Early postoperative gadolinium-DTPA-enhanced MR imaging after successful lumbar discectomy.

A prospective study was undertaken to establish the normal spectrum of early gadolinium-enhanced magnetic resonance (MR) imaging findings in patients who had resolution of symptoms after lumbar discectomy. Thirty-four patients underwent MR examinations 6 weeks and 6 months after lumbar discectomy on a 1.5 T superconducting unit, including sagittal and axial spin-echo (SE) T1-weighted images before and after intravenous administration of gadolinium-DTPA, as well as sagittal turbo (or fast-) SE T2-weighted images. All patients showed soft tissue enhancement along the surgical track in the subcutaneous soft tissue lateral to the spinous process and in the epidural space. There was only minimal (45%) or no (55%) mass effect on the dural sac associated with epidural scar formation 6 months after surgery, but often the nerve root at the operative level was surrounded by this enhancing tissue. Facet joint enhancement was seen in most patients 6 weeks (63%) and 6 months (53%) after surgery. Intrathecal nerve root enhancement was observed in six patients, 6 weeks after surgery. Nine patients (20%) had residual mass effect on the neural elements with an enhancement pattern suggestive of a disc fragment. Enhancement of the intervertebral space was seen in 67% of patients 6 weeks after surgery and in 86% of patients after 6 months. It may be concluded that, despite the use of gadolinium-DTPA, MR studies obtained in the initial postoperative period are difficult to interpret, because of the normal sequence of changes. Consequently, the clinical picture still remains the major indicator for recurrent surgery.

Changes in metabolism of cerebral glucose after stereotactic leukotomy for refractory obsessive-compulsive disorder: a case report.

Brain glucose metabolism was investigated with PET and [18F]fluorodeoxyglucose, before and after a bifrontal stereotactic leukotomy in a 37 year old woman with refractory obsessive-compulsive disorder. A bilateral decrease in glucose metabolism was found in the orbital frontal cortex after psychosurgery. Glucose metabolism was decreased to a lesser degree in Brodmann's area 25, in the thalamus, and in the caudate nucleus. Clinical improvement in obsessive-compulsive disorder after stereotactic tractotomy seems to be associated with metabolic changes in the brain, in particular, in the orbital part of the frontal lobe.

Long-term pain relief during spinal cord stimulation. The effect of patient selection.

We reviewed our experience with spinal cord stimulation (SCS) in treating 116 patients with pain in one or both legs. All these patients were selected for an initial week of trial stimulation by the criteria: pain due to a known benign organic cause, failure of conventional pain control methods and absence of major personality disorders. Selected patients included 78 with the Failed Back Surgery Syndrome (FBSS), in whom proven correlation existed between the clinical picture and the neuroradiological and electromyogram abnormalities. Eighty-four out of 116 selected patients underwent definitive SCS implantation after 1 week of trial stimulation with excellent results (more than 75% pain relief). They were followed clinically every 3 months for a mean follow-up period of 47 months. Forty-five patients (54%) continued to experience at least 50% of pain relief at the latest follow up. Seventy-seven patients (91%) were able to reduce their medication intake and 50 patients (60%) reported an improvement in lifestyle. FBSS patients responded more positively to the trial stimulation than the other patients. However, the later outcome was not affected by patient selection as long-term benefit was similar in all definitive SCS patients irrespective of aetiology.

Technical possibilities and limitations of stereotaxy.

The availability of CT-Scanners and MRI coupled to stereotactic systems has made a stereotactic neurosurgical intervention an everyday tool. The indications, contra-indications and complications concerning intracranial tumours, the hypophysis, combined open stereotactic procedures, third ventriculostomy, diseases of the extrapyramidal motor system, pain, epilepsy, psychosurgery and the transplantation of embryonal cells are discussed.

Stereotaxic target calculation. Theory and practice.

Modern neuro-imaging techniques have significantly increased the accuracy of stereotactic procedures and have thereby generated a renewed interest in guided brain surgery. This paper describes the neuroradiological aspects of stereotaxic target calculation (x-, y-, z- coordinates) using the Riechert-Mundinger (Fisher) frame for computed tomography (CT). Selected cases are shown, illustrating patient positioning, CT technique, target identification and calculation. The importance of obtaining pre- and post-stereotaxic CT examinations is emphasized. Finally, future developments such as magnetic resonance (MR) guided stereotaxis and integrated functional-anatomical computer generated 3-dimensional maps, are briefly discussed.

[Preoperative radiotherapy and medial maxillectomy. Treatment concept for carcinomas of the nasal cavity and paranasal sinuses]. / Preoperatieve radiotherapie en mediale maxillectomie. Behandelingsconcept voor carcinoma's van neusholte en paranasale sinussen.

Multimodal treatment modality for paranasal sinus malignancies is discussed. Therapy consists in pre-operative 50 Gy radiotherapy delivered over 5 weeks, followed three weeks later by a medial maxillectomy. Although local control rate is improved through this treatment, an increase in late metastases is observed.

Intracranial subdural hematoma after spinal anesthesia.

We describe a 68-year old male patient with late onset signs of an intracranial subdural hematoma after repetitive spinal anesthesia procedures for urethral dilatation. The proposed mechanism is that of cerebrospinal fluid efflux. The potential for the development of such complications is so important, that it must be considered in every patient.

Consequences and complications of glycerol injection in the cavum of Meckel: a series of 120 consecutive injections.

From 1983 to 1989, 120 injections of glycerol into the trigeminal ganglion were performed to treat facialgias of different origin. The subjective and objective consequences and complications are reviewed. Since this operation yielded most often mild, transient and well tolerated consequences and complications for the patient, we now propose this method as first choice for trigeminal neuralgia when there is no anamnestic or clinical evidence of damage to the trigeminal system.

Gadolinium-DOTA enhanced MR imaging of intracranial lesions.

Gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N",N"'-tetraacetic acid (Gd-DOTA) is the first of a new class of macrocyclic paramagnetic magnetic resonance (MR) contrast agents (gadolinium cryptelates) to be used in clinical practice. Gadolinium-DOTA possesses relaxation properties similar to those of gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). We report our initial clinical experience in 38 patients with intracranial lesions studied with MR before and after injection of Gd-DOTA. Diseases included primary and metastatic brain tumor, cerebral infarct, vascular malformation, meningioma, hemangiopericytoma, schwannoma, and pituitary macroadenoma. Gadolinium-DOTA was administered intravenously in a dosage of 0.1 mmol/kg body weight. All studies were performed on a superconductive 0.5 T system. As compared to noncontrast T1- and T2-weighted images (WI), Gd-DOTA enhanced T1 WI were useful in defining the anatomy of malignant intraaxial tumors (high-grade glioma, metastasis) and in tumor versus edema differentiation. Low-grade gliomas did not enhance; in these cases the precontrast T2-weighted sequence was found to be more informative. In post-operative patients, Gd-DOTA allowed us to demonstrate residual tumor or tumor recurrence. Extraaxial tumors (meningioma, hemangiopericytoma, neuroma) enhanced markedly, presumably reflecting tumor vascularity. In our experience, the use of Gd-DOTA improves the anatomic definition of cerebral lesions and in some cases increases both MR sensitivity and specificity. We found Gd-DOTA to be a well tolerated and effective paramagnetic contrast agent. Gadolinium-DOTA can be considered as an alternative water-soluble MR contrast agent to Gd-DTPA.

Transcranial Doppler sonography.

A general review of the physical principles and the applications of transcranial Doppler (TCD) sonography is given. This new non-invasive technique is presented as an important diagnostic tool in neurology, neurosurgery and intensive care medicine. The applications are documented using our own patient material.

Intracerebral hemorrhage due to cerebral amyloid angiopathy. Case report.

The case is presented of a 59-year-old man with cerebral amyloid angiopathy and three consecutive hemorrhages in the occipital lobes. The clinicopathological features and the relationship to Alzheimer's dementia are discussed. The correct treatment of intracerebral hemorrhage related to cerebral amyloid angiopathy is a matter of controversy.

Familial oligodendroglioma. Case report.

A case of familial oligodendroglioma, occurring in a mother and her daughter, is presented.

Lumbosacral spinal fibrosis (spinal arachnoiditis). Its diagnosis and treatment by spinal cord stimulation.

From 1973 to 1981, 94 patients suffering from low-back pain, with or without spread into the lower extremities, were candidates for therapeutic spinal cord stimulation. The etiology of pain in all cases was lumbosacral spinal fibrosis due to multiple myelographies and surgical interventions on the lumbar spine. The long-term results, based on a four-year follow-up, reveal a 60% subjective improvement of pain, a 40% substantial reduction of medication, and a 26% increase in working capacity. The concept of spinal arachnoiditis is reviewed and the term lumbosacral spinal fibrosis proposed. The treatment of this chronic painful and disabling disease is discussed.

[Parameters of high-frequency thermocoagulation of the Gasserian ganglion in the treatment of trigeminal neuralgia in order to obtain analgesia without anesthesia]. / Etude des paramètres de thermocoagulation a haute fréquence du ganglion de Gasser dans le traitement de la névralgie du trijumeau pour l'obtention d'une analgésie sans anesthésie.

Voltage and current within Gasserian ganglion have been measured during a therapeutical high frequency coagulation of the Gasserian ganglion in 25 consecutive cases. From these values, the impedance (Ohm), the work (Watt) and the total energy (Joule) necessary to obtain an analgesia without anesthesia have been calculated. The study has shown that the temperature and the time of coagulation in correlation with the length of the non isolated tip of the electrode are actually the only constancy in the control of the therapeutical lesions.