Faculty Bibliography

Studies of hand manipulation neurons in posterior parietal cortex of monkeys suggest that their spike trains represent objects by the hand postures needed for grasping or by the underlying patterns of muscle activation. To analyze the role of hand kinematics and object properties in a trained prehension task, we correlated the firing rates of neurons in anterior area 5 with hand behaviors as monkeys grasped and lifted knobs of different shapes and locations in the workspace. Trials were divided into four classes depending on the approach trajectory: forward, lateral, and local approaches, and regrasps. The task factors controlled by the animal-how and when he used the hand-appeared to play the principal roles in modulating firing rates of area 5 neurons. In all, 77% of neurons studied (58/75) showed significant effects of approach style on firing rates; 80% of the population responded at higher rates and for longer durations on forward or lateral approaches that included reaching, wrist rotation, and hand preshaping prior to contact, but only 13% distinguished the direction of reach. The higher firing rates in reach trials reflected not only the arm movements needed to direct the hand to the target before contact, but persisted through the contact, grasp, and lift stages. Moreover, the approach style exerted a stronger effect on firing rates than object features, such as shape and location, which were distinguished by half of the population. Forty-three percent of the neurons signaled both the object properties and the hand actions used to acquire them. However, the spread in firing rates evoked by each knob on reach and no-reach trials was greater than distinctions between different objects grasped with the same approach style. Our data provide clear evidence for synergies between reaching and grasping that may facilitate smooth, coordinated actions of the arm and hand

Cases of carcinoma metastatic to the nasal cavity are rare. We report the case of a 63-year-old woman with a metastasis to the nasal cavity from a primary tracheal adenoid cystic carcinoma (ACC). The nasal tumor was treated with surgical resection. No evidence of any local recurrence was observed at 4 years of follow-up. To the best of our knowledge, no case of a tracheal ACC metastatic to the nasal cavity has been previously reported in the literature. Although rare, metastatic disease to the nasal cavity should be considered in patients who have a known primary carcinoma elsewhere and who present with nasal symptoms.

OBJECTIVE: The objective of this study was to assess whether training on speech processed with an eight-channel noise vocoder to simulate the output of a cochlear implant would produce transfer of auditory perceptual learning to the recognition of nonspeech environmental sounds, the identification of speaker gender, and the discrimination of talkers by voice. DESIGN: Twenty-four normal-hearing subjects were trained to transcribe meaningful English sentences processed with a noise vocoder simulation of a cochlear implant. An additional 24 subjects served as an untrained control group and transcribed the same sentences in their unprocessed form. All subjects completed pre- and post-test sessions in which they transcribed vocoded sentences to provide an assessment of training efficacy. Transfer of perceptual learning was assessed using a series of closed set, nonlinguistic tasks: subjects identified talker gender, discriminated the identity of pairs of talkers, and identified ecologically significant environmental sounds from a closed set of alternatives. RESULTS: Although both groups of subjects showed significant pre- to post-test improvements, subjects who transcribed vocoded sentences during training performed significantly better at post-test than those in the control group. Both groups performed equally well on gender identification and talker discrimination. Subjects who received explicit training on the vocoded sentences, however, performed significantly better on environmental sound identification than the untrained subjects. Moreover, across both groups, pre-test speech performance and, to a higher degree, post-test speech performance, were significantly correlated with environmental sound identification. For both groups, environmental sounds that were characterized as having more salient temporal information were identified more often than environmental sounds that were characterized as having more salient spectral information. CONCLUSIONS: Listeners trained to identify noise-vocoded sentences showed evidence of transfer of perceptual learning to the identification of environmental sounds. In addition, the correlation between environmental sound identification and sentence transcription indicates that subjects who were better able to use the degraded acoustic information to identify the environmental sounds were also better able to transcribe the linguistic content of novel sentences. Both trained and untrained groups performed equally well ( approximately 75% correct) on the gender-identification task, indicating that training did not have an effect on the ability to identify the gender of talkers. Although better than chance, performance on the talker discrimination task was poor overall ( approximately 55%), suggesting that either explicit training is required to discriminate talkers' voices reliably or that additional information (perhaps spectral in nature) not present in the vocoded speech is required to excel in such tasks. Taken together, the results suggest that although transfer of auditory perceptual learning with spectrally degraded speech does occur, explicit task-specific training may be necessary for tasks that cannot rely on temporal information alone

PURPOSE: To systematically review the literature examining the effects of neuromuscular electrical stimulation (NMES) on swallowing and neural activation. The review was conducted as part of a series examining the effects of oral motor exercises (OMEs) on speech, swallowing, and neural activation. METHOD: A systematic search was conducted to identify relevant studies published in peer-reviewed journals from 1960 to 2007. All studies meeting the exclusion/inclusion criteria were appraised for quality and categorized as efficacy or exploratory research based on predetermined criteria. RESULTS: Out of 899 citations initially identified for the broad review of OMEs, 14 articles relating to NMES qualified for inclusion. Most of the studies (10/14) were considered exploratory research, and many had significant methodological limitations. CONCLUSIONS: This systematic review reveals that surface NMES to the neck has been most extensively studied with promising findings, yet high-quality controlled trials are needed to provide evidence of efficacy. Surface NMES to the palate, faucial pillars, and pharynx has been explored in Phase I research, but no evidence of efficacy is currently available. Intramuscular NMES has been investigated in a single Phase I exploratory study. Additional research is needed to document the effects of such protocols on swallowing performance.

OBJECTIVES: To determine the efficacy and describe the evolution of the "components separation" technique for abdominal wall repair in 200 consecutive patients. DESIGN: Retrospective medical record review. SETTING: Northwestern Memorial Hospital, Chicago, Illinois. PATIENTS: Two hundred consecutive patients who underwent ventral hernia repair using the components separation technique. INTERVENTIONS: Biological and permanent meshes were used in select patients to augment the repair of the midline fascial closure but were not used as "bridging" materials. MAIN OUTCOME MEASURES: Hernia recurrence rates and major and minor complication rates for the overall series and for the different techniques. RESULTS: Primary components separation (n = 158) yielded a 22.8% recurrence rate. Closure of the midline tissues with augmentation of the repair using an acellular cadaveric dermis underlay (n = 18) had a 33.3% recurrence rate requiring a second operation, whereas intra-abdominal soft polypropylene mesh (n = 18) had 0% recurrence (P = .04). Elevated body mass index was a significant risk factor predicting hernia recurrence (P = .003). Contamination (P = .04) and enterocutaneous fistula (P = .02) at the time of surgery were associated with increased major complications, whereas body mass index (P = .01) and diabetes mellitus (P = .04) were associated with increased minor complications. CONCLUSIONS: Large complex hernias can be reliably repaired using the components separation technique despite the presence of open wounds, the need for bowel surgery, and numerous comorbidities. The long-term strength of the hernia repair is not augmented by acellular cadaveric dermis but seems to be improved with soft polypropylene mesh.

A 40-year-old man presented with bradycardia, left eye pain, and intermittent nausea 1 day after blunt trauma to the left orbit. Imaging revealed a large orbital floor fracture with significant herniation of orbital contents but no obvious extraocualar muscle entrapment. Oculocardiac reflex was suspected, and the fracture was repaired surgically within 24 hours of presentation. His bradycardia resolved immediately postoperatively. This case is a unique presentation of the oculocardiac reflex in a large orbital floor fracture with significant herniation of orbital contents but without extraocualar muscle entrapment