Vessel shape alterations of the vertebrobasilar arteries in Mucopolysaccharidosis type IVa (Morquio A) patients.

PURPOSE: Main symptom of mucopolysaccharidosis type IVa (MPS IVa) is progressive systemic skeletal dysplasia. This is routinely monitored by cerebral and spinal MRI. The vascular system is generally not in the primary focus of interest. In our population of MPS IVa patients we observed vessel shape alterations of the vertebrobasilar arteries, which has not been described before. MATERIAL AND METHODS: MRI-datasets of 26 patients with MPS IVa acquired between 2008 and 2015 were eligible for retrospective analysis of the vertebrobasilar arteries. The vessel length and angle of the basilar artery (BA) and both vertebral arteries (VA) were analyzed. A deflection angle between 90° and 130° in the vessel course was defined as tortuosity, less than 90° as kinking. The results were compared to a matched control group of 23 patients not suffering from MPS. RESULTS: The deflection angle [°] of the VA and BA was significantly decreased in the majority (85%) of MPS IVa patients compared to the control group: BA 132±24 vs. 177±6, BA/VA transition 113±21 vs. 152±13, right VA 108±23 vs. 156±13, left VA 110± 22 vs. 157±14 (all p<0.005). Likewise, vessels of MPS IVa patients were significantly longer compared to the control group: BA 27±4 vs. 21±2, right VA 20±6 vs. 10±1, left VA 18±5 vs. 11±2 (all p<0.005). CONCLUSION: MPS IVa is associated with significantly increased tortuosity of vertebrobasilar arteries. Therefore the vascular system of MPS IVa patients should be monitored on routinely basis, as vessel shape alterations had been associated with dissections, leading to a higher risk of cerebrovascular events.

When things don't talk: knowledge and belief in the inter-war humanism of Charles Singer (1876-1960).

The science historian Charles Singer might seem to have shared with positivists a widely held commitment to observation as the foundation of knowledge. Yet in fact Singer's historiography was peculiarly unconcerned with instruments, models and other artefacts. Such tools might have been expected to present crucial empirical evidence for the historical arguments and ideal material for the didactics which pioneers such as Singer associated with their mission of a 'scientific humanism'. In their hands, physical things did not translate into epistemic things. This was deliberate. Yet while the configuration of science history which would distance it from material objects seems to speak of a shift from the visual to texts, the ocular technologies deployed in Singer's histories rather point to a co-existence of different kinds of visuality in that period's scholarship. As the academic and the museological aspects of science history pulled apart, the visuality of the museum came to be complemented by texts that vitally relied on images. The function of such images was to create proximity with the cognitive desires around whose traffic these histories became paper theatres of knowing. In bypassing material theatres and crafting realities that he understood to be empirically undemonstrable, Singer purposefully developed the story of understanding nature not as entailing obedience to its established results, but instead as embodying an attitude of continuing enquiry.