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Biomedical subjects

C Matthies

Publications and source records attributed to C Matthies.

At least 55 records · Page 3Linked to original sources
PubMed1996

Management of petroclival meningiomas: a critical analysis of surgical treatment.

Treatment of petroclival meningiomas have been a matter of discussion in neurosurgery. Since the advent of microsurgery, and with development of new skull base approaches more recently, the treatment of these tumours has become standardised, and the post-operative results considerably improved. However, potential complications have been related with the surgical removal of these lesions. The authors describe their experience and summarise the major reports of the literature on this subject.

Adolescent↗
PubMed1996

Meningiomas of the tentorial notch: surgical anatomy and management.

Twenty-five meningiomas located at the tentorial notch were surgically treated between 1978 and 1993 at the Neurosurgical Department of Nordstadt Hospital in Hannover, Germany. Nineteen meningiomas were classified as originating from the lateral tentorial incisura (Group I) and six were from the posteromedial tentorial incisura (Group II). Clinically, the most common symptom was trigeminal neuralgia, followed by headache. Neuroradiologically, 64% of the meningiomas were larger than 30 X 30 mm. Further evaluation revealed signs of brainstem compression in 88% of the patients. Radical surgical removal (Simpson I and II) was achieved in 88% of the cases. There was no mortality. Follow up revealed that 80% of patients were able to return to their premorbid activity. Surgical approaches to the tentorial notch included the suboccipital retrosigmoidal or the combined subtemporal-presigmoidal approach for Group I tentorial notch meningiomas; and the supracerebellar-infratentorial or the suboccipital-transtentorial approaches for Group II meningiomas. Because the best surgical approach to the tentorial incisura is still a matter of debate, the anatomy of the tentorial incisura, the clinical presentation of the patients, diagnostic indications, surgical findings, and follow up are discussed, with reference to the literature.

Adult↗
PubMed1996

Microendoscopy of the internal auditory canal in vestibular schwannoma surgery.

Intraoperative microendoscopy was performed for eight patients to access the fundus of the internal auditory canal after retrosigmoid transmeatal surgery of vestibular schwannomas. The transmeatal procedure is usually limited laterally by the labyrinth block. The restricted opening of the internal auditory canal bears a potential risk of incomplete tumor resection. For eight patients with vestibular schwannomas, intraoperative microendoscopy was performed after tumor resection to expose the "blind" area of the internal auditory canal fundus. An excellent view of the fundus contents was obtained, including Cranial Nerves VII and VIII and the crista transversa. Tumor remnants were not observed in this series. Microendoscopy was shown to be an ideal adjunct to hearing-preserving transmeatal surgery of vestibular schwannomas, enabling the removal of intracanalicular tumors with direct control of the lateral intracanalicular nerve portions.

Adolescent↗
PubMed1995

Hearing preservation in acoustic tumour surgery.

900 acoustic neurinomas were removed by the suboccipital approach at Nordstadt Neurosurgical Department from 1978 to 1992 by the same surgeon (M. S.). While 247 patients were deaf on the involved side before surgery, there were 653 patients ears with some preoperative hearing. Preservation of the cochlear nerve was always attempted, and the overall-rate of hearing preservation was 38% (249 of 653), regardless of pre- and postoperative quality of hearing or of tumour sizes. In small tumour sizes below 3 cm of diameter preservation rate was 51%, in large tumours above 3 cm of diameter it was 22%. A classification system of hearing quality was made up considering pure tone audiometric hearing losses (PTA HL) at 1 to 3 kHz, and individual maximum speech discrimination scores. The usefulness of the preserved hearing is further evaluated considering the quality of hearing in the contralateral ear, and by application of other classification schemes. Presentation of the surgical strategies and their refinements by personal experience provide the base for discussion questioning whether and how further progress may still be anticipated.

Adult↗
PubMed1995

Acoustic neurinomas associated with vascular compression syndromes.

Trigeminal neuralgia and hemifacial spasm are caused by vascular compression of the cranial nerves at the brainstem in the majority of cases. Trigeminal neuralgia occurring in 3.3% of acoustic neurinomas is usually assumed to be a sign of large tumour size; if associated with small tumour size, an additional pathology, such as typical vascular compression must be suspected and has to be explored at surgery. While facial paresis will usually lead to immediate radiological diagnosis of a possible cerebellopontine angle (CPA) neoplasm, facial spasm is usually not expected to be associated with a CPA tumour. We report on clinical presentation, operative findings, surgical treatment and results in 9 cases of small acoustic neurinomas associated with trigeminal neuralgia and on 4 cases associated with hemifacial spasm. The importance of the clinical characteristics is stressed; if these are typical of a vascular compression syndrome, further exploration at the time of tumour surgery and specific treatment by vascular decompression are necessary.

Adult↗
PubMed1995

Proliferative activity of acoustic neurilemomas without neurofibromatosis determined by monoclonal antibody MIB 1.

Microscopic sections obtained from paraffin blocks of 30 consecutive neurilemomas stored in 1989 were investigated immunohistochemically with the new monoclonal antibody MIB 1 directed against recombinant parts of Ki-67 antigen. The immunohistochemical staining was carried out on dewaxed microwave-oven-processed paraffin sections of formalin-fixed tumour tissues. The labelling index (LI) obtained was below 1% in 21 cases, 1-3% in 7 cases and more than 3% in 2 cases. There was no correlation between the LI and the age of the patients or the tumour size. The major advantage of MIB 1 over previous immunohistochemical methods is its usefulness in long preserved sections which are ideal for retrospective studies.

Adult↗
PubMed1994

Indication, technique and results of facial nerve reconstruction.

160 patients with various intra- or extracranial pathologies were treated by microsurgical facial nerve reconstruction at Nordstadt Neurosurgical Clinic between 1978 and 1993. Facial nerve reconstruction was accomplished along the anatomical course of the facial nerve from its origin at the brainstem, within the mastoid, at the stylomastoid foramen and within the face. Mostly, reconstruction was indicated because of nerve discontinuity (n = 61), whereas facial nerve reanimation with a donor nerve such as the contralateral facial nerve or the ipsilateral hypoglossal nerve was indicated in 99 cases of loss of a proximal nerve stump. Depending on the site of the lesion reinnervation started at 5 to 15 months postoperatively lasting for 2 to 3 years with overall satisfactory results. 69% of all the patients regained good symmetry on rest, complete eye closure equivalent to House-Brackmann-Score III: Patients with complete failures either suffered of non-related diseases such as cancer leading to death before the estimated time of recovery or were exposed to radiation or received facial nerve reconstruction after long-standing facial deficit and marked muscular atrophy. The indication of the adequate method depends on the clinical course with or without preexisting facial paresis, on considering the intraoperative state of the facial nerve, the identification and microsurgical preparation of adequate nerve stumps, as well as on the adaptation techniques and the postoperative guidance of the patient. We conclude that facial nerve reconstruction by transplantation at either site of the nerve course or by reanimation with a donor nerve are effective and reliable procedures of treatment leading to satisfactory functional and cosmetic results.

Adolescent↗
PubMed1994

Facial nerve reconstruction in neurofibromatosis 2.

Between 1979 and 1989, 13 patients with neurofibromatosis 2 underwent reconstructions of the facial nerve after removal of bilateral acoustic or facial neurinomas. Seven patients received hypoglossal-facial nerve anastomosis, and five received sural nerve grafting in the cerebellopontine angle. End-to-end anastomosis and intracranial-intratemporal sural grafting were performed for one patient each, respectively. Re-innervation was seen in all cases. The results were good in 11 cases. Two patients presented with poor results due to development of neurinomas close to the site of the nerve reconstruction. The importance of reconstructive surgery in patients with neurofibromatosis is stressed. The problems regarding failure of re-innervation in some cases and difficulties in their management are discussed.

Adolescent↗
PubMed1992

Energy conservation in fermentative glutarate degradation by the bacterial strain WoG13.

Dicarboxylic acids with 2-5 carbon atoms can be degraded fermentatively by pure cultures of various strictly anaerobic bacteria. The small amount of free energy released in these decarboxylations (about 20-25 kJ mol-1) is conserved as sole source of growth energy either through sodium-pumping decarboxylases or through electrogenic substrate/product transport devices. In the glutarate-fermenting bacterial strain WoG13 a glutaconyl-CoA-decarboxylating enzyme activity was detected. This enzyme was inhibited by avidin and was stimulated by sodium ions. The enzyme activity was partially associated with the cytoplasmic membrane, indicating that energy conservation is accomplished through a sodium-ion-pumping glutaconyl-CoA decarboxylase enzyme.

Bacteria, Anaerobic↗
PubMed1992

Fermentative degradation of glutarate via decarboxylation by newly isolated strictly anaerobic bacteria.

Two strains of new strictly anaerobic, gram-negative bacteria were enriched and isolated from a freshwater (strain WoG13) and a saltwater (strain CuG11) anoxic sediment with glutarate as sole energy source. Strain WoG13 formed spores whereas strain CuG11 did not. Both strains were rod-shaped, motile bacteria growing in carbonate-buffered, sulfide-reduced mineral medium supplemented with 2% of rumen fluid. Both strains fermented glutarate to butyrate, isobutyrate, CO2, and small amounts of acetate. With methylsuccinate, the same products were formed, and succinate was fermented to propionate and CO2. No sugars, amino acids or other organic acids were used as substrates. Molar growth yields (Ys) were very small (0.5-0.9 g cell dry mass/mol dicarboxylate). Cells of strain WoG13 contained no cytochromes, and the DNA base ratio was 49.0 +/- 1.4 mol% guanine-plus-cytosine. Enzyme activities involved in glutarate degradation could be demonstrated in cell-free extracts of strain WoG13. A pathway of glutarate fermentation via decarboxylation of glutaconyl-CoA to crotonyl-CoA is suggested which forms butyrate and partly isobutyrate by subsequent isomerization.

Acetates↗
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

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

Glomerular hemodynamics of the clipped kidney: effects of captopril and diltiazem.

Glomerular hemodynamics of the clipped kidney in two kidney-one clip Goldblatt-hypertensive rats were studied by micropuncture techniques after administration of either captopril (20 mg/kg of b.wt./day p.o.) or diltiazem (3 mg/kg of b.wt./hr i.v.). Both drugs decreased mean arterial and poststenotic renal arterial pressure to comparable levels. Total kidney glomerular filtration rate was not significantly different in the three groups (0.78 +/- 0.09 in hypertensive controls, 0.62 +/- 0.11 after captopril and 0.74 +/- 0.07 ml/min/g of kidney weight after diltiazem). Glomerular capillary pressure fell significantly in both treated groups but was lower in captopril-treated animals (60 +/- 2 in hypertensive controls, 45 +/- 2 after captopril and 53 +/- 1 mm Hg after diltiazem, both P < .05 vs. hypertensive controls). Afferent arteriolar resistance was lowered in both treatment groups to the same extent, whereas only captopril decreased efferent arteriolar resistance. Single nephron filtration rate of cortical nephrons was not altered significantly by captopril due to a 96% increase in the ultrafiltration coefficient and a 58% rise in glomerular plasma flow, whereas diltiazem increased ultrafiltration coefficient by 62% but did not affect glomerular plasma flow. These studies indicate that, despite of decreased effective filtration pressure, glomerular filtration rate is well preserved after converting enzyme inhibition. Captopril and diltiazem have different effects on glomerular hemodynamics within the stenosed kidney.

Angiotensin II↗
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↗