No abstract

obJective The middle meningeal artery (MMA) is suspected to play an important role in the development of chronic subdural hematoma (CSDH). The aim of this study was to clarify whether the MMA was enlarged in patients with CSDHs. Methods The authors retrospectively assessed 55 patients in whom CSDH was diagnosed between 2010 and 2014 and who underwent MR angiography (MRA) after the onset of CSDH. The authors compared MMA diameters between hemispheres with and without CSDHs on MR angiograms. A case-control study was also performed with 55 sex- and age-matched patients with incidental unruptured aneurysms as controls. results In 55 patients with CSDHs, the diameters of the 79 MMAs on the CSDH side were significantly larger than the diameters of the 31 MMAs on the non-CSDH side (p < 0.05). In 24 patients with bilateral CSDHs, no significant difference was found between the MMA diameters on the larger hematoma side and those on the smaller hematoma side. In 13 patients who underwent MRA before the onset of the CSDH, the MMAs on MR angiograms acquired after onset of the CSDH were significantly larger than those on MR angiograms acquired before the CSDH onset (p < 0.05). The diameters of the MMAs in 55 patients with CSDHs were significantly larger than those of the MMAs in the 55 control patients (p < 0.05). coNclusioNs The MMA is enlarged with development of a CSDH. Information about the MMA observed on MRA in patients with CSDHs may be useful in developing a strategy for future treatment of CSDHs.

The location of corpus callosum injury was investigated using magnetic resonance imaging in 92 patients. The anatomical relationships in the region around the corpus callosum were also evaluated to clarify involvement in the mechanism of corpus callosum injury in 20 normal volunteers. Lesions in the posterior half of the corpus callosum accounted for 80% of corpus callosum injuries. The falx was increasingly elongated toward the posterior portion of the corpus callosum and the corpus callosum was thinnest at the body-splenium junction in the normal volunteers. The mechanism of corpus callosum injury apparently involves the following factors. The posterior half of the falx is closer to the corpus callosum than the anterior half. Therefore, the anterior part of the corpus callosum easily moves with lateral movement of the cerebral hemispheres, and the strain is likely to be concentrated in the posterior half of the corpus callosum, because the falx greatly limits lateral movement of the hemisphere in the posterior region. The corpus callosum is easily distorted at the thinnest part of the body-splenium junction. Therefore, corpus callosum injury predominantly occurs in the posterior half of the corpus callosum.

Although arachnoid cysts (ACs) are associated with chronic subdural hematomas (CSDHs), especially in young patients, the detailed features of CSDHs associated with ACs remain poorly understood. The objective of this study was to clarify the relationship between the location of CSDHs and ACs and the significance of ACs in young patients with CSDHs. We retrospectively assessed 605 consecutive patients 7 years of age and older who were diagnosed with a CSDH between 2002 and 2014. Twelve patients (2%) had ACs, and 10 of the 12 patients were 7–40 years of age. Patients with ACs as a complication of CSDHs were significantly younger than those without ACs (p < 0.05). Three different relationships between the location of CSDHs and ACs were found: a CSDH contacting an AC, an ipsilateral CSDH apart from an AC, and a CSDH contralateral to an AC. In 21 patients with CSDHs who were 7–40 years of age, 10 (47.6%) had ACs (AC group) and 7 (33.3%) had no associated illnesses (non-AC group). All 10 young patients with ACs showed ipsilateral CSDHs including a CSDH apart from an AC. All 17 patients in both the AC and non-AC groups showed headache but no paresis at admission. The pathogenesis of CSDHs associated with ACs may be different among the three types of locations. The clinical characteristics of patients with a combination of a CSDH and an AC including headache as a major symptom may be attributed to young age in the majority of patients with ACs.

The MRXO suite, which combines OR and imaging equipment, represents a significant milestone in the improvement of neurosurgical diagnosis and treatment and other interventional procedures. Another advantage of the MRXO suite is its cost-effectiveness, which is partly due to its streamlined imaging procedure.