The midbrain to pons ratio: A simple and specific MRI sign of progressive supranuclear palsy

Neurology. 2013 Apr 24. [Epub ahead of print]

Massey LA, Jäger HR, Paviour DC, O'Sullivan SS, Ling H, Williams DR, Kallis C, Holton J, Revesz T, Burn DJ, Yousry T, Lees AJ, Fox NC, Micallef C.

Source

From the Sara Koe PSP Research Centre (L.A.M., D.C.P., S.S.O., H.L., J.H., T.R., A.J.L.), Rita Lila Weston Institute for Neurology Studies and Queen Square Brain Bank, Department of Molecular Neurosciences, UCL Institute of Neurology, London, UK; Department of Brain Repair and Rehabilitation (H.R.J., T.Y., C.M.), UCL Institute of Neurology and Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, Queen Square, London; Dementia Research Centre (N.C.F.), UCL Institute of Neurology, London; Van Cleef Roet Centre for Nervous Diseases (D.R.W.), Monash University, Melbourne, Australia; Forensic Psychiatry Research Unit (C.K.), Queen Mary, University of London; and Institute for Ageing and Health (D.J.B.), Newcastle University, Newcastle upon Tyne, UK.

Abstract

OBJECTIVES:

MRI-based measurements used to diagnose progressive supranuclear palsy (PSP) typically lack pathologic verification and are not easy to use routinely. We aimed to develop in histologically proven disease a simple measure of the midbrain and pons on sagittal MRI to identify PSP.

METHODS:

Measurements of the midbrain and pontine base on midsagittal T1-weighted MRI were performed in confirmed PSP (n = 12), Parkinson disease (n = 2), and multiple system atrophy (MSA) (n = 7), and in controls (n = 8). Using receiver operating characteristic curve analysis, cutoff values were applied to a clinically diagnosed cohort of 62 subjects that included PSP (n = 21), Parkinson disease (n = 10), MSA (n = 10), and controls (n = 21).

RESULTS:

The mean midbrain measurement of 8.1 mm was reduced in PSP (p < 0.001) with reduction in the midbrain to pons ratio (PSP smaller than MSA; p < 0.001). In controls, the mean midbrain ratio was approximately two-thirds of the pontine base, in PSP it was <52%, and in MSA the ratio was greater than two-thirds. A midbrain measurement of <9.35 mm and ratio of 0.52 had 100% specificity for PSP. In the clinically defined group, 19 of 21 PSP cases (90.5%) had a midbrain measurement of <9.35 mm.

CONCLUSIONS:

We have developed a simple and reliable measurement in pathologically confirmed disease based on the topography of atrophy in PSP with high sensitivity and specificity that may be a useful tool in the clinic.

Posted with Blogsy