Elective trepanation for acute epidural hematoma by Dr. Nicolaes Tulp (1593-1674).

The improved knowledge of human anatomy in the 16th century led to an increase in the practice of cranial trepanation in clinical cases, and detailed definitions of indications for performing this operation were provided by several authors. It was not until the 18th century, however, that detailed data on patient selection, decision making, and the postoperative course of this surgical procedure became available through individual case reports. In this historical context, a report written in 1641 by the Dutch physician Dr. Nicolaes Tulp is remarkable. This report, one of the first individual commentaries on the surgical treatment of an acute epidural hematoma, has not yet gained international recognition.

Comparative double blind clinical trial of phenytoin and sodium valproate as anticonvulsant prophylaxis after craniotomy: efficacy, tolerability, and cognitive effects.

OBJECTIVE: To determine the efficacy, tolerability, and impact on quality of life and cognitive functioning of anticonvulsant prophylaxis with phenytoin or sodium valproate in patients after craniotomy. METHODS: A prospective, stratified, randomised, double blind single centre clinical trial was performed, comparing two groups of 50 patients each, who underwent craniotomy for different pathological conditions and who were treated for 1 year after surgery with either 300 mg phenytoin/day or 1500 mg sodium valproate/day. During the study period patients were seen in the outpatient clinic at 1.5, 3, 6, and 12 months, when medical history, adverse events, and drug plasma concentrations were evaluated. Neuropsychological functioning and quality of life were assessed on the last three visits. In cases of a seizure an EEG was performed, drug plasma concentration assessed, and medication subsequently increased. RESULTS: Of the 100 included patients 14 (seven in each group) experienced one or more postoperative seizures. Severity of the seizures was comparable in the two groups. In all patients, drug plasma concentrations were in the low or subtherapeutic ranges at the time of the first postoperative seizure. Five patients in the phenytoin group and two in the valproate group had to stop their treatment due to drug related adverse events. Sixty patients completed the 12 month period. Analysis of neuropsychological and quality of life data showed no significant differences. CONCLUSION: For efficacy, tolerability, impact on cognitive functioning, and quality of life, no major differences were found between phenytoin and valproate prophylaxis. Valproate is an alternative for anticonvulsant prophylaxis in patients after craniotomy.

Clinical assessment of a novel antiadhesion barrier gel: prospective, randomized, multicenter, clinical trial of ADCON-L to inhibit postoperative peridural fibrosis and related symptoms after lumbar discectomy.

A prospective, multicenter, randomized, double-blind, controlled study of ADCON-L Anti-Adhesion Barrier Gel (a medical device by Gliatech Inc, Cleveland, OH) was conducted in 298 patients undergoing first-time lumbar discectomy to evaluate the safety and effectiveness of ADCON-L in preventing postoperative peridural fibrosis and in improving patient clinical outcome. After lumbar discectomy, patients were randomized to receive either ADCON-L gel or nothing (control group) at the conclusion of the surgical procedure. Six months after surgery, peridural scar was evaluated by magnetic resonance imaging, and postoperative pain and straight-leg-raise angle were assessed. No statistically significant differences between the ADCON-L and control groups were observed in terms of adverse events or wound healing characteristics. ADCON-L gel was shown to be safe and to significantly inhibit peridural scar compared with the control group (P = 0.002). That peridural scarring was reduced with ADCON-L gel was further supported by direct visualization of scar tissue at reoperation in both groups. ADCON-L-treated patients had better clinical outcomes than did control patients. The incidence of activity-related pain was significantly reduced (P = 0.013), straight-leg-raise examination scores were significantly improved (P = 0.024 on the operative side and P = 0.015 on the nonoperative side), and ADCON-L reduced low back pain when it was most severe (P = 0.047) and at the end of the day (P = 0.044).

Morphology of the human internal vertebral venous plexus: a cadaver study after intravenous Araldite CY 221 injection.

Reviewing the literature on the vascular anatomy of the spinal epidural space, it appeared that the knowledge of the internal vertebral venous plexus is limited. Injection studies of the entire internal vertebral venous plexus after application of modern techniques, to the best of our knowledge, have never been performed. Based on the clinical importance of these structures, it was decided to study the human vertebral venous system after Araldite CY 221 injection, in order to update the morphological characteristics of the internal vertebral venous system. The vertebral venous systems of ten fresh human cadavers, between 64 and 93 years of age, were injected with Araldite CY 221 mixture. All cadavers were dissected and the posterior and anterior internal vertebral venous plexuses were studied in detail. The anterior part of the internal vertebral venous plexus is fairly constant. On the contrary, the posterior internal vertebral venous plexus showed a striking segmental and interindividual variability. In the thoracic area, two types of traversing veins are observed. Both types show a somewhat symmetrical "inversed V" configuration. No anatomical valves were observed. Nevertheless, anterograde flushing (via the femoral veins) of the vertebral venous system appeared to proceed much faster than retrograde flushing (via the superior vena cava). The classical picture of the internal vertebral venous plexus appears a simplification of the actual situation. Especially in the posterior part, segmental and interindividual differences are prominent. The preferential direction of the flow during flushing suggests the presence of functional valves, which are probably located in the thoracic part of the posterior internal vertebral venous plexus, resulting from the typical shape of the veins in this area. This might explain the difficulties with imaging of the posterior part of the internal vertebral venous plexus in vitro as well as in vivo. Further study is needed to determine whether the configuration of the posterior internal vertebral venous plexus in younger individuals is different, compared with the presently studied aged subjects.

Operative treatment of spontaneous spinal epidural hematomas: a study of the factors determining postoperative outcome.

OBJECTIVE: We clarify the factors affecting postoperative outcomes in patients who have suffered spontaneous spinal epidural hematomas. METHODS: We review 330 cases of spontaneous spinal epidural hematomas from the international literature and three unpublished cases of our own. Attention was focused on sex, age, medical history, mortality, size and position of the hematoma, vertebral level of the hematoma, preoperative neurological condition, operative interval, and postoperative result. RESULTS: Sex, age, and size and position of the hematoma did not correlate with postoperative outcome. Mortality correlated highly with cervical or cervicothoracic hematomas, especially in patients with cardiovascular disease and those undergoing anticoagulant therapy. Incomplete preoperative sensorimotor deficit correlated highly with favorable outcomes (P < 0.0005), and recovery was significantly better when decompression was performed in < or = 36 hours in patients with complete sensorimotor loss (P < 0.05) and in < or = 48 hours in patients with incomplete sensorimotor deficit (P < 0.005). CONCLUSION: The critical factors for recovery after spontaneous spinal epidural hematoma are the level of preoperative neurological deficit and the operative interval. The vertebral level of the hematoma did not correlate with postoperative results, which suggests that local compression, rather than vascular obstruction, is the main factor in producing neurological deficit.

Hypofractionated radiation therapy in patients with glioblastoma multiforme: results of treatment and impact of prognostic factors.

PURPOSE: Median survival of patients with glioblastoma multiforme (GBM) is only about 4 months with surgery and about 9 months for surgery followed by radiotherapy. Prolonged treatment is futile for many patients and the time of treatment and hospitalization should be minimized. METHODS AND MATERIALS: This was a prospective, nonrandomized study of 30 patients treated with a hypofractionated radiation scheme (42 Gy in 14 fractions). RESULTS: Median survival was 36 weeks. Age, Karnofsky performance status (KPS) and extent of surgery were strongly interrelated and all correlated with survival (p < 0.05). Three prognostic groups were identified. Patients with three favorable prognostic factors (age <50, KPS 80-100, and > or = 75% of the tumor removed) had the best prognosis (median survival 50 weeks). Patients with no favorable prognostic factors (age > or = 50, KPS < or = 70, and < 75% of the tumor removed) had the worst prognosis (median survival 25 weeks). Median survival of the intermediate group (with one or two favorable prognostic factors) was 38 weeks. No severe acute or late toxicity was observed. CONCLUSION: The treatment results are comparable to those achieved with conventional radiotherapy schemes. Based on the number of favorable prognostic factors (age < 50, KPS 80-100 and > or = 75% of tumor resected) the radiation schedule should be selected.

Fluorescence localization in tumour and normal brain after intratumoral injection of haematoporphyrin derivative into rat brain tumour.

In the intracerebral 9L rat gliosarcoma, the spatial distribution of the photosensitizer haematoporphyrin derivative (HpD) was studied after intratumoral injection. The fluorescence volume was measured in histological sections from 10 min up to 5 days after injection. Complete sensitization of the tumours could not be achieved by slow stereotactical injection of 4 mm3 HpD (mean HpD fluorescence volume, 13 +/- 11 mm3). Larger parts of the tumour could be loaded with HpD (39 +/- 23 mm3, p = 0.0001) by increasing the injection velocity and the volume to 50 mm3. Again, complete sensitization of the tumours was not achieved during a time scale of 5 days after intratumoral injection. Although the fluorescence volume did not change significantly with time, it was influenced by the injection site within the tumour. Injection of HpD within 1 mm from the tumour border resulted in significantly smaller fluorescence volumes in the tumour than injection into the tumour centre. Large injection volumes caused an increased leakage of HpD to normal brain, leading to the loss of selectivity of photosensitizer content and the occurrence of dark toxicity of normal brain while the tumours still appeared vital.

Effect of intermittent blood pressure elevation on the growth of experimental saccular aneurysms in the rat.

In this study we applied the technique described in the previous paper (see pp. 103-106 of previous issue (1991); 13(2)) to rats with experimental saccular aneurysms. We found that the mean sizes and some growth ratios of experimental aneurysms were significantly larger in the intermittent blood pressure elevation groups than in the control groups. The increase of growth ratios was proportional to the number of transient blood pressure elevations. The morphological structure of these saccular aneurysms showed that the regenerative processes in the aneurysm wall had obviously been interfered with in animals with intermittent blood pressure elevation. The effective mechanism of this influential factor is discussed.

Primary spinal epidural extraosseous Ewing's sarcoma.

The case of a 7-year-old boy with a spinal epidural extraosseous Ewing's sarcoma (EES) is presented. He is in complete remission without neurologic deficit 40 months after diagnosis. Another 15 cases were found in the literature and are discussed together with this patient. Twelve of them were male patients. The mean age of the patients was 17.5 years (range, 4 to 47). Symptoms included back pain and/or radicular pain (100%), paresis of one or both legs (83%), sensory disturbances, and bladder and bowel dysfunction. The mean diagnostic delay was 5.8 months. Each patient underwent laminectomy; complete resection of the tumor was impossible in more than 50% of the cases. Most patients received radiation therapy and/or chemotherapy. Four patients suffered from local recurrence, eight from metastases. Ten (63%) patients died, 1 to 48 months (mean, 16) after diagnosis. The differential diagnosis is discussed, including disk herniation and several benign and malignant tumors.

A method for temporary and repeated increase of blood pressure in the rat, using intraperitoneal adrenaline injections.

In experimental studies, permanent hypertension has been considered to be an important factor in aneurysm formation and growth. However, in clinical studies it has been found that saccular aneurysms often develop and rupture in some patients without persistent hypertension. Environmental events that temporarily and repeatedly increase blood pressure do not take an equivalent length of time in vivo but have been noted as factors in the growth or rupture of saccular aneurysms. In order to test the effect of intermittent blood pressure elevations on saccular aneurysm formation and growth, a reliable method for temporarily and repeatedly increasing blood pressure should be developed first and in this paper, such a model is described. It is based on the intraperitoneal injections of adrenaline in rats, a route which does not seem to have been used so far.

Pathological changes in experimental saccular aneurysms in the carotid artery of the rat.

Although the reason for development of saccular aneurysms in humans has still not been elucidated, the process might be observed and explained using a reproducible aneurysm model in vivo. In this paper, a sequential pathological study of the experimental saccular aneurysms was made. No additional influential factors were applied. At all stages of the development between the induction and 6 months, the histology of the aneurysm wall was similar to that of human aneurysms. The imbalance of the degeneration and regeneration processes during the development of these experimental aneurysms is discussed according to the pathological findings in different periods. Haemodynamic stress and different regenerative speeds in different arterial tissues must be responsible for the saccular aneurysm formation and growth.

Effect of contralateral carotid ligation on experimental carotid artery aneurysm in the rat.

Haemodynamic factors in the formation and development of saccular aneurysms have been widely studied. Saccular aneurysms could appear and grow at the side of the increased blood flow. The effects of contralateral carotid ligation on the formation and growth of our experimental saccular aneurysms were studied. Measurement and pathological examination showed that the haemodynamic changes could facilitate the development of saccular aneurysms, but by itself could not bring about their formation.

Multiple cerebral de novo aneurysms.

The new development of two remarkable cerebral mirror aneurysms is described in two female patients, who had been surgically treated for a mid-line aneurysm several years previously. The phenomenon of mirror aneurysms makes it likely that an inborn weakness of the vessel wall is one of the underlying causes of cerebral aneurysms. Acquired alterations of the vessel wall and hemodynamic forces, on the other hand, also play an important role in the genesis of aneurysms.

Pathogenesis and histopathology of saccular aneurysms: review of the literature.

In this paper, the major theories on the formation and growth of saccular aneurysms are reviewed on the basis of previous clinical, pathological and experimental studies. Which is the critical layer is still the focus of debate. Current ideas can be summarized as follows: most researchers think that disruption of the internal elastic lamina is an essential requirement for the creation of saccular aneurysms because it is this layer that provides most of the strength to the arterial wall, especially in cerebral arteries. Degeneration of this layer is a constant feature of all saccular aneurysms. A coexisting medial defect and haemodynamic stress at an apex may aggravate degeneration at that point. Hypertension does not seem to be the major factor in some aneurysm patients, but it may facilitate the formation and growth of saccular aneurysms. An atheroma is often associated with saccular aneurysms, but its effect on this pathological process is still unknown. Other factors are discussed concisely. Previous experimental methods and their results pertaining to the formation and growth of this type of aneurysm are also reviewed. A reproducible animal model is still required to allow various theories to be tested.

An acute experimental model of saccular aneurysms in the rat.

A new and reproducible saccular aneurysm model has been developed at the bifurcation of the common carotid artery in rats. The details of the experimental methods and results are described. It is strongly suggested that the internal elastic lamina is a critical layer in saccular aneurysm formation, because an experimental saccular aneurysm can be produced immediately by transluminally damaging the inside of the arterial wall at the bifurcation of the common carotid artery. This saccular aneurysm model has several advantages: (i) it can be induced quickly and the success rate approaches 100% in rats; (ii) this technique can produce satisfactory experimental saccular aneurysms for other aneurysm studies, and in the future it will also be possible to use this technique to produce experimental saccular aneurysms in cerebral arteries of large animals.

Observations on experimental saccular aneurysms in the rat after 2 and 3 months.

After 2 and 3 months we re-exposed 20 experimental saccular aneurysms. Under the operating microscope, we measured their sizes and compared them with the sizes immediately after induction. All aneurysms had grown significantly and none was thrombosed. Pathological examinations showed that the sac of the aneurysm was similar to that of the human saccular aneurysms. Based on the operating microscopy and pathological findings we postulate that abnormal histological structure and haemodynamic stress are the major causes of aneurysm enlargement. We also noted that there were some regenerative processes in these experimental aneurysm walls. The results prove that this model is reliable, because these aneurysms have the main characteristics of human saccular aneurysms, not only grossly but also microscopically.

[Revised guidelines for the treatment of patients with severe traumatic brain injury]. / Herziene richtlijnen voor de behandeling van patiënten met ernstig traumatisch hersenletsel.

The early assessment and acute treatment of patients with severe traumatic brain injury require a well structured and organized policy. This policy should include rapid transport to, and effective first aid in trauma centres especially equipped for this purpose, adequate communication of information between the (para-)medical workers successively involved and a multidisciplinary handling of diagnostics and treatment of the various traumatic and posttraumatic conditions. This requires the imposition of unequivocal priorities known to all concerned. In this paper, which was written in cooperation with the different medical disciplines concerned, the main features of the acute treatment of severe head injury, about which a wide agreement was reached, are worked out in 18 theses. The guidelines regard the admission and first aid, the diagnostic procedures and the conservative and surgical treatment of patients with severe head injury. These guidelines can be developed in the different hospitals into detailed blueprints for the treatment, in accordance with the local situation.