Intracerebral temperature monitoring in severely head injured patients.

In a series of 6 severely head injured patients, intraventricular as well as rectal, bladder and jugular vein temperature is recorded. The relationship between these temperatures in different conditions is evaluated. Intracerebral temperature is 0.5 +/- 0.2 degrees C (mean +/- SD) higher than bladder temperature except in conditions such as brain death. It is concluded that rectal temperature is not representative and therefore not a good alternative to the measurement of brain temperature. More data on human intracerebral temperature are mandatory as well as prospective studies correlating intracerebral temperature with final outcome in head injury.

Failure of a modified posterior lumbar interbody fusion technique to produce adequate pain relief in isthmic spondylolytic grade 1 spondylolisthesis patients. A prospective study of 20 patients.

A modified posterior lumber interbody fusion procedure is described: this technique basically uses only two tricortical bone grafts and does not produce a distraction at the interspace while inserting the bone grafts. Twenty patients with intractable back and leg pain due to an isthmic spondylolysis and a grade 1 spondylolisthesis were operated using this technique and a prospective study with a mean follow-up of 41 months was conducted to evaluate the results. The final evaluation involved a questionnaire, a clinical examination, and a lumbar spine radiographic series. Fourty-five percent of the patients had good or excellent results whereas 55% had fair or poor results. The possible reasons for these unfavorable results are discussed.

Photochemically-induced cerebral infarction in the rat: comparison of NMR imaging and histologic changes.

The evolution of a photochemically induced cerebral thrombotic infarction was followed in rats during the first week after the insult by means of NMR imaging and histology. Heavily T2-weighted images provided an excellent lesion detection and a high specificity for the discrimination of different histological abnormalities. The T2-weighted images showed a brain lesion evolving during the first 24 h from a homogeneous hyperintense area, histologically corresponding to diffuse vasogenic and cytotoxic oedema with concomitant neuronal necrosis, to an iso-intense area with a hyperintense seam, which microscopically correlated with increased vascular permeability at the periphery of the lesion. The hyperintense seam was observed up to day 7, but at that time coincided with gliomesodermal repair reaction which could be verified histochemically and ultrastructurally. It may be concluded that NMR-micro-imaging at a moderately high field, enables early detection and adequate follow-up of small cerebral infarctions in rats.

Postsurgical follow-up by MRI of anterior cervical discectomy without fusion.

Postoperative magnetic resonance imaging (MRI) findings are described in selected patients with cervical radiculopathy and a cervical soft disc herniation, treated by anterior cervical discectomy (ACD) without fusion. Six months postoperatively, 45 patients underwent MRI examination using a 0.5 T superconductive unit. T1- and T2-weighted spin echo sequences were acquired on sagittal and axial planes. A low signal intensity on T2-weighted images was visualized at the ACD level in all patients. Five patients were found to have a slight kyphosis at the discectomy level. There was no residual disc material at any ACD level. In 5 patients, areas of diminished signal intensity on T1- and T2-weighted images on adjacent vertebrae was noticed, indicating sclerosis of the cortical bone adjacent to the ACD level. In 3 patients, cervical disc protrusions without impression on the dura were visualized postoperatively: 2 below and 1 above the ACD level. One patient developed a cervical disc herniation without complaints one level above the operated one. No patient developed infolding or degenerative swelling of the ligamenta flava and no intrinsic cord abnormalities were present. MRI provided useful information on pathology, allowing a non-invasive evaluation following ACD and enabling a better understanding of surgical consequences.

MR imaging of tuberculous spondylitis.

This case report describes a patient presenting with symptoms of progressive paresis of both legs. An X-ray of the thorax demonstrated an aspect consistent with miliary tuberculosis. Magnetic resonance imaging (MRI) of the thoracic spine revealed medullary compression. The patient underwent a laminectomy and the diagnosis of spinal epidural tuberculoma was made. The patient has been treated with isoniazid, rifampicin and pyrazinamide. After a period of six months, she made a complete recovery.

The course of vasospasm following subarachnoid haemorrhage in rats. A vertebrobasilar angiographic study.

The course of vasospasm following subarachnoid haemorrhage in rats was studied using vertebrobasilar angiography. Wistar and Sprague Dawley rats were compared with respect to vasospastic response after bleeding. A more pronounced vasospasm was found in Sprague Dawley rats. In order to avoid a possible toxic effect on the contrast medium, only one angiogram per animal was initially performed. However, a comparison with the results obtained in a separate series of non-challenged animals demonstrated a difficulty due to high variability in basilar artery size in the latter group. Therefore, vasospasm can be more readily shown if multiple angiograms are used in the same animal so that the vasospasm can be expressed as a percentage of the initial diameter of the basilar artery. It was found that multiple angiograms are well tolerated when non-ionic contrast media are used.

Loss of constitutional heterozygosity in human astrocytomas.

Inactivation of tumour suppressor genes or anti-oncogenes as well as activation of dominant acting oncogenes seem to be important mechanisms in the pathogenesis of gliomas. We compared constitutional and tumoural genotypes at different restriction fragment length polymorphism loci (RFLP) on chromosomes 10 and 17 in 15 unrelated individuals. Loss of heterozygosity (LOH) pointing to chromosomal loss or deletions was detected for at least one chromosome 17 marker in 11 gliomas (astrocytomas grades I-III and glioblastoma multiforme), whereas LOH for chromosome 10 loci was only detected in 3 out of 9 cases of glioblastoma multiforme and was not detected in low grade gliomas. Since LOH for chromosome 10 loci seems to be restricted only to glioblastoma multiforme, it is possible that recessive mutations on chromosome 10 are engaged in tumour progression from astrocytomas to glioblastoma multiforme. As LOH of chromosome 17 markers occurs in astrocytomas as in glioblastoma multiforme, chromosome 17 loci probably are involved in early tumour development.

Haemodynamic, intracranial pressure and electrocardiographic changes following subarachnoid haemorrhage in rats.

Experimental induction of subarachnoid haemorrhage in rats resulted in acute haemodynamic changes. Heart rate decreased concomitantly with a rise in arterial blood pressure. Intracranial pressure increased and consequently cerebral perfusion pressure dropped. These changes as well as the observed electrocardiographic (ECG) changes were comparable to those reported in patients. Apart from blood also saline, when introduced into the cisterna magna, was able to elicit such abnormalities. The haemodynamic and electrocardiographic changes, which result from subarachnoid haemorrhage, may even become aggravated, when repetitive injections of blood or saline are given into the cisterna magna and when cerebral angiography is performed prior to induction of the subarachnoid haemorrhage. Chronic intracranial pressure monitoring during the 48 hours following subarachnoid haemorrhage revealed no significant rise in pressure. A thorough control of the experimental conditions is thus of utmost importance in order to give a valid interpretation of the observed anomalies.

Virus inactivation of fresh frozen plasma by a solvent detergent procedure: biological results.

In order to increase the safety of blood products, we have developed a procedure for the virus inactivation of fresh frozen plasma. Several batches have been prepared and with the first 10 batches, each of them composed of 60 litres of plasma, we have determined a set of biological parameters. Virus inactivation was realised using TnBP (1%) and Octoxynol 9 (1%). After their elimination with castor oil using chromatography on insolubilized C18 resin, glycine was added and the pH of the plasma was adjusted to 7.4. Plastic bags were aseptically filled with a mean volume of 200 ml of plasma. The mean levels of coagulation factors were all over 0.7 U/ml and their recovery from initial plasma was nearly the same as total protein except for factor VIII:C. The net loss in factor VIII:C was 16%, when including the dilution of plasma. In vivo and in vitro tests demonstrated that in the final product there were no activated factors. As in fresh frozen plasma, the protein concentration was over 50 g/l and the potassium level lower than 5 mmol/l. According to these results, virus-inactivated plasma has the same qualities of fresh frozen plasma and could now replace it.

Intracerebral hemorrhage after lumbar myelography with iohexol: report of a case and review of the literature.

Intracranial hemorrhage is an uncommon complication of dural puncture. In most instances, hematomas are subdural; they may be unilateral or bilateral. Rarely are intraparenchymal cerebral hemorrhages related to dural puncture. This report describes a delayed occurrence of bilateral intraparenchymal hemorrhages in a 38-year-old woman 7 days after lumbar myelography with iohexol. A review of the literature is presented.

Singlet oxygen induced cerebral vasospasm: an experimental study in rats.

A new experimental model is described which can be used as an alternative to study the effects of subarachnoid hemorrhage (SAH) in rats. Vasospasm of the basilar artery is induced photochemically after transpalatal illumination of intracisternally injected rose bengal in two different rat strains. Singlet oxygen, generated in the subarachnoid space, elicits vasospasm which has been demonstrated angiographically at 90 min and 24 h after photosensitisation. Sprague Dawley rats responded better than Wistar rats. Dilution of rose bengal in water was more vasospastic than dilution of rose bengal in artificial CSF. Since the action of singlet oxygen is similar to that of free radicals, this experiment gives an argument for the hypothesis that free radicals play a leading role in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage.

Fiberoptic intracranial pressure monitoring in rats.

An adaptation of a fiberoptic intracranial pressure monitoring system for clinical use is described. The method allows easy and reliable acute and chronic intracranial pressure registration in anesthetized as well as conscious rats. The disposable fiberoptic probes, originally designed for human use, can be re-used limitlessly. The fiberoptic method is compared with conventional monitoring procedures under different experimental conditions. The validity of intraparenchymal and epidural measurements is discussed. The importance of chronic intracranial pressure registration in conscious laboratory animals is stressed.

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.

Transcranial Doppler sonography in subarachnoid hemorrhage.

Ten patients presenting a subarachnoid hemorrhage (SAH) due to rupture of a middle cerebral or an anterior communicating aneurysm are presented. Transcranial Doppler (TCD) values are obtained at different time intervals after SAH. The correlation of TCD values, vasospasm and clinical course is discussed.

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.

Craniostenosis: the importance of the anesthesiologist.

Based on the experience with 15 patients operated for craniostenosis in our hospital, guidelines were determined for the anesthetic and postoperative management with optimal maintenance of vital parameters. Subgaleal accumulation of blood may cause a spectacular drop of hemoglobin level during the first postoperative days. Since it is better to prevent than to cure, systematic anti-convulsive and antibiotic prophylaxis must be considered.