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Biomedical subjects

B E Kendall

Publications and source records attributed to B E Kendall.

At least 109 records · Page 6Linked to original sources

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↗

Ectasia of arteries beyond the circle of Willis.

Isolated fusiform ectasia involving branches of the carotid and vertebral arteries is very rare, only two cases have been recorded. Recently we have encountered two cases affecting the right posterior and left middle cerebral arteries. Both patients were young and there was no evidence of acquired arterial pathology. It is considered likely that the condition is a local congenital abnormality which may be related to an abnormality of the elastic substance in the arterial wall. In the first case, a selective injection of the right posterior cerebral artery clarified the nature of the lesion and provided an example of the value of the relatively new superselective technique.

Adult↗

Identifiable causes for poor outcome in surgery for cervical spondylosis. Post-operative computed myelography and MR imaging.

Outcome from surgery for cervical spondylosis is often disappointing. To identify possible causes of poor outcome 56 such patients referred for post-operative computed myelography or MRI were evaluated, 22 of which eventually had further surgery. Alternative diagnoses to cervical spondylosis were eventually established in 14.3%; 26.8% had spinal cord atrophy 15.6% of which also had myelomalacia; 28.6% had diffuse spinal canal stenosis; and in 57.1% surgery had failed to decompress the spinal canal. These findings can be partly explained by patient selection criteria; nevertheless they do serve to emphasises the point often ignored in discussions of the efficacy of surgery in cervical spondylosis, that operations significantly often fail to achieve adequate decompression. Furthermore there was no evidence in this material that osteophytes regress after spinal fusion.

Adult↗

Acute disseminated encephalomyelitis. MRI findings and the distinction from multiple sclerosis.

Brain MRI was performed on 12 patients with acute disseminated encephalomyelitis (ADEM). Multifocal white matter lesions indistinguishable from those seen in multiple sclerosis (MS) were found in 10. In 5 there were rather extensive symmetric abnormalities in the cerebral (2) or cerebellar white matter (2), or basal ganglia (1). Follow-up MRI after intervals of 2 wks to 18 months demonstrated partial resolution of the abnormalities, but some persisting lesions. New MRI lesions were found at follow-up in only 1 case after an interval of 2 wks. Serial MRI makes a useful contribution to the distinction between MS and ADEM.

Acute Disease↗

Breakdown of the blood-brain barrier precedes symptoms and other MRI signs of new lesions in multiple sclerosis. Pathogenetic and clinical implications.

From an extensive serial magnetic resonance imaging (MRI) study in multiple sclerosis (MS) we have identified 4 cases in which disruption of the blood-brain barrier, as detected by gadolinium-DTPA enhancement, preceded other MRI abnormalities and in 1 case clinical evidence of the new lesion. This supports the view that a defect in the blood-brain barrier, and therefore inflammation, is an early and possibly crucial event in the pathogenesis of the new lesion in MS. These cases showed a marked discrepancy between MRI abnormality and symptoms. The mechanisms contributing to this disparity are discussed, and it is concluded that far from being surprising it is to be expected.

Adult↗

Magnetic resonance imaging of inflammatory and demyelinating white-matter diseases of childhood.

Magnetic resonance imaging (MRI) was performed on 36 children and two adults (with clinical presentation during childhood) with white-matter disease of the central nervous system. Abnormalities were readily demonstrated in patients with multiple sclerosis, acute disseminated encephalomyelitis, leucodystrophies and subacute sclerosing panencephalitis: MRI demonstrated the extent and distribution of abnormalities more clearly than computed tomography for all these disorders. The abnormalities tended to be asymmetrical and multifocal in multiple sclerosis and acute disseminated encephalomyelitis, and more confluent and symmetrical in the leucodystrophies. Children with clinically isolated optic neuritis had a significantly lower frequency of MRI brain-lesions than adults with the same disorder. MRI should be regarded as the radiological investigation of choice when white-matter disease is suspected in children.

Adolescent↗

Myelination patterns on magnetic resonance of children with developmental delay.

Magnetic resonance (MR) imaging was performed in 30 children with unexplained developmental delay who had associated neurological abnormalities such as seizures, spasticity, hypotonia, ataxia or poor vision. No child had a history of regression, preterm birth or neonatal cerebral injury. CT scans were performed before MR in all cases and were either normal or showed only mild atrophy. At least two MR sequences were obtained for all patients. Nine children had delayed or absent myelination on MR, one had patchy white-matter abnormalities, and in one patient myelination was topographically normal, but of inappropriately low signal intensity. MR was abnormal in six of seven children who had abnormal brainstem auditory evoked potentials (BAEP), and was normal in nine of 11 patients who had a normal BAEP. MR may have a useful rôle in demonstrating abnormal white-matter maturation in children with unexplained neurodevelopmental delay, particularly when abnormalities are found on BAEP studies.

Brain↗

Heterogeneity of blood-brain barrier changes in multiple sclerosis: an MRI study with gadolinium-DTPA enhancement.

We performed 15 dynamic gadolinium-DTPA (Gd-DTPA)-enhanced MRI studies in 8 patients with relapsing and remitting multiple sclerosis; 7 were follow-up studies. We measured the time course of enhancement in 102 enhancing lesions for up to 384 minutes, with rest breaks. Immediate postcontrast MRIs demonstrated many different patterns of enhancement. We observed both uniformly enhancing and ring enhancing lesions. The enhancing regions were often less extensive than the corresponding high signal on T2-weighted images. Three lesions were seen with Gd-DTPA but not on unenhanced scans; 1 was seen on unenhanced scans 10 days later, suggesting that blood-brain barrier disturbance may precede other MRI signs of MS lesions. Three months later, some high-signal areas on T2-weighted scans had decreased in size to resemble the areas previously outlined by Gd-DTPA. This technique provides useful information about the pathogenesis and behavior of MS lesions.

Adolescent↗

Three cases of craniopharyngioma showing optic tract hypersignal on MRI.

Three patients presenting with visual failure had MRIs with hypersignal extending from the region of the optic chiasm along both optic tracts in 2 cases, and along 1 optic tract in the 3rd. In all patients intrinsic tumor of the chiasm was the most likely diagnosis based on MRI appearances, but all 3 had craniopharyngioma.

Adult↗

Impact of vessel distortion on transcranial Doppler velocity measurements: correlation with magnetic resonance imaging.

Because transcranial Doppler ultrasound is a blind procedure, it is not possible to routinely correct for insonation angle errors, which are presumed to be small. In anatomically normal brains this is a valid assumption; however, in some patients with distorted vascular anatomy (as in hydrocephalus) a small insonation angle cannot be assumed, and measurements of flow velocity may be misleadingly low. The orientation of the middle cerebral arteries was studied on magnetic resonance images of 17 control patients and three patients with hydrocephalus, and estimates of insonation angle errors in velocity measurements were made. When asymmetrical vessel distortion is present, relative flow to each hemisphere may not be accurately reflected in the measured velocities. Under these circumstances, the resistivity index may be a more reliable hemodynamic parameter.

Blood Flow Velocity↗

The neurological complications of Anderson-Fabry disease (alpha-galactosidase A deficiency)--investigation of symptomatic and presymptomatic patients.

Anderson-Fabry disease is an X-linked inborn error of metabolism characterized by subnormal activity of the lysosomal hydrolase, alpha-galactosidase A. We have assessed the incidence and nature of neuropathy in 12 patients (seven affected men and five carrier females). Abnormalities of cutaneous thermal sensation were common, even in asymptomatic carriers, with a unique predilection for cold sensitivity which suggests involvement of small myelinated nerve fibres. Intracranial abnormalities were frequently detected by magnetic resonance imaging (MRI) in males, both with and without overt cerebrovascular disease, and were more extensive in older patients. Such abnormalities were not detected in carriers. Auditory and vestibular abnormalities were present in six patients, only one of whom was symptomatic. Cranial MRI and assessment of cutaneous thermal thresholds are sensitive techniques which can identify neurological involvement in asymptomatic patients. They may be of benefit in monitoring the effectiveness of enzyme replacement therapy and excluding the carrier state for the defective gene.

Adolescent↗

The early risk of multiple sclerosis following isolated acute syndromes of the brainstem and spinal cord.

A combined clinical and magnetic resonance imaging follow-up study was undertaken to determine the risk of early progression to multiple sclerosis in patients who present with clinically isolated lesions of the brainstem or spinal cord. Progression to multiple sclerosis was seen in 13 patients (57%) who had a brainstem syndrome and in 14 patients (42%) who had a spinal cord syndrome after mean intervals of 15 and 16 months, respectively. The risk of progression was increased by the presence of oligoclonal bands in the cerebrospinal fluid of patients with either syndrome and by the presence of disseminated brain lesions, as detected by magnetic resonance imaging, in those with a spinal cord syndrome. Follow-up revealed evidence of multiphasic disease in 24 (69%) of 35 patients who had disseminated lesions on magnetic resonance imaging scans at presentation, suggesting that multiple sclerosis is the usual cause of such lesions.

Adult↗

Lesions of the brain stem: assessment by magnetic resonance imaging.

Ninety-six magnetic resonance imaging (MRI) studies demonstrating solitary brain stem lesions were reviewed in order to establish distinguishing features between tumours and other lesions. Histological confirmation of the radiological diagnoses was obtained in 33% of patients. The morphology of the lesion rather than its signal characteristics was the most useful feature in differential diagnosis, except after haemorrhage. However, areas of abnormal T2 recovery time were significantly more extensive than areas of abnormal T1 recovery time in tumours at presentation. In other lesions and in tumours following radiotherapy induced regression, the extent of abnormal T1 and T2 signal was the same. Possible reasons for this observation are discussed. The accuracy of computed tomography (CT) and MRI were similar for lesions causing brain stem expansion but for small lesions MRI was more sensitive and provided better topographical information.

Adolescent↗