Bilateral endoscopic optic nerve decompression in an infant with osteopetrosis.

Osteopetrosis is a rare disorder of bone remodeling characterized by defective resorption leading to excessive skeletal mass including optic canal. Compression of the optic nerve from the narrowed optic canal is the most common cause of vision loss in children with osteopetrosis. We report the case of a 6-month old girl with osteopetrosis who underwent bilateral optic canal decompression via endoscopic transcaruncular approach for progressive deterioration of visual function secondary to compressive optic neuropathy from narrowed optic canals. The patient showed improvement in visual function postoperatively.

Endoscopic Endonasal Surgery for Tumors of the Cavernous Sinus: A Series of 234 Patients.

BACKGROUND: Cavernous sinus (CS) tumors often are considered inoperable. We present our experience with endoscopic endonasal surgery (EES) and compare the outcomes for different tumor. METHODS: EES (medial or lateral approach) was used in 234 patients with CS tumors. The cohort included 175 (75%) pituitary adenomas and 59 (25%) nonadenomatous lesions. RESULTS: Presenting symptoms were significantly different between the 2 groups, with cranial neuropathies occurring mainly in nonadenomas (P < 0.0001). The overall gross total tumor resection rate from the CS was 37.3% (37.1% in adenomas, 38.1% in non-adenomas). In total, preexisting cranial nerve (CN) dysfunction improved in 56.4% of the patients. After treatment completion (including radiation of residual tumor), 83.3% of acromegalic patients, 50% of prolactinomas and 33.3% of Cushing's disease, were in remission. Visual loss improved in 86.8% of adenomas and in 70.8% of nonadenomas. Intracavernous CN palsies improved in 77.3% of adenomas and 42.4% of nonadenomas. New permanent CN palsies occurred in 7 nonadenomas, which is significantly greater than in adenomas (P = 0.007). The leak rate of cerebrospinal fluid was 6.3% for adenomas and 11.9% for nonadenomas. Four patients suffered an internal carotid artery injury with no neurologic sequelae in 3 cases and 1 death (0.4%). CONCLUSIONS: EES provides an easily accessible midline corridor to the CS with equivalent or superior results to transcranial approaches in the management of select tumors. Symptomatology due to CS invasion is more likely to improve in pituitary adenomas and the rate of surgical complications is greater in nonadenomas. Using a team approach, the overall mortality due to vascular injury is low.

Communication between functional and denervated muscles using radiofrequency.

OBJECTIVE: This article focuses on establishing communication between a functional muscle and a denervated muscle using a radiofrequency communications link. The ultimate objective of the project is to restore the eye blink in patients with facial nerve paralysis. STUDY DESIGN AND SETTING: Two sets of experiments were conducted using the gastrocnemius leg muscles of Sprague-Dawley rats. In the initial tests, varying magnitudes of voltages ranging from 0.85 to 2.5 V were applied directly to a denervated muscle to determine the voltage required to produce visible contraction. The second set of experiments was then conducted to determine the voltage output from an in vivo muscle contraction that could be sensed and used to coordinate a signal for actuation of a muscle in a separate limb. After designing the appropriate external communication circuitry, a third experiment was performed to verify that a signal between a functional and a denervated muscle can be generated and used as a stimulus. RESULTS: Voltages below 2 V at a 10-millisecond pulse width elicited a gentle, controlled contraction of the denervated muscle in vivo. It was also observed that with longer pulse widths, higher stimulation voltages were required to produce sufficient contractions. CONCLUSION: It is possible to detect contraction of a muscle, use this to generate a signal to an external base station, and subsequently cause a separate, denervated muscle to contract in response to the signal. SIGNIFICANCE: This demonstration in vivo of a signaling system for pacing of electrical stimulation of 1 muscle to spontaneous contraction of another, separate muscle, using radiofrequency communication without direct connection, may be used in numerous ways to overcome nerve damage.