Standard clinical computed tomography fails to precisely visualise presence, course and branching points of deep cerebral perforators.

BACKGROUND: Standard computed tomography (CT) images have earned a well-established position in neuroimaging. Despite that, CT is somehow limited by its resolution, which does not enable to distinctively visualise structures smaller than 300 µm in diameter. Perforating arteries, most of which measure 100-400 µm in diameter, supply important subcortical structures (thalamus, basal ganglia, internal capsule). Consequently, pathologies affecting these vessels (e.g. lacunar strokes) can have a devastating clinical outcome. The aim of our study was to assess standard CT's ability to visualise perforators and compare it with microscopic and micro-CT pictures. MATERIALS AND METHODS: We have obtained 6 brainstem and 17 basal ganglia specimens. We infused them with barium sulphate contrast medium administered into either vertebral or internal cerebral artery. After that, the specimens were fixed in formalin and subsequently a series of CT, micro-CT and microscopic examinations were performed. RESULTS: The median number of visualised perforators in brainstem and basal ganglia specimens was 8 and 3, respectively for CT and 18 and 7 for micro-CT (p < 0.05). Standard CT failed to clearly visualise branching points and vessels smaller than 0.25-0.5 mm (1-2 voxels) in diameter. Parallel vessels, like lenticulostriate arteries could not be differentiated in standard CT due to their proximity being smaller that the resolution. CONCLUSIONS: Basing on our results, we infer that CT is a poor modality for imaging of the perforators, presenting both quantitative and qualitative flaws in contrast with micro-CT.

Moving day doesn't begin (or end) on moving day.

Making the transition from an old setting to a new one includes much more than changing the place people report to work. Besides touring the new setting, nursing personnel should decide on locations for stock supply areas, as well as "experiencing" the unit before actual moving of patients. No policy and procedure changes should be made at this time except those directly related to the move. Strong leadership is essential during this stressful time.

Beta-mannosidosis: lesions of the distal peripheral nervous system.

Beta-Mannosidosis, an inherited glycoprotein metabolic disorder so far identified only in the caprine species, is characterized by deficiency of beta-mannosidase, oligosaccharide accumulation and excretion, neurovisceral cytoplasmic lysosomal storage vacuoles and central nervous system myelin and axonal lesions. In this investigation, transmission electron microscopy was used to study peripheral nerve elements in the gingiva of five affected goats and a control animal. Merkel and Schwann cells were vacuolated. Accumulations of dense bodies distended Merkel cell end plates and free-ending axons in the prickle cell layer as well as Pacinian corpuscle axons, and myelinated, unmyelinated, and demyelinated axons in the lamina propria. Unlike central nervous system myelin paucity, loss of peripheral nerve myelin was exclusively related to axonal dense body accumulation and enlargement. The identification of these lesions may facilitate detection of beta-mannosidosis in man and other species.