The Effects of Hook Plates on the Subacromial Space. A Clinical and MRI Study

Abstract   The disruption of the acromioclavicular joint is a relatively common injury of the shoulder girdle, often occurring in young athletes. The therapy of third degree injuries (Tossy III or Rockwood III–VI) is still controversial, and several operative techniques are practiced. In a retrospective study, 28 (= 72%) of the total number of 39 cases with a Tossy III disruption operated in our hospital between January 1998 until December 2002 with a hook plate according to Dreithaler were followed up. The average reexamination interval was 3.0 years (range 1.2–5.6 years) after surgery. Special emphasis was laid upon the question, if the hook had any effects on the subacromial space. The study included clinical, sonographic and MRI examinations of both shoulders in direct side-to-side comparison. About 86% of the patients were satisfied with the functional outcome, but only 54% with the cosmetic result. This was mostly due to remaining elevation of the lateral clavicula and heterotopic ossifications around the acromioclavicular joint, which were found in 43% of the patients without any functional deficit. The outcome-scores (DASH, Taft, Constant–Murley) yielded on the whole very good and good results. Instability of the AC-joint under load was found in seven patients, in three of these instability was severe, and two patients had a chronic subluxation with functional impairment. The sonographic investigation revealed no specific lesions of the rotator cuff in any patient. Age related degenerative changes were seen in 46%, however, the accentuation of the operated side was only 14%. In MRI there was no case of a complete rotator cuff tear. Corresponding to the sonographic examination increased numbers of exostoses, heterotopic ossifications, and arthrosis of the AC-joint were observed.     

Quantification of subtle blood-brain barrier disruption in non-enhancing lesions in multiple sclerosis: a study of disease and lesion subtypes

Few attempts have been made to detect subtle blood-brain barrier (BBB) leakage in visibly non-enhancing MRI lesions in multiple sclerosis (MS). For 19 patients, longitudinal relaxation time (T1) maps were generated from MRI scans obtained before, and at 20, 40 and 60 minutes after injection of gadolinium (Gd)-DTPA (0.3 mmol/kg). Regions of interest (ROI) were placed around non-enhancing lesions, and in paired contralateral normal appearing brain tissue (NABT). Post-Gd rate of R1 (=1/T1) rise (DeltaR1/Deltat), was used to quantify leakage. DeltaR1/Deltat was greater in lesions than paired NABT (P < or = 0.001 at all post-Gd timepoints). DeltaR1/Deltat was greater in T1 hypointense than isointense lesions (P = 0.001 and 0.01 for first and second timepoints respectively), and negatively related to lesion cross sectional area (P < or = 0.001 at all post-Gd timepoints). Relapsing remitting (RRMS) lesions had a greater initial DeltaR1/Deltat than secondary progressive (SPMS) lesions ( P = 0.04), but this was not seen in subsequent timepoints. DeltaR1/Deltat in visibly enhancing lesions was significantly greater than in visibly non-enhancing lesions, with no overlap in the normal ranges of the two populations. Subtle BBB leakage is a consistent feature in non-enhancing lesions, and is distinct from the overt BBB leakage observed in visibly enhancing lesions. It is detectable using quantitative contrast-enhanced MRI. It is apparent in all clinical and lesion subtypes studied, and greater in T1 hypointense and smaller lesions. Larger initial DeltaR1/Deltat in RRMS than SPMS lesions may reflect differences in blood volume rather than BBB leakage.     

Relationship of triple dose contrast enhanced lesions with clinical measures and brain atrophy in early relapsing-remitting multiple sclerosis: a two-year longitudinal study

Gadolinium (Gd) enhancement of lesions indicates inflammatory lesion activity in multiple sclerosis (MS). The question arises whether early inflammatory lesion activity--measured sensitively using triple dose Gd--is related to the future clinical course, or to the development of brain atrophy that is thought to reflect the underlying pathological progression of the disease. In this study, 26 patients with early relapsing-remitting (RR) MS (median disease duration: 1.7 years) were followed up over two years. Associations were explored between their levels of Gd-lesion enhancement in the first six months and later clinical (Expanded Disability Status Scale (EDSS) and MS Functional Composite Score (MSFC)) and magnetic resonance imaging (MRI) (brain volume, T(2) and T(1) lesion volumes) measures. The extent of Gd-enhancement in the first six months correlated weakly with concurrent relapses (P =0.041), but there was no consistent correlation with clinical and MRI outcomes at two years. More prolonged follow-up is warranted to clarify the relationship between early inflammatory lesions and long-term clinical course.     

Normal-appearing grey and white matter T1 abnormality in early relapsing-remitting multiple sclerosis: a longitudinal study

OBJECTIVE: To investigate the presence and evolution of T(1) relaxation time abnormalities in normal-appearing white matter (NAWM) and grey matter (GM), early in the course of relapsing-remitting multiple sclerosis (MS). METHODS: Twenty-three patients with early relapsing-remitting MS and 14 healthy controls were imaged six monthly for up to three years. Mean follow-up was 26 months for MS patients and 24 months for controls. Dual-echo fast-spin echo and gradient-echo proton-density and T(1)-weighted data sets (permitting the calculation of a T(1) map) were acquired in all subjects. GM and NAWM T(1) histograms were produced and a hierarchical regression model was used to investigate changes in T(1) over time. RESULTS: At baseline, significant patient-control differences were seen, both in NAWM (P <0.001) and in GM (P =0.01). At follow-up, there was no evidence for a serial change in either mean T(1) or peak-location for either NAWM or GM. There was weak evidence for a decline in patient NAWM peak-height and also evidence for a decline in control GM peak-height. CONCLUSION: There are significant and persistent abnormalities of NAWM and GM T(1) in early relapsing-remitting MS. Further studies should address whether such T(1) measures have a role in prognosis or therapeutic monitoring.     

Charcot–Marie–Tooth disease associated with recurrent optic neuritis

The factors precipitating central nervous system (CNS) demyelination, including optic neuritis, remain largely unknown but are likely to represent a complex interplay between the patient’s environment and their genetic background. We report the development of sequential demyelinating optic neuritis in a patient with genetically confirmed Charcot–Marie–Tooth disease type 1A, a hereditary neuropathy. This neuropathy is characterized by duplication of peripheral myelin protein 22 (PMP22), which results in structurally abnormal peripheral myelin. By characterizing peripheral T-cell responses in this patient to a panel of myelin epitopes expressed in the CNS we describe an immunological process which indicates that overexpression of PMP22 may be causative and account for this association.     

Fact vs fiction—how paratextual information shapes our reading processes

Our life is full of stories: some of them depict real-life events and were reported, e.g. in the daily news or in autobiographies, whereas other stories, as often presented to us in movies and novels, are fictional. However, we have only little insights in the neurocognitive processes underlying the reading of factual as compared to fictional contents. We investigated the neurocognitive effects of reading short narratives, labeled to be either factual or fictional. Reading in a factual mode engaged an activation pattern suggesting an action-based reconstruction of the events depicted in a story. This process seems to be past-oriented and leads to shorter reaction times at the behavioral level. In contrast, the brain activation patterns corresponding to reading fiction seem to reflect a constructive simulation of what might have happened. This is in line with studies on imagination of possible past or future events.     

Apolipoprotein E,gender, and Alzheimer’s disease: an overlooked,but potent and promising interaction

Alzheimer’s disease (AD) is an increasingly prevalent, fatal neurodegenerative disease that has proven resistant, thus far, to all attempts to prevent it, forestall it, or slow its progression. The ε4 allele of the Apolipoprotein E gene (APOE4) is a potent genetic risk factor for sporadic and late-onset familial AD. While the link between APOE4 and AD is strong, many expected effects, like increasing the risk of conversion from MCI to AD, have not been widely replicable. One critical, and commonly overlooked, feature of the APOE4 link to AD is that several lines of evidence suggest it is far more pronounced in women than in men. Here we review previous literature on the APOE4 by gender interaction with a particular focus on imaging-related studies.     

Characterization of a chip-based bioreactor for three-dimensional cell cultivation via Magnetic Resonance Imaging

We describe the characterization of a chip-based platform (3^D-KITChip) for the three-dimensional cultivation of cells under perfusion conditions via magnetic resonance imaging (MRI). Besides the chip, the microfluidic system is comprised of a bioreactor housing, a medium supply, a pump for generating active flow conditions as well as a gas mixing station. The closed circulation loop is ideally suited for a characterization via MRI since the small bioreactor setup with active perfusion, driven by the pump from outside the coils, not only is completely MRI-compatible but also can be transferred into the magnetic coil of an experimental animal scanner. We have found that the two halves of the chip inside the bioreactor are homogeneously perfused with cell culture medium both with and without cells inside the 3^D-KITChip. In addition, the homogeneity of perfusion is nearly independent from the flow rates investigated in this study, and furthermore, the setup shows excellent washout characteristics after spiking with Gadolinium-DOTA which makes it an ideal candidate for drug screening purposes. We, therefore, conclude that the 3^D-KITChip is well suited as a platform for high-density three-dimensional cell cultures, especially those requiring a defined medium flow and/or gas supply in a precisely controllable three dimensional environment, like stem cells.