Biomedical subjects
Publications and source records attributed to M Samii.
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.
We report here two cases of vascular tumors arising within the internal auditory canal, both of which presented with cerebellopontine angle symptoms and simulated acoustic neurinomas. The first case was an arteriovenous malformation that caused moderate sensorineural hearing loss, tinnitus, vertigo with lateropulsion, facial weakness, and trigeminal hypoesthesia on the same side. The second case was a venous angioma, to our knowledge the first ever reported in this location, which presented with sudden complete deafness and progressive hemifacial spasm. The latter subsided completely after successful total extirpation of this unique tumor. The literature on these extremely rare lesions is also reviewed.
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.
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.
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Head trauma of different degrees is present in about two-thirds of multiple trauma patients admitted to hospital. As the primary brain damage is irreversible, our objective should be the recognition and specific treatment of both early and late complications. Stabilization of cardiorespiratory parameters must first be achieved. Secondly, only the diagnosis and treatment of life-threatening hemorrhages is of greater importance than the diagnostic and therapeutic measures undertaken by the neurosurgeon. Coma is assessed according to the Glasgow Coma Scale. The indications for CT investigation in trauma patients are: (1) loss of consciousness for more than 30 min (GCS score under 8); (2) manifest neurological deficit; (3) open head injury; (4) deterioration of clinical and neurological status after admission; (5) skull fracture. An algorithm for the management of head trauma, including the above-listed criteria and based on Schweiberer's "Graduated Schedule for Diagnosis and Treatment of Multiple Trauma" is presented. We also list the indications for urgent early neurosurgical intervention: (1) space-occupying intracranial hemorrhages, epi- or subdural, and intracerebral; (2) open head injury; (3) space-occupying impression fractures; (4) any combination of the above. In some cases neurosurgery may be performed after further stabilization, e.g., in: (1) fronto- and otobasal injuries (the latter often heal spontaneously); (2) small contusions; (3) not-space-occupying extracerebral hematomas with no tendency to increase; (4) not-space-occupying impression fractures. As soon as neurological deficit appears in the presence of one of the above, operative treatment is mandatory.
From 1981 to 1988, 24 patients with craniopharyngiomas were operated at the Neurosurgical Clinic of the City Hospital of Hannover. Eleven patients were females and 13 males. The median age was 39 years. Ten patients were 20 years of age or younger at the time of surgery. Among these there were four patients who had large (more than 3 cm in greatest diameter), prevalently retrochiasmatic tumors. They represent 40% of the patients up to 20 years of age. Their age ranged from 8 to 17 years; they were all females. Two patients presented with increased intracranial pressure secondary to hydrocephalus, one patient with decreased vision, and one patient presented with seizures. One patient had been previously operated twice elsewhere. A preoperative shunting procedure was necessary in two patients (in one it was bilateral). All patients were preoperatively evaluated with enhanced and nonenhanced computerized tomography (CT) and with angiography. The major tumor diameter was 4 cm or more in three patients and between 3 and 4 cm in one patient. All tumors were prevalently retrochiasmatic. Three tumors extended to the level of the middle clivus. The tumor was approached subfrontally in two patients and subfrontotemporally in two patients. There was no operative mortality. No patient was neurologically worse postoperatively. All patients required hormonal replacement. Adjuvant therapy was not given. All four patients are clinically and CT recurrence free 5 and 20 months and 3 and 4 years after the surgery.
Four cases of primary intraosseous meningiomas were seen among 373 cases of intracranial meningiomas operated upon in the Neurosurgical Clinic of the Krankenhaus Nordstadt, Hannover, FRG between January 1978 and December 1988. These 4 cases represent 1% of all intracranial meningiomas. Patients' age ranged between 21 and 66 years; 2 were females and 2 males. Presenting symptoms were localized orbital pain in 1 case, protrusion of the eye in 1 patient, pain in the orbit and forehead and protrusion of the eye in 1 patient, and peripheral facial palsy in 1 case. Symptoms lasted between 3 and 10 years. Two tumours were in the bony orbit, 1 in the bony orbit and in the frontal bone and 1 in the temporal bone. All tumours were surgically completely removed. All patients are clinically and computer tomography free of tumour 1 to 8 years after the operation.
An unusual case of cavernous angioma in the cavernous sinus ("cavernous cavernoma") is presented. The acute onset of symptoms simulated Tolosa-Hunt syndrome, and after neuroradiological investigations, the suspected diagnosis was an intracavernous meningioma. Macroscopical intraoperative and histopathological findings demonstrated a cavernous angioma. The lesion was completely removed from the cavernous sinus without additional neurological deficits and with improvement of the symptoms. Three additional cases in the literature are reviewed. The rarity of these lesions and the management problems related to their location in the cavernous sinus are stressed.
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A 14-year-old boy developed mutism 24 h after the removal of a vermian low-grade astrocytoma. The mutism was not accompanied by long tract signs or cranial nerve palsies. He started to regain his speech 3 weeks postoperatively, and 4 months after the operation he was minimally dysarthric. Seven similar cases of transient muteness following cerebellar operations and not accompanied by long tract signs or cranial nerve palsies have been reported in the literature. In most of them there was delayed postoperative onset of the mutism. In all patients the recovery of speech started to appear 2 weeks to 3 months postoperatively and passed through a dysarthric phase. The absence of long tract or other brain stem signs, together with the presence of dysarthria during the recovery of speech, suggests a cerebellar cause for the transient muteness.
Two patients with vertebral arteriovenous fistulae were treated at the Neurosurgical Clinic of the City Hospital of Hannover between 1981 and 1988. Both patients were males, 19 and 29 year old. The fistulae were secondary to cervical gunshot wounds. Both patients complained of a loud cephalic noise; 1 patient had a non pulsating neck mass. A systolic cervical bruit was heard in both cases. One patient had an incomplete mid-cervical Brown-Sequard syndrome. The fistulae involved the second portion of the vertebral artery: 1 fistula was fed, in addition to the vertebral artery, by the deep cervical artery. Venous drainage was through intraspinal plexus, vertebral vein, deep cervical veins and internal jugular vein. One patient was treated with a direct surgical trapping of the vertebral artery proximal and distal to the fistula: the other patient, in addition to direct surgical vertebral artery trapping, received an endovascular balloon occlusion of the deep cervical artery. After treatment the fistulae disappeared, both clinically and angiographically.
In the past eleven years we have performed 438 microsurgical ventral discectomies with bilateral foraminotomy followed by fusion with palacos in the cervical spine in our clinic. An analysis of the preoperative symptoms shows a great variability and overlapping of the various segments. To determine the right level for the operation it is crucial that the results of the clinical and the radiological examinations be evaluated. The results of ascending myelography and CT scans are of great value. In cases of cervical myelopathy a multisegmental operation is often necessary to obtain good results. The complication rate was small in our patients and a second operation was only necessary in a few cases. We had very good postoperative results in radicular pain and muscle weakness. In patients with symptoms of cervical myelopathy we achieved considerable improvement.
The authors report eight cases of chronic epidural hematoma, classified according to macroscopical operative findings and histological studies of the hematomas. Clinical, radiological, and pathological findings are described. A review of 63 cases of the literature is presented, and the accepted concepts for classification and management of these lesions are discussed.
Twenty-four patients with petroclival meningiomas were operated upon at the neurosurgical clinic of the City Hospital of Hannover between 1978 and 1987. Seventeen were women and seven men; the mean age was 45 years. Symptoms were usually present for more than 2 years before the diagnosis was made. The most common symptom was disturbance of gait; the most common preoperative sign was cranial nerve deficit, mainly of the 7th and 8th nerves. Preoperative neuroradiological evaluation included computed tomography and four-vessel cerebral angiography. Fifteen patients (62%) had a tumor larger than 2.5 cm in its major diameter. The surgical approaches used were the retromastoid, pterional, subtemporal, and combined retromastoid-subtemporal. We developed a modification of the retromastoid-subtemporal approach with preservation of the transverse sinus and used this in the last 2 patients. There was no postoperative death; 11 patients (46%) suffered postoperative complications, mainly in the form of cranial nerve deficits, often reversible. "Total" tumor removal was achieved in 17 patients (71%). Twenty patients (83%) were independent at the time of discharge from the hospital. With accurate neuroradiological evaluation, careful choice of the surgical approach, and sound application of microsurgical techniques, petroclival meningiomas may be "totally" and safely resected in a significant number of patients.
After 18 years of close cooperation between ORL and neurosurgery in the treatment of the base of the skull, the authors present their surgical conception and technique for the treatment of malignant tumors of the paranasal sinuses involving the base of the skull. Three basically different surgical procedures are possible: 1. Extracranial partial resection of the anterior base of the skull sparing the contents of the orbit. 2. Radical revision of superior maxilla, ethmoid bone, and base of the skull including exenteratio orbitae. 3. Combined intra-extracranial approach. An interdisciplinary cooperation and the combination of macro- and microsurgery will be more successful with respect to survival chances, functional and esthetic results.
Nine patients with tumours located at the petro-clival region were operated upon from June 1985 to June 1988 using a combined supra- and infratentorial approach anterior to the sigmoid sinus. Two patients had petroclival meningiomas. 4 foramen jugulare neurinomas and 3 glomus jugulare tumours. There was no mortality. Total tumour removal was accomplished in all the patients. All patients remained independent postoperatively. The surgical approach used involves a temporal craniotomy, a suboccipital craniectomy, an extensive mastoidectomy and petrous pyramid drilling without entering the bony labyrinth, the middle ear or the Fallopian canal. The dura is incised supratentorially over the posterior temporal lobe and infratentorially in front of the sigmoid sinus. The temporal lobe is retracted superiorly and the cerebellum and the sigmoid sinus medially. This approach makes use of a very short distance to the petroclival area, offers a multiangled exposure, preserves the dural sinuses, does not iatrogenically impair hearing and minimizes temporal lobe retraction. This exposure is particularly useful in large tumours.
A xenon-CT examination was performed on a patient who had received a STA-MCA bypass. Evaluation of cerebral blood flow (CBF) pre- and postoperatively shows a post-operative increase of about 60%. During manual compression of STA, a decrease of 20% was observed so that one third of the total CBF increase could be attributed to anastomosis. The remaining two thirds may originate from the natural collateral circulation.