[Anterior cervical fusion in the lower cervical spine. Locked vs nonlocked screw plate, pure cancellous bone vs tricortical strut]. / Vordere Spondylodesen an der unteren Halswirbelsäule. Winkelinstabile vs. winkelstabiler Platte, reine Spongiosa vs. trikortikalem Span.

Physical alterations in cervical fusions endanger healing. Experimentally we determined less stability loss in fixations using cancellous bone grafts than in those using tricortical grafts. Four hundred eighty-five Patients underwent anterior cervical fusion, for a total of 700 Segments. Patients were divided into four groups: (1) nonlocked H plate with autogenous cancellous bone, (2) nonlocked H plate with autogenous tricortical graft, (3) locked cervical plate with tricortical graft, and (4) stand-alone cage with cancellous bone. Evaluations included X-ray and random CT scan examinations. Our results suggest that anterior cervical fusions using nonlocked H screw plate systems with pure autogenous cancellous bone grafts provide the fastest (6 weeks) and most secure bone healing (P=0.00001), whereas fixations using nonlocked or locked screw plate systems and tricortical autograft require prolonged healing and develop nonunions more frequently. Complete consolidation was achieved using stand-alone cages filled with pure autogenous cancellous bone, but bony healing was delayed due to the cage. Rate of nonunions were: groups 1 and 4 0%, and groups 2 and 3 4.5% and 21%, respectively.

Comparison of clinical symptoms and magnetic resonance angiographic (MRA) results in patients with trigeminal neuralgia and persistent idiopathic facial pain. Medium-term outcome after microvascular decompression of cases with positive MRA findings.

Neurovascular compression (NC) seems to have been confirmed as the major cause of classical trigeminal neuralgia (TN). In spite of the large number of surgically positive cases, however, there are still cases where no vascular compression of the trigeminal nerve can be found. To evaluate whether NC could be demonstrated preoperatively, high-resolution magnetic resonance angiography (MRA) was performed in 287 consecutive patients with TN and persistent idiopathic facial pain (PIFP) on a 0.5-T and a 1-T MR unit. Depending on the clinical symptoms, the TN cases were divided into typical TN and trigeminal neuralgia with non-neuralgic interparoxysmal pain (TNWIP) groups. Microvascular decompression (MVD) was performed in 103 of the MRA-positive cases. The patients were followed up postoperatively for from 1 to 10 years. The clinical symptoms were compared with the imaging results. The value of MRA was assessed on the basis of the clinical symptoms and surgical findings. The outcome of MVD was graded as excellent, good or poor. The clinical symptoms were compared with the type of vascular compression and the outcome of MVD. The MRA image was positive in 161 (56%) of the 287 cases. There were significant differences between the clinical groups: 66.5% of the typical TN group, 47.5% of the TNWIP group and 3.4% of the PIFP group were positive. The quality of the MR unit significantly determined the ratio of positive/negative MRA results. The surgical findings corresponded with the MRA images. Six patients from the MRA-negative group were operated on for selective rhizotomy and no NC was found. Venous compression of the trigeminal nerve was observed in a significantly higher proportion in the background of TNWIP than in that of typical TN on MRA imaging (24.1% and 0.8%, respectively) and also during MVD (31.2% and 1.2%, respectively). Four years following the MVD, 69% of the patients gave an excellent, 23% a good and 8% a poor result. The rate of some kind of recurrence of pain was 20% in the typical TN and 44% in TNWIP group. The rate of recurrence was 57% when pure venous compression was present. The only patient who was operated on from the PIFP group did not react to the MVD. The clinical symptoms and preoperative MRA performed by at least a 1-T MR unit furnish considerable information, which can play a role in the planning of the treatment of TN.

Three-dimensional time-of-flight MR angiography in trigeminal neuralgia on a 0.5-T system.

The goal of this study was to analyze the diagnostic value of three-dimensional time-of-flight magnetic resonance angiography (3D TOF MRA), performed on a 0.5-T system in the detection of neurovascular compression in patients with trigeminal neuralgia (TN). One hundred seventy-two TN patients were examined using plain and contrast-enhanced 3D TOF MRA on a 0.5-T system. Maximum intensity projection (MIP) reconstruction was performed in three standard planes. Both the original and the reconstructed images were studied to search for vascular compression shown by close neurovascular contact and/or dislocation of the trigeminal nerve. Forty-two TN patients underwent surgical exploration of the posterior fossa. Results of MRA were compared with clinical data in all cases and to result of surgery in the surgically treated cases. Neurovascular contact at the root entry zone of the trigeminal nerve was detected on the symptomatic side in 94 patients, and on the asymptomatic side in 12 patients. Sensitivity, specificity, accuracy, as well as positive and negative predictive value of 3D TOF MRA in the detection of neurovascular compression in the patient group undergoing surgery, were 97.6, 92.5, 95.0, 93.0, and 97.4%, respectively. Three-dimensional TOF MRA performed on a 0.5-T system appears to be not less effective than similar examinations by higher field strength devices in the detection of neurovascular contact. This sequence accurately demonstrates the presence of neurovascular compression, and in this way valuable information may be achieved for the planning of surgical therapy of patients with trigeminal neuralgia.

[Evaluation of the nature of brain tumors using methods of nuclear medicine]. / Agydaganatok természetének vizsgálata nukleáris medicinai módszerekkel.

FDG-PET studies permit an assessment of the degree of brain tumour malignancy and detection of tumour recurrence. MIBI-SPECT also affords promising results in this respect. In this work, the diagnostic value of MIBI-SPECT was compared with that of FDG-PET for the determination of primary brain tumours malignancy and the detection of recurrent brain tumours. SPECT and PET examination were carried out within a week in 14 patients (12 males, 2 females, mean age: 40 years, range 16-61 years) with brain tumours. Seven patients had a primary tumour, and in a further 7 MRI or the clinical signs and symptoms let to a suspicion of tumour recurrence. All tumours were verified histologically to be gliomas of grades I-IV. The SPECT and PET images were analysed visually and semiquantitatively. In 3 of the investigated 7 primary glioma patients, there was a visibly enhanced MIBI-positive cases, only one had an increased FDG uptake. In 4 of the 7 tumour recurrence cases, either the MIBI or the FDG uptake was visibly increased. All of these were histologically high-grade gliomas. In the remaining low grade tumours (primary of recurrent), neither MIBI nor FDG revealed a pathologically increased uptake. The intensity of radiopharmaceutical uptake at the site of the tumours was visually and semiquantitatively higher for MIBI that for FDG. It is concluded that MIBI-SPECT is a valuable and simple tool for evaluation of the biological characteristics of brain tumours, showing increased uptake of MIBI according to the malignancy and tumour recurrence of brain tumours.

[Central neurocytoma: a rare tumor of the cerebral ventricles]. / Centralis neurocytoma: az agykamrák ritka daganata.

The case of a 33-year-old man is presented, who acutely developed disturbance of consciousness, symptoms of raised intracranial pressure and unilateral neurological signs. The underlying lesion was a hemorrhagic tumor located in the left lateral ventricle. On histological examination, the surgically resected mass proved to be a central neurocytoma, a benign neuroectodermal neoplasia. Difficulties in differential diagnosis by imaging technics and histopathology render this unusual lesion worth publishing. To the best of our knowledge, no similar report on this recently described rare entity has been published in Hungary.

[Cavernous angioma of the central nervous system]. / A központi idegrendszer cavernosus angiomáiról.

The developmental and morphological characteristics, clinical course, diagnostic and therapeutic possibilities of cavernous angiomas of the central nervous system are summarized on the basis of the literature. The clinical courses of 27 patients with cavernous angiomas are presented. The surgical treatment of cavernous angiomas has had a good outcome when the indications and microsurgical principles were adhered to. Special attention should be paid to cavernous angiomas located near or inside the ventricles because of the danger they may cause.

1H nuclear magnetic resonance study of intervertebral discs. A preliminary report.

In vitro 1H pulse nuclear magnetic resonance (NMR) studies on human intervertebral disc tissues were performed to establish the characteristics of relaxation processes. The spin-lattice relaxation time, bound water and dry matter content were measured. Biopsy material from fresh cadavers was taken from different discs along the spinal column and from different sectors of some single discs. It is suggested that the measured parameters correlate with the biomechanical behavior of discs, which in turn is influenced by function, by exposure to physical stresses, or by aging.