Lateral sellar angiolipomas: a therapeutic challenge. Our experience on two cases and review of the literature.

Angiolipomas are rare benign mesenchymal tumours, most commonly found in the subcutaneous tissue of the extremities. These neoplasms are rarely located in the central nervous system (CNS), with spinal localization being the most common in this group. Intracranial location is extremely infrequent, and only ten cases have been described in the sellar region. We report on two more patients with skull-base (intracranial) angiolipomas, the former presented with a long history of headache and the latter complained diplopia. Both patients were postoperatively verified as angiolipoma. Neuroimaging studies and peroperative features are presented and the role of microsurgery is discussed. On the basis of these tumours' characteristics, the management strategy of choice usually does not consist on surgical total removal, often a partial excision could be satisfying to improve the patient symptomatology. Nowadays, Gamma Knife surgery is standing out as an effective, additional and/or alternative, treatment modality.

Spontaneous intraparenchymal tension pneumocephalus triggered by compulsive forceful nose blowing.

The case is described of a 50-year-old man, treated for 10 years in an outpatient psychiatric clinic for an obsessive compulsive disorder, who presented with acute loss of consciousness after forceful nose blowing. A CT scan revealed an intraparenchymal air collection with tension signs in the left frontal lobe and a bone defect in the roof of the ethmoid sinus. After emergency left frontal craniotomy and dura opening, the gaseous collection was evacuated by a ventricular catheter inserted into the brain and the bone defect was repaired with pericranium flap and muscle. The postoperative course was uneventful with neurocognitive improvement and regained motility. Spontaneous tension pneumocephalus is a rare life-threatening condition which is often caused by a bone defect near the tegmen tympani. This case illustrates both an unusual cause and a unique surgical treatment for spontaneous tension intraparenchymal pneumocephalus. It can be a dangerous entity with potential for early mortality and long-term morbidity if not promptly decompressed. The pathogenesis, diagnosis and surgical strategies for spontaneous tension pneumocephalus are briefly discussed.

[The recrudescence of spondylodiscitis due to migratory flows. The role of magnetic resonance as a method of first instance in diagnosis and follow-up]. / Recrudescenza della spondilodiscite da incremento dei flussi migratori. Ruolo della Risonanza Magnetica come metodica di prima istanza nella diagnosi e nei controlli.

PURPOSE: We report 15 cases of spondylodiscitis due to infective processes of different etiology and stress the role of MRI in the diagnosis and follow-up of this condition, whose high epidemiologic recrudescence is probably related to an increased westward migratory flow. PATIENT AND METHODS: February through December, 1996, fifteen patients with acute spinal pain were submitted to MRI (1.0 T superconductive magnet, Magnetom SP42E, Siemens, Erlangen, Germany). In all cases both the painful spinal tract and the rest of the spine were studied to detect any infiltrative processes elsewhere in the spine. All patients underwent MR follow-up, according to the evolution of subjective symptoms, until complete recovery of the infections. RESULTS: MRI always permitted the correct diagnosis to be made and the correct evaluation of infection evolution, allowing adequate (medical and/or surgical) treatment to be carried out in the early stage of infections. DISCUSSION: MRI can be considered the best diagnostic tool study osteomedullary inflammations and, particularly, to diagnose and follow-up spondylodiscitis. This technique permits clear differentiation between the different evolution stages of the infections, as well as the evaluation of bone, disks, epidural spaces and spinal cord involvement. Moreover the MR findings permit adequate treatment choices, which results in much fewer complications and therefore better prognosis. CONCLUSIONS: The role of MRI in the diagnosis and follow-up of spondylodiscitis has been fully discussed in the literature. Our report is aimed at stressing the important role of MRI as the technique of choice for the diagnosis of suspected spondylodiscitis, especially considering the high recrudescence of this condition in Western populations which is probably related to increased westward migrations.

Transient "cerebellar" mutism in lesions of the mesencephalic-cerebellar region.

Four patients aged from 20 to 48 years with transient mutism are presented: 3 patients underwent surgery for midline tumours of the mesencephalic-cerebellar region (medulloblastoma in two cases and pinealoblastoma in one), at times attached to one or both lateral recesses of the IV ventricle. One patient was hospitalized and treated for brain-stem ischemia. All patients developed mutism 48 to 72 hours after surgery; in the patient with brain-stem softening mutism appeared 72 hours after admission. All the patients had unimpaired consciousness and no deficits of lower cranial nerves. Speech, always normal in the first hours after surgery, was regained after a period of 6-16 weeks. Various hypotheses for this speech disorder are analyzed.

Cavernous angioma does not exist?

12 cases of cerebral "venous angioma" are reported; pathological, clinical and radiological features of the lesion are reviewed. "Venous angioma" should be regarded as a developmental anatomic variation of the venous drainage system of the white matter. Its clinical significance is controversial, although it has been reported to cause hemorrhage, seizures, progressive neurological deficits, headaches. The clinical presentation of our patients was variable and, in some of them, dependent also on associated lesions. An hematoma was found in three patients, infarction in one and tumor in one. Angiography, CT and MRI demonstrated the typical appearance of the anomaly. Surgery was performed in one patient harboring a significant cerebellar hematoma and the coexistence of a cavernoma was pathologically confirmed. Venous developmental anomalies are often identified as the source of symptoms due to other conditions, that should be treated independently sparing the anomaly.

[Hypertensive pneumocephalus, postoperative complication of chronic subdural hematomas]. / Pneumocefalo iperteso, complicanza post-operatoria degli ematomi sottodurali cronici.

The authors report 3 cases of subdural tension pneumocephalus developed after surgery for subdural chronic hematomas. The mechanisms involved in the pathogenesis of this complication are discussed; the importance of the computed tomography in the assessment of the subdural tension pneumocephalus is stressed. Surgery is always indicated in cases of increased tension of the air collection and generally resolves the neurological deficits.

[Postoperative lumbar discitis]. / Le disciti lombari post-operatorie.

The authors report our experience on 19 cases of discitis developed after operations for herniated lumbar disc. Because of the negativity of the neuroradiological studies in the acute stage, the recognition of the typical syndrome (severe back pain, spasm of the paravertebral lumbar muscles, limited spinal motility, fever) beginning 3-30 days post-operatively and the study of some laboratory tests (elevated Erythrocyte sedimentation rate (ESR) and midly to moderately elevated white blood cells (WBC) are very important for diagnosis. The first radiographic findings (disc space narrowing, ecc.) are detectable only 4 to 6 weeks after the first symptoms; other X-ray findings are not seen post-operatively before 6 months-2 years. The CT-scan is diagnostic of discitis only when the following three specific signs are present: a) anterior paravertebral soft tissue swelling with obliteration of paravertebral fat planes; b) fragmentation or erosion of vertebral end plates; c) paravertebral fluid collection (abscess). In our experience a period of immobilization of the spine with a plaster body jackets and the use of adequate antibiotic therapy are the more effective treatment. Undoubtedly the discits are the results of an infection that must be prevented adhering to the aseptic principles not only during surgery but also during the procedures performed in the radiology suite.

Low-grade astrocytomas: treatment with unconventionally fractionated external beam stereotactic radiation therapy.

Fourteen patients with nonoperable low-grade astrocytomas were treated with unconventionally fractionated stereotactic radiation therapy. The target volume was defined with computed tomography (CT) performed under stereotactic conditions. The treatment was carried out with a technique producing multiple noncoplanar arc irradiation, with the center of the target volume placed at the isocenter of the linear accelerator. A total dose of 16-50 Gy was administered in either one fraction or two fractions 8 days apart. The concentration of dose within the target volume allowed reduction of dose absorbed by adjacent critical structures of the intact brain. Patients were followed up for 11-48 months. Twelve of 14 patients had a partial or complete response to treatment, as demonstrated by CT. Stereotactic radiation therapy appears to be effective in the control of small radioresistant cerebral neoplasms, without damaging surrounding healthy tissues.

Dosimetric considerations on multiple arc stereotaxic radiotherapy.

The aim of this paper is to present the physical and dosimetrical features of the stereotaxic radiosurgical method already published by the authors. This method concentrates the dose into the stereotaxic target volume, placed at the isocenter of a 4 MV X-ray beam. Computer calculations showed that: 9-17 arcs provide almost spherical dose distributions; the optimal photon beam quality is about 4-6 MV. The angle between adjacent rotation planes is 20-40 degrees and the arcs are 100-160 degrees wide. In this way the dose to healthy tissue is minimized. The dose distribution was experimentally verified both by ionometric and photodensitometric methods. The procedure for dose calculation at isocenter of fields as small as required by the radiotherapist, has been investigated.

New technique for three-dimensional linear accelerator radiosurgery.

A new method for external stereotactic focal irradiation of three-dimensional irregular target volumes is proposed. In this method the target is irradiated by a linear accelerator set in various angular positions around the isocenter. During the irradiation the target is translated in a direction perpendicular to the beam. By controlling the velocity of the translation it is possible to modify the configuration of therapeutic isodoses so as to make them follow the borders of the target.

Radiosurgery using a 4MV linear accelerator. Technique and radiobiologic implications.

In the authors' technique, the stereotactically localized target is fixed to the isocenter of a 4 MV linear accelerator. The irradiation is carried out along 9-17 non-coplanar arcs distributed on a 160 degrees cylindrical sector. High doses (10-50 Gy) are delivered in one or two sessions. From 1982, 65 patients have been treated (shortest follow-up 6 months). The dose was chosen according to the pathology and to the volume of the lesion. Good clinical results have been obtained in low-grade gliomas, acoustic neuromas, arteriovenous malformations, and other selected types of intracranial lesions. Therapeutic effects in terms of clinical condition and size of the lesions have been plotted in relation to time elapsed and dose employed.

Spinal ossifying arachnoiditis. Case report.

A case of low dorsal spinal cord compression, due to ossifying arachnoiditis, is reported. Its relationship with a venous malformation overlying the dorsal surface of the spinal cord is mentioned. The literature is reviewed and possible etiopathogenetic factors favouring this rare condition are discussed in the light of few similar reports. The value of surgical treatment is stressed.

Stereotactic radiosurgery of intracranial tumors in childhood.

The Authors have developed an original stereotactic technique by which the radiation dose erogated by a 4 MV linear accelerator is focused into the target volume with a steep dose gradient at its borders. The technique has been employed in a series of 30 patients affected by deep seated brain tumors and AVMs. The paper deals with the preliminary results obtained in a series of 10 patients in pediatric age.

External stereotactic irradiation by linear accelerator.

Stereotactic radiotherapy has two advantages: (a) the possibility of giving high radiation doses to small but spatially well-defined target volumes and (b) the presence of a stepped dose gradient between the target volume and the surrounding healthy tissues. To utilize these advantages, the authors built a new stereotactic head frame by which the intracranial target is fixed to the rotational isocenter of a 4-MV linear accelerator. The collimator openings are selected according to the volume and the three-dimensional configuration of the target, and the radiation dose is based on the radiosensitivity of the lesion. After the patient is fixed to the frame, the radiation source and the patient are rotated so that the target is irradiated through infinite portals distributed over the convexity of the skull. It is thereby possible to obtain very high radiation doses centered into the target with a stepped dose gradient. The preliminary radiodosimetric tests and the operative technique are described. The advantages of this technique compared to interstitial radiotherapy and Leksell's radiosurgery are emphasized. This noninvasive procedure has been used to treat a series of intracranial tumors.

Stereotactic radiosurgery utilizing a linear accelerator.

The authors have developed a radiosurgical technique based on multiple arc irradiations. The target is fixed to the rotational isocenter of a Varian 4 MV linear accelerator. The first irradiation is carried out while the radiating source is rotating on a 100-140 degrees arc. The patient is then rotated around a vertical axis passing through the target, and arc irradiations are repeated in different angular positions. By this technique it is possible to obtain very steep dose gradients at the borders of the target volume. High doses are usually delivered in two shots. 47 patients have been treated so far in a clinical trial that started in November 1982. The paper deals with the preliminary results (more than 6 months' follow-up) obtained in patients affected by nonresectable brain tumors and AVMs.

Surgical management of acute cerebellar infarction.

After reviewing the literature, a personal series of 10 adult patients with cerebellar infarction diagnosed by CT scan is described. The clinical picture in young adult men is characterized by rapid onset of headache, vomiting, vertigo, ataxia and blurred vision. After this sudden onset the patients may present a stable course or a rapid or delayed onset of brain stem compression, revealed by impairment of consciousness. CT scan is the diagnostic method of choice. The correlation between angiographic and CT localization of the infarction is not good. For therapy the following policy is suggested: in alert and clinically stable patients: medical treatment (mannitol, glycerol, dexamethason), ICP and serial CT monitoring; in alert patients with hydrocephalus or mass effect: medical treatment and monitoring as mentioned before; ventricular drainage if ICP surpasses 350 mm H2O; in patients with impaired consciousness and hydrocephalus or mass effect: immediate ventricular drainage. If it is not followed by prompt improvement of the level of consciousness, an emergency suboccipital craniectomy with removal of the infarcted tissue should be done.

The significance of microcirculatory modifications in traumatic lesions of the spinal cord. A preliminary, morphological study on experimentally induced spinal cord traumas.

The authors have studied the histological modifications in rabbit spinal cords after injury by a 20 g weight dropping from a 10 cm height. The animals were sacrificed at various time intervals from trauma (after 30', 60', 90', 2 h, 3 h, 4 h, 5 h, 6 h). The traumatized spinal cords are characterized by edema, regressive alterations of neurons as well as of glia and of fibres, and by microcentres of myelinolysis. The prominent and very precocious presence of edema is very likely one of the main factors causing regressive alterations in the cells present in myelinolysis centres.

Valuation of some biological parameters in acute spinal cord trauma: experimental study in rabbits.

The authors investigated the formation of edema consequent to Spinal Cord Injury in rabbits. The goal of this project was to study the accumulation of Water, Sodium, Potassium and Ferrum in traumatized cords in the early time after the acute injury. To this aim a spinal cord trauma was induced in forty unselected animals using the weight-drop method; Water content was measured by wet and dry weight method; Sodium, Potassium and Ferrum content were measured by atomic absorbance spectrophotometry. These parameters were recorded at various time from the cord trauma (30 minutes up to 14 days). The results are presented and discussed with a particular view to the relationships between biological variation and time from the injury.