Nasal orientation device to control head movement during CT and MR studies

Cooperative patients can often keep still during a long examination of the brain provided that they are given cues about their position in space. In a U-shaped head support, the only movements likely are rotation in the sagittal or transverse planes. These can be detected by a nasal orientation device (NOD), simply a ring around the nose, close but not touching. Any unintentional movement is felt on the nose by the patient, who can return to the original (nontouching) position. With this device the patient can keep immobile to within approximately +/- 2 mm during long examinations. We have used the NOD to improve the quality of dynamic Gd-DTPA scanning for the measurement of blood-brain barrier permeability. The NOD can be of value in any neurological imaging procedure that is currently degraded by head movement

Behçet's disease with slowly enlarging midbrain mass on MRI: resolution following steroid therapy

We describe a case of Behçet's disease with a slowly enlarging midbrain mass on magnetic resonance imaging, which resolved after 4 months of oral steroids

Posterior cingulate neurometabolite profiles and clinical phenotype in frontotemporal dementia

Proton magnetic resonance spectroscopy was used to compare metabolite levels from a posterior cingulate voxel in a group of patients with 2 syndromic subtypes of frontotemporal dementia (n = 10) and an age and education-matched group with Alzheimer disease (n = 10). Overall, frontotemporal dementia was indistinguishable from Alzheimer disease, though differences in N-acetylaspartate emerged between patients with the SD and progressive nonfluent aphasia subtypes, attributable to 2 atypical results among the latter. Such values may index cases with atrophy in posterior cortical regions presenting with progressive nonfluent aphasi

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

Pathogenesis of progressive multiple sclerosis

Letters to the Edito

Early lesion of multiple sclerosis

No abstract availabl

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

Changing activity in MS lesions: An MRI study

No abstract availabl

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

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