Primary cerebral lymphomas are rare tumors. In the last years the frequency of these space occupying lesions is increasing. Diagnosis by image-generating methods is often difficult. Stereotactic biopsy is a reliable diagnostic tool. Explorative craniotomy with tumor resection should be avoided if possible. An effective multimodal therapeutic regimen is the combination of radiotherapy and chemotherapy. Epidemiologic data, diagnostic methods and therapeutic proceedings are presented and discussed on a series of 7 patients with primary cerebral lymphomas treated in our department.

A cystic process in the right frontal lobe of the brain in a man of 35 years of age, and an intramedullary cyst in the upper cervical spinal cord in a 29-year old woman, are described. In both cases, the wall of the cyst consisted of mucosal cells and cells having cilia pointing to the inside, located on a thin tissue layer, the structure of which resembled that of a meningioma. Central nervous cysts of this kind are usefully classified together with other, similar cysts (bronchogenic, ependymal and others) as epithelial cysts". They must be differentiated from neoplastic tumours. Analysis of the cystic contents can prove helpful.

In open brain surgery, access to processes in the midline region is difficult. Exact diagnosis of the tumour type is crucial to the choice of therapeutic modality. In many cases, modern imaging procedures such as CT and MRI are useful diagnostic tools. The diagnosis is confirmed by direct biopsy and histological examination. Selected cases of tumours close to the midline (germinoma, pilocytic astrocytoma, primary cerebral malignant lymphoma) are presented. CT and MRI are helpful in demonstrating space-occupying processes. The tumour's histological type is determined by CT-stereotactic biopsy. The histopathological diagnosis is established by means of a crush preparation. Appropriate forms of therapy are proposed on the basis of the diagnosis of tumour type. The results are impressive, due to the efficacy of stereotactic procedures as an additional means of diagnosing and treating space-occupying processes of the midline region.

5-Hydroxytryptamine1A (5-HT1A) receptor agonists have been shown to inhibit the activity of hippocampal, cortical, and dorsal raphé neurons. We tested urapidil and a new 5-HT1A agonist, CM 57493 [4-(3-trifluoromethylphenyl)-1-(2-cyanoethyl)-1,2,3,6-tetrahydropyridine ], for their neuroprotective activity in models of focal and global cerebral ischemia in rodents. After middle cerebral artery-occlusion (MCA-0) in mice, the infarct size was reduced dose dependently by both urapidil and CM 57493. In MCA-occluded rats, CM 57493 (1 and 5 mg/kg) reduced the cortical infarct volume by 30% and application of 10 mg/kg CM 57493 led to a 40% reduction in the cortical infarct volume. The striatal damage could not be influenced by CM 57493 treatment. Furthermore, 1 and 5 mg/kg CM 57493 significantly reduced the neuronal damage within the CA1 sector of the rat hippocampus after 10 min of forebrain ischemia followed by 7 days of recovery. Measurement of cerebral and rectal temperature revealed that the neuroprotective effect of CM 57493 was not caused by a hypothermic effect. We assume that the neuroprotective activity of 5-HT1A agonists is mediated by an inhibitory action on neurons.

A cystic process in the right frontal lobe of the brain in a man of 35 years of age, and an intramedullary cyst in the upper cervical spinal cord in a 29-year old woman, are described. In both cases, the wall of the cyst consisted of mucosal cells and cells having cilia pointing to the inside, located on a thin tissue layer, the structure of which resembled that of a meningioma. Central nervous cysts of this kind are usefully classified together with other, similar cysts (bronchogenic, ependymal and others) as "epithelial cysts". They must be differentiated from neoplastic tumours. Analysis of the cystic contents can prove helpful.

In open brain surgery, access to processes in the midline region is difficult. Exact diagnosis of the tumour type is crucial to the choice of therapeutic modality. In many cases, modern imaging procedures such as CT and MRI are useful diagnostic tools. The diagnosis is confirmed by direct biopsy and histological examination. Selected cases of tumours close to the midline (germinoma, pilocytic astrocytoma, primary cerebral malignant lymphoma) are presented. CT and MRI are helpful in demonstrating space-occupying processes. The tumour's histological type is determined by CT-stereotactic biopsy. The histopathological diagnosis is established by means of a crush preparation. Appropriate forms of therapy are proposed on the basis of the diagnosis of tumour type. The results are impressive, due to the efficacy of stereotactic procedures as an additional means of diagnosing and treating space-occupying processes of the midline region.

A cystic process in the right frontal lobe of the brain in a man of 35 years of age, and an intramedullary cyst in the upper cervical spinal cord in a 29-year old woman, are described. In both cases, the wall of the cyst consisted of mucosal cells and cells having cilia pointing to the inside, located on a thin tissue layer, the structure of which resembled that of a meningioma. Central nervous cysts of this kind are usefully classified together with other, similar cysts (bronchogenic, ependymal and others) as "epithelial cysts". They must be differentiated from neoplastic tumours. Analysis of the cystic contents can prove helpful.

The sensitivity of the diagnostic procedures in space occupying lesions of the spine have been markedly improved in the recent past, mainly due to the application of CT and MRI--technology and the introduction of superselective angiography. Despite these 'high-tech'-investigations, neurological examination still provides the sole in neurological diagnosis. To show the discrepancies between the techniques mentioned, we present a case of a vascular malformation of the spine with secondary myelopathy (so-called "Foix-Alajouanine-syndrome").

We investigated the effect of the known antagonist of platelet-activating factor (PAF), ginkgolide B, on postischemic neuronal damage in the rat. Neuronal necroses were evaluated in the hippocampus 7 days after a 10-min forebrain ischemia. Preischemic application of ginkgolide B (50 mg/kg p.o.) significantly reduced neuronal damage. It is suggested that the antagonism of PAF is responsible for this beneficial effect of ginkgolide B.

The present study investigates the effects of the 5-hydroxytryptamine1A agonist ipsapirone on electroencephalography and somatosensory evoked potentials after middle cerebral artery occlusion in the rat. We implanted 17 silver ball electrodes symmetrically distributed over the skull in 14 rats and registered electroencephalography activity and somatosensory evoked potentials before, 1 hour, and 1 week after permanent occlusion of the left middle cerebral artery. Before vessel occlusion, a symmetric distribution of electroencephalography power was seen over both hemispheres. Middle cerebral artery occlusion caused a complete abolishment of electroencephalography power in the frontolateral aspects of the affected hemisphere. When electroencephalographic recordings 7 days after the insult were superimposed with three-dimensional-reconstructed pictures of the infarct, a close correspondence of the extention and spatial orientation was noted. Two negative and two positive peaks were consistently recorded before middle cerebral artery occlusion. In both control and ipsapirone-treated (30 mg/kg i.p. 30 minutes after induction of ischemia) animals, the vessel occlusion caused a severe reduction in amplitudes of somatosensory evoked potentials in all areas under record (p less than 0.05). One week after middle cerebral artery occlusion, amplitudes of somatosensory potentials over the lesioned hemisphere were still significantly (p less than 0.05) lower than preischemic values in the control group. When compared with the corresponding values 1 hour after middle cerebral artery occlusion, an albeit insignificant tendency toward increased amplitudes was observed in most areas under record. By contrast, in ipsapirone-treated animals, significant differences compared with preischemic values were no longer present 1 week after the vessel occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

The purpose of the present study was to investigate the neuroprotective action of nimodipine. Furthermore, the influence of nimodipine on postischemic local CBF (LCBF) was examined. Forebrain ischemia of the rat was performed for 10 min by bilateral carotid clamping, administration of trimethaphan, and blood withdrawal to obtain an MABP of 40 mm Hg. LCBF was measured after 10 min of postischemic recirculation by injecting [14C]iodoantipyrine in saline solution. Nimodipine (0.1, 0.3, and 1.0 mg/kg) was suspended in miglyol oil and applied orally 60 min prior to ischemia. Histological evaluation was performed 7 days after ischemia. Hippocampal neuronal damage was determined as the percentage of necrotic neurons. After preischemic application of nimodipine, neuronal damage was significantly reduced in the hippocampal CA1 subfield. Postischemic LCBF was not affected by treatment with nimodipine. These findings show that nimodipine is able to protect neurons against ischemic damage. The neuroprotective effect of nimodipine was not mediated by a postischemic cerebral vasodilation, but by a direct action on the neurons.

Stereotactic procedures in brain tumour diagnosis and therapy are used increasingly because small lesions are more frequently detected and methods of interstitial irradiation are gaining wide acceptance among neurosurgeons. The diagnosis of underlying pathological processes has to be performed from very small tissue samples. The method of smear and/or squash preparations therefore has long been used by neurosurgeons. Neuropathologists, formerly reluctant, are becoming more and more enthusiastic over this simple and elegant method. Since the diagnostic reliability in such small samples is questioned, we have undertaken to analyse 200 open tumour biopsies in a comparative investigation: the diagnosis from smear preparation on the one hand has been performed without knowledge of the lesion, and on the other hand the remaining material was submitted to the whole pattern of diagnostic methods including frozen sections, paraffin sections with special staining, immunohistochemistry, electron microscopy and tissue culture. Diagnostic reliability was estimated in a four step procedure: Is there tumour or not--is there neuroepithelial newgrowth or metastasis--what kind of tumour is it--has the degree of malignancy--according to the criteria of the WHO--been estimated correctly? The overall diagnostic reliability in our material is about 75%. This is less than the diagnostic reliability of other methods, mostly due to the lack of histologic "architecture" criteria in evaluating the cytological biopsies.

It has been pointed out in numerous papers [4, 6, 7,18,19] that the disturbed calcium homeostasis plays a pivotal role in the pathogenesis of neuronal cell damage caused by ischemia. Calcium ions can fulfill their function as second messengers only when the cytosolic concentration of free Ca2+ is maintained at a level of approximately 10−7mol/l whereas the extracellular concentration of Ca2+ is around 10−3 mol/l.