Faculty Bibliography

This paper proposes a parametric model for saccadic waveforms. The model has a small number of parameters, yet it effectively simulates a variety of physiologic saccade properties. In particular, the model reproduces the established relationship between peak saccadic angular velocity and saccadic amplitude (i.e., the saccadic main sequence). The proposed saccadic waveform model can be used in the evaluation and validation of methods for quantitative saccade analysis. For example, we use the proposed saccade model to evaluate four well-known saccade detection algorithms. The comparison indicates the most reliable algorithm is one by Nystrom et al. We further use the proposed saccade model to evaluate the standard technique used for the estimation of peak saccadic angular velocity. The evaluation shows the occurrence of systematic errors. We thus suggest that saccadic angular velocity values determined by the standard technique (low-pass differentiation) should be interpreted and used with caution.

Objective: Progressive ataxia with palatal tremor (PAPT) is a rare clinical syndrome characterized by progressive imbalance, dysarthria and visual disturbances. Neuroimaging typically demonstrates hypertrophy and T2 hyperintensity of the olivary complexes. To date, only a few cases of sporadic PAPT have been reported in the literature. Here, we present a patient with idiopathic, degenerative progressive cerebellar ataxia with palatal tremor. Methods: An 80-year-old male presented with two-year history of slowly progressive truncal ataxia, incoordination, dysarthria, dysphagia and visual disturbances. The patient had no history of stroke, demyelinating disease, autonomic dysfunction or other movement disorders. There was no significant family history. Results: Neurological examination was significant for dysarthric speech, dysmetria on finger-nose-finer test, dysdiadochokinesis, axial ataxia, mild bradykinesia, subtle hypermetric saccades and palatal myoclonus 2 Hz, (without an audible click). There was no nystagmus. Paraneoplastic antibodies, including GAD-65, were not present. MRI showed bilateral, symmetric hypertrophy and T2/FLAIR hyperintensity in the inferior olivary nuclei. Conclusion: Sporadic PAPT may be more common than previously thought. Careful clinical examination (including observation of the soft palate for myoclonic movements) may help to reveal the diagnosis. This presentation should be included in the differential diagnosis of hypertrophic olivary degeneration secondary to vascular or demyelinating lesion within the triangle of Guillain-Mollaret

Although primary dystonia is defined by its characteristic motor manifestations, non-motor signs and symptoms have increasingly been recognized in this disorder. Recent neuroimaging studies have related the motor features of primary dystonia to connectivity changes in cerebello-thalamo-cortical pathways. It is not known, however, whether the non-motor manifestations of the disorder are associated with similar circuit abnormalities. To explore this possibility, we used functional magnetic resonance imaging to study primary dystonia and healthy volunteer subjects while they performed a motion perception task in which elliptical target trajectories were visually tracked on a computer screen. Prior functional magnetic resonance imaging studies of healthy subjects performing this task have revealed selective activation of motor regions during the perception of 'natural' versus 'unnatural' motion (defined respectively as trajectories with kinematic properties that either comply with or violate the two-thirds power law of motion). Several regions with significant connectivity changes in primary dystonia were situated in proximity to normal motion perception pathways, suggesting that abnormalities of these circuits may also be present in this disorder. To determine whether activation responses to natural versus unnatural motion in primary dystonia differ from normal, we used functional magnetic resonance imaging to study 10 DYT1 dystonia and 10 healthy control subjects at rest and during the perception of 'natural' and 'unnatural' motion. Both groups exhibited significant activation changes across perceptual conditions in the cerebellum, pons, and subthalamic nucleus. The two groups differed, however, in their responses to 'natural' versus 'unnatural' motion in these regions. In healthy subjects, regional activation was greater during the perception of natural (versus unnatural) motion (P < 0.05). By contrast, in DYT1 dystonia subjects, activation was relatively greater during the perception of unnatural (versus natural) motion (P < 0.01). To explore the microstructural basis for these functional changes, the regions with significant interaction effects (i.e. those with group differences in activation across perceptual conditions) were used as seeds for tractographic analysis of diffusion tensor imaging scans acquired in the same subjects. Fibre pathways specifically connecting each of the significant functional magnetic resonance imaging clusters to the cerebellum were reconstructed. Of the various reconstructed pathways that were analysed, the ponto-cerebellar projection alone differed between groups, with reduced fibre integrity in dystonia (P < 0.001). In aggregate, the findings suggest that the normal pattern of brain activation in response to motion perception is disrupted in DYT1 dystonia. Thus, it is unlikely that the circuit changes that underlie this disorder are limited to primary sensorimotor pathways.

Introduction Pituitary neoplasms are benign entities that require distinct diagnostic and treatment considerations. Recent advances in endoscopic transsphenoidal surgery have resulted in shorter lengths of stay (LOS). We implemented a postoperative day (POD) 1 discharge paradigm involving a multidisciplinary approach and detailed preoperative evaluation and review of both medical and socioeconomic factors. Methods The experience of a single neurosurgeon/ears, nose, throat (ENT) team was reviewed, generating a preliminary retrospective database of the first 30 patients who underwent resection of pituitary lesions under the POD 1 discharge paradigm. We assessed multiple axes from their preoperative, in-house, and postoperative care. Results There were 14 men and 16 women with an average age of 53.8 years (range: 27-76 years). There were 22 nonsecretory and 8 secretory tumors with average size of 2.80 cm (range: 1.3-5.0 cm). All 30 patients underwent preoperative ENT evaluation. Average LOS was 1.5 +/- 0.7 days. A total of 18 of 30 patients were discharged on POD 1. The insurance status included 15 with public insurance such as emergency Medicaid and 15 with private insurance. Four patients had transient diabetes insipidus (DI); none had permanent DI. Overall, 28 of 30 patients received postoperative steroids. Factors that contributed to LOS > 1 day included public insurance status, two or more medical comorbidities, diabetes mellitus, transient panhypopituitarism, and DI. Conclusion The implementation of a POD 1 discharge plan for pituitary tumors is feasible and safe for elective patients. This implementation requires the establishment of a dedicated Pituitary Center model with experienced team members. The consistent limitation to early discharge was socioeconomic status. Efforts that incorporate the analysis of social disposition parameters with proper management of clinical sequelae are crucial to the maintenance of ideal LOS and optimal patient outcomes.

An 18-year-old woman underwent an uneventful ascending aortic aneurysm repair then developed progressive supranuclear palsy-like syndrome. Extensive neuroimaging including contrasted fat-suppressed cranial and orbital magnetic resonance imaging (MRI), MRI tractography, and functional MRI (fMRI) revealed no clear radiographic involvement except for a single tiny hypoechoic midbrain dot on the T2*-weighted gradient-echo imaging, which is not considered sufficient to account for the patient's deficits. This case attests to the occult nature of this rare and devastating syndrome.

OBJECTIVE: This study examined components of the Sports Concussion Assessment Tool, 3rd Edition (SCAT3) and a vision-based test of rapid number naming (King-Devick [K-D]) to evaluate sports and non-sports concussion patients in an outpatient, multidisciplinary concussion center. While the Symptom Evaluation, Standardized Assessment of Concussion (SAC), modified Balance Error Scoring System (BESS), and K-D are used typically for sideline assessment, their use in an outpatient clinical setting following concussion has not been widely investigated. METHODS: K-D, BESS, SAC, and SCAT3 Symptom Evaluation scores were analyzed for 206 patients who received concussion care at the Concussion Center at NYU Langone Medical Center. Patient age, gender, referral data, mechanism of injury, time between concussive event and first concussion center appointment, and the first specialty service to evaluate each patient were also analyzed. RESULTS: In this cohort, Symptom Evaluation scores showed a higher severity and a greater number of symptoms to be associated with older age (r=0.31, P=0.002), female gender (P=0.002, t-test), and longer time between the concussion event and first appointment at the concussion center (r=0.34, P=0.008). Performance measures of K-D and BESS also showed associations of worse scores with increasing patient age (r=0.32-0.54, P