✓ Active plasmin, available plasmin, and total plasminogen were measured by Enzodiffusion fibrin plate techniques in 11 cases and level of tissue activator and tissue fibrinolytic activities in another 11 cases with chronic subdural hematoma. The values were too small to be measured in some instances. Anti-plasmin in the hematoma was less than in the blood plasma. The outer membrane contained about three times more tissue activator than the dura mater, although the inner membrane contained none. Increased tissue activator, which exudes from the extremely vascular outer membrane, transforms plasminogen into plasmin in subdural hematoma, so that plasmin breaks down fibrin and fibrinogen and induces continuous hemorrhage.
Haruhide Ito, Toshio Komai and Shinjiro Yamamoto
Haruhide Ito, Shinjiro Yamamoto, Toshio Komai and Hidetaka Mizukoshi
✓ The authors describe studies performed on material aspirated from chronic subdural hematomas. Patients were given 51Cr-labeled red cells prior to aspiration, and it was possible to demonstrate that the mean daily hemorrhage into the hematoma space amounted to 10.2% of its volume. Immunoelectrophoresis of the aspirated hematoma fluid by monospecific anti-human fibrinogen revealed the presence of fibrin and fibrinogen degradation products that, measured by hemagglutination-inhibition immunoassay techniques, varied between 5.0 and 10,500 µg/ml with an average of 2604 µg/ml in 18 cases. The tissue activator was demonstrated by Todd's histological localization in the outer membrane of the chronic subdural hematoma in 11 cases, but not in the inner membrane. These results indicate that if a clot in the subdural space causes the formation of neomembrane, and excessive fibrinolysis occurs, the subdural clot would not only liquefy, but also enlarge by continuous hemorrhage from the neomembrane. Therefore, local hyperfibrinolysis and continuous bleeding are important in the etiology of the chronic subdural hematoma.
Kenichi Saito, Haruhide Ito, Takeshi Hasegawa and Shinjiro Yamamoto
✓ Levels of the plasmin-α 2-plasmin inhibitor complex (PLN-A2PI complex) and α 2-plasmin inhibitor (A2PI) were determined by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies in 59 patients with 66 chronic subdural hematomas (SDH's). Normal concentrations of the PLN-A2PI complex and A2PI in plasma are below 0.8 µg/ml and 60.5 ± 16.1 µg/ml, respectively (mean ± 2 standard deviations). The hematoma fluid contained high concentrations of the PLN-A2PI complex (4.58 ± 2.60 µg/ml) and low concentrations of A2PI (10.32 ± 4.81 µg/ml), while both values in the plasma of 12 patients with chronic SDH's were within the normal range. This represents local hyperfibrinolytic activity in the hematoma.
Stuporous or comatose patients had higher PLN-A2PI complex levels than did the alert and the drowsy or disoriented patients. The layering type of hematoma as seen on computerized tomography scans showed the highest PLN-A2PI complex levels among five types of hematoma. In the fluid drained postoperatively from the subdural cavities of chronic SDH's, both the PLN-A2PI complex and A2PI levels decreased gradually in healing cases. In two patients with hematoma reaccumulation after surgery, both levels increased. The postoperative increase of the PLN-A2PI complex represents the recurrence of intermittent cycles of fibrinolysis, bleeding, coagulation, and hemostasis in the subdural space.
Shinya Kida, Tetsumori Yamashima, Toshihiko Kubota, Haruhide Ito and Shinjiro Yamamoto
✓ The structure of human arachnoid villi was investigated by light and electron microscopy with the aid of immunohistochemical techniques. The human arachnoid villi examined were basically composed of four portions: a fibrous capsule, an arachnoid cell layer, a cap cell cluster, and a central core. The arachnoid cell layer encompassing the central core was mostly covered by the thin fibrous capsule with an endothelial investment. However, the fibrous capsule was often absent at the apical portion of the villus and a factor VIII-related antigen stain failed to confirm the investment of endothelial cells. Instead, the arachnoid cell layer abutted directly upon the lumen of a lateral lacuna or the sinus. The arachnoid cell layer was thickened in places, forming cap cell clusters; it usually consisted of outer and inner zones. On vimentin staining, the former was slightly positive while the latter was strongly positive. The central core contained a network of arachnoid cells intermingled with connective tissue fibers and was in continuity with the cranial subarachnoid space. Electron microscopy showed that the arachnoid cells contained a larger number of intermediate filaments in the inner zone than the outer zone. Ultrastructural immunohistochemical localization showed that vimentin was localized at the intermediate filaments and desmosomal plaques of the arachnoid cells. The arachnoid cells showed a marked variety in both the cell forms and the number of intermediate filaments or desmosomes, depending on their location.
Takeshi Hasegawa, Haruhide Ito, Shinjiro Yamamoto, Katsuhiko Haba and Hideaki Murata
✓ The authors describe a case of atypical unilateral prominent hyperostosis frontalis interna in a 50-year-old Japanese woman with psychiatric symptoms. Radiological, computerized tomographic, operative, and histological findings of this rare case are presented.
Haruhide Ito, Shinjiro Yamamoto, Kenichi Saito, Kiyonobu Ikeda and Kinichi Hisada
✓ Red cell survival studies using an infusion of chromium-51-labeled erythrocytes were performed to quantitatively estimate hemorrhage in the chronic subdural hematoma cavity of 50 patients. The amount of hemorrhage was determined during craniotomy. Between 6 and 24 hours after infusion of the labeled red cells, hemorrhage accounted for a mean of 6.7% of the hematoma content, indicating continuous or intermittent hemorrhage into the cavity. The clinical state of the patients and the density of the chronic subdural hematoma on computerized tomography scans were related to the amount of hemorrhage. Chronic subdural hematomas with a greater amount of hemorrhage frequently consisted of clots rather than fluid.
Wen-Zern Hwang, Takeshi Hasegawa, Haruhide Ito, Takashi Shimoji and Shinjiro Yamamoto
✓ A case of focal cerebral syphilitic gumma of the right temporal lobe is reported. Angiography showed moderate focal hypervascularity with stretched vessels, and irregularity of the vessel walls. Plain computerized tomography revealed an area of low density that enhanced strongly after intravenous administration of contrast medium.
Takeshi Hasegawa, Haruhide Ito, Katsuo Shoin, Yuzaburo Kogure, Toshihiko Kubota and Shinjiro Yamamoto
✓ A case of Nelson's syndrome with an adrenocorticotropic hormone-secreting pituitary chromophobe microadenoma is presented to demonstrate the potential capability of rapid sequential (dynamic) computerized tomography (CT) scanning for the diagnosis of a pituitary microadenoma that was isodense with the adjacent pituitary gland on conventional enhanced CT scanning. The dynamic CT scans showed transient high density in this microadenoma contrasting with the pituitary gland in the early-enhancement phase, and thereafter the contrast density was indistinguishable from that of the pituitary gland in the delayed-enhancement phase. For the detection of pituitary microadenoma, dynamic CT combined with subsequent delayed CT scanning can provide diagnostic and localizing information.