Signal intensity on MRI of basal ganglia in multiple sclerosis.

Abstract

It has been reported that a relative reduction in signal intensity on T2 weighted ART 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. (3 Neurol Neurolosurg Psychiatry 1995;59:306-308) and patients undergoing inve §tigation for headache, vertigo, or middle ear disorders in whom multiple sclerosis was excluded clinically. These two groups were defined as follows: sex ratio (M/F) in patients with multiple sclerosis 0 77 and controls 0-68, mean (SD, range) age of patients with multiple sclerosis 39 9 (11 1, 19-64) years and controls 43-3 (11 8 , 24-72) Signal characteristics of the basal ganglia on long TE images were first analysed in several regions: caudate nucleus, putamen, globus pallidus, dentate and red nuclei, substantia nigra, and thalamus. Signal change within the basal ganglia was rated according to the method proposed by Drayer et al,2 which involves comparing the signal characteristics of the basal ganglia relative to the globus pallidus. Three different patterns are described. Normal-decreased signal intensity in the globus pallidus, more prominent than in the putamen and much more prominent than in the thalamus. Equivocal-decreased signal intensity in the globus pallidus, slightly more prominent than in the putamen and more prominent than in the thalamus. Abnormal-decreased signal intensity in the globus pallidus equal to or less prominent than that in the putamen and caudate and only minimally more prominent or equally prominent to that in the thalamus.To assess the visual perception of the degree of basal ganglia hypointensity as an absolute rather than one nucleus relative to another a different method was also used. Each of the basal ganglia was scored separately on an arbitrary scale with cortical grey matter as the internal reference (0 = isointense, 3 = maximum low signal intensity).The size and number of white matter lesions were subsequently scored, with both short and long TE images. All discrete white matter lesions were registered and weighted 306 on 9 May 2018 by guest. Protected by copyright.

Quantitative Assessment of Iron Accumulation in the Deep Gray Matter of Multiple Sclerosis by Magnetic Field Correlation Imaging

“…However, their findings were contradictory to those by Grimaud et al, 29 who reported that only a mild degree of low signal intensity in the thalamus and low signal intensity in the basal ganglia are rarely seen. More recently, Bakshi et al, 15 in 2001, have confirmed abnormal hypointensity on T2-weighted imaging not only in the deep gray matter but also in the cortical regions.…”

Biomarkers and surrogate outcomes in neurodegenerative disease: Lessons from multiple sclerosis

“…4,101 Although they may be valuable for monitoring clinically relevant disease progression they should not be considered as specific markers of neurodegeneration. Another abnormality reported in MS is a decrease in signal on T2-weighted images of deep gray matter structures, 102 which probably reflects increased iron deposition; whether or not this correlates with neuronal loss is unclear.…”

Multiple Sclerosis and the Accumulation of Iron in the Basal Ganglia: Quantitative Assessment of Brain Iron Using MRI T₂ Relaxometry

“…The T 2 hypointensity, first described by Drayer et al [2] and later by Grimaud et al [3], is supposed to reflect iron deposition and gray matter degeneration. Bakshi et al [4] analyzed signal reduction on T 2 -weighted imaging (T 2 WI) in more detail.…”