Robot-Assisted Transoral Odontoidectomy : Experiment in New Minimally Invasive Technology, a Cadaveric Study

OBJECTIVE: In the field of spinal surgery, a few laboratory results or clinical cases about robotic spinal surgery have been reported. In vivo trials and development of related surgical instruments for spinal surgery are required before its clinical application. We investigated the use of the da Vinci(R) Surgical System in spinal surgery at the craniovertebral junction in a human cadaver to demonstrate the efficacy and pitfalls of robotic surgery. METHODS: Dissection of pharyngeal wall to the exposure of C1 and odontoid process was performed with full robotic procedure. Although assistance of another surgeon was necessary for drilling and removal of odontoid process due to the lack of appropriate end-effectors, successful robotic procedures for dural sutures and exposing spinal cord proved its safety and dexterity. RESULTS: Robot-assisted odontoidectomy was successfully performed in a human cadaver using the da Vinci(R) Surgical System with few robotic arm collisions and minimal soft tissue damages. Da Vinci(R) Surgical System manifested more dexterous movement than human hands in the deep and narrow oral cavity. Furthermore, sutures with robotic procedure in the oral cavity demonstrated the advantage over conventional procedure. CONCLUSION: Presenting cadaveric study proved the probability of robot-assisted transoral approach. However, the development of robotic instruments specific to spinal surgery must first precede its clinical application.

The Effect of Minocycline on Motor Neuron Recovery and Neuropathic Pain in a Rat Model of Spinal Cord Injury

OBJECTIVE: Minocycline, a second-generation tetracycline-class antibiotic, has been well established to exert a neuroprotective effect in animal models and neurodegenerative disease through the inhibition of microglia. Here, we investigated the effects of minocycline on motor recovery and neuropathic pain in a rat model of spinal cord injury. METHODS: To simulate spinal cord injury, the rats' spinal cords were hemisected at the 10th thoracic level (T10). Minocycline was injected intraperitoneally, and was administered 30 minutes prior surgery and every second postoperative day until sacrifice 28 days after surgery. Motor recovery was assessed via the Basso-Beattie-Bresnahan test. Mechanical hyperalgesia was measured throughout the 28-day post-operative course via the von Frey test. Microglial and astrocyte activation was assessed by immunohistochemical staining for ionized calcium binding adaptor molecule 1 (Iba1) and glial fibrillary acidic protein (GFAP) at two sites: at the level of hemisection and at the 5th lumbar level (L5). RESULTS: In rats, spinal cord hemisection reduced locomotor function and induced a mechanical hyperalgesia of the ipsilateral hind limb. The expression of Iba1 and GFAP was also increased in the dorsal and ventral horns of the spinal cord at the site of hemisection and at the L5 level. Intraperitoneal injection of minocycline facilitated overall motor recovery and attenuated mechanical hyperalgesia. The expression of Iba1 and GFAP in the spinal cord was also reduced in rats treated with minocycline. CONCLUSION: By inhibiting microglia and astrocyte activation, minocycline may facilitate motor recovery and attenuate mechanical hyperalgesia in individuals with spinal cord injuries.

Visual Outcome after Transsphenoidal Surgery in Patients with Pituitary Apoplexy

OBJECTIVE: Pituitary apoplexy is one of the most serious life-threatening complications of pituitary adenoma. The purpose of this study is to investigate the visual outcome after early transsphenoidal surgery for the patients with pituitary apoplexy. METHODS: We retrospectively reviewed the 31 patients with pituitary apoplexy who were admitted due to acute visual acuity or field impairment and treated by transsphenoidal surgery. Five patients were excluded because of the decreased conscious level. The visual acuity of each individual eye was evaluated by Snellen's chart. Visual fields were also checked using automated perimetry. To compare the visual outcome according to the surgical timing, we divided the patients into 2 groups. The first group, 21 of the patients have been undertaken transsphenoidal approach (TSA) within at least 48 hours after admission. The second group included 8 patients who have been undertaken TSA beyond 48 hours. All patients were monitored at least 12 months after surgery. RESULTS: Patients were 21 males and 8 females (M : F=2.6 : 1) with the mean age of 42.4 years. Among the enrolled 29 patients, 26 patients presented with decreased visual acuity and 23 patients revealed the defective visual field respectively. Postoperatively, improvement in the visual acuity was seen in 15 patients (83.3%) who underwent surgery within the first 48 hours of presentation, as compared to those in whom surgery was delayed beyond 48 hours (n=5; 62.5%) (p=0.014). Improvement in the visual field deficits was observed in 15 (88.2%) of patients who had been operated on within the first 48 hours of presentation, as compared to those in whom surgery was delayed beyond 48 hours (n=3; 50.0%) (p=0.037). CONCLUSION: This study suggests that rapid transsphenoidal surgery is effective to recover the visual impairment in patients with pituitary apoplexy. If there are associated abnormalities of visual acuity or visual fields in patients with hemorrhagic pituitary apoplexy, early neurosurgical intervention within 48 hours should be also required to recover visual impairment.

Resolution of Isolated Unilateral Hypoglossal Nerve Palsy Following Microvascular Decompression of the Intracranial Vertebral Artery

Isolated hypoglossal nerve paresis due to mechanical compression from a vascular lesion is very rare. We present a case of a 32-year-old man who presented with spontaneous abrupt-onset dysarthria, swallowing difficulty and left-sided tongue atrophy. Brain computed tomographic angiography and magnetic resonance imaging of the brainstem demonstrated an abnormal course of the left vertebral artery compressing the medulla oblongata at the exit zone of the hypoglossal rootlets that was relieved by microvascular decompression of the offending intracranial vertebral artery. This case supports the hypothesis that hypoglossal nerve palsy can be due to nerve stretching and compression by a pulsating normal vertebral artery. Microvascular decompression of the intracranial nerve and careful evaluation of the imaging studies can resolve unexpected isolated hypoglossal nerve palsy.