✓ 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.
Takeshi Hasegawa, Haruhide Ito, Shinjiro Yamamoto, Katsuhiko Haba and Hideaki Murata
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.
Isabel Fernández-Conejero and Vedran Deletis
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.
Eiji Ito, Masahiro Ichikawa, Takeshi Itakura, Hitoshi Ando, Yuka Matsumoto, Keiko Oda, Taku Sato, Tadashi Watanabe, Jun Sakuma and Kiyoshi Saito
Dysphasia is one of the most serious complications of skull base surgeries and results from damage to the brainstem and/or cranial nerves involved in swallowing. Here, the authors propose a method to monitor the function of the vagus nerve using endotracheal tube surface electrodes and transcranial electrical stimulation during skull base surgeries.
Fifteen patients with skull base or brainstem tumors were enrolled. The authors used surface electrodes of an endotracheal tube to record compound electromyographic responses from the vocalis muscle. Motor neurons were stimulated using corkscrew electrodes placed subdermally on the scalp at C3 and C4. During surgery, the operator received a warning when the amplitude of the vagal motor evoked potential (MEP) decreased to less than 50% of the control level. After surgery, swallowing function was assessed clinically using grading criteria.
In 5 patients, vagal MEP amplitude permanently deteriorated to less than 50% of the control level on the right side when meningiomas were dissected from the pons or basilar artery, or when a schwannoma was dissected from the vagal rootlets. These 5 patients had postoperative dysphagia. At 4 weeks after surgery, 2 patients still had dysphagia. In 2 patients, vagal MEPs of one side transiently disappeared when the tumors were dissected from the brainstem or the vagal rootlets. After surgery, both patients had dysphagia, which recovered in 4 weeks. In 7 patients, MEP amplitude was consistent, maintaining more than 50% of the control level throughout the operative procedures. After surgery all 7 patients were neurologically intact with normal swallowing function.
Vagal MEP monitoring with transcranial electrical stimulation and endotracheal tube electrode recording was a safe and effective method to provide continuous real-time information on the integrity of both the supranuclear and infranuclear vagal pathway. This method is useful to prevent intraoperative injury of the brainstem corticobulbar tract or the vagal rootlets and to avoid the postoperative dysphagia that is often associated with brainstem or skull base surgeries.
Chika Somagawa, Tomonori Ono, Ryoko Honda, Hiroshi Baba, Takeshi Hiu, Ryujiro Ushijima, Keisuke Toda, Kei Sato, Masahiro Ito and Keisuke Tsutsumi
Lhermitte-Duclos disease (LDD) is a neurological disease caused by a hamartomatous lesion in the cerebellum. Clinically, LDD is commonly associated with progressive space-occupying lesion effects in the posterior fossa, increasing intracranial pressure, occlusive hydrocephalus, and focal neurological deficits of adjacent structures. The authors report the case of a 10-year-old boy with LDD who had been suffering from vomiting attacks (VAs). These VAs had been brief in duration but extremely frequent, and they had been resistant to antiemetic drugs since the early postnatal period. Magnetic resonance imaging at 8 months of age revealed a right cerebellar lesion with very little space-occupying lesion effect, but the causal relationship with VAs was not evident at that point, because no clinical symptoms or signs other than vomiting were suggestive of increased intracranial pressure. The VAs were initially diagnosed as autonomic ataxia and had been treated with antiemetic drugs for approximately 10 years, but the patient’s symptoms were not improved at all in frequency or duration. He developed convulsive seizures at 9 years of age and was referred to the authors’ epilepsy center. The VAs were initially speculated to represent an aspect of seizures, but antiepileptic agents proved ineffective against this symptom despite remission of convulsive seizures. Video-electroencephalography monitoring did not show any evolving ictal patterns associated with the vomiting. Careful reevaluation of MRI studies revealed that the cerebellar lesion was fused with the cerebellum, middle and inferior cerebellar peduncles, and dorsolateral medulla oblongata with some distortion. FDG-PET identified hypermetabolism in the cerebellar lesion. After establishing the diagnosis of LDD, the authors performed subtotal resection of the lesion based on the likelihood of a causal relationship between the cerebellar lesion and the vomiting center of the medulla oblongata. Postoperatively and for 2 years, VAs have remained completely suppressed. The authors hypothesize that the pathophysiology of VAs in LDD includes a tumor-like space-occupying effect on the vomiting center of the medulla oblongata, and even partial resection of the lesion may prove effective.
Hiroaki Takei, Jun Shinoda, Soko Ikuta, Takashi Maruyama, Yoshihiro Muragaki, Tomohiro Kawasaki, Yuka Ikegame, Makoto Okada, Takeshi Ito, Yoshitaka Asano, Kazutoshi Yokoyama, Noriyuki Nakayama, Hirohito Yano and Toru Iwama
Positron emission tomography (PET) is important in the noninvasive diagnostic imaging of gliomas. There are many PET studies on glioma diagnosis based on the 2007 WHO classification; however, there are no studies on glioma diagnosis using the new classification (the 2016 WHO classification). Here, the authors investigated the relationship between uptake of 11C-methionine (MET), 11C-choline (CHO), and 18F-fluorodeoxyglucose (FDG) on PET imaging and isocitrate dehydrogenase (IDH) status (wild-type [IDH-wt] or mutant [IDH-mut]) in astrocytic and oligodendroglial tumors according to the 2016 WHO classification.
In total, 105 patients with newly diagnosed cerebral gliomas (6 diffuse astrocytomas [DAs] with IDH-wt, 6 DAs with IDH-mut, 7 anaplastic astrocytomas [AAs] with IDH-wt, 24 AAs with IDH-mut, 26 glioblastomas [GBMs] with IDH-wt, 5 GBMs with IDH-mut, 19 oligodendrogliomas [ODs], and 12 anaplastic oligodendrogliomas [AOs]) were included. All OD and AO patients had both IDH-mut and 1p/19q codeletion. The maximum standardized uptake value (SUV) of the tumor/mean SUV of normal cortex (T/N) ratios for MET, CHO, and FDG were calculated, and the mean T/N ratios of DA, AA, and GBM with IDH-wt and IDH-mut were compared. The diagnostic accuracy for distinguishing gliomas with IDH-wt from those with IDH-mut was assessed using receiver operating characteristic (ROC) curve analysis of the mean T/N ratios for the 3 PET tracers.
There were significant differences in the mean T/N ratios for all 3 PET tracers between the IDH-wt and IDH-mut groups of all histological classifications (p < 0.001). Among the 27 gliomas with mean T/N ratios higher than the cutoff values for all 3 PET tracers, 23 (85.2%) were classified into the IDH-wt group using ROC analysis. In DA, there were no significant differences in the T/N ratios for MET, CHO, and FDG between the IDH-wt and IDH-mut groups. In AA, the mean T/N ratios of all 3 PET tracers in the IDH-wt group were significantly higher than those in the IDH-mut group (p < 0.01). In GBM, the mean T/N ratio in the IDH-wt group was significantly higher than that in the IDH-mut group for both MET (p = 0.034) and CHO (p = 0.01). However, there was no significant difference in the ratio for FDG.
PET imaging using MET, CHO, and FDG was suggested to be informative for preoperatively differentiating gliomas according to the 2016 WHO classification, particularly for differentiating IDH-wt and IDH-mut tumors.