Tadashi Aiba

Retrospective analysis of long-term surgical results in acromegaly: preoperative and postoperative factors predicting outcome

OBJECTIVE Sixty‐one of 83 patients with acromegaly treated between 1969 and 1993 were analysed retrospectively to clarify which early postoperative factors were significant predictors of a successful long‐term outcome and which preoperative factors significantly influenced the early postoperative results.

Enterogenous cyst of the cerebellopontine angle cistern: case report.

A case of an enterogenous cyst located in the cerebellopontine angle cistern is presented. These cysts have usually been found in the spinal canal, and their intracranial occurrence is exceptional. In the present case, the cyst was lined histologically by a single epithelial layer of cuboidal cells with some glandular structures resembling the fundic glands of the stomach. The unusual location of the cyst and its histological features are discussed.

Early and late postoperative hearing preservation in patients with acoustic neuromas.

OBJECTIVE To examine the incidence of postoperative hearing preservation and the factors that influence early and late postoperative hearing in patients with acoustic neuromas. METHODS We reviewed the results of surgery and follow-up in 73 consecutive patients. RESULTS Of 73 patients, 51 demonstrated preoperative hearing levels equal to or better than Class 3, according to the classification system of Gardner and Robertson (8). After surgery, 21 (41.2%) of the 51 patients retained Class 1, 2, or 3 hearing. Hearing was more likely to be preserved after surgery if the tumor was small and if the preoperative hearing was good. The early postoperative hearing grade declined in 7 (33.3%) of the 21 patients, compared with the preoperative hearing level. The long-term follow-up of 17 patients in whom measurable hearing was retained after surgery indicated that 3 (17.6%) experienced delayed worsening of hearing, without evidence of tumor recurrence. The extent of hearing loss in patients with successful hearing preservation was not correlated with tumor size, preoperative hearing, patient age, or the shape of the cochlear nerve on the tumor surface. Hearing at long-term follow-up was significantly better in patients with excellent preoperative hearing. CONCLUSION Postoperative long-term preservation of hearing is more likely if surgery is performed while the tumor is still small and hearing is still excellent. Under these circumstances, it is more likely that the early and late hearing loss will be compensated.

Angiography in pulseless disease.

In pulseless disease, comprehensive angiographic studies of all major vessels are necessary because of the high incidence of multiple and diffuse vascular involvement. Total brachiocephalic angiography—consisting of thoracic aortography, retrograde brachial arteriography, and vertebral arteriography—and abdominal aortography, performed in 31 cases, demonstrated characteristic angiographic patterns of the vascular lesions and collateral pathways not previously known or appreciated.

Cerebellopontine angle medulloblastoma: Case report and literature review

The occurrence of cerebellopontine angle (CPA) medulloblastoma is a rare phenomenon. We report such a case in a 19-year-old girl who had 6th and 8th cranial nerve palsies as well as cerebellar dysfunction. The tumour arose from the left flocculus or adjacent cerebellar hemisphere and projected into the CPA. She was treated by subtotal removal of the tumour, followed by entire neuroaxis irradiation and immunochemotherapy. The clinical characteristics and pathogenesis of CPA medulloblastoma are reviewed and discussed.

Atypical manifestations of tuberculous meningitis

We describe 2 patients with tuberculous meningitis who exhibited unusual changes of their cerebrospinal fluid (CSF) which led to confusion in their management. Patient 1 was a 25-year-old man who displayed persistent polymorphonuclear dominant pleocytosis in his CSF. Autopsy revealed marked hypoplasia of the thymus and T cell areas of the lymph nodes, consistent with the Nezelof syndrome, as well as disseminated tuberculosis. Patient 2 was a 39-year-old woman who demonstrated, during appropriate antituberculous chemotherapy, an atypical exacerbation consisting of prolonged fever, polymorphonuclear dominant pleocytosis in her CSF and multiple cerebral infarcts. The neurological abnormalities in the patient underwent marked improvement following oral prednisolone therapy.

A rare case of acoustic neuroma extending from the cerebellopontine angle to the external auditory canal

A 57-year-old woman presented with tinnitus and complete hearing loss in her right ear and a mild right-sided facial palsy. She was found to have an atypical acoustic neuroma involving the internal auditory canal, labyrinth, and middle ear, extending into both the cerebellopontine angle and the external auditory canal. The tumour was completely removed as a two-stage surgical procedure. The underlying mechanism for the atypical extension is discussed.

Growth Hormone and Prolactin Gene Expression in Human Densely and Sparsely Granulated Somatotroph Adenomas by In Situ Hybridization with Digoxigenin-labeled Probes

We studied growth hormone (GH) and prolactin (PRL) messenger ribonucleic acids (mRNAs) in 14 cases with densely granulated somatotroph (DG) adenomas and 10 cases with sparsely granulated somatotroph (SG) adenomas using in situ hybridization with digoxigenin-labeled probes and correlated these data with their immunohistochemical results. A good correlation between in situ hybridization results and immunohistochemical data was found in most cases examined. The DG adenomas generally had a diffuse and intense GH immunoreactivity and GH hybridization signal, whereas in SG adenomas the number of cells exhibiting a GH mRNA signal and the strength of the GH mRNA signal in these cells were relatively lower than those of DG adenomas, indicating that lower expression of the GH mRNA signal is responsible for lower GH production in SG adenomas. In addition, PRL mRNA expression differed in the two types of adenoma; in DG adenomas, seven cases (50%) expressed PRL mRNA signal with a focal or scattered distribution despite normal serum PRL levels, but two showed no PRL immunoreactivity. In contrast, in SG adenomas, only one case contained a few cells possessing a PRL mRNA signal despite having no PRL immunoreactivity. It can be concluded that DG and SG adenomas, which have been considered variants of the same tumor, display definite differences as to GH or PRL gene expression in each type of adenoma.

Intraoperative Identification of the Central Sulcus: a Practical Method

A practical method of intraoperative identification of the central sulcus using cortical evoked potentials (EP) was reported. The method herein proposed is unique with stimulation to the trigeminal and tibial nerve in addition to median nerve stimulation, depending on the location of the lesion. Thus, a wide coverage of the rolandic fissure was possible. Eighteen adult patients with peri-rolandic lesions were investigated. Fourteen cases had a malignant tumour but all except 3 showed only a minor neurological deficit preoperatively. In 13 cases, the central sulcus could be identified through the phenomenon of the phase-reversal of cortical EP across the central fissure. Of the remaining 5 cases, cortical EP were not detected in 3 (all showed hemiplegia and/or aphasia) and EP without phase-reversal were obtained in 2. As a result, in most cases showing only a trivial neurological deficit before surgery, aggressive removal of the tumour was successfully carried out without producing severe motor dysfunction.

Intrasellar gangliocytoma with multiple immunoreactivities

The authors report a rare case of intrasellar gangliocytoma without endocrinopathy. The tumor, removed by transsphenoidal surgery, exhibited immunoreactivities for VIP and galanin in the cytoplasm of several nerve cells, a-subunit, somatostatin, and serotonin in the cytoplasm of few nerve cells. Our case indicates that gangliocytomas can produce unusual combinations of peptides which, despite their known biologic activity, do not invariably cause clinical abnormalities.