Faculty Bibliography

Hand manipulation neurons in areas 5 and 7b/anterior intraparietal area (AIP) of posterior parietal cortex were analyzed in three macaque monkeys during a trained prehension task. Digital video recordings of hand kinematics synchronized to neuronal spike trains were used to correlate firing rates of 128 neurons with hand actions as the animals grasped and lifted rectangular and round objects. We distinguished seven task stages: approach, contact, grasp, lift, hold, lower, and relax. Posterior parietal cortex (PPC) firing rates were highest during object acquisition; 88% of task-related area 5 neurons and 77% in AIP/7b fired maximally during stages 1, 2, or 3. Firing rates rose 200-500 ms before contact, peaked at contact, and declined after grasp was secured. 83% of area 5 neurons and 72% in AIP/7b showed significant increases in mean rates during approach as the fingers were preshaped for grasp. Somatosensory signals at contact provided feedback concerning the accuracy of reach and helped guide the hand to grasp sites. In error trials, tactile information was used to abort grasp, or to initiate corrective actions to achieve task goals. Firing rates declined as lift began. 41% of area 5 neurons and 38% in AIP/7b were inhibited during holding, and returned to baseline when grasp was relaxed. Anatomical connections suggest that area 5 provides somesthetic information to circuits linking AIP/7b to frontal motor areas involved in grasping. Area 5 may also participate in sensorimotor transformations coordinating reach and grasp behaviors and provide on-line feedback needed for goal-directed hand movements

BACKGROUND: Evidence-based medicine calls for a critical evaluation of the scientific evidence for treatments of disease. This report synthesizes the available evidence supporting the indications for image guidance in sinus surgery, examining two important questions: (1) Does image-guided sinus surgery (IGSS) reduce complication rates? (2) Does IGSS improve clinical outcomes? METHODS: Primary research articles evaluated for this report were identified using appropriate search terms and a PubMed search. Two authors independently reviewed each article. Articles were assigned an evidence level based on accepted guidelines: level 1 = randomized trials, level 2 = prospective cohort studies with comparison group, level 3 = case-control studies, level 4 = retrospective case series, and level 5 = expert opinion. RESULTS: We identified 105 articles for full review and highlight 5 articles in our report. Primarily, there is expert opinion (level 5) and case series (level 4) with and without comparison groups supporting the indications for IGSS. In addition, authors point out that sample size and design issues preclude definitive randomized trials using IGSS. CONCLUSION: Although randomized trials of IGSS are not practical, ethical, or feasible, clinical experience, expert opinion, and case series support the current indications for IGSS. Studies designed to draw conclusions about the role of IGSS in decreasing major complications of sinus surgery are not possible

OBJECTIVE: Emerging evidence in auditory neuroscience suggests that central auditory pathways process speech asymmetrically. In concert with left cortical specialization for speech, a 'right-ear advantage' in speech perception has been identified. The purpose of this study is to determine if this central asymmetry in speech processing has implications for selecting the ear for cochlear implantation. STUDY DESIGN: Retrospective cohort study. SETTING: Academic university medical center PATIENTS: One hundred one adults with bilateral severe-to-profound sensorineural hearing loss INTERVENTION: Cochlear implantation with the Nucleus 24 Contour device. MAIN OUTCOME MEASUREMENTS: Patients were divided into two groups according to the ear implanted. Results were compared between left-ear- and right-ear-implanted patients. Further subgroup analysis was undertaken, limited to right-handed patients. Postoperative improvement on audiograms and scores on speech perception tests (Hearing in Noise test, City University of New York in quiet and in noise test, Consonant-Vowel Nucleus- Consonant words, and phonemes) at 1 year was compared between groups. Analysis of covariance was used to control for any intergroup differences in preoperative characteristics. RESULTS: The groups were matched in age, duration of hearing loss, duration of hearing aid use, percentage implanted in the better hearing ear, and preoperative audiologic testing. Postoperatively, there were no differences between left-ear- and right-ear-implanted patients in improvement on speech recognition tests. CONCLUSION: Despite central asymmetry in speech processing, our data do not support a right-ear advantage in speech perception outcomes with cochlear implantation. Therefore, among the many factors in choosing the ear for cochlear implantation, central asymmetry in speech processing does not seem to be a contributor to postoperative speech recognition outcomes

OBJECTIVE: Diagnosis and treatment of asymptomatic, unruptured intracranial aneurysms (UIA) are areas of longstanding controversy in the neurologic and neurosurgical literature. Treatment decisions require careful consideration of both the potential for aneurysm rupture as well as the risks associated with repair. Studies examining the natural history of UIA, the morbidity and mortality associated with subarachnoid hemorrhage (SAH), and the various treatment options have led to general guidelines for UIA management. In the literature, the simultaneous presence of otologic disease and UIA has not been introduced or addressed. It is unknown whether surgical treatment of middle ear disease has an effect on the natural history of UIA. STUDY DESIGN: Two illustrative patients with UIA discovered incidentally on radiographic evaluation of middle ear disease are presented. METHODS: Patients were managed according to diagnostic and treatment strategies developed and validated in the neurosurgical literature. RESULTS: Both patients underwent uneventful endovascular embolization of their intracranial aneurysms before middle ear surgery. The intra- and postoperative courses were uncomplicated without symptoms related to either their history of intracranial aneurysms or the prior embolization. CONCLUSIONS: Application of neurosurgical diagnostic and treatment algorithms to otology patients in the perioperative setting is appropriate. Established risk factors such as the size and location of the intracranial aneurysm, prior SAH, and patient age should guide treatment planning in all cases of UIA. Additional research is needed to evaluate the influence of otologic procedures on the natural history of UIA. In addition, studies are needed to evaluate the role of preoperative screening for UIA in otologic surgery candidates

Segmental mandibulectomy leads to a great deficit in the form and function of the patient. Vascularised bone flaps have become the choice of the method of reconstruction of the mandible in an oncologic setting. Fibula osseous or oseteocutaneous flaps have become the favored method in centers across the world. This article reviews certain pertinent and practical points with regards to fibula flap reconstruction of the mandible. Methods of osteosynthesis, merits of inclusion of the FHL muscle in the flap and use of osteointegrated implants are discussed in detail. The reader will also be able at the end to understand the role of pre operative vascular imaging, steps taken when there is an irreversible flap failure and steps to maintain and rehabilitate occlusion as practiced in the author's service