A Novel Approach With “Skeletonised MTR” Measures Tract-Specific Microstructural Changes in Early Primary-Progressive MS.

A novel approach with “skeletonised MTR” measures tract-specific microstructural changes in early primary-progressive MS.

Hum Brain Mapp. 2013 Apr 24;
Bodini B, Cercignani M, Toosy A, Stefano ND, Miller DH, Thompson AJ, Ciccarelli O

We combined tract-based spatial statistics (TBSS) and magnetization transfer (MT) imaging to assess white matter (WM) tract-specific short-term changes in early primary-progressive multiple sclerosis (PPMS) and their relationships with clinical progression. Twenty-one PPMS patients within 5 years from onset underwent MT and diffusion tensor imaging (DTI) at baseline and after 12 months. Patients’ disability was assessed. DTI data were processed to compute fractional anisotropy (FA) and to generate a common WM “skeleton,” which represents the tracts that are “common” to all subjects using TBSS. The MT ratio (MTR) was computed from MT data and co-registered with the DTI. The skeletonization procedure derived for FA was applied to each subject’s MTR image to obtain a “skeletonised” MTR map for every subject. Permutation tests were used to assess (i) changes in FA, principal diffusivities, and MTR over the follow-up, and (ii) associations between changes in imaging parameters and changes in disability. Patients showed significant decreases in MTR over one year in the corpus callosum (CC), bilateral corticospinal tract (CST), thalamic radiations, and superior and inferior longitudinal fasciculi. These changes were located both within lesions and the normal-appearing WM. No significant longitudinal change in skeletonised FA was found, but radial diffusivity (RD) significantly increased in several regions, including the CST bilaterally and the right inferior longitudinal fasciculus. MTR decreases, RD increases, and axial diffusivity decreases in the CC and CST correlated with a deterioration in the upper limb function. We detected tract-specific multimodal imaging changes that reflect the accrual of microstructural damage and possibly contribute to clinical impairment in PPMS. We propose a novel methodology that can be extended to other diseases to map cross-subject and tract-specific changes in MTR. Hum Brain Mapp, 2013. © 2013 Wiley Periodicals, Inc. HubMed – rehab

Erratum to: What is the Long-term Survival of Impaction Allografting of the Femur?

Clin Orthop Relat Res. 2013 Apr 25;
Garvin KL, Konigsberg BS, Ommen ND, Lyden ER

HubMed – rehab

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

Neurology. 2013 Apr 24;
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

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. HubMed – rehab

Cochlear implantation in patients with vestibular schwannoma: A single United Kingdom center experience.

Laryngoscope. 2013 Apr 24;
Pai I, Dhar V, Kelleher C, Nunn T, Connor S, Jiang D, O’Connor AF

OBJECTIVES/HYPOTHESIS: To evaluate the outcome of cochlear implantation (CI) in patients with vestibular schwannoma (VS). STUDY DESIGN: A retrospective case series from a tertiary auditory implant center. METHODS: A retrospective case note review was carried out to evaluate patients with bilateral profound hearing loss and VS who underwent unilateral CI within the Auditory Implant Centre at St. Thomas’ Hospital, London, between 2000 and 2012. This included both bilateral VS with neurofibromatosis type 2 (NF2) and unilateral sporadic VS. Outcome measures included speech perception with Bamford-Kowal-Bench and City University of New York sentences, sound-field thresholds with warble tones, and the subjective benefits reported by patients. RESULTS: The study included five patients with NF2 and bilateral VS and two patients with sporadic unilateral VS. The standard preoperative audiologic assessment for CI often could not be carried out in NF2 patients. Preoperative testing was more complete in the two patients with sporadic VS. The audiologic outcome was variable. Open-set speech perception was achieved in three out of five NF2 patients, and another reported significant improvement in environmental sound perception and ease of communication. The outcome was overall better in patients with sporadic VS, both of whom were able to use the telephone in their implanted ear. CONCLUSIONS: Good speech perception can be achieved in some cases, and CI should be considered as an option for auditory rehabilitation in patients with VS. LEVEL OF EVIDENCE: 4. Laryngoscope, 2013. HubMed – rehab