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Chemical and Histological Analysis of Leptomeningeal Plaques
Author(s) -
Coovert Daniel,
MillspaughStorms Brittany,
Fitch Richard
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.lb703
Subject(s) - pathology , staining , dissection (medical) , arachnoiditis , medicine , autopsy , silver stain , anatomy , radiology
Study Objective This study was carried out to investigate the composition of arachnoidal plaques discovered during routine cadaver dissection during gross anatomy courses at Indiana State University. Background Leptomeningeal calcified plaques are uncommon formations that have been periodically described in dissection or in autopsy for over 100 years (1,2). These typically benign leptomeningeal plaques are usually asymptomatic, and are distinct from those associated with the chronic proliferative disorder Arachnoiditis ossificans (AO). The etiological cause of arachnoidal plaques and AO are unknown, but iatrogenic, traumatic, metastatic, and infective factors have been associated with these disorders (2). Methods Leptomeningeal plaques identified during routine cadaver dissection were excised and examined by SDS‐PAGE, histological stains, and electron microscopy. Proteins present in the inclusion were resolved on a 10% gel, and were detected using silver staining. Presence of surface protein was detected using amidoblack. Ultrastructral analysis and elemental composition was carried out using a JOEL 7008F Field Emission Scanning Electron Microscope at the Integrated Nanosystems Development Institute (INDI) at Purdue University Indianapolis. Results Amidoblack staining indicated the plaques are covered by a thin protein layer derived from the arachnoid. Electron microscopy confirmed the surface is composed of a fibrous network, presumably collagen fibers derived from the arachnoid. These results indicate the plaque formation process initiates within the arachnoid rather than aggregating on the luminal surface of the arachnoid and growing into the subarachnoid space. Elemental analysis indicates the plaque is highly biased toward carbon with little nitrogen and lacks calcium or phosphorus. This suggests the plaque is highly enriched with lipid. Protein analysis indicated the protein composition was similar to the composition of the arachnoid. Conclusions Leptomeningeal plaques are lipid rich inclusions that form within the arachnoid layer.