigated across a broad range of patients with multiple sclerosis.

METHODS

A prospective study in which 150 adults with clinically definite multiple sclerosis completed a battery of questionnaires evaluating generic health status, disability, handicap, and emotional wellbeing. Of these, 44 patients undergoing inpatient rehabilitation completed the questionnaires before and after intervention to evaluate responsiveness.

RESULTS

Score distributions demonstrated significant floor and ceiling effects in four of the eight dimensions which were particularly marked when patient selection was restricted to a narrow band of disease severity (as is the case in most clinical trials). Internal consistency exceeded the standard for group comparisons for all dimensions. Convergent and discriminant construct validity was supported by the direction, magnitude, and pattern of correlations with other health measures. In comparison with instruments measuring associated constructs, the responsiveness of the SF-36 was poor in evaluating change in moderate to severely disabled patients participating in a programme of inpatient rehabilitation.

CONCLUSIONS

The SF-36 has some limitations as an outcome measure in multiple sclerosis. The results highlight the need for all instruments to be examined in the specific sample population under question and for the specific research question being investigated. In multiple sclerosis clinical trials, the SF-36 should be supplemented with other relevant measures.

A comparison of neuropsychological deficits in primary and secondary progressive multiple sclerosis

Neuropsychological deficits and the relationship to brain pathology were examined in 13 primary progressive (PP) and 12 secondary progressive (SP) multiple sclerosis patients with a similar duration of the progressive phase and comparable physical disability. A battery of neuropsychological tests to assess attention, short-term and working memory was administered to the patients, and their performance was compared to that of 20 healthy controls matched for age and premorbid IQ. Total cerebral lesion load on T2-weighted magnetic resonance imaging was measured in the patients. Both PP and SP patients performed significantly worse than controls in most of the neuropsychological tests. There were only subtle differences between SP and PP on the working memory task although magnetic resonance imaging lesion load was significantly higher in SP than in PP patients. In this exploratory study only subtle differences in cognitive impairment were detected between SP and PP patients matched for physical disability and relevant illness features. The results also suggest that the severity of cognitive impairment cannot be fully explained by the extent of abnormalities detected on conventional T2-weighted magnetic resonance images, and that other pathological abnormalities such as in normal-appearing white matter are likely to be involved.

A questionnaire assessment of unmet needs for rehabilitation services and resources for people with multiple sclerosis: results of a pilot survey in five European countries. Needs Task group of MARCH (Multiple Sclerosis and Rehabilitation, Care and Health Services Research in Europe)

OBJECTIVE

To develop an international services and needs assessment instrument (SUN) for people with multiple sclerosis and their carers and to pilot this in different countries of the European Community.

DESIGN

Interview study of people with multiple sclerosis, their carers and nominated key professionals examining the unmet needs of patients and carers.

SETTING

Belgium, Estonia, Greece, Italy and the United Kingdom.

MAIN OUTCOME MEASURES

Needs assessment questionnaire.

RESULTS

The study comprised 137 people with multiple sclerosis, 125 carers and 111 professionals. Patients reported on average 2.9 unmet needs for themselves; their carers and professionals reported on average 2.4. Needs were categorized into seven broad categories. Due to difficulties experienced by the local researchers in distinguishing between needs and objectives a large proportion of needs had to be assigned to the 'other' category.

CONCLUSIONS

The SUN is a valuable and practicable tool for the identification of unmet needs for people with multiple sclerosis and their carers. Formal validation and reliability testing of the different language versions is recommended.

Does the extent of axonal loss and demyelination from chronic lesions in multiple sclerosis correlate with the clinical subgroup?

OBJECTIVE

To determine non-invasively the relation between the degree of axonal loss and the extent of demyelination in chronic lesions visible on MRI in patients with different subgroups of clinically definite multiple sclerosis using (1)H magnetic resonance spectroscopy ((1)H MRS) and magnetisation transfer imaging (MT). Conventional MRI is unable to differentiate between the various pathological processes occurring in the multiple sclerosis lesion. There are, however, newer MR techniques which show promise in this respect.

METHODS

(1)H MRS and MT were performed in 18 patients with clinically definite multiple sclerosis who had a wide range of disability and disease duration.

RESULTS

A significant correlation was found between a reduction in the concentration of N-acetyl aspartate (NAA; an in vivo marker of axonal loss or dysfunction) and a reduction in MT ratio (a probable marker of demyelination) in patients who had entered the secondary progressive stage of the disease. Patients with minimal disability after a disease duration of greater than 10 years-so called benign multiple sclerosis-showed a relative preservation of NAA and MT.

CONCLUSIONS

Because a reduction in MT seems to be a relative marker for demyelination and a reduction of NAA from chronic lesions is indicative of axonal loss, this study supports the hypothesis that demyelination and axonal loss occur in the same chronic multiple sclerosis lesions. In addition, the degree of axonal loss and demyelination correlates with clinical heterogeneity.

1H magnetic resonance spectroscopy of normal appearing white matter in primary progressive multiple sclerosis

Recent magnetic resonance imaging (MRI) and pathological studies have indicated that axonal loss is a major contributor to disease progression in multiple sclerosis. 1H magnetic resonance spectroscopy (MRS), through measurement of N-acetyl aspartate (NAA), a neuronal marker, provides a unique tool to investigate this. Patients with primary progressive multiple sclerosis have few lesions on conventional MRI, suggesting that changes in normal appearing white matter (NAWM), such as axonal loss, may be particularly relevant to disease progression in this group. To test this hypothesis NAWM was studied with MRS, measuring the concentration of N-acetyl derived groups (NA, the sum of NAA and N-acetyl aspartyl glutamate). Single-voxel MRS using a water-suppressed PRESS sequence was carried out in 24 patients with primary progressive multiple sclerosis and in 16 age-matched controls. Ratios of metabolite to creatine concentration (Cr) were calculated in all subjects, and absolute concentrations were measured in 18 patients and all controls. NA/Cr (median 1.40, range 0.86-1.91) was significantly lower in NAWM in patients than in controls (median 1.70, range 1.27-2.14; P = 0.006), as was the absolute concentration of NA (patients, median 6.90 mM, range 4.62-10.38 mM; controls, median 7.77 mM, range 6.60-9.71 mM; P = 0.032). There was no significant difference in the absolute concentration of creatine between the groups. This study supports the hypothesis that axonal loss occurs in NAWM in primary progressive multiple sclerosis and may well be a mechanism for disease progression in this group.

Axonal loss in multiple sclerosis lesions: magnetic resonance imaging insights into substrates of disability

Magnetic resonance imaging (MRI) monitoring of disease progression in multiple sclerosis is limited by the lack of correlation of abnormalities seen on T2-weighted imaging, and disability. We studied the histopathology of multiple sclerosis lesions, as depicted by MRI, in a large postmortem sample, focusing on axonal loss. Tissue samples from 17 patients were selected immediately postmortem for histopathological analysis on the basis of T2-weighted imaging, including normal appearing white matter and T1 hypointense lesions. In each region, we measured magnetization transfer ratios (MTR), T1 contrast ratio, myelin, and axonal density. T2 lesions (109 samples) were heterogeneous with regard to MRI appearance on T1 and MTR, whereas axonal density ranged from 0% (no residual axons) to 100% (normal axonal density). Of 64 T2 lesions, 17 were reactive (mild perivascular inflammation only), 21 active, 15 chronically active, and 11 chronically inactive. MTR and T1 contrast ratio correlated strongly with axonal density. Also in normal appearing white matter (24 samples), MTR correlated with axonal density. In conclusion, postmortem tissue sampling by using MRI revealed a range of pathology, illustrating the high sensitivity and low specificity of T2-weighted imaging. T1 hypointensity and MTR were strongly associated with axonal density, emphasizing their role in monitoring progression in multiple sclerosis.

Nuclear magnetic resonance monitoring of treatment and prediction of outcome in multiple sclerosis

Magnetic resonance (MR) techniques provide an objective, sensitive and quantitative assessment of the evolving pathology in multiple sclerosis. There is an increasing definition of the pathological specificity of newer techniques, and more robust correlations with clinical evolution are emerging. As the pathophysiological basis of in vivo nuclear MR signal abnormalities is further elucidated, it is likely that the importance of MR as a tool to monitor new therapies will increase.

Multisequence MRI in clinically isolated syndromes and the early development of MS

OBJECTIVE

To apply multisequence MRI techniques to patients with clinically isolated syndromes, to document the pattern and frequency of abnormalities at baseline and early follow-up, and to determine their predictive values for the early development of clinical MS.

BACKGROUND

Disseminated lesions on T2-weighted brain MRI confer an increased risk of progression to clinically definite MS. Newer MRI techniques increase detection of lesions in both brain and spinal cord, and clarify further their pathology. The predictive value of such techniques for the development of clinical MS needs to be defined.

METHODS

Brain and spinal MRI were performed on 60 patients after their first demyelinating event. A total of 50 patients were followed for 1 year, and 49 underwent repeat brain MRI 3 months after the initial scan.

RESULTS

At baseline, 73% of patients had lesions on T2-weighted fast spin-echo (FSE) brain images and 42% had asymptomatic spinal cord lesions. Fast fluid-attenuated inversion-recovery brain did not improve detection of brain lesions. Repeat brain MRI demonstrated new FSE lesions in 43% of patients. After 1 year, 26% of patients developed MS. The MRI features that provided the best combination of sensitivity and specificity for the development of MS were the presence of new FSE lesions at follow-up and enhancing lesions at baseline. The frequency of developing clinical MS was higher for those with both brain and spinal cord lesions at baseline (48%) than brain lesions alone (18%).

CONCLUSIONS

The combination of baseline MRI abnormalities and new lesions at follow-up, indicating dissemination in space and time, was associated with a high sensitivity and specificity for the early development of clinical MS. These data suggest a potential role for new diagnostic criteria for MS based on early MRI activity. Such criteria may be useful in selecting patients for therapeutic trials at this early clinical stage.

Correlation of magnetic resonance imaging parameters with clinical disability in multiple sclerosis: a preliminary study

Magnetic resonance imaging (MRI) is frequently used to monitor new treatments in multiple sclerosis (MS), but its role is limited by the uncertain relationship between MRI parameters and clinical disability. A brain MRI study using nine MRI parameters was undertaken in 15 MS patients with a wide spectrum of disability to evaluate the relationship between each parameter and disability. A strong correlation was found between disability (measured using Kurtzke's EDSS) and total lesion load on both proton density (PD; r = 0.79) and T1 (r = 0.71) weighted sequences. There was also a strong correlation of disability with average lesion magnetisation transfer ratio (MTR; r = -0.74) and calculated T1 (r = 0.71) but not with calculated T2 or the average signal intensity of lesions on the conventional T1-weighted, PD-weighted and heavily T2-weighted images. Thus, four parameters which measured either the extent of lesions (PD lesion load) or their pathological severity (MTR, calculated T1, hypointense T1-lesion load) were correlated significantly with disability. While this suggests that such parameters will be useful in treatment trial monitoring, further multi-parameter MRI studies, of larger cohorts and using a wider range of techniques, are indicated.

Magnetisation transfer of normal appearing white matter in primary progressive multiple sclerosis

Patients with primary progressive multiple sclerosis may develop severe disability despite a paucity of lesions on conventional magnetic resonance imaging, raising the possibility that intrinsic changes in normal appearing white matter (NAWM) contribute to disability. This study has measured magnetisation transfer ratio (MTR), an index of tissue damage, of NAWM in 52 patients with primary progressive multiple sclerosis and 26 healthy controls. Absolute values of MTR were obtained from the genu of the corpus callosum and pons, and mean values were calculated from bilateral regions in the centrum semiovale, frontal white matter, parieto-occipital white matter and posterior limb of the internal capsule. The median MTR was lower in all regions in patients compared to controls. Median values (per cent units) were significantly lower in corpus callosum (39.73 vs 40.63; P=0.01), frontal white matter (39.11 vs 39.59; P=0.01) and centrum semiovale (37.21 vs37.82; P<0.05). This study has demonstrated small but widespread decreases in MTR in NAWM in primary progressive multiple sclerosis supporting the hypothesis that there are intrinsic changes in NAWM which may contribute to disability in this patient group.

Measuring handicap in multiple sclerosis

Handicap, shortly to be renamed participation, is a well defined though somewhat neglected entity which addresses an important aspect of the impact disease has on the individual. It is particularly relevant in Multiple Sclerosis (MS) which has such a major impact on issues such as employment, relationships, transport and social integration. Few validated measuring tools exist, and the generic London Handicap Scale is probably the best currently available but is only appropriate for group comparison. Handicap should be monitored in MS and is particularly appropriate in the evaluation of rehabilitation strategies.

Problems in designing and recruiting to therapeutic trials in primary progressive multiple sclerosis

Patients with primary progressive multiple sclerosis have atypical clinical and magnetic resonance imaging (MRI) characteristics which present unique problems in designing and recruiting to therapeutic trials. The first randomised controlled therapeutic trial specifically for primary progressive multiple sclerosis is now underway. Although only an exploratory phase II study, it has provided further insight into difficulties in diagnosis, classification and choice of clinical and MRI outcome measures. Patients with primary progressive multiple sclerosis have a wide differential diagnosis and do not readily conform to the Poser criteria. They may therefore present diagnostic uncertainty, particularly as their classification often relies on a retrospective history. This was highlighted during the recruitment to this study of interferon-beta1a. Of the 138 patients referred with a definite diagnosis of primary progressive multiple sclerosis only 50 were enrolled in the study. Of the 88 patients not included, 50% either did not have primary progressive multiple sclerosis, or the diagnosis was not secure. Outcome measures pose particular problems. Clinically the focus must be on progression, and the measure should be both responsive and reliable. In relation to MRI, the currently recommended measures for therapeutic trials in relapsing/remitting and secondary progressive multiple sclerosis show little change in primary progressive multiple sclerosis, and therefore more pathologically specific MRI measures are required. Strict clinical guidelines and further developments in clinical and MRI measures are required to facilitate future therapeutic trials in primary progressive multiple sclerosis.

Cognitive function in primary progressive and transitional progressive multiple sclerosis: a controlled study with MRI correlates

The relative rarity of primary progressive (PP) and transitional progressive (TP) multiple sclerosis has meant that little documentation of cognitive function in such patients is currently available. The aim of this study was to investigate the cognitive skills of patients with PP and TP multiple sclerosis relative to matched healthy controls, and to examine the relationship of this impairment to MRI parameters. Sixty-three patients (43 PP, 20 TP) were individually matched with healthy controls, who undertook the same cognitive tasks as the patient group. The neuropsychological assessment comprised Rao's brief repeatable battery, a reasoning test, and a measure of depression. Patients also underwent T1- and T2-weighted brain MRI. These patients were taken from a larger cohort (158 PP, 33 TP) in whom it had been demonstrated that the re were no significant differences between the mean scores of the PP and TP groups on any of the cognitive variables. The 63 patients were therefore taken as one group for comparison with the healthy controls. These patients performed significantly worse than the controls in tests of verbal memory, attention, verbal fluency and spatial reasoning. An impairment index was constructed and applied to the patient data. This correlated modestly with T2-lesion load (r = 0.45, P = 0.01), T1-hypointensity load (r = 0.45, P = 0.01) and cerebral volume (r = -0.35, P = 0.01). Thus, PP and TP multiple sclerosis patients demonstrate significant cognitive dysfunction when compared with matched healthy controls. The relationship between this impairment and MRI parameters is moderate, suggesting that cognitive dysfunction in PP and TP multiple sclerosis has a complex and multifactorial aetiology, which is not adequately explained by pathology as demonstrated on conventional MRI.

Molecular and genetic characterization of a novel pleiotropic tomato-ripening mutant

In this paper we describe a novel, dominant pleiotropic tomato (Lycopersicon esculentum)-ripening mutation, Cnr (colorless nonripening). This mutant occurred spontaneously in a commercial population. Cnr has a phenotype that is quite distinct from that of the other pleiotropic tomato-ripening mutants and is characterized by fruit that show greatly reduced ethylene production, an inhibition of softening, a yellow skin, and a nonpigmented pericarp. The ripening-related biosynthesis of carotenoid pigments was abolished in the pericarp tissue. The pericarp also showed a significant reduction in cell-to-cell adhesion, with cell separation occurring when blocks of tissue were incubated in water alone. The mutant phenotype was not reversed by exposure to exogenous ethylene. Crosses with other mutant lines and the use of a restriction fragment length polymorphism marker demonstrated that Cnr was not allelic with the pleiotropic ripening mutants nor, alc, rin, Nr, Gr, and Nr-2. The gene has been mapped to the top of chromosome 2, also indicating that it is distinct from the other pleiotropic ripening mutants. We undertook the molecular characterization of Cnr by examining the expression of a panel of ripening-related genes in the presence and absence of exogenous ethylene. The pattern of gene expression in Cnr was related to, but differed from, that of several of the other well-characterized mutants. We discuss here the possible relationships among nor, Cnr, and rin in a putative ripening signal cascade.

Reproducibility of magnetic resonance imaging measurements of spinal cord atrophy: the role of quality assurance

A sensitive magnetic resonance imaging (MRI) method to measure spinal cord cross-sectional area with the potential to monitor disease progression has recently been developed. As changes in cord area due to disease are usually small, assessment of the reliability of the methodology is essential in serial studies of spinal cord atrophy. The aim of this study was to institute and evaluate a protocol of quality assurance to determine long-term reproducibility of serial studies. Serial MRI of the spinal cord was carried out in five healthy volunteer controls over 1 year. Cross-sectional spinal cord areas were measured in a total of 46 scans. The mean coefficient of variation of all subjects over one year was 1.35%. The intra-observer coefficient of variation for same scan analysis was 0.63%. This study has confirmed high reliability of our serial data over one year and the on-going quality assurance protocol enables continuing evaluation of the reproducibility of results in serial studies. Quality assurance is an essential and practical component of all serial MRI studies, without which the clinical implications of change cannot be reliably evaluated.

Diffusion tensor imaging of lesions and normal-appearing white matter in multiple sclerosis

OBJECTIVE

To determine whether diffusion tensor imaging (DTI) can detect structural changes in normal-appearing white matter, and to distinguish between plaques of different pathologic severity, in patients with MS.

BACKGROUND

Conventional MRI detects lesions sensitively in MS but has limited pathologic specificity. The diffusion of water molecules in brain tissue, most fully expressed mathematically by a tensor quantity, reflects its intrinsic microstructure. It is now possible to estimate the diffusion tensor noninvasively in the human brain using MR DTI. This method is unique in providing precise and rotationally invariant measurements of the amount and directional bias (anisotropy) of diffusion in white matter tracts relating to tissue integrity and orientation.

METHODS

DTI was performed in six patients with MS and in six age-matched control subjects. Diffusion was characterized in normal-appearing white matter in both groups, and in lesions of different pathologic subtypes (inflammatory, noninflammatory, T1 hypointense, and T1 isointense).

RESULTS

DTI identified significantly altered water diffusion properties in the normal-appearing white matter of patients compared with control subjects (p < 0.001), and distinguished between lesion types. The highest diffusion was seen in destructive (T1 hypointense) lesions, whereas the greatest change in anisotropy was found in inflammatory (gadolinium-enhancing) lesions.

CONCLUSIONS

DTI detects diffuse abnormalities in the normal-appearing white matter of MS patients, and the findings in lesions appear to relate to pathologic severity. Its use in serial studies and in larger clinical cohorts may increase our understanding of pathogenetic mechanisms of reversible and persistent disability.

Multiple sclerosis: a preliminary study of selected variables affecting rehabilitation outcome

PROBLEM

The diversity of physical and cognitive impairments seen in progressive multiple sclerosis (MS), make it difficult to identify the factors that influence neurorehabilitation outcome. Improvements in a motor disability scale must be considered in the context of the patient's physical and cognitive starting points, if the process of neurorehabilitation is to be properly understood.

METHOD

Data was collected from 38 patients (mean age 41 years, 16 men and 22 women) with clinically definite MS (of whom all but one were in the progressive phase of the disease), who were consecutively admitted to a neurorehabilitation unit. Patients' physical disability was assessed on the motor scale of the Functional Independence Measure (FIM) on admission and discharge. Cognitive and neurological assessments were completed on admission. The cognitive battery comprised the WAIS-R, NART, RMT, CVLT CMT, GNT, GDA, and VOSP (some in short form). Emotional measures were the STAI, STAXI and BDI.

RESULTS

The mean improvement on the FIM was 6 points. A multiple regression analysis was performed to determine which cognitive and neurological variables related to reduced disability after neurorehabilitation. To take account of each patient's starting point, the model included their FIM admission score. This variable, together with vocabulary skills and cerebellar function accounted for 57% of the variance in the patients' improvements. These results suggest that verbal intelligence and cerebellar function are influential in determining rehabilitation outcome. Although these findings will be unsurprising to clinicians, this is the first quantitative demonstration of these effects.

Measuring change in disability after inpatient rehabilitation: comparison of the responsiveness of the Barthel index and the Functional Independence Measure

BACKGROUND

The importance of evaluating disability outcome measures is well recognised. The Functional Independence Measure (FIM) was developed to be a more comprehensive and "sensitive" measure of disability than the Barthel Index (BI). Although the FIM is widely used and has been shown to be reliable and valid, there is limited information about its responsiveness, particularly in comparison with the BI. This study compares the appropriateness and responsiveness of these two disability measures in patients with multiple sclerosis and stroke.

METHODS

Patients with multiple sclerosis (n=201) and poststroke (n=82) patients undergoing inpatient neurorehabilitation were studied. Admission and discharge scores were generated for the BI and the three scales of the FIM (total, motor, and cognitive). Appropriateness of the measures to the study samples was determined by examining score distributions, floor and ceiling effects. Responsiveness was determined using an effect size calculation.

RESULTS

The BI, FIM total, and FIM motor scales show good variability and have small floor and ceiling effects in the study samples. The FIM cognitive scale showed a notable ceiling effect in patients with multiple sclerosis. Comparable effect sizes were found for the BI, and two FIM scales (total and motor) in both patients with multiple sclerosis and stroke patients.

CONCLUSION

All measures were appropriate to the study sample. The FIM cognitive scale, however, has limited usefulness as an outcome measure in progressive multiple sclerosis. The BI, FIM total, and FIM motor scales show similar responsiveness, suggesting that both the FIM total and FIM motor scales have no advantage over the BI in evaluating change.

Primary and transitional progressive MS: a clinical and MRI cross-sectional study

BACKGROUND

Ten percent of patients with MS have a progressive course from onset with no history of relapses or remissions. A smaller subgroup follow a similar progressive course but have a single relapse at some point (transitional progressive [TP] MS). To date these patients have been excluded from receiving licensed treatments for MS and from most therapeutic trials.

OBJECTIVE

To document the clinical and MRI characteristics of a large cohort of progressive patients, including 158 with primary progressive (PP) MS and 33 with TPMS. Data from a small reference group of 20 patients with secondary progressive (SP) MS are also presented for reference.

METHODS

Patients were recruited from six European centers. All underwent a clinical assessment including scoring on the Expanded Disability Status Scale (EDSS) and MRI of the brain and spinal cord.

RESULTS

The men-to-women ratio was 81:77 (51% men) in the PP group, 14:19 (42% men) in the TP group, and 5:15 (25% men) in the SP group. The mean age at disease onset was significantly higher in the PP group than it was in the other two groups (PP 40.2 years, TP 34.9 years, SP 28.7 years). On MRI the PP group had lower mean brain T2 and T1 hypointensity lesion loads than the SP group (T2 12.02 versus 27.74 cm3, p = 0.001; T1 4.34 versus 7.04 cm3, p = 0.015). The SP and TP cohorts had significantly more T2-weighted lesions in the spinal cord than the PP patients, and the SP cohort had the greatest degree of atrophy. There was a correlation in the PP and TP patients between EDSS score and brain and spinal cord atrophy (r = 0.3, 0.2, p < or = 0.006) but not with brain lesion load. The PP and TP patients who presented with spinal cord pathology had significantly lower brain T2 and T1 lesion loads than those with non-spinal cord presentations (p = 0.002).

CONCLUSIONS

The monitoring of disease progression in PPMS is difficult, although measures of atrophy correlate with the EDSS and appear most promising. This study increases our understanding of this unique patient group, which will be further expanded with the acquisition of serial data.

A direct demonstration of both structure and function in the visual system: combining diffusion tensor imaging with functional magnetic resonance imaging

The relationships between functional activation patterns and the structural properties of brain pathways have not been widely studied. The recently developed magnetic resonance imaging technique of diffusion tensor imaging (DTI) allows a full characterization of water molecule mobility in three dimensions, providing new structural information that is not available from other in vivo imaging techniques. The directional bias of diffusion (anisotropy) may be derived from the diffusion tensor, and is related to fiber tract integrity and orientation. Since DTI and functional magnetic resonance imaging (fMRI) both require rapid (generally echoplanar) imaging it is possible to obtain geometrically matched images from the two modalities. fMRI and DTI were combined in a visual system study using photic stimulation to demonstrate the feasibility of combining the two methods and to investigate the structural properties of activated regions compared to the white matter tracts. Blood oxygenation level-dependent (BOLD) fMRI activation maps were directly overlayed upon fractional anisotropy (FA) maps, avoiding registration and spatial transformation by carefully matching acquisition parameters. Activated regions had lower FA than optic radiation white matter, supporting the hypothesis that most BOLD signal change occurs within the relatively isotropic cortical grey matter. The combination of these modalities in future studies may provide further insights into relationships between brain structure and function in both health and disease.

Correlates of executive function in multiple sclerosis: the use of magnetic resonance spectroscopy as an index of focal pathology

Proton magnetic resonance spectroscopy (MRS) was performed in a group of patients with multiple sclerosis (MS) and matched control subjects to examine the relationship between frontal lobe pathology and performance on tests of executive function. The N-acetyl aspartate/creatine ratio (NAA/Cr) was significantly reduced in frontal lesions and/or normal-appearing white matter in the patient group compared with the control group, but choline/creatine ratios did not differ. Although MRS abnormalities and executive deficits were not correlated for MS patients as a group, a few patients with more severe abnormalities of NAA/Cr ratio performed worse than other patients on the spatial working memory test, suggesting that subtle frontal neuropathological abnormalities detected by MRS may contribute to executive deficits. Further investigation is warranted to determine the value of MRS as an index of the pathophysiological processes leading to cognitive deficit.

Myometrial constitutive nitric oxide synthase expression is increased during human pregnancy

Nitric oxide (NO), derived from L-arginine by the action of nitric oxide synthase (NOS), is a mediator of many diverse biological activities, including vasodilation, neurotransmission and inhibition of platelet adhesion. A role for NO in the maintenance of rat and rabbit pregnancy is supported by a variety of studies. A recent study in women demonstrated that myometrial inducible NOS (iNOS) expression was greater in the early third trimester than either the late third trimester or in the non-pregnant condition, suggesting that increased iNOS expression is involved in the maintenance of human pregnancy. Constitutive NOS (cNOS) expression was not determined. The aim of this study was to compare constitutive NOS (both eNOS and bNOS) expression in the human non-pregnant uterus, preterm pregnant uterus (25-34 weeks gestation) and term pregnant uterus (>37 weeks gestation) using immunohistochemistry and Western blotting. Preterm pregnant samples were taken from women with a variety of pathologies necessitating early delivery. We found that eNOS and bNOS protein concentrations were greater in the preterm pregnant myometrium than non-pregnant myometrium. eNOS, but not bNOS, protein concentration was lower in myometrial samples obtained at term compared with those obtained preterm. We conclude that the constitutive isoforms of NOS are also up-regulated in human pregnancy and may play a role in the maintenance of myometrial quiescence.

Quantitative MRI in patients with clinically isolated syndromes suggestive of demyelination

OBJECTIVE

To assess the long-term predictive value of quantitative lesion load measurement on brain MRIs in patients after a 10-year follow-up who presented initially with a clinically isolated syndrome of the optic nerve, brainstem, or spinal cord.

BACKGROUND

Quantitative MRI measurement is being used in treatment trials as a surrogate marker in MS, but there is a lack of long-term MRI follow-up data in assessing the natural course of the disease from the earliest stages.

METHODS

Using a semiautomated threshold technique, the total lesion volume (TLV), the course of the disease, and disability were assessed in 58 patients at onset and after 5 and 10 years.

RESULTS

The TLV at presentation correlated significantly (r = 0.81, p = 0.0001) with the TLV and also with the Expanded Disability Status Scale (EDSS) score (r = 0.45, p = 0.001) at 10-year follow-up. In contrast there was no correlation of the TLV at 5 years with subsequent change in EDSS score over the next 5 years (r = 0.18, p = 0.12). The change in TLV over the first 5 years in patients who developed clinically definite MS (CDMS) differed significantly according to the type of disease course (relapsing-remitting with disability, secondary progressive, or benign) manifesting at 10-year follow-up.

CONCLUSION

Quantification of changes detected by T2-weighted brain MRI at the earliest clinical stages is strongly predictive of the subsequent development of CDMS as well as the clinical course and level of disability 10 years later.

Inpatient rehabilitation in multiple sclerosis: do the benefits carry over into the community?

OBJECTIVE

To determine the duration and pattern of carry-over of benefits gained after a short period of multidisciplinary inpatient rehabilitation.

BACKGROUND

Few studies have evaluated the outcome of rehabilitation after discharge. Long-term follow-up is required to establish whether gains made during the inpatient stay are sustained over time and in the patient's own environment.

METHODS

Prospective single-group longitudinal study. Fifty consecutive patients with progressive MS undergoing inpatient rehabilitation were followed for 12 months after discharge. Assessments were undertaken on admission (A), at discharge, and subsequently at 3-month intervals for 1 year (1Y) with a battery of measures addressing neurologic status, disability, handicap, quality of life, and emotional well-being. The time taken to return to baseline level was calculated using summary measures, and trends in performance levels were plotted.

RESULTS

Twelve-month data were collected for 92% of patients. Although neurologic status declined (median Expanded Disability Status Scale scores: A = 6.8, 1Y = 8.0), improvements were maintained in disability and handicap for 6 months, emotional well-being for 7 months, and health-related quality of life (physical component) for 10 months.

CONCLUSIONS

The benefits gained from rehabilitation were partly maintained after discharge despite worsening neurologic status. Carry-over of benefits, however, declined over time, reinforcing the need for continuity of care between the inpatient setting and the community.

Cerebral tuberculomas in Northern Ireland

Two children presenting with very different clinical pictures were both found to have intracranial tuberculomas. This condition, although rare in developed countries, should be suspected in any child with enhancing cerebral lesions or cranial computed tomography.

On-line high-performance liquid chromatography/mass spectrometric investigation of amyloid-beta peptide variants found in Alzheimer's disease

Abeta peptides are the major components of amyloid deposits in Alzheimer's disease. The presence of N-terminally truncated Abeta variants in amyloid may be a critical factor in Alzheimer's disease pathogenesis. These Abeta variants are less soluble and more amyloidogenic than full-length Abeta, making their separation, purification and identification difficult. High-performance liquid chromatography (HPLC) at elevated temperatures, coupled to electrospray ionization (ES) mass spectrometry (MS), enables rapid separation and identification of N-terminally truncated Abeta variants. This methodology provides a potential tool for exploring the importance of these Abeta variants in both the pathogenesis and diagnosis of Alzheimer's disease.

The structural and functional mechanisms of motor recovery: complementary use of diffusion tensor and functional magnetic resonance imaging in a traumatic injury of the internal capsule

OBJECTIVES

Recovery from focal motor pathway lesions may be associated with a functional reorganisation of cortical motor areas. Previous studies of the relation between structural brain damage and the functional consequences have employed MRI and CT, which provide limited structural information. The recent development of diffusion tensor imaging (DTI) now provides quantitative measures of fibre tract integrity and orientation. The objective was to use DTI and functional MRI (fMRI) to determine the mechanisms underlying the excellent recovery found after a penetrating injury to the right capsular region.

METHODS

DTI and fMRI were performed on the patient described; DTI was performed on five normal controls.

RESULTS

The injury resulted in a left hemiplegia which resolved fully over several weeks. When studied 18 months later there was no pyramidal weakness, a mild hemidystonia, and sensory disturbance. fMRI activation maps showed contralateral primary and supplementary motor cortex activation during tapping of each hand; smaller ipsilateral primary motor areas were activated by the recovered hand only. DTI disclosed preserved structural integrity and orientation in the posterior capsular limb by contrast with the disrupted structure in the anterior limb on the injured side.

CONCLUSIONS

The findings suggest that the main recovery mechanism was a preservation of the integrity and orientation of pyramidal tract fibres. The fMRI studies do not suggest substantial reorganisation of the motor cortex, although ipsilateral pathways may have contributed to the recovery. The initial deficit was probably due to reversible local factors including oedema and mass effect; permanent damage to fibre tracts in the anterior capsular limb may account for the persistent sensory deficit. This study shows for the first time the potential value of combining fMRI and DTI together to investigate mechanisms of recovery and persistent deficit in an individual patient.