Abstract
Recent neuropathologically confirmed clinical data suggest that the midbrain-to-pons ratio, as calculated from conventional brain MRI, has high specificity and sensitivity for the diagnosis of progressive supranuclear palsy (PSP). Here, we aimed to replicate these findings in an independent autopsy-confirmed cohort of 6 PSP patients and 23 non-PSP patients. Patients with confirmed PSP had clearly lower midbrain-to-pons ratios compared to non-PSP patients (p < 0.0001). All non-PSP patients had midbrain-to-pons ratios higher than 0.50, whereas all but one PSP patient had a ratio lower than 0.50. The positive predictive value (PPV) of the ratio (<0.50) was 100% and the negative predictive value (NPV) was 95.8 %. The results of this second autopsy-confirmed sample confirm that midbrain-to-brain ratios constitute reliable and clinically useful estimates of diagnostic midbrain atrophy in relation to PSP pathology.

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Massey LA, Jäger HR, Paviour DC, O’Sullivan SS, Ling H, Williams DR et al (2013) The midbrain to pons ratio: a simple and specific MRI sign of progressive supranuclear palsy. Neurology 80:1856–1861. doi:10.1212/WNL.0b013e318292a2d2
Joutsa J, Gardberg M, Röyttä M, Kaasinen V (2014) Diagnostic accuracy of Parkinsonism syndromes by general neurologists. Parkinsonism Relat Disord. doi:10.1016/j.parkreldis.2014.04.019
Quattrone A, Nicoletti G, Messina D, Fera F, Condino F, Pugliese P et al (2008) MR imaging index for differentiation of progressive supranuclear palsy from Parkinson disease and the Parkinson variant of multiple system atrophy. Radiology 246:214–221. doi:10.1148/radiol.2453061703
Morelli M, Arabia G, Salsone M, Novellino F, Giofrè L, Paletta R et al (2011) Accuracy of magnetic resonance parkinsonism index for differentiation of progressive supranuclear palsy from probable or possible Parkinson disease. Mov Disord 26:527–533. doi:10.1002/mds.23529
Morelli M, Arabia G, Messina D, Vescio B, Salsone M, Chiriaco C et al (2014) Effect of aging on magnetic resonance measures differentiating progressive supranuclear palsy from Parkinson’s disease. Mov Disord 29:488–495. doi:10.1002/mds.25821
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This study was supported by the Academy of Finland (Grant #256836) and the Turku University Hospital (ERVA-funds).
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Kaasinen, V., Kangassalo, N., Gardberg, M. et al. Midbrain-to-pons ratio in autopsy-confirmed progressive supranuclear palsy: replication in an independent cohort. Neurol Sci 36, 1251–1253 (2015). https://doi.org/10.1007/s10072-015-2184-3
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DOI: https://doi.org/10.1007/s10072-015-2184-3