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D G MacManus

Publications and source records attributed to D G MacManus.

At least 55 records · Page 3Linked to original sources
PubMed1994

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.

Adult↗
PubMed1994

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.

Brain↗
PubMed1994

Benign and secondary progressive multiple sclerosis: a preliminary quantitative MRI study.

In a preliminary study, we compared by means of quantitative magnetic resonance imaging (MRI) methods (1) the T2 values and the decay characteristics of chronic brain lesions, (2) the T2 values of normal-appearing frontal white matter (NAWM) and (3) brain lesion volumes in patients with benign and secondary progressive multiple sclerosis (MS) in order to evaluate the mechanisms underlying the development of disability. Eleven clinically definite MS patients with either benign MS (n = 5) or secondary progressive MS (n = 6) were studied. Fifty-two chronic lesions (identified by comparison with MRI scans obtained at least 12 months previously) were identified. The mean T2 of large lesions (cross-sectional area greater than 41 mm2) and of the NAWM was similar in both clinical groups. However, small lesions had higher mean T2 values (P < 0.01) in the benign group, probably at least in part because of partial volume effects. Analysis of large lesions revealed biexponential T2 relaxation in 6 of 8 "secondary progressive" and in 2 of 16 "benign" lesions, perhaps indicating a greater degree of axonal loss in large lesions of patients with secondary progressive MS. Patients with secondary progressive MS had higher (although not significant) total and infratentorial lesion loads than those of the benign group. These preliminary findings suggest, but do not establish, that variations in the extent, site and pathological nature of lesions may all contribute to different patterns of disease evolution in MS.

Adolescent↗
PubMed1994

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.

Adult↗
PubMed1994

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.

Adolescent↗
PubMed1994

Quantitative brain MRI lesion load predicts the course of clinically isolated syndromes suggestive of multiple sclerosis.

We performed semiautomated quantitative measurement of brain magnetic resonance imaging (MRI) abnormalities seen at presentation and at 5-year follow-up in 84 patients presenting with an acute clinically isolated syndrome of the optic nerves, brainstem, or spinal cord suggestive of multiple sclerosis (MS). At follow-up, 34 (40%) had developed clinically definite and four (5%) clinically probable MS. Patients who developed MS during follow-up had a higher lesion load at presentation than those who did not. There was a strong correlation of the MRI lesion load at presentation with both the increase in lesion load over the next 5 years and disability at follow-up. Increasing initial lesion load correlated with a decreasing time to development of MS clinically (r = -0.328, p < 0.05). At follow-up, disability and brain lesion load were strongly correlated in patients who had developed MS. These results establish that MRI at presentation with clinically isolated syndromes suggestive of MS is useful in predicting the subsequent clinical course and the development of new MRI lesions. This suggests that quantitative brain MRI will be helpful in selecting patients with early clinical MS for treatment trials and for subsequent monitoring of their response to treatment.

Adolescent↗
PubMed1993

The significance of brain magnetic resonance imaging abnormalities at presentation with clinically isolated syndromes suggestive of multiple sclerosis. A 5-year follow-up study.

A 5-year follow-up study was performed on 89 patients who had undergone brain magnetic resonance imaging (MRI) at presentation with an acute clinically isolated syndrome of the optic nerves, brainstem or spinal cord of a type suggestive of multiple sclerosis. At presentation, MRI was abnormal, revealing one or more asymptomatic cerebral white matter lesions in 57 (64%), and was normal in 32 (36%). At follow-up, progression to clinically definite multiple sclerosis had occurred in 37 out of 57 (65%) with an abnormal MRI and one out of 32 (3%) with normal MRI. Human leucocyte antigen (HLA) typing was performed in 70 patients and cerebrospinal fluid (CSF) was examined at presentation in 36. The presence of HLA-DR2 antigen or cerebrospinal fluid oligoclonal IgG bands were both associated with a significantly increased risk of progression to multiple sclerosis, but MRI was much more powerful in predicting outcome. The presence of four or more MRI lesions at presentation was associated with a higher rate of progression to multiple sclerosis, more frequent development of moderate or severe disabilities and a greater number of new MRI lesions at follow-up. The results indicate that brain MRI at presentation with a clinically isolated syndrome suggestive of multiple sclerosis is a powerful predictor of the clinical course over the next 5 years. This observation, combined with an ability to detect other sometimes treatable disorders which can also cause such syndromes, suggests that MRI is the investigation of choice in evaluating this group of patients.

Adolescent↗
PubMed1993

Seizures due to multiple sclerosis: seven patients with MRI correlations.

The MRI data of seven patients with clinically definite multiple sclerosis who developed epileptic seizures are presented. Six of these cases demonstrated new or enhancing lesions. Cerebral biopsy in one of these lesions confirmed inflammation with myelin breakdown products. Lesions implicated in the causation of seizures involved the cortex or subcortical area. In one patient, a new lesion was associated with EEG abnormalities which resolved as the lesion reduced in size. In three patients epileptic activity was the only clinical manifestation of disease. Large, unresolving lesions tended to be associated with continuing seizures.

Adult↗
PubMed1993

Magnetic resonance imaging of the central nervous system in Behçet's disease.

Magnetic resonance imaging (MRI) was performed in 25 patients with Behçet's disease, of whom 15 had clinical involvement of the central nervous system (CNS). Brain MRI was abnormal in 11/15 with and in 1/10 without CNS involvement. The most common sites of MR lesions were the cerebral white matter and brainstem. Lesions were also seen in the basal ganglia, cerebellum, optic nerves and spinal cord. The cerebral white matter lesions were always asymptomatic and usually small, whereas the brainstem lesions were often symptomatic and sometimes extensive. Follow-up MRI in 2 patients presenting with brainstem syndromes and treated with immunosuppression showed resolution of a large lesion in 1 patient in whom there was clinical remission, and the development of marked brainstem atrophy in the other who became severely disabled. The pattern of MRI abnormalities may assist the diagnosis and suggests a role for MRI in monitoring the effect of treatment in patients with neurological Behçet's disease.

Adolescent↗
PubMed1993

Spinal cord MRI using multi-array coils and fast spin echo. I. Technical aspects and findings in healthy adults.

It is time-consuming to detect intrinsic spinal cord lesions in multiple sclerosis (MS) by MRI using conventional surface coils and T2-weighted spin-echo pulse sequences. Multi-array coils and fast spin-echo pulse sequences permit the generation of high-resolution T2-weighted sagittal images of the whole spinal cord in about 5 minutes. Using these advances, we found an area of high signal within the cord in only 1/45 (2%) healthy subjects aged 18 to 72 years, whereas 26% of those who underwent brain imaging had cerebral white matter abnormalities. Degenerative vertebral column changes, especially in the cervical region, were present in 64% and were associated with cord compression in 11%. Cord cross-sectional areas in mm2, measured from axial gradient-echo images, were usually highly reproducible and showed a significant correlation with the subject's height. We conclude that (1) MRI signal abnormalities within the spinal cord may be more specific for MS than cerebral white matter lesions, especially in subjects over 50 years old; (2) asymptomatic degenerative changes in the vertebral column are common, even in younger adults; (3) measurement of cord cross-sectional area should allow accurate quantitation of the degree of atrophy in MS and other spinal cord diseases; and (4) multi-array coils and fast spin echo represent an important advance in MRI of the spinal cord.

Adolescent↗
PubMed1993

Spinal cord MRI using multi-array coils and fast spin echo. II. Findings in multiple sclerosis.

We performed MRI of brain and spinal cord on 80 patients with multiple sclerosis (MS). Using multi-array coils and fast spin echo, 139 intrinsic lesions were identified in 59 patients (74%). Lesions were more common in the cervical than in the thoracic cord. Cross-sectional areas of the cord, measured from axial images at four levels, showed atrophy in 40%. Clinical disability correlated with cord atrophy but not with cord lesion load. These results show that the use of multi-array coils and fast spin echo allows rapid and sensitive detection of spinal cord lesions in MS and that the cord is involved in the majority of patients. A lack of association between cord lesions and disability may relate to limitations in MR resolution but also suggests that the mechanisms of disability in MS are complex and multifactorial.

Adult↗
PubMed1992

High dose steroids in acute relapses of multiple sclerosis: MRI evidence for a possible mechanism of therapeutic effect.

The integrity of the blood-brain barrier (BBB) in multiple sclerosis (MS) was monitored by serial gadolinium-(Gd)-DTPA enhanced MRI during and after the treatment of acute relapses with a three day course of high dose intravenous methylprednisolone (IVMP). During treatment there was a rapid reduction of BBB abnormalities in 96% of enhancing lesions. In spite of sustained clinical improvement, many lesions re-enhanced within a few days of stopping IVMP, and new lesions frequently appeared within one month. It is possible that the rapid, albeit transient, reversal of BBB abnormalities contributes to the accelerated recovery from relapses associated with IVMP treatment.

Adult↗
PubMed1992

Symptomatic retrochiasmal lesions in multiple sclerosis: clinical features, visual evoked potentials, and magnetic resonance imaging.

We have studied 18 patients with relapsing-remitting multiple sclerosis (MS) who had symptomatic visual field defects due to retrochiasmal lesions. In 17, the lesion responsible was identified by magnetic resonance imaging (MRI), computed x-ray tomography (CT), or both. The lesion responsible involved the posterior optic radiations in eight cases, the optic tract and lateral geniculate nucleus in six, and the posterior limb of the internal capsule in three. The prognosis for recovery of the field defect was good; complete recovery occurred in 14 patients, and only two showed no recovery at all. The striking characteristic of the lesions was that most were unusually large; indeed, many were detectable on CT as well as MRI. Half-field asymmetries of either amplitude or latency of the visual evoked potentials (VEPs), consistent with a postchiasmal lesion, were present in only five out of 13 patients acutely. In only three of these did the abnormality persist at follow-up. We conclude that only large postchiasmal lesions are likely to cause symptomatic homonymous field defects in MS, usually characterized by rapid recovery. Hemifield VEPs have a low sensitivity for the detection of postchiasmal as compared with prechiasmal abnormalities.

Adult↗
PubMed1992

Frequent involvement of the optic radiation in patients with acute isolated optic neuritis.

Magnetic resonance imaging revealed asymptomatic lesions in white matter regions corresponding with the optic radiations in 20 of 28 patients (71%) with clinically isolated optic neuritis. In contrast to the findings with symptomatic lesions, there was no relationship between the latency of the visual evoked potential and the presence of these asymptomatic posterior visual pathway lesions.

Acute Disease↗
PubMed1991

Major differences in the dynamics of primary and secondary progressive multiple sclerosis.

In patients with primary and secondary progressive multiple sclerosis (MS), major differences in the pattern and extent of abnormality on cerebral magnetic resonance imaging (MRI) between the two groups have recently been demonstrated. In the present study, 24 patients, matched for age, sex, duration of disease, and disability, had serial gadolinium diethylenetriaminepentaacetic acid-enhanced MRI over a 6-month period. The 12 patients in the secondary progressive group had a total of 109 new lesions over this time (18.2 lesions per patient per year) and 87% of these enhanced. Enhancement also occurred within and at the edge of preexisting lesions. In contrast, only 20 new lesions were seen in the primary progressive group (3.3 lesions per patient per year) and only one of these enhanced. There was no difference in the degree of clinical deterioration between the two groups over the 6-month period. These findings may indicate a difference in the dynamics of disease activity between the two forms of progressive MS, particularly in relation to the inflammatory component of the lesions, and have important implications for the selection of patients and the monitoring of disease activity in therapeutic trials.

Adult↗
PubMed1991

The pathophysiology of acute optic neuritis. An association of gadolinium leakage with clinical and electrophysiological deficits.

Eighteen patients with acute optic neuritis underwent optic nerve magnetic resonance imaging (MRI) before and after injection of gadolinium-diethylene triamine pentacetic acid (Gd-DTPA). Ten were re-examined 4 weeks later. Leakage of Gd-DTPA across the blood-optic nerve barrier was a consistent finding in the acute lesion, and its presence was associated with abnormal visual acuity and colour vision, retro-ocular pain on eye movement, and afferent pupillary defect, and a reduced amplitude of the P100 component of the visual evoked potential. Gd-DTPA leakage had ceased in 9/11 nerves when restudied 4 wks later, and this evolution was associated with improved visual acuity and an increased P100 amplitude. Leakage is likely to reflect inflammation, and we conclude that the latter plays an important part in the production of conduction block and clinical deficit, and that its resolution is an important step in clinical remission from acute episodes of demyelination.

Adolescent↗
PubMed1990

Patterns of disease activity in multiple sclerosis: clinical and magnetic resonance imaging study.

OBJECTIVE: To compare the abnormalities shown by magnetic resonance imaging of the brain in three clinically distinct groups of patients with multiple sclerosis, and to correlate the extent of abnormality with the degree of clinical disability in the three groups. DESIGN: All patients underwent magnetic resonance imaging and full neurological examination, and their disability was scored according to the expanded Kurtzke disability state scale. SETTING: National Hospital for Nervous Diseases (Multiple Sclerosis NMR Research Group). PATIENTS: Three groups of patients with confirmed multiple sclerosis were studied: 12 patients with minimal disability despite a long (greater than 10 years) duration of illness (benign multiple sclerosis), 16 who had developed progressive disability after a relapsing and remitting course (secondary progressive multiple sclerosis), and 13 who had had progressive disability from the onset of the disease (primary progressive multiple sclerosis). MAIN OUTCOME MEASURES: Number and size of lesions in 17 anatomically defined sites; total lesion load, estimated with an arbitrary scoring system weighted for the size of lesions; and disability score. RESULTS: Magnetic resonance imaging showed that all 41 patients had abnormalities. These were extensive in the groups with secondary progressive and benign disease compared with the group with primary progressive disease. The lesions in the patients with secondary progressive disease were larger and more confluent than those in the two other groups (p = 0.007). Most lesions (85%) in the patients with primary progressive disease were under 5 mm in diameter; this percentage was higher than that in the two other groups (p = 0.032). Consequently the patients with primary progressive disease had the lowest mean lesion load (36.7); that in the patients with benign disease was 52.7 and that in the patients with secondary progressive disease 64.6 (p = 0.05). No correlation existed between disability and total lesion load. The distribution of brain lesions and of detectable lesions of the spinal cord, and the frequency of cortical atrophy, were similar in all groups. CONCLUSIONS: No relation was found between the degree of clinical disability and the extent of abnormality shown by magnetic resonance imaging: patients with clinically benign disease often had extensive abnormalities and those with primary progressive disease had surprisingly few lesions. Though magnetic resonance imaging increases knowledge of the disease process in multiple sclerosis and is invaluable in diagnosis, it is not helpful in predicting disability in individual patients.

Adult↗