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Biomedical subjects

M Samii

Publications and source records attributed to M Samii.

At least 199 records · Page 11Linked to original sources
PubMed1993

Solitary brain metastasis 13 years after removal of renal adenocarcinoma.

We report a case of a patient who developed a single brain metastasis to the cerebellum 13 years after removal of a renal adenocarcinoma. The cerebellar metastasis was removed twice due to local recurrence one year after the first operation. The patient is alive and doing well 18 months after the second neurosurgical procedure. The metastasis was not associated with any other evidence of disease. Brain metastasis may present many years after removal of kidney adenocarcinoma and when not associated with other evidence of disease their operative treatment may carry a good prognosis.

Adenocarcinoma↗
PubMed1993

Somatosensory evoked potentials and intracranial pressure during chronic dilatation of an artificial extraparenchymal space-occupying lesion in cats.

Somatosensory evoked potentials (SEP) and intracranial pressure (ICP) were studied in cats, suffering from a chronic space-occupying lesion produced by enlargement of an epidural balloon over the left sensomotory cortex. Our study shows that latency alterations of SEP are not dependent on the degree of ICP. Additionally, the results obtained demonstrate that chronic space-occupying lesions cause continuous prolongation of SEP latencies, probably produced by atrophy of the compressed tissue. Regarding the clinical importance of SEP measurements, we concluded that they are not suitable for estimating the degree of ICP. However, they are useful to evaluate tissue damage caused by mass effects in the acute and chronic phase of various space-occupying processes.

Animals↗
PubMed1993

Surgical management of high jugular bulb in acoustic neurinoma via retrosigmoid approach.

Of 200 patients with acoustic neurinoma undergoing an operation via the retrosigmoid transmeatal approach in the semisitting position, 18 patients had a high jugular bulb on the tumor side. The frequency was 9%. From a neurosurgical point of view, a jugular fossa above the low border of the internal auditory canal (IAC) is classified as a high one. All 200 patients were evaluated by computed tomography with bone window reconstruction of high-resolution thin axial slices (1.5 mm). High jugular bulbs were classified into three grades as follows: Grade I, jugular bulb situated less than 1.5 mm above the low border of IAC; Grade II, jugular bulb between 1.5 and 3.0 mm above the low border of the IAC; Grade III, jugular bulb > 3 mm above the low border of IAC. There were eight patients with Grade I, six patients with Grade II, and four patients with Grade III. In these patients, in order to open the IAC without concomitant injury of the jugular bulb, the superior posterior portion of the porus was drilled away. Opening the jugular fossa was unavoidable in Grade III cases. No difference was noted in functional preservation of facial or cochlear nerve between HJB cases and normal jugular bulb cases, but HJB cases had a higher frequency of air embolism during tumor removal than did normal cases (16 versus 5%), especially Grade III cases (two of four). There was no mortality or morbidity in the cases of air embolism. Details of the surgical procedure in such cases are discussed.

Adolescent↗
PubMed1993

Neurofibromatosis 2 in the pediatric age group.

Bilateral acoustic neurofibromatosis or neurofibromatosis 2 (NF2) is an autosomal dominant disease predisposing to the formation of multiple tumors in the central and peripheral nervous system. Vestibular schwannomas (VSs) are considered to be the hallmark of the disease, but other tumors and ocular findings occur as well. In patients that do not carry the NF2 mutation, VSs usually occur in the fifth or sixth decade of life. VSs in patients with NF2 are often bilateral and become symptomatic in the third or fourth decade of life. In order to define the early manifestations of NF2, we examined nine children who either had one parent with NF2 or had multiple skin or spinal tumors suggestive of NF2. In addition to neurological, dermatological, and ocular examinations, all patients were studied by gadolinium-enhanced magnetic resonance imaging of the brain and spine. None of the children exhibited symptoms or signs due to VSs. However, VSs were detected during the neuroradiological work-up in six children. Seven children developed symptoms or signs due to skin or spinal tumors. Slit lamp examination detected cataracts in four patients as young as 10 years of age. The diagnosis of NF2 in the pediatric age group requires a high degree of suspicion and should be considered in children with multiple central nervous system or skin tumors without cafe-au-lait spots or Lisch nodules. Because VSs are unlikely to produce the signs seen at the time of admission, careful examination of the skin and eyes is necessary and should be followed by gadolinium-enhanced magnetic resonance imaging of the brain and spine. First-degree relatives need to be examined as well.

Adolescent↗
PubMed1993

Immunohistochemical detection of female sex hormone receptors in meningiomas: correlation with clinical and histological features.

Sixty-one meningiomas from 60 patients were screened for estrogen receptors and progesterone receptors (PgR) with monoclonal antibodies in an immunohistochemical assay. In addition, 43 of the cases were evaluated for tumor size and peritumoral edema, as seen on computed tomographic scans and magnetic resonance images. Sixty-one percent of the tumors contained significant amounts of PgR, whereas no estrogen receptor-positive tumor was observed. Thirteen percent of all tumors were classified as nonbenign variants (atypical and anaplastic meningiomas) and were more frequently found in male patients (P < 0.05). Nonbenign tumors more frequently showed an absence of PgR (P < 0.05), and there was a tendency for PgR-negative tumors to be larger than PgR-positive ones. No correlation was found between PgR status and edema. It is concluded that PgR status in meningiomas is related to tumor differentiation and may be of prognostic value with regard to biological behavior and clinical outcome.

Adolescent↗
PubMed1993

[Ganglia of peripheral nerves].

The authors present two different types of ganglion affecting the peripheral nerves: extraneural and intraneural ganglion. Compression of peripheral nerves by articular ganglions is well known. The surgical management involves the complete removal of the lesion with preservation of most nerve fascicles. Intraneural ganglion is an uncommon lesion which affects the nerve diffusely. The nerve fascicles are usually intimately involved between the cysts, making complete removal of all cysts impossible. There is no agreement about the best surgical management to be applied in these cases. Two possibilities are available: opening of the epineural sheath lengthwise and pressing out the lesion; or resection of the affected part of the nerve and performing a nerve reconstruction. While in case of extraneural ganglion the postoperative clinical evolution is very favourable, only long follow up studies will reveal in case of intraneural ganglion the best surgical approach.

Adolescent↗
PubMed1993

Introduction of a score system for the clinical evaluation of patients with spinal processes.

To facilitate statistical analysis of the clinical course of patients with spinal lesions such as tumours, dysraphic malformations, inflammation, or syringomyelia, we have developed a score system for each of the following symptoms and signs: sensory deficits, dysaesthesiae, pain, motor weakness, gait, bladder and bowel function. For each a score between 0 and 5 is given. The grading is designed in such a way that levels of functional significance receive separate scores: 0 = no function, 1 = severely disabled, 2 = disabled, 3 = severely compromised but function preserved, 4 = slightly compromised, and 5 = normal function. In general, scores between 0 and 2 indicate insufficient functional capacity and an unsatisfactory condition. Scores between 3 and 5 represent levels of function which should be the aim of treatment. We have used this scoring system for evaluation of almost 500 patients with spinal lesions both retrospectively and prospectively with good results in terms of reproducibility and validity.

Disability Evaluation↗
PubMed1992

Experience with 36 surgical cases of petroclival meningiomas.

Thirty-six patients with petroclival meningiomas underwent surgery between 1978 and 1990. The tumours accounted for 13% of a total of 284 skull base meningiomas operated upon during the same time period. The most frequent neurological signs related to cranial nerve deficits, mainly of the 8th, 5th, and 7th nerves respectively. The approaches to the petroclival region were: retromastoid, pterional, subtemporal, and combined retromastoid-subtemporal. In 12 patients we used a modification of the retromastoid-subtemporal approach with preservation of the sigmoid and transverse sinus (presigmoid approach). "Total" tumour removal was achieved in 27 cases (75%). There was no postoperative death, and in 83% of cases no severe morbidity. With careful pre-operative evaluation, improved operative approaches and microsurgical techniques the treatment of petroclival meningiomas has been considerably improved.

Adolescent↗
PubMed1992

Acoustic neurinoma in the elderly: factors predictive of postoperative outcome.

The authors present the results of acoustic neurinoma surgery in 61 elderly patients (age, > or = 65 years). All the patients were operated upon via the lateral suboccipital approach. Complete tumor removal was achieved in all but two patients. There was no operative mortality. Fifty-seven patients (93%) were independent of nursing assistance at the time of discharge from the hospital. Preservation of the facial nerve was achieved in 95% of the patients, and hearing was preserved in 41%. A risk analysis identified three factors exerting a significant influence on the outcome in these cases: the American Society of Anesthesiology score, the preoperative Karnofsky score, and the size of the tumor. The patients' age was not correlated with the postoperative outcome. These results suggest that, in the majority of elderly patients with acoustic tumors, complete tumor removal can be achieved safely and with minimal postoperative morbidity. Preoperative clinical, neurological, and radiological factors can be helpful in the selection of patients for surgical treatment and may predict postoperative outcome.

Activities of Daily Living↗
PubMed1992

Meningeal melanocytoma of the C8 nerve root: case report.

A case of a meningeal melanocytoma involving the C8 nerve root is presented. The clinical symptoms and the radiological investigations resembled a neurinoma of the spinal nerve root. Intraoperatively the tumor was seen to be firmly attached to the dural covering of the dorsal nerve root. By using microsurgical technique, complete removal of the tumor with preservation of the ventral nerve root was accomplished. Histological examination revealed a typical meningeal melanocytoma as described by Limas and Tio in 1972. Ten additional cases of previously reported spinal meningeal melanocytomas are reviewed. The importance of differentiating this benign lesion from meningeal malignant pigmented tumors is stressed.

Adult↗
PubMed1992

The significance for postoperative hearing of preserving the labyrinth in acoustic neurinoma surgery.

Among 186 patients with preoperative hearing, a total of 189 acoustic neurinomas were removed through a lateral suboccipital approach with anatomical preservation of the cochlear nerve. Functional hearing was preserved in 92 (49%) of these patients; despite anatomical preservation of the cochlear nerve, deafness was the result in 51% of the series. Many factors have been considered to cause hearing loss in patients whose cochlear nerve was intact after surgery; these include nerve retraction, nerve or cochlear ischemia, overheating and vibration damage to the nerve, and opening of the labyrinth. To evaluate the significance of injury to the labyrinth in postoperative hearing loss, a prospective study was undertaken. High-resolution computerized tomography studies through the inner ear with bone algorithm were performed pre- and postoperatively. The postoperative status of the labyrinth was classified into three patterns: intact, fenestrated, and widely opened. Injury to the labyrinth occurred in 30% of the cases. The most frequently injured labyrinth structures were the crus commune of the posterior and superior semicircular canals (52%), the posterior semicircular canal (23%), the vestibule (21%), and the superior semicircular canal (4%). A statistically significant relationship was found between injury to the labyrinth and deafness, elevated thresholds, and lower discrimination values at pure-tone audiograms and speech audiometry (p < 0.0001). The degree of the injury (comparison between fenestration and wide opening of the labyrinth) was also significantly related to postoperative deafness (p < 0.0001). Disturbance of the inner-ear fluids was considered to be the cause of the hearing loss. In 12 patients labyrinth injury was not associated with deafness. This finding may support the existence of mechanisms of cochlear protection. The homeostatic function of the endolymphatic sac was considered to play an important role in recovery of damaged hearing in these 12 cases.

Adolescent↗
PubMed1992

[Turcot syndrome illustrated by two clinical cases].

Turcot syndrome denotes the association between either familial polyposis coli (FPC) or sporadic non-familial polyposis coli, and primary neuroepithelial tumors of the central nervous system (CNS). The clinical and morphological intestinal features in both FPC and Turcot syndrome are the same: the histological picture shows typical (tubular) adenomas, often with adenocarcinomatous transformation. As associated CNS tumors astrocytomas, glioblastomas, spongioblastomas, and medulloblastomas are reported. As a modification of ITOH's classification of 1985 we distinguish between four groups: patients with fewer than 100 polyps (group I); patients with fewer than 10 polyps (group II); patients with FPC or sporadic non-familial polyposis (group III); patients with either CNS tumors or FPC with a direct relative with Turcot syndrome and/or FPC (group IV). In patients belonging to the fourth group the diagnosis of Turcot syndrome should not be made. We report on two patients belonging to group II and group IV respectively, and depict the clinical features as well as the heterogenic appearance of Turcot syndrome as outlined in the literature.

Adenomatous Polyposis Coli↗
PubMed1991

Management of intracavernous tumours: an 11-year experience.

Seventy-one patients with tumours involving the cavernous sinus (CS) were operated upon between 1979 and 1989. Fifty-four patients underwent a direct approach to the CS. The average age of these latter patients was 47 (9-69) years. The lesions included 51 benign tumours (26 meningiomas, 16 [7 invasive] pituitary adenomas, 3 trigeminal neurinomas, one chordoma, one chondroma, one craniopharyngioma, one epidermoid tumour, and one cavernous haemangioma), and 3 malignant tumours (one chondrosarcoma, one adenoid cystic carcinoma and one metastatic adenocarcinoma). Dissecting tumour away from the carotid artery was the management of choice for intracavernous tumours which involved the internal carotid artery, except when the carotid artery had already pre-operatively presented with advanced narrowing or occlusion by encasing tumour. Microsurgical technique facilitated dissection and preservation of the cranial nerves. Patients treated radically by direct CS surgery had improvement of their symptoms and signs more frequently than those patients treated by subtotal tumour removal. However, operative complications in direct CS surgery were higher than in subtotal tumour removal without CS entry.

Adenoma↗
PubMed1991

The lounging position for posterior fossa surgery: anesthesiological considerations regarding air embolism.

The sitting position for operations in the posterior fossa remains controversial in both adults and children, primarily because of the risk of air embolism. The reports on the incidence of this complication are varied. We retrospectively reviewed the data on 704 patients (age range 1-82 years) operated on in a lounging position for varied posterior fossa pathology from January 1984 up to December 1989. As diagnostic monitoring, we uniformly employed a Doppler ultrasound device, an atrial catheter, and capnometry. In 37 adults (5.5%) and 9 children (9/34) air embolism was diagnosed, without either morbidity or mortality. A lounging position, together with adequate infusion therapy and ventilation with PEEP, considerably reduces the risk of air embolism.

Adolescent↗
PubMed1991

Intraventricular cavernous angioma. A survey.

Since the availability of CT diagnosis 23 cases of intraventricular cavernous angioma (IVCA) have been published in the literature. Three additional cases have been operated upon in our Department. Based on these 26 cases the clinical data, radiological findings, treatment and outcome of IVCAs are reviewed.

Adult↗
PubMed1991

Peritumoral blood flow in intracranial meningiomas.

Blood flow was measured in intratumoral tissue, the cerebral hemispheres and particularly in the peritumoral area of 12 patients with intracranial meningiomas using the stable xenon-enhanced computed tomographic scan. Tumor blood flow frequently showed a heterogeneous pattern of enhancement with high flow at the tumor periphery and a central area of hypoperfusion. Blood flow values were on average 28% lower in the peritumoral area than in the ipsilateral cerebral hemisphere. In individual cases, blood flow values in the peritumoral edematous area were very low. These findings suggest that the hypodense area surrounding meningiomas does not solely represent vasogenic edema, but may actually represent tumor pressure ischemia.

Adult↗
PubMed1991

Intracanalicular acoustic neurinomas.

The cases of 16 patients with acoustic neurinomas confined to the intracanalicular area are presented. These represent 2.7% of the 600 patients with acoustic neurinomas consecutively operated upon at the Neurosurgical Clinic at Nordstadt Hospital during the last 8 years. The comparatively earlier onset of vestibular symptoms and signs was characteristic of this group and precipitated diagnosis. The diagnostic reliability of magnetic resonance imaging was at least equivalent to that of air computed tomographic cisternography. Complete tumor removal was accomplished via the suboccipital approach in all patients, with 100% preservation of facial nerve and facial function; the cochlear nerve was preserved anatomically in 100% of the patients and functionally in 57%. No recurrence has occurred during follow-up periods of up to 8 years in all 16 patients. A broad spectrum of the current literature is considered, and purely intracanalicular acoustic neurinomas are discussed with regard to clinical characteristics, diagnostic steps-including neuroradiological and neurophysiological approaches-and surgical treatment and results.

Adult↗