Daily urinary neopterin excretion as an immunological marker of disease activity in multiple sclerosis.

The aim of this study was to assess neopterin, a marker of interferon gamma (IFN-gamma) induced macrophage activity, as a possible surrogate marker of inflammation in patients with multiple sclerosis. Urinary neopterin to creatinine ratios (UNCRs) were measured daily in 10 primary progressive (PP). 10 relapsing remitting (RR) and 11 secondary progressive (SP) patients with multiple sclerosis, and 14 normal control (NC) subjects, for periods of up to 12 weeks. After excluding measurements related to infection, the median of the individuals' average UNCRs was significantly higher in patients than in controls (P < 0.001 for all patients and P < 0.01 for each of the three groups of patients); the median UNCRs (and interquartile ranges) were 187 (135-231), 187 (165-277), 218 (164-517) and 134 (97-152) mumol/mol for PP, RR, SP patients and controls, respectively. Similarly, patients had a greater median proportion of days with a UNCR above normal (P < 0.001 for all patients and P < 0.01 for each group); the median percentage (and interquartile ranges) were 16 (6-62), 28 (21-36), 49 (14-86) and 0 (0-6)% for PP, RR, SP patients and controls, respectively. They also had a greater number of peaks in their serial UNCR measurements than controls (P < 0.001 for all patients and P < 0.01 for each group); the means +/- SD peaks/subject/month were: 2.1 +/- 1.8; 3.0 +/- 1.7; 3.3 +/- 2.3 and 0.2 +/- 0.6 for PP, RR, SP patients and controls, respectively. Nine relapses occurred in nine patients during the study, and all were associated with increased neopterin excretion, which tended to be greater than that on days not associated with a relapse. Three of the nine relapses were preceded by an upper respiratory tract infection. In eight out of 13 patients who had infections during the study, increased neopterin excretion was noted for periods of up to 6 weeks post-infection, significantly longer than that which occurred after infections in controls. This confirms infection as a potent inducer of symptomatic and asymptomatic disease activity in mutiple sclerosis, and provides further support of a pivotal role for IFN-gamma in te pathogenesis of mutiple sclerosis. Urinary neopterin excretion is increased in patients with both progressive and relapsing mutiple sclerosis, and therefore has potential as a surrogate marker of the inflammatory component of mutiple sclerosis disease activity.

Brain and spinal cord MRI in motor neuron disease.

Motor neuron disease causes widespread degeneration of motor neurons within both the brain and spinal cord. Brain and spinal cord MRI were performed in 11 patients with motor neuron disease, and in 17 controls. Symmetric areas of high signal within the corticospinal tracts were found in nine patients on T2 weighted spin echo (SE) or fast spin echo (FSE) images of the brain and in eight on T2 or T2* weighed images of the spinal cord. High signal within the posterior limbs of the internal capsules was also found in four controls; this finding in isolation is therefore not pathological. No controls had abnormalities within the spinal cord. Low signal within the motor cortex was found in 10 patients, but was also seen in six controls. Thus MRI often displays characteristic abnormalities within the corticospinal tracts in patients with motor neuron disease, and should be considered in the investigation of suspected cases.

Macroscopic and microscopic assessments of disease burden by MRI in multiple sclerosis: relationship to clinical parameters.

We have evaluated macroscopic white matter abnormalities (visible lesions) together with microscopic abnormalities in the normal appearing white matter (NAWM) of patients with multiple sclerosis (MS) to determine their relative contributions to the development of disability. The total visible lesion volume (TLV) was computed as a measure macroscopic changes, whereas both texture analysis and T2 were used as possible indicators of diffuse disease in the NAWM. Dual echo T2-weighted SE images were obtained from 41 patients with definite MS: 10 primary progressive (PP), 11 secondary progressive (SP), 10 benign (BE), 10 early relapsing remitting (ERR), as well as from 10 healthy controls. Calculation of T2 and texture parameters were performed in a region of frontal NAWM of patients and controls. The TLV of each patient was measured using a semiautomated lesion detection program. No significant differences were found between the controls and the patients for all texture parameters examined. However, NAWM T2 was longer in the patients than in the controls (P = .02). Mean TLV was highest for SP and lowest for BE and ERR patients. A significant correlation was found between TLV and EDSS (P < .01) but not between NAWM T2 or texture and expanded disability status score (EDSS). Our study suggest that: (a) diffuse changes are present in NAWM, (b) texture analysis is unable to detect any subtle structure in the NAWM abnormalities, possibly because of the limited image resolution; (c) in the development of disability in MS, macroscopic lesions are more important than microscopic abnormalities in the NAWM.

Patterns of disease activity in multiple sclerosis patients: a study with quantitative gadolinium-enhanced brain MRI and cytokine measurement in different clinical subgroups.

In this study we assessed the subclinical disease activity in 45 patients with primary progressive, secondary progressive or relapsing-remitting multiple sclerosis (MS). The patients had gadolinium-enhanced brain MRI scans, which were analysed using a semiquantitative method both for lesion load and for degree of enhancement. At the same time cerebrospinal fluid (CSF) and serum samples were collected and, from these, cytokine levels were measured in most cases by enzyme-linked immunoassay using commercially available kits. Enhancing lesions on MRI were found in 73% of the patients. The sensitivity of this test was greatly increased by our method of analysis as far as the primary progressive patients are concerned (70% vs 40% for conventional evaluation). CSF interleukin-1 beta (IL-1 beta) levels were above the normal range in 22% and IL-6 levels in 13% of patients, while tumour necrosis factor alpha (TNF-alpha) was undetectable or below the upper normal limits in all the samples tested. Serum IL-1 beta was above the normal limits in 40%, IL-6 in 42% and TNF-alpha in 7% of patients. No significant differences in cytokine profiles were found between the clinical subgroups. This study confirms the high sensitivity of gadolinium-enhanced MRI in detecting MS activity, which was further increased by our method of analysis. Longitudinal studies performed with more sensitive immunological techniques are needed to define better the relationship between cytokine, clinical and MRI data in MS patients.

Spinal MRI in patients with suspected multiple sclerosis and negative brain MRI.

Although MRI detects the white matter lesions of multiple sclerosis within the brain with high sensitivity, a minority of patients have normal brain MRI. We describe 20 patients, selected from over 170 who had undergone brain imaging with minimal (n = 12) or no (n = 8) abnormalities (median number of lesions = I, range, 0-3) but in whom spinal MRI was abnormal. Twelve had clinically definite or laboratory supported definite multiple sclerosis according to the Poser criteria; one had clinically probable disease and seven, not fulfilling the Poser criteria, were classified as possible multiple sclerosis. All had presented with symptoms and signs referable to the spinal cord or optic nerves. Eleven had a primary progressive course, eight relapsing-remitting and only one secondary progressive. Moderate or severe disability was the rule in the primary progressive cases; all the relapsing-remitting patients had minimal disability. All had at least one lesion visible in the spinal cord (median 2; range 1-6). In patients in whom the diagnosis of multiple sclerosis is not supported by abnormalities on brain MRI, imaging of the spinal cord can be of considerable value.

Serial gadolinium-enhanced MRI of the brain and spinal cord in early relapsing-remitting multiple sclerosis.

Although serial MRI studies of the brain in relapsing-remitting MS have demonstrated frequent asymptomatic disease activity, less is known about the spinal cord. We carried out monthly gadolinium-enhanced brain and spinal cord MRI scans over 1 year in 10 patients with relapsing-remitting MS. Six of the patients had a total of 11 clinical relapses, eight of which involved the spinal cord. A total of 167 active (enhancing or new nonenhancing) lesions in the brain and 19 in the spinal cord were present. Only one active brain lesion was symptomatic compares with six spinal cord lesions. Overall, one-third of new spinal cord lesions were symptomatic, and three-quarters of clinical spinal cord relapses were associated with a new MRI lesion in a location appropriate to the symptoms. Activity in both the spinal cord and brain was more common around the time of relapse. There was a strong association between the spinal cord and brain MRI activity. We did not detect progressive spinal cord atrophy from measurements of a spinal cord cross-sectional area. We conclude that, in relapsing-remitting MS, imaging of the brain alone will detect 90% of active lesions; spinal cord MRI using current technology will therefore provide only modest gains in treatment trials in which lesion activity is the primary outcome measure. The lack of ++progressive spinal cord atrophy in these patients, suggesting that significant axonal loss has not occurred, is in keeping with their good recovery after relapse. That brain and spinal cord lesions occur concurrently implies a systemic trigger for disease activity.

MRI dynamics of brain and spinal cord in progressive multiple sclerosis.

OBJECTIVE: To assess the usefulness of serial cord MRI in patients with progressive multiple sclerosis. METHODS: Monthly MRI of the brain and spinal cord with and without gadolinium enhancement was carried out in 19 patients with progressive multiple sclerosis (10 primary progressive, nine secondary progressive) over the course of one year. RESULTS: During this period there were 132 active lesions in the brain and only six in the cord. One hundred and twelve (85%) active brain lesions occurred in the secondary progressive group; three new cord lesions occurred in each group. In the secondary progressive group MRI activity was high in patients who had superimposed relapses, whereas in those who progressed without relapse and in the primary progressive group it was low. Cross sectional areas of the cord decreased at the C5 level in both groups, implying progressive atrophy of fibre tracts. There was no relation between either brain or cord MRI activity and change in disability over the study period. CONCLUSIONS: Although the detection of new lesions by frequent cord imaging using current technology has little role in the monitoring of disease activity in progressive multiple sclerosis, the serial measurement of cord cross sectional area may be important. There is also evidence to suggest that the mechanism underlying irreversible disability in patients with progressive multiple sclerosis may be different in patients who continue to relapse than in those who do not.

Soluble E-selectin in multiple sclerosis: raised concentrations in patients with primary progressive disease.

OBJECTIVE: To determine whether concentrations of soluble E-selectin (sE-selectin), an immunological marker of endothelial activation, were correlated with gadolinium-DPTA enhancement on MRI in patients with multiple sclerosis. METHODS: Serial sE-selectin concentrations were measured in 28 patients with multiple sclerosis undergoing monthly gadolinium (Gd) enhanced MRI of the brain and spinal cord, and in 10 control subjects. C reactive protein (CRP), von Willebrand factor (vWF), and tumour necrosis factor-alpha (TNF alpha) were also determined. RESULTS: Primary progressive patients had significantly increased sE-selectin concentrations compared with the relapsing remitting and secondary progressive patients who had normal sE-selectin concentrations (22.2 (SD1 6.1) ng/ml v 9.8 (SD2.1) ng/ml and 7.7 (SD2.7) ng/ml, respectively, P = 0.03). This difference was attributable to five of the 10 primary progressive patients who had persistently raised sE-selectin concentrations, with relatively inactive MRI studies. No correlation could be found between sE-selectin concentrations and Gd enhancement on MRI, but a close correlation existed between mean concentrations of sE-selectin and TNF alpha (r = 0.71, P < 0.001). Despite raised sE-selectin and TNF alpha concentrations, primary progressive patients had normal CRP concentrations (1.03 (SD1.14) mg/l), which were significantly lower than the relapsing remitting (3.16 (SD2.54) mg/l) and secondary progressive patients (2.28 (SD2.1) mg/l, P = 0.03). Raised CRP concentrations did correlate with infectious episodes, clinical relapse, and Gd enhancement, and were significantly raised when no MRI activity was found. Concentrations of vWF were normal in all patient groups. CONCLUSIONS: The results further high-light the differences between patients with primary progressive and those with relapsing remitting/secondary progressive multiple sclerosis.

Magnetisation transfer ratios and transverse magnetisation decay curves in optic neuritis: correlation with clinical findings and electrophysiology.

Conventional MRI sequences do not permit the distinction between the different pathological characteristics (oedema, demyelination, gliosis, axonal loss) of the multiple sclerosis plaque. Magnetisation transfer imaging and transverse magnetisation decay curve (tMDC) analysis may be more specific. These techniques have been applied to the optic nerves in 20 patients with optic neuritis and the results correlated with clinical and visual evoked potential (VEP) findings. tMDC analysis failed to identify separate intracellular and extracellular water compartments within the optic nerve but gave a measure of transverse relaxation time (T2) without the confounding effects of CSF in the nerve sheath. Both T2 and magnetisation transfer ratio (MTR) were abnormal after an episode of optic neuritis. T2 did not correlate with visual function or with VEP latency or amplitude. There was a significant correlation between MTR reduction and prolongation of VEP latency: this increased latency may reflect an effect of myelin loss on MTR. Longer lesions were associated with worse visual outcome, implying that the overall extent of pathological involvement is likely to influence the degree of functional deficit.

Signal intensity on MRI of basal ganglia in multiple sclerosis.

It has been reported that a relative reduction in signal intensity on T2 weighted MRI may be seen in the basal ganglia of patients with multiple sclerosis and furthermore that this is due to excessive iron deposition. The basal ganglia are, however, rarely involved clinically or pathologically in multiple sclerosis, casting some doubt on this finding. Therefore MRI was carried out in 46 patients with definite multiple sclerosis and 42 age matched controls. Contiguous, 5 mm thick axial dual echo spin-echo images of the brain were obtained on a 1.5T imager. Visual rating scales were used to measure the lesion load as well as the signal intensity of the globus pallidus, putamen, caudate nucleus, substantia nigra, red nucleus, and thalamus. There was a mild degree of low signal intensity in the patient group in the thalamus only. The signal intensity of the thalamus and putamen was never lower than that of the globus pallidus. Low signal in the basal ganglia is rarely, if ever, found in multiple sclerosis and is not a useful radiological sign.

Comparison of Cannabis sativa by random amplification of polymorphic DNA (RAPD) and HPLC of cannabinoids: a preliminary study.

Methods are described for the HPLC and genetic analysis of herbal Cannabis sativa. The latter method was applied to 17 plants grown simultaneously, at the same site. Sixteen of these samples were also compared using HPLC, which resulted in differentiation of the plants into 3 groups. Within two of these groups, the members could not be distinguished. By RAPD analysis, using certain combinations of primers and cladistic analysis, differentiation was possible between all but two of the plants. The use of the RAPD technique enables differentiation between samples that cannot be differentiated by HPLC analysis alone.

Dynamic gadolinium-enhanced MRI in the detection of spinal arteriovenous malformations.

Arteriovenous fistulae and malformations (AVFs and AVMs) of the spinal cord are rare, potentially treatable causes of progressive disability. Although a variety of MRI abnormalities has been described, the diagnosis rests on the findings on selective spinal angiography. Collecting T2*-weighted MR images during the passage of a gadolinium bolus gives information about perfusion and blood volume. We carried out dynamic MRI in seven patients with vascular abnormalities (5 dural AVFs, 1 intramedullary AVM, 1 cryptic angioma) and in two patients without an AVM. High resolution T1- and T2-weighted sagittal images of the whole spinal cord were first obtained using a multiarray receiver coil. Sagittal radiofrequency spoilt gradient echo images (GE34/25, flip angle 10 degrees) were then obtained during bolus injection of gadolinium-DTPA. Abnormalities were seen in all seven patients with AVFs or AVMs. In the patient with an intramedullary AVM and four of the five with dural AVFs transient signal reduction was seen within the perimedullary venous plexus during passage of the bolus. The findings correlated well with those from selective spinal angiography. We conclude that dynamic MRI offers a useful adjunct to angiography and may localise an arteriovenous shunt when conventional MRI fails to do so. In combination with high-resolution imaging of the entire spinal cord the technique may make myelography redundant; it is simple, well tolerated and can be carried out without significant time penalty.

Correlation of magnetization transfer ratio with clinical disability in multiple sclerosis.

We performed spin echo magnetic resonance imaging with and without application of an off-resonance saturation pulse in 43 patients with multiple sclerosis (MS), 10 age-matched controls, and 4 elderly asymptomatic patients with the radiological diagnosis of small-vessel disease. Magnetization transfer (MT) ratio images were obtained from these. All MS subgroups (primary progressive, secondary progressive, benign, early relapsing-remitting) showed significantly lower average lesion MT ratios than small-vessel disease patients. Secondary progressive MS patients showed significantly lower lesion MT ratios than those with benign disease, and there was an inverse correlation of disability with average lesion MT ratio. The degree of reduction of MT ratios is an indicator of the extent of tissue destruction. Thus, reduced MT ratios in MS may provide an indication of the degree of demyelination and axonal loss, both of which are likely to cause functional deficits in MS. We conclude that MT measurement is (1) a robust quantitative method that may increase the pathological specificity of magnetic resonance imaging, (2) has the potential to differentiate demyelination in MS from less destructive pathological changes, and (3) may be useful in monitoring modifications in tissue structure brought about by treatment.

A comparison between fast and conventional spin-echo in the detection of multiple sclerosis lesions.

Long repetition time (TR) spin-echo (SE) with T2- or proton density weighting is the sequence of choice to detect the brain lesions of multiple sclerosis (MS). Fast spin-echo (FSE) permits the generation of T2-weighted images with similar contrast to SE but in a fraction of the time. We compared the sensitivity of FSE and SE in the detection of the brain lesions of MS. Six patients with clinically definite MS underwent brain imaging with both dual echo (long TR, long and short echo time (TE) SE and dual echo FSE. The SE and FSE images were first reviewed independently and then compared. A total of 404 lesions was detected on SE and 398 on FSE. Slightly more periventricular lesions were detected using SE than FSE (145 vs 127), whereas more posterior cranial fossa lesions were detected by FSE (77 vs 57). With both SE and FSE the short TE images revealed more lesions than the long echo. These results suggest that FSE could replace SE as the long TR sequence of choice in the investigation of MS.

British Isles survey of multiple sclerosis in twins: MRI.

64/105 subjects who have a twin with multiple sclerosis included in a study of clinical concordance also underwent MRI of the brain. 8/23 monozygotic and 1/41 dizygotic co-twins from this subgroup were clinically concordant of whom 8/9 had MRI appearances typical of multiple sclerosis. Of the 48 clinically discordant twins aged less than 60, abnormalities on MRI were detected in 6/15 (40%) monozygotic and 13/33 (39%) dizygotic twins compared with 7/37 (19%) healthy age-matched controls. Abnormalities on MRI typical of multiple sclerosis (defined by the Fazekas criteria) were, however, present in only 2/15 (13%) monozygotic and 3/33 (9%) dizygotic twins and 0/37 controls. These results suggest that about 10% of monozygotic and dizygotic twins have "subclinical multiple sclerosis". It is likely that most of the MRI abnormalities seen in clinically discordant twins, however, represent incidental pathology.

Short tau inversion recovery fast spin-echo (fast STIR) imaging of the spinal cord in multiple sclerosis.

The short tau inversion recovery fast spin-echo pulse sequence (fast STIR) combines the synergistic T1 and T2 contrast mechanism of conventional STIR with the reduced imaging time of fast spin-echo (FSE). We have compared fast STIR with T2-weighted FSE in evaluating the spinal cord lesions in 17 patients with multiple sclerosis and 12 healthy controls. Intrinsic lesions were seen only in patients. Twenty-five of the 58 lesions identified were more clearly demonstrated by fast STIR, 22 by FSE. Signal-to-noise and contrast-to-noise ratios were higher in all cases on FSE, suggesting other mechanisms, in particular choice of window settings and brightness of surrounding structures, must play a part in lesion conspicuousness. Fast STIR is a useful adjunct to FSE in the evaluation of multiple sclerosis in the spinal cord.

The British Isles survey of multiple sclerosis in twins.

During a 27-month recruitment period, we identified 146 individuals with multiple sclerosis (MS) who have a twin. A single clinician interviewed and examined 105 pairs of twins, and we confirmed zygosity using minisatellite probes. Including two suspected cases, 11 of 44 (25%) monozygotic twin pairs were concordant compared with two of 61 (3%) dizygotic twin pairs--two of 33 (6%) like-sexed and zero of 28 (0%) opposite-sexed. MRI was performed in 64 of 105 co-twins, and showed abnormalities consistent with demyelination in 13% of monozygotic and 9% of dizygotic co-twins who were clinically unaffected. These findings are similar to the results of most previous studies of MS in twins in which zygosity was not unequivocally established and where the majority of clinically unaffected co-twins were not studied by MRI; the difference in concordance rates in monozygotic and dizygotic twins indicates a significant genetic component in the etiology of MS.