Favored gyral sites of supratentorial astrocytic tumors

It is well known that the predilective sites of extrinsic tumors (meningiomas, chordomas, etc) are at the skull base and along the calvarium. Although intrinsic tumors or glial tumors have also been seen to have anatomic and functional predilective sites within the central nervous system, these have not been well documented. We conducted this study to investigate if supratentorial astrocytic tumors have a predilection for specifi c gyri. We investigated the clinical and radiological records of 60 successive patients who had been operated on at our institution and had had histologically confi rmed supratentorial astrocytic tumors (36 males, 24 females, mean age: 52 years). Coronal sections were selected from the pre-operative contrast enhanced T1-weighted magnetic resonance imaging (MRI). The labeling of gyral areas for analysis of MRI was done using Yaşargil’s method. Additional information obtained from 3-dimensional MRI and surgical fi ndings was taken into account when it was diffi cult to distinguish the specifi c gyrus in which the tumor was located. The middle portions of the frontal gyri, insular gyri and the supramarginal gyrus and its surroundings were among the most common locations for the development of tumors. Interestingly, with the exception of one case, none of the tumors was situated in the precentral or postcentral gyri. It seems that supratentorial astrocytic tumors have a predilection for specifi c gyri and disfavor some other gyri. This cannot be explained simply by the different sizes of the cerebral lobes. A classical lobar concept of cerebral anatomy may lead to a misunderstanding of cerebral pathophysiology.

Atypical Presentation of Orbital Pseudotumor with Visual Loss as an Initial Manifestation

BACKGROUND: An orbital pseudotumor typically presents with periorbital pain, cranial nerve palsies and proptosis. Although visual deterioration is not unexpected in this pathology, its presentation solely with visual loss is unusual. CASE REPORT: In this short report, we summarize a case of orbital pseudotumor which presented solely with a decrease in visual acuity, and discuss the clinical and radiological findings. CONCLUSIONS: This atypical presentation likely resulted from the orbital pseudotumor originating in the optic foramen, leaving the neurovascular structures of the superior orbital fissure untouched initially. In the early clinical period, an orbital pseudotumor may manifest itself solely by visual loss. It should therefore be included in the differential diagnosis of visual pathologies-even in the absence of orbital pain and symptoms related to ocular movements.

Does Serum Osmolarity Change as a Result of the Reflex Neuroprotective Mechanism of Cerebral Osmo-Regulation after Minor Head Trauma?

OBJECTIVE: It is well known that changes in cerebral hemodynamics occur after traumatic brain injury (TBI). Osmo-regulation in the brain is important for maintaining a constant milieu in the central nervous system. Nevertheless, to our knowledge, early osmolarity changes after minor head injury have not been studied until now. METHODS: In this study, serum osmolarity was measured in 99 patients with minor head trauma. As a control group, blood samples were drawn from 99 patients who had a minor trauma in an extremity. Serum osmolarity was estimated using a fully automatic biochemical autoanalyzer within the first 3 hours after the trauma. RESULTS: The mean serum osmolarity levels were 286.08+/-10.17 mOsm/L in the study group and 290.94+/-5.65 mOsm/L in the control group (p<0.001). However, after age adjustment between the study and control groups, this statistical significance was found to be valid only for patients over 30 years of age. CONCLUSION: It was noted that serum osmolarity levels decrease in the first 3 hours following minor head trauma in patients over 30 years of age. Further studies into this area could provide guidance for the management/treatment of elderly patients.