Orbital porencephalic cyst following penetrating orbitocranial trauma.

In a 10-year-old boy an orbitocranial penetrating wound produced by an umbrella tip caused an orbital roof bone fragment to penetrate up to the anterior part of the third ventricle behind the left foramen of Monro. Hemorrhages and encephalomalacia developed along the trajectory of the fragment and subsequently a porencephalic cyst was formed at this site. Six months after the trauma, increased pressure developed in the left ventricular system due to obstructive hydrocephalus and consequently the porencephalic cyst herniated into the orbit through the orbital roof fracture, producing intermittent diplopia, left exophthalmos, and palpebral swelling. A ventriculo-peritoneal shunt led to shrinkage of the orbital cyst content and resolution of the symptoms.

Patient positioning for the operative approach to midline intracerebral lesions: technical note.

Patients undergoing craniotomies for intracerebral lesions are generally positioned in such a way that the lesion is highest in the field. For midline lesions alongside the falx, patients are commonly positioned on their backs for an anatomically symmetrical approach. We propose positioning the patient in the lateral decubitus position ipsilateral to the lesion to take advantage of gravity by allowing the brain to fall away from the midline, thus obviating the need for retraction. We have used this position in 15 cases of falcine and parafalcine tumors to great advantage, without encountering untoward operative or anesthetic complications.

Myelomeningocele repair by a combined fasciocutaneous flap closure. Technical note.

The principles of myelomeningocele repair have been clearly described in the literature and generally delineate a technique that calls for the dissection and closure of five separate layers: arachnoid, dura, fascia a subcutaneous layer, and skin. We should like to describe our technique of repairing the myelomeningocele defect following dural separation and closure by shifting complete fasciocutaneous tissue blocks from either side of the defect to the midline following dural closure. A full thickness primary closure can be obtained even in large defects.

Meningioma presenting at a site of a previously aspirated brain abscess.

We report the case of a meningioma which developed in the parieto-occipital lobe at the site where a brain abscess had been aspirated 9 years previously. There was no history of head trauma. To the best of our knowledge this is the first reported case of a meningioma associated and possibly aetiologically related to a previous inflammatory process in the absence of head trauma. The association of chronic inflammation and the subsequent development of a meningioma is discussed.

The ambivalent effects of early and late administration of mannitol in cold-induced brain oedema.

This study was undertaken in order to determine whether early administration of mannitol is different from late administration in its effect on brain oedema. Cold-induced brain oedema, which was confirmed by high resolution CT scan, was produced in 2 groups of cats. In group one mannitol was given early (90 minutes after injury); in group two 3-4 hours after the injury (late). Repeated CT scans following mannitol administration showed that the early group exhibited significantly greater dehydration (p less than 0.0001) while the late group showed significant hydration, in the lesioned hemisphere. The contralateral control hemisphere responded to mannitol with similar dehydration effect in both groups.