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Christopher D. Sturm, William A. Frisella and Kong-Woo Yoon

✓ Glutamate has been shown to play an important role in delayed neuronal cell death occurring due to ischemia. Attenuation of synaptically released glutamate can be accomplished by modulators such as adenosine and baclofen. This study focused on the ability of adenosine to attenuate the excitotoxicity secondary to glutamate receptor activation in vitro after exposure to potassium cyanide (KCN) in hippocampal neuronal cell cultures.

For this study, hippocampal cell cultures were obtained from 1-day-old rats and trypan blue staining was used for assessment of cell viability. It was found that the N-methyl-D-aspartate-specific antagonist MK801 (10 µM) attenuated neuronal cell death resulting from exposure to 1 mM KCN for 60 minutes. Adenosine (10 to 1000 µM) decreased neuronal cell death secondary to the same concentration of KCN in a dose-dependent manner. This same neuroprotective effect is mimicked by the adenosine A1-specific receptor agonist N6-cyclopentyladenosine (10 µM). The A1-specific receptor antagonist 8-cyclopentyl-1,3-dimethylxanthine (10 to 1000 nM) blocked the neuroprotective effect of adenosine in a dose-dependent manner. Therefore, neuronal cell death produced by KCN in the experimental model described was mediated at least in part by glutamate. This neuronal cell death was attenuated by adenosine via the A1-specific mechanism.

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Temporoparietal craniopagus

Case report and review of the literature

Richard D. Bucholz, Kong-Woo Yoon and Raymond E. Shively

✓ A case of craniopagus twins joined in the temporoparietal area is presented, along with a review of the literature on craniopagus. A large area of brain was shared between the neurologically normal infants, with defects in the scalp, skull, and dura. The twins were separated in a three-step procedure. First, areas of shared brain were divided and separated with silicone sheets. The second procedure consisted of the insertion of scalp expanders to allow primary skin closure. In the third procedure complete separation was performed which was complicated by severe hypotension in one infant that was due to dural sinus hemorrhage. Cerebrospinal fluid leak was the most difficult problem encountered in the postoperative period; this was treated with lumboperitoneal and ventriculoperitoneal shunts. After 2 years, one twin is neurologically normal; the other is severely developmentally delayed, possibly related to the severe hypotension experienced during the third procedure. A review of the literature on craniopagus is presented. Analysis of data in the literature suggests that the area involved in the craniopagus as well as the venous connections are closely related to survival following separation of craniopagus twins.

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Jaewoo Shin, Chanho Kong, Jae Sung Cho, Jihyeon Lee, Chin Su Koh, Min-Sik Yoon, Young Cheol Na, Won Seok Chang and Jin Woo Chang

OBJECTIVE

The application of pharmacological therapeutics in neurological disorders is limited by the ability of these agents to penetrate the blood-brain barrier (BBB). Focused ultrasound (FUS) has recently gained attention for its potential application as a method for locally opening the BBB and thereby facilitating drug delivery into the brain parenchyma. However, this method still requires optimization to maximize its safety and efficacy for clinical use. In the present study, the authors examined several sonication parameters of FUS influencing BBB opening in small animals.

METHODS

Changes in BBB permeability were observed during transcranial sonication using low-intensity FUS in 20 adult male Sprague-Dawley rats. The authors examined the effects of FUS sonication with different sonication parameters, varying acoustic pressure, center frequency, burst duration, microbubble (MB) type, MB dose, pulse repetition frequency (PRF), and total exposure time. The focal region of BBB opening was identified by Evans blue dye. Additionally, H & E staining was used to identify blood vessel damage.

RESULTS

Acoustic pressure amplitude and burst duration were closely associated with enhancement of BBB opening efficiency, but these parameters were also highly correlated with tissue damage in the sonicated region. In contrast, MB types, MB dose, total exposure time, and PRF had an influence on BBB opening without conspicuous tissue damage after FUS sonication.

CONCLUSIONS

The study aimed to identify these influential conditions and provide safety and efficacy values for further studies. Future work based on the current results is anticipated to facilitate the implementation of FUS sonication for drug delivery in various CNS disease states in the near future.

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Doo-Sik Kong, Stephanie Ming Young, Chang-Ki Hong, Yoon-Duck Kim, Sang Duk Hong, Jung Won Choi, Ho Jun Seol, Jung-Il Lee, Hyung Jin Shin, Do-Hyun Nam and Kyung In Woo

OBJECTIVE

Cranioorbital tumors are complex lesions that involve the deep orbit, floor of the frontal bone, and lesser and greater wing of the sphenoid bone. The purpose of this study was to describe the clinical and ophthalmological outcomes with an endoscopic transorbital approach (TOA) in the management of cranioorbital tumors involving the deep orbit and intracranial compartment.

METHODS

The authors performed endoscopic TOAs via the superior eyelid crease incision in 18 patients (16 TOA alone and 2 TOA combined with a simultaneous endonasal endoscopic resection) with cranioorbital tumors from September 2016 to November 2017. There were 12 patients with sphenoorbital meningiomas. Other lesions included osteosarcoma, plasmacytoma, sebaceous gland carcinoma, intraconal schwannoma, cystic teratoma, and fibrous dysplasia. Ten patients had primary lesions and 8 patients had recurrent tumors. Thirteen patients had intradural lesions, while 5 had only extradural lesions.

RESULTS

Of 18 patients, 7 patients underwent gross-total resection of the tumor and 7 patients underwent planned near-total resection of the tumor, leaving the cavernous sinus lesion. Subtotal resection was performed in 4 patients with recurrent tumors. There was no postoperative CSF leak requiring reconstruction surgery. Fourteen of 18 patients (77.8%) had preoperative proptosis on the ipsilateral side, and all 14 patients had improvement in exophthalmos; the mean proptosis reduced from 5.7 ± 2.7 mm to 1.5 ± 1.4 mm. However, some residual proptosis was evident in 9 of the 14 (64%). Ten of 18 patients (55.6%) had preoperative optic neuropathy, and 6 of them (60.0%) had improvement; the median best-corrected visual acuity improved from 20/100 to 20/40. Thirteen of 18 patients showed mild ptosis at an immediate postoperative examination, all of whom had a spontaneous and complete recovery of their ptosis during the follow-up period. Three of 7 patients showed improvement in extraocular motility after surgery.

CONCLUSIONS

Endoscopic TOA can be considered as an option in the management of cranioorbital tumors involving complex anatomical areas, with acceptable sequelae and morbidity.