New experimental model of acute aqueductal blockage in cats: effects on cerebrospinal fluid pressure and the size of brain ventricles.

It is generally assumed that cerebrospinal fluid (CSF) is secreted in the brain ventricles, and so after an acute blockage of the aqueduct of Sylvius an increase in the ventricular CSF pressure and dilation of isolated ventricles may be expected. We have tested this hypothesis in cats. After blocking the aqueduct, we measured the CSF pressure in both isolated ventricles and the cisterna magna, and performed radiographic monitoring of the cross-sectional area of the lateral ventricle. The complete aqueductal blockage was achieved by implanting a plastic cannula into the aqueduct of Sylvius through a small tunnel in the vermis of the cerebellum in the chloralose-anesthetized cats. After the reconstitution of the occipital bone, the CSF pressure was measured in the isolated ventricles via a plastic cannula implanted in the aqueduct of Sylvius and in the cisterna magna via a stainless steel cannula. During the following 2 h, the CSF pressures in the isolated ventricles and cisterna magna were identical to those in control conditions. We also monitored the ventricular cross-sectional area by means of radiography for 2 h after the aqueductal blockage and failed to observe any significant changes. When mock CSF was infused into isolated ventricles to imitate the CSF secretion, the gradient of pressure between the ventricle and cisterna magna developed, and disappeared as soon as the infusion was terminated. However, when mock CSF was infused into the cisterna magna at various rates, the resulting increased subarachnoid CSF pressure was accurately transmitted across the brain parenchyma into the CSF of isolated ventricles. The lack of the increase in the CSF pressure and ventricular dilation during 2 h of aqueductal blockage suggests that aqueductal obstruction by itself does not lead to development of hypertensive acute hydrocephalus in cats.

The investigation of cerebrospinal fluid formation by ventriculo-aqueductal perfusion method in cats.

OBJECTIVES: The perfusion of cerebrospinal fluid (CSF) spaces by artificial CSF (aCSF) containing an indicator, is an indirect method used to calculate CSF formation. To evaluate this method, we have developed a ventriculo-aqueductal perfusion method, which enables a direct measurement of CSF formation in the ventricles. METHODS: In chloralose anaesthetized cats, the aqueduct of Sylvius was cannulated so that the outflow end of the plastic cannula was positioned extracranially. Both lateral ventricles were also cannulated, with one cannula for infusion of aCSF containing blue dextrane and the other for measurement of CSF pressure. RESULTS: During ventriculo-aqueductal perfusion (direct method) under physiological CSF pressure, the outflow rate from aqueductal cannula did not differ significantly from the inflow rate, i.e. no CSF formation was observed. When the indirect method based on dilution of blue dextran in the outflowing perfusate was used, the formation of approximately 5 microl/min of CSF was obtained. CONCLUSION: Results of the direct method indicate that net CSF formation inside brain ventricles does not exist. The opposite results obtained by the indirect method questions this method as a reliable study of CSF formation.

Spinal contribution to CSF pressure lowering effect of mannitol in cats.

OBJECTIVES: After application of hyperosmolar mannitol the cerebrospinal (CSF) pressure is usually lowered within 30 min but this effect cannot be explained either by changes in intracranial blood volume and flow or by changes in brain volume. We assume that this effect of mannitol my be consequence of CSF volume decrease primarily in the spinal CSF due to high compliance of the spinal dura. METHODS: To explore such a possibility we planned to separate spinal and cerebral CSF. In chloralose anaesthetized cats dorsal laminectomy of C2 vertebrae was performed and a plastic semi ring was positioned extradurally separating cranial and spinal CSF. CSF pressures were recorded via cannulas positioned in lateral ventricle and lumbar subarachnoid space at L3 vertebrae, respectively. RESULTS: After intravenous bolus of 20% mannitol (0.5 or 1.0 g/kg/ 3 min) in control animals without cervical stenosis, the fall of both ventricular and lumbar CSF pressures was equal over time. At 15 min after mannitol application in cats with cervical stenosis an slight increase of ventricular and a fall of lumbar CSF pressures were observed, while at 30 min a gradient of these pressures of 5.5 and 7 cm H2O at lower and higher dose of mannitol, respectively, were registered. However, after removal of cervical stenosis these gradients disappeared. CONCLUSION: The observed changes of CSF pressures in spinal and intracranial space indicate that spinal subarachnoid space contributes a great deal to overall fall of CSF pressure and volume in the early period after mannitol application probably due to high compliance of the spinal dura.

Does the secretion and circulation of the cerebrospinal fluid really exist?

The secretion and circulation of cerebrospinal fluid have been studied in anaesthetized cats by means of a plastic cannula introduced into the aqueduct of Sylvius and by inspection of free escape of cerebrospinal fluid out of the end of the cannula. The fact that during the 120-minute period of observation not a single drop of CSF escaped out of the cannula, at physiological pressure, indicates that cerebrospinal fluid does neither secrete nor circulate.

[Recent modalities in the treatment of severe head injuries]. / Suvremeni principi u lijecenju teske ozljede mozga.

Intracranial pressure (ICP) monitoring represents today a critical point in the treatment of patients with severe head injuries. Medical therapy depends on the intracranial pressure level. The most important in therapy is to maintain the cerebral prefusion pressure at the level of 70 mmHg or above. The use of corticosteroids, prophylactic hyperventilation and prophylactic antiseizures drugs for the late posttraumatic seizures, is not recommended. High dose barbiturates can be used only in patients in whom other treatment modalities failed to decrease the raised intracranial pressure.

Hypnotherapy in the treatment of irritable bowel syndrome: methods and results in Amsterdam.

BACKGROUND: Irritable bowel syndrome (IBS) is frequently observed, but its etiology and pathogenesis are still unknown. However, it is clear that individual perception plays an important part in pathogenesis (hypersensitive, hyperreactive gut). There is no easy medical treatment of IBS. However, in recent years, hypnotherapy (HT) has been shown to be successful in the treatment of IBS. METHODS: Recently we started treating IBS patients using hypnotherapy. All our patients remained symptomatic, despite medical therapy. We applied the gut-targeted method, adding to it the view that the therapy should be tailored to the individual, in accordance with each person's unique representational style. RESULTS: So far, 27 patients have been treated, with good results, comparable to results elsewhere. Of these patients two stopped the therapy prematurely, and one remained symptomatic. All other patients experienced clear improvement: pain and flatulence was reduced or completely disappeared, and bowel habits normalized. CONCLUSION: Based on data from the literature and supported by our own experience, we conclude that hypnotherapy is a valuable addition to the conventional treatment of IBS. To improve our knowledge of sensitivity to hypnotherapy, further research is necessary to recognize cases with more hypersensitivity and those dominated by hypervigilance. More generally, we need a theoretical model of hypnotherapy as applied to treating physiological disorders.

[Surgical treatment of lumbar disc hernias in athletes]. / Kirursko lijecenje lumbalne diskus hernije u sportasa.

In a 7-year period (1988-1995) a series of 55 patients was surgically treated at our Department for lumbar disk herniation following a certain sports activity, i.e. sports injury. The above number accounts for 2% of the total number of lumbar disk patients operated upon at our Department. The majority of patients in our series were amateur athletes, whereas a few of them were active or professional athletes. The most common cause of disk herniation among our patients was playing soccer (13 cases), which is followed by basketball (8), field athletics (7), tennis (6) and handball (4). In most cases our surgical method of choice was flavectomy (interlaminectomy). Most commonly seen intraoperative finding was intervertebral disk extrusion. In some athletes the onset of symptoms was due to a change of their usual sports activity, for example a tennis player who was injured in skiing. We believe that the onset of disk herniation in athletes is a consequence of numerous micro traumas of the intervertebral disk which are further compounded by the syndrome of overstraining. In the case of a positive indication, surgical treatment leads to a faster recovery in professional athletes.

[Purulent osteomyelitis with epidural abcess in an adult over a decade after cervical spine injury]. / Eiternde Osteomyelitis mit Epiduralabszess bei einem Erwachsenen mehr als ein Jahrzehnt nach zervikaler Wirbelsäulenverletzung.

Cervical osteomyelitis and epidural abscess are rare and potentially fatal conditions with severe neurological manifestations. Changes on plain radiography and computed tomography are non-specific, while contrast enhanced magnetic resonance imaging shows high sensitivity and specificity in establishing early diagnosis.

[Leiomyosarcoma uteri]. / Leiomyosarcoma uteri.

The authors present a 55-year-old patient with leiomyosarcoma uteri who died six months after surgical and subsequent radiation therapy. They point out difficulties in diagnosing the disease owing to a very scarce symptomatology. The fast growth of the myoma is considered very symptomatic of a malign alteration. In the patient presented, in only eight months, a slightly myomatously increased uterus gew to the size of two male fists.

The effect of implementation of guidelines for the management of severe head injury on patient treatment and outcome.

The authors retrospectively analysed two groups of consecutive patients who were similarly matched for brain injury severity. From a total of 39 severe head injury patients, 23 were treated according to the Guidelines for the Management of Severe Head Injury with intracranial pressure (ICP) monitoring ("Guidelines group"). Such an approach allowed the maintenance of ICP within normal values, especially in patients with intraventricular ICP monitoring allowing the release of cerebrospinal fluid (CSF) from the ventricular system. In the Guidelines group only two patients were administered barbiturates, after all other means of ICP lowering had been exhausted. The second group consisted of 16 patients who were not monitored for ICP ("non-Guidelines group"). In this group, management consisted of the prophylactic administration of barbiturates, high dose osmotic diuretics and hyperventilation usually at levels below 25 mm Hg. In the Guidelines group the mortality rate was 30% compared to 44% in the non-Guidelines group. Almost twice as many patients achieved a "favourable" (good recovery and moderate disability) outcome (49%) compared to the non-Guidelines treated patients (25%). Furthermore, there was a 32% decrease in severe neurological disabilities in those patients in the Guidelines group. It seems that the implementation of "Guidelines" in the treatment of severe head injury, based on the result of our clinical study, reduces death and disability rates in patients with severe head injury. The administration of therapy based on the "Guidelines principles" and monitoring of ICP, can minimise the application of those therapeutic modalities (barbiturate coma and prolonged hyperventilation) which, in addition to favourable effects, may also have harmful effects on patients with severe head injury.

Internal jugular vein thrombosis after cervical traction.

A clinically and roentgenographically typical case of internal jugular vein thrombosis is presented in a patient having undergone repeated sessions of Glisson traction for neck and backache. In this mode of therapy, axial traction is applied to the neck by attaching a weight, via a pulley, to a construction of straps encompassing the head. This particular trauma to the neck has not previously been described to be associated with spontaneous internal jugular vein thrombosis.

Objective tests for upper motor neuron involvement in amyotrophic lateral sclerosis (ALS).

OBJECTIVE: To develop objective markers for upper motor neuron (UMN) involvement in ALS, the value of single-voxel MR spectroscopy (MRS) and transcranial magnetic stimulation (TMS) was studied. METHODS: Test results of 164 ALS patients who had MRS only (n = 91), TMS only (n = 13), or both (n = 60) were analyzed; also, 11 autopsy examinations were evaluated. RESULTS: Abnormal test results consistent with UMN involvement were found in 134 patients with clinical UMN signs: 86% on MRS, 77% on TMS, and 70% on MRS and TMS together. Among 30 patients with solely LMN signs (progressive muscular atrophy), UMN results were found in 63% on MRS, 63% on TMS, and 46% on both tests together. There was a significant association of the degree of abnormal N-acetyl aspartate/creatine ratios with UMN signs (p = 0.01). The sensitivity to detect UMN involvement was 0.86 for MRS (specificity 0.37) and 0.77 for TMS (specificity 0.38). At autopsy, all 11 patients had pathologic UMN abnormalities, including 4 with normal MRS and 1 with normal TMS in life. CONCLUSIONS: MRS is highly sensitive, somewhat more than TMS, and shows good correlation with clinical UMN signs. Combining MRS and TMS results in the same patient with further refinement may help in the early diagnosis of ALS.