Preoperative diagnosis of posterior fossa tumors (author's transl)]

The wide-scale use of the CT Scanner has completely modified the radiological approach in the diagnosis of infratorial tumors. In the cerebello pontine angle tumors, computerized tomography offers enough information for surgery (at least in those cases where enlargement of porus is noticeable on the skull film). On the other hand, if clinical picture is incomplete or CT scann atypical (spontaneous hyperdensity), a vertebral angiography is necessary to recognize a meningioma or a neurinoma of the firth nerve. A low density suggesting a cyst (epidermoid or other) is a good indication for pneumoencephalography. In cerebellar tumors of the hemispheres, vertebral angiography should be performed in the case of multiple tumors (except if there is a good chance of metastases) and also with a single tumor showing a high enhancement with contrast; in a solitary cyst, angiography is recommanded when clinical signs suggest hemangioblastoma. Isotopic scanning is only indicated when there is a suspicion of metastases. In midline tumors, one has to consider the relationship with the 4th ventricle; no other radiological exams are necessary if tumor is likely located in the cerebellar vermis; on the contrary, if the ventricular cavity is barely visible positive ventriculography is helpful. In the anteriorly located neoplasms, pneumoencephalography with tomography may precise the exact situation in relation with the brain stem. Regardless of the anteroposterior location, a highly contrasted tumor should be explored by angiography.     

An interhemispheric subdural abscess (author's transl)]

A subdural abscess which is cinfined to the interhemispheric space alone, which does not extend over the convexity is rare. This is a specific form and is a complication of a common intracranial subdural abscess. It is of great practical importance to determins this uncommon location, and cerebral angiography is most useful. Multiple trephinations or craniotomy for exploration and evacuation must be performed near the midline. A 20 year old female was in a comatose state on admission. There was a flaccid paralysis of the right lower extremity and a dilated left pupil. Examination of the eyegrounds showed bilateral choked discs. Left cerebral angiography revealed the proximal pericallosal artery to be shifted to the right side and the callosomarginae artery was displaced from the midline parallel to the distal pericallosal artery. Although 20 ml of pus was evacuated through the parietal burr hole, which was located a bout 2.5 cm from the midline, she died. At autopsy, a subsural abscess was found in the interhemispheric space. It extended from the frontal pole to the occipital and had a thick membrane which adhered firmly to the falx medially. We could find no other subdural nor intracerebral pus collections. The left cerebral hemisphere was edematous. The superior sagittal sinus had a thick wall and was almost occluded. This dural sinus thrombophlebitis may have developed into the interhemispheric subdural abscess. It is emphasized that this uncommon location for subdural abscess poses a specific problem in clinical practice.     

Primary interhemispheric subdural abscess--case report (author's transl)]

A case of primary interhemispheric subdural abscess was reported, which was not accompanied by abscess formation in other places such as subdural spaces of the convexity or in the brain. A 13-year-old school boy was admitted with 8 days' history of fever, headache and progressive weakness of the left lower extremity. Prior to admission he developed 2 spells of jacksonian seizure initiating from the left leg. Right carotid angiography was performed on admission and separation of the pericallosal and callosomarginal arteries with small avascular area was shown indicating possible abscess formation in the interhemispheric fissure. There was no evidence of purulent infection in the laboratory findings including the CSF and EEG showed diffuse slow wave discharge, more in the right frontocentral leads. He was placed on the vigorous treatment with antibiotics and steroids, and one month later the left lower weakness as well as the EEG abnormality showed some improvement. However, the separation of the anterior cerebral arterial branches became more prominent and formed a lens shaped avascular area, although the pericallosal artery was in the midline. A diagnosis of interhemispheric subdural abscess was made and was confirmed by surgery. Patient showed progressive recovery of the left lower paralysis, and the abscess was totally collapsed in the repeated angiographic follow-up study. Angiographic characteristics of the interhemispheric subdural abscess were described and particular emphasis was placed on the peculiar neurological symptoms referring to the previous reports in the literature.     

Extra-dural hematoma of the posterior fossa (author's transl)

10 cases of posterior fossa extra-dural hematoma are reported and 100 other published cases reviewed. It appears that the sole clinical evaluation frequently leads to wrong or delayed diagnosis. In only one out of five cases the cerebellar signs and the palsy of one or several cranial nerves (VII, IX, X, XI, XII) are prominent. In contrast, all other cases do not present specific signs. Furthermore, the presence of a concomitant supratentorial traumatic lesion may contribute to prevent the finding of evidences for cerebellar extra-dural hematoma. The possibility for such hematoma must always been kept in mind when an occipital fracture is shown by radiography. Venous phases in carotid arteriography permit to ascertain the extradural hematoma if there is a displacement of the torcular Herophili or of the transverse sinus. Data from carotid arteriography may be normal and the lesion may be ascertained by vertebral arteriography which will demonstrate: anterior displacement of the basilar artery against the clivus--anterior displacement of posterior inferior cerebellar and posterior meningeal arteries--crescentic displacement of brain substance from the inner table--displacement of the venous sinuses.     

Posterior fossa subdural hygroma with supratentorial chronic subdural haematoma

Posterior fossa subdural hygromas are very rare. They tend to occur following direct occipital trauma. We present an unusual case of complex subdural hygroma of the posterior fossa, which was associated with a supratentorial chronic subdural haematoma. This developed after an apparently minor injury to the head. The unusual features of our case are discussed. We also review the literature and discuss the natural history and pathogenesis of subdural hygroma.     

Acute calculous cholecystitis (author's transl)]

The authors studied 333 acute cholecystitis out of 2,200 operated on for lithiasis of the gall-bladder, 186 bacteriological tests were carried out on the vesicular liquid and wall. They insist on the main anatomo-pathological characteristic: early, partial or total destruction of the mucous together with acute inflammatory lesions of the wall and even sometimes necrosis. This irreversible lesion is due to the acute obstruction of the gall-bladder by blockage of a calculus. Acute cholecystitis are practically always aseptic at the beginning. Sepsis is a secondary complication. These anatomo-pathological and bacteriological elements have two therapeutic corollaries: 1. The patient has to be operated very early at the aseptic stage. 2. Preliminary antibiotherapy becomes useless. Under these conditions there is practically no death before the age of 65. Mortality concern old people, operated late and suffering from other disease.