Swallow Tail Sign Research Articles

Ultra high-field SWI of the substantia nigra at 7T: reliability and consistency of the swallow-tail sign

BackgroundThe loss of the swallow-tail sign of the substantia nigra has been proposed for diagnosis of Parkinson’s disease. Aim was to evaluate, if the sign occurs consistently in healthy subjects and if it can be reliably detected with high-resolution 7T susceptibility weighted imaging (SWI).MethodsThirteen healthy adults received SWI at 7T. 3 neuroradiologists, who were blinded to patients’ diagnosis, independently classified subjects regarding the swallow-tail sign to be present or absent. Accuracy, positive and negative predictive values (PPV and NPV) as well as inter- and intra-rater reliability and internal consistency were analyzed.ResultsThe sign could be detected in 81% of the cases in consensus reading. Accuracy to detect the sign compared to the consensus was 100, 77 and 96% for the three readers with PPV reader 1/2/3 = 1/0.45/0.83 and NPV = 1/1/1. Inter-rater reliability was excellent (inter-class correlation coefficient = 0.844, alpha = 0.871). Intra-rater reliability was good to excellent (reader 1 R/L = 0.625/0.786; reader 2 = 0.7/0.64; reader 3 = 0.9/1).ConclusionThe swallow-tail sign can be reliably detected. However, our data suggest its occurrence is not consistent in healthy subjects. It may be possible that one reason is an individually variable molecular organization of nigrosome 1 so that it does not return a uniform signal in SWI.

MRI of the Swallow Tail Sign: A Useful Marker in the Diagnosis of Lewy Body Dementia?

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. 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. Interrater agreement was moderate (κ = 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%. The swallow tail sign has diagnostic potential in Lewy body dementia and may be a complement in the diagnostic work-up of this condition.

Can loss of the swallow tail sign help distinguish between Parkinson Disease and the Parkinson-Plus syndromes?

PurposeTo determine if loss of the swallow tail sign (STS) can distinguish Parkinson Disease (PD) from the Parkinson-Plus syndromes. MethodsTwenty-five patients with PD, 21 with Parkinson-Plus syndromes, and 14 control patients were included. Presence of the STS was assessed. ResultsThe STS was present in 79% of controls, statistically greater than the PD/Parkinson-Plus patients. There was no difference in the presence of the STS between the PD/Parkinson-Plus subgroups or when scanning at 1.5 T or 3 T. ConclusionsLoss of the STS could not distinguish between PD and Parkinson-Plus patients. The STS can be identified at both 1.5 T and 3 T.

Nigrosome-1 on Susceptibility Weighted Imaging to Differentiate Parkinson's Disease From Atypical Parkinsonism: An In Vivo and Ex Vivo Pilot Study.

SummaryBackgroundPrevious case-control studies have suggested that the absence of a swallow-tail appearance in the substantia nigra on high-resolution SWI, representing nigrosome-1, has high accuracy to identify Parkinson’s disease (PD). The first goal of our study was to evaluate nigrosome-1 ex vivo using optimized high-resolution susceptibility sensitive MRI. Our second goal was to evaluate its diagnostic value in vivo using a clinical 3T SWI sequence to differentiate between PD and atypical parkinsonism (AP) in a cohort of patients with early-stage parkinsonism.Material/MethodsCase-control pilot study to evaluate nigrosome-1 ex vivo (2 PD, 2 controls), using high-resolution susceptibility sensitive sequences at 11.7 T MRI. Next, evaluation of nigrosome-1 in vivo using a clinical 3 T SWI sequence in a prospective cohort of 60 patients with early-stage parkinsonism (39 PD, 21 AP). Moreover, 12 control subjects were scanned.The bilateral substantia nigra was evaluated by two neuroradiologists for the presence, absence or indecisive presence of nigrosome-1. The discriminative power was evaluated by Receiver-Operating Characteristic.ResultsWe identified nigrosome-1 in ex vivo control subjects. Nigrosome-1 was not identified in the ex vivo PD cases. In our prospective clinical cohort study, the AUC for the swallow-tail sign to discriminate between PD and AP was 0.56 (0.41–0.71) for reader 1 and 0.68 (0.55–0.82) for reader 2.ConclusionsThe diagnostic accuracy of the swallow-tail sign was marginal to discriminate between PD and AP using our clinical 3 T SWI sequence.

Depletion of Nigrosome 1 in Parkinsonian Brains as Demonstrated by the Loss of the “Swallow Tail Sign” on 3T MRI-SWI (P4.337)

Depletion of Nigrosome 1 in Parkinsonian Brains as Demonstrated by the Loss of the “Swallow Tail Sign” on 3T MRI-SWI (P4.337)

The swallow-tail sign: a test of deltoid function

The Journal of Bone and Joint Surgery. British volumeVol. 77-B, No. 1 ArticlesFree AccessThe swallow-tail sign: a test of deltoid functionN Nishijma, T Yamamuro, K Fujio, M OhbaN NishijmaSearch for more papers by this author, T YamamuroSearch for more papers by this author, K FujioSearch for more papers by this author, M OhbaSearch for more papers by this authorPublished Online:1 Jan 1995https://doi.org/10.1302/0301-620X.77B1.7822375AboutSectionsPDF/EPUB ToolsAdd to FavouritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InRedditEmail FiguresReferencesRelatedDetailsCited ByExamination of the Adult Brachial Plexus Patient3 July 2021Axillary nerve injury associated with glenohumeral dislocationA review and algorithm for managementDuncan Avis, Dominic Power26 March 2018 | EFORT Open Reviews, Vol. 3, No. 3Biceps-Related Physical Findings Are Useful to Prevent Misdiagnosis of Cervical Spondylotic Amyotrophy as a Rotator Cuff TearAsian Spine Journal, Vol. 12, No. 1Axillary Nerve Palsy and Deltoid Muscle Atony4 July 2017 | JBJS Reviews, Vol. 5, No. 7Axillary Nerve Palsy9 September 2017Nerve Lesions Around the Shoulder16 August 2016Latissimus Dorsi Tendon Transfer for the Treatment of Irreparable Rotator Cuff TearsJournal of the Korean Society for Surgery of the Hand, Vol. 21, No. 4Injuries of the axillary nerve11 August 2015 | Obere Extremität, Vol. 10, No. 3Abduction in Internal Rotation: A Test for the Diagnosis of Axillary Nerve PalsyThe Journal of Hand Surgery, Vol. 36, No. 12Outcome of axillary nerve injuries treated with nerve grafts5 May 2011 | Journal of Hand Surgery (European Volume), Vol. 36, No. 7Results after delayed axillary nerve reconstruction with interposition of sural nerve graftsJournal of Shoulder and Elbow Surgery, Vol. 19, No. 3Axillary nerve repair by triceps motor branch transfer through an axillary access: anatomical basis and clinical resultsJournal of Neurosurgery, Vol. 107, No. 2Arthroscopic Treatment of Isolated Fracture of the Posterolateral Angle of the AcromionArthroscopy: The Journal of Arthroscopic & Related Surgery, Vol. 23, No. 7Shoulder painBest Practice & Research Clinical Rheumatology, Vol. 17, No. 1Isolated fracture of the posterior angle of the acromion: A case reportJournal of Shoulder and Elbow Surgery, Vol. 9, No. 6The deltoid extension lag sign for diagnosis and grading of axillary nerve palsyJournal of Shoulder and Elbow Surgery, Vol. 7, No. 2 Vol. 77-B, No. 1 Metrics Downloaded 863 times History Published online 1 January 1995 Published in print 1 January 1995 InformationCopyright © 1995, The British Editorial Society of Bone and Joint Surgery: All rights reservedPDF download