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MRI of the swallow tail sign : A useful marker in the diagnosis of lewy body dementia?

Shams, Sara ; Fällmar, David ; Schwarz, S. T. ; Wahlund, L. O. ; Van Westen, D. LU orcid ; Hansson, O. LU orcid ; Larsson, E. M. LU and Haller, S. (2017) In American Journal of Neuroradiology 38(9). p.1737-1741
Abstract

BACKGROUND AND PURPOSE: There are, to date, no MR imaging diagnostic markers for Lewy body dementia. Nigrosome 1, containing dopaminergic cells, in the substantia nigra pars compacta is hyperintense on SWI and has been called the swallow tail sign, disappearing with Parkinson disease. We aimed to study the swallow tail sign and its clinical applicability in Lewy body dementia and hypothesized that the sign would be likewise applicable in Lewy body dementia. MATERIALS AND METHODS: This was a retrospective cross-sectional multicenter study including 97 patients (mean age, 65 ± 10 years; 46% women), consisting of the following: controls (n = 21) and those with Lewy body dementia (n = 19), Alzheimer disease (n = 20), frontotemporal lobe... (More)

BACKGROUND AND PURPOSE: There are, to date, no MR imaging diagnostic markers for Lewy body dementia. Nigrosome 1, containing dopaminergic cells, in the substantia nigra pars compacta is hyperintense on SWI and has been called the swallow tail sign, disappearing with Parkinson disease. We aimed to study the swallow tail sign and its clinical applicability in Lewy body dementia and hypothesized that the sign would be likewise applicable in Lewy body dementia. MATERIALS AND METHODS: This was a retrospective cross-sectional multicenter study including 97 patients (mean age, 65 ± 10 years; 46% women), consisting of the following: controls (n = 21) and those with Lewy body dementia (n = 19), Alzheimer disease (n = 20), frontotemporal lobe dementia (n = 20), and mild cognitive impairment (n = 17). All patients underwent brain MR imaging, with susceptibility- weighted imaging at 1.5T (n = 46) and 3T (n = 51). The swallow tail sign was assessed independently by 2 neuroradiologists. RESULTS: Interrater agreement was moderate (- = 0.4) between raters. An abnormal swallow tail sign was most common in Lewy body dementia (63%; 95% CI, 41%-85%; P = .001) and had a predictive value only in Lewy body dementia with an odds ratio of 9 (95% CI, 3-28; P < .001). The consensus rating for Lewy body dementia showed a sensitivity of 63%, a specificity of 79%, a negative predictive value of 89%, and an accuracy of 76%; values were higher on 3T compared with 1.5T. The usefulness of the swallow tail sign was rater-dependent with the highest sensitivity equaling 100%. CONCLUSIONS: The swallow tail sign has diagnostic potential in Lewy body dementia and may be a complement in the diagnostic work-up of this condition.

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author
; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
MRI, Lewy body, dementia
in
American Journal of Neuroradiology
volume
38
issue
9
pages
5 pages
publisher
American Society of Neuroradiology
external identifiers
  • scopus:85029223794
  • pmid:28705819
  • pmid:28705819
  • wos:000409827200016
ISSN
0195-6108
DOI
10.3174/ajnr.A5274
language
English
LU publication?
yes
id
91be85f5-6811-4bdf-87b3-5bf4f5c21ab8
date added to LUP
2017-10-09 16:38:02
date last changed
2024-06-24 01:47:19
@article{91be85f5-6811-4bdf-87b3-5bf4f5c21ab8,
  abstract     = {{<p>BACKGROUND AND PURPOSE: There are, to date, no MR imaging diagnostic markers for Lewy body dementia. Nigrosome 1, containing dopaminergic cells, in the substantia nigra pars compacta is hyperintense on SWI and has been called the swallow tail sign, disappearing with Parkinson disease. We aimed to study the swallow tail sign and its clinical applicability in Lewy body dementia and hypothesized that the sign would be likewise applicable in Lewy body dementia. MATERIALS AND METHODS: This was a retrospective cross-sectional multicenter study including 97 patients (mean age, 65 ± 10 years; 46% women), consisting of the following: controls (n = 21) and those with Lewy body dementia (n = 19), Alzheimer disease (n = 20), frontotemporal lobe dementia (n = 20), and mild cognitive impairment (n = 17). All patients underwent brain MR imaging, with susceptibility- weighted imaging at 1.5T (n = 46) and 3T (n = 51). The swallow tail sign was assessed independently by 2 neuroradiologists. RESULTS: Interrater agreement was moderate (- = 0.4) between raters. An abnormal swallow tail sign was most common in Lewy body dementia (63%; 95% CI, 41%-85%; P = .001) and had a predictive value only in Lewy body dementia with an odds ratio of 9 (95% CI, 3-28; P &lt; .001). The consensus rating for Lewy body dementia showed a sensitivity of 63%, a specificity of 79%, a negative predictive value of 89%, and an accuracy of 76%; values were higher on 3T compared with 1.5T. The usefulness of the swallow tail sign was rater-dependent with the highest sensitivity equaling 100%. CONCLUSIONS: The swallow tail sign has diagnostic potential in Lewy body dementia and may be a complement in the diagnostic work-up of this condition.</p>}},
  author       = {{Shams, Sara and Fällmar, David and Schwarz, S. T. and Wahlund, L. O. and Van Westen, D. and Hansson, O. and Larsson, E. M. and Haller, S.}},
  issn         = {{0195-6108}},
  keywords     = {{MRI; Lewy body; dementia}},
  language     = {{eng}},
  month        = {{09}},
  number       = {{9}},
  pages        = {{1737--1741}},
  publisher    = {{American Society of Neuroradiology}},
  series       = {{American Journal of Neuroradiology}},
  title        = {{MRI of the swallow tail sign : A useful marker in the diagnosis of lewy body dementia?}},
  url          = {{http://dx.doi.org/10.3174/ajnr.A5274}},
  doi          = {{10.3174/ajnr.A5274}},
  volume       = {{38}},
  year         = {{2017}},
}