17 results found
Fu RZ, Anwar DR, Laban JT, et al., 2017, Pre-emptive intrathecal vancomycin therapy reduces external ventricular drain infection: a single centre retrospective case-control study, British Journal of Neurosurgery, Vol: 31, Pages: 16-20, ISSN: 0268-8697
Seemungal BM, Yousif N, Abou-El-Ela-Bourquin B, et al., 2016, Dopamine activation preserves visual motion perception despite noise interference of human V5/MT, Journal of Neuroscience, Vol: 36, Pages: 9303-9312, ISSN: 1529-2401
When processing sensory signals, the brain must account for noise, both noise in the stimulus and that arising from within its own neuronal circuitry. Dopamine receptor activation is known to enhance both visual cortical signal-to-noise-ratio (SNR) and visual perceptual performance; however, it is unknown whether these two dopamine-mediated phenomena are linked. To assess this, we used single-pulse transcranial magnetic stimulation (TMS) applied to visual cortical area V5/MT to reduce the SNR focally and thus disrupt visual motion discrimination performance to visual targets located in the same retinotopic space. The hypothesis that dopamine receptor activation enhances perceptual performance by improving cortical SNR predicts that dopamine activation should antagonize TMS disruption of visual perception. We assessed this hypothesis via a double-blinded, placebo-controlled study with the dopamine receptor agonists cabergoline (a D2 agonist) and pergolide (a D1/D2 agonist) administered in separate sessions (separated by 2 weeks) in 12 healthy volunteers in a William's balance-order design. TMS degraded visual motion perception when the evoked phosphene and the visual stimulus overlapped in time and space in the placebo and cabergoline conditions, but not in the pergolide condition. This suggests that dopamine D1 or combined D1 and D2 receptor activation enhances cortical SNR to boost perceptual performance. That local visual cortical excitability was unchanged across drug conditions suggests the involvement of long-range intracortical interactions in this D1 effect. Because increased internal noise (and thus lower SNR) can impair visual perceptual learning, improving visual cortical SNR via D1/D2 agonist therapy may be useful in boosting rehabilitation programs involving visual perceptual training.
Braga RM, Fu RZ, Seemungal BM, et al., 2016, Eye movements during auditory attention predict individual differences in dorsal attention network activity, Frontiers in Human Neuroscience, Vol: 10, ISSN: 1662-5161
The neural mechanisms supporting auditory attention are not fully understood. A dorsal frontoparietal network of brain regions is thought to mediate the spatial orienting of attention across all sensory modalities. Key parts of the this network, the frontal eye fields (FEF) and the superior parietal lobes (SPL), contain retinotopic maps and elicit saccades when stimulated. This suggests that their recruitment during auditory attention might reflect crossmodal oculomotor processes; however this has not been confirmed experimentally. Here we investigate whether task-evoked eye movements during an auditory task can predict the magnitude of activity within the dorsal frontoparietal network. A spatial and non-spatial listening task was used with on-line eye-tracking and functional magnetic resonance imaging. No visual stimuli or cues were used. The auditory task elicited systematic eye movements, with saccade rate and gaze position predicting attentional engagement and the cued sound location, respectively. Activity associated with these separate aspects of evoked eye-movements dissociated between the SPL and FEF. However these observed eye movements could not account for all the activation in the frontoparietal network. Our results suggest that the recruitment of the SPL and FEF during attentive listening reflects, at least partly, overt crossmodal oculomotor processes during non-visual attention. Further work is needed to establish whether the network’s remaining contribution to auditory attention is through covert crossmodal processes, or is directly involved in the manipulation of auditory information.
Zebian B, Hogg FRA, Fu RZ, et al., 2015, Yawning as a presenting symptom of Chiari malformation Type I: report of 2 cases, Journal of Neurosurgery: Pediatrics
awning is thought to be a behavior regulated by the brainstem. Although excessive yawning has been reported in brainstem strokes, demyelination, and tumors, the cases presented here are the first reports of excessive yawning in patients with Chiari malformation Type I (CM-I). The authors believe that brainstem compression at the craniocervical junction and ensuing edema were implicated in this curious symptomatology. They describe excessive yawning as a presenting feature of CM-I in 2 adolescent females. The presentation was acute in the first case and more chronic in the second. Both patients underwent foramen magnum decompression, which resulted in complete cessation of the excessive yawning.
Wong PY, Fu R, Marsh H, 2014, Handover practice in neurosurgery, The Online Journal of Clinical Audits, Vol: 6, ISSN: 2042-4779
Fu RZ, Geoghegan O, 2014, Neurosurgery: Practical procedures: Cerebrospinal fluid (CSF) sampling & intrathecal antibiotic administration via external ventricular drains (EVDs), Core Surgery Journal, Vol: 4, Pages: 54-60, ISSN: 2046-0198
Fu RZ, Naushahi MJ, Adams A, et al., 2014, Sub-caudal pedunculopontine nucleus (PPN) deep brain stimulation (DBS) best predicts improvements in freezing of gait questionnaire (FOGQ) scores in Parkinson’s disease patients, 18th International Congress of Parkinson’s Disease and Movement Disorders
Anwar DR, Fu RZ, Laban JT, et al., 2014, Prophylactic intrathecal (IT) antibiotics effectively reduce external ventricular drain (EVD)-related infections, Spring Meeting of the Society of British Neurological Surgeons, Publisher: Informa Healthcare, Pages: 148-148, ISSN: 0268-8697
Fu RZ, Naushahi MJ, Adams A, et al., 2014, Identifying optimal target regions for deep brain stimulation of the pedunculopontine nucleus (PPN) in Parkinson’s disease – Correlating clinical outcome with active electrode position, Spring Meeting of the Society of British Neurological Surgeons, Publisher: Informa Healthcare, Pages: 178-178, ISSN: 0268-8697
Lin D, Fu R, 2013, Osteoarthritis rates post double-bundle anterior cruciate ligament reconstruction: the story so far, 4th Bone Research Society and British Orthopaedic Research Joint Meeting, Oxford, UK
Fu RZ, Lin DD, 2013, Surgical and Biomechanical Perspectives on Osteoarthritis and the ACL Deficient Knee: A Critical Review of the Literature, The Open Orthopaedics Journal, Vol: 7, Pages: 292-300, ISSN: 1874-3250
Braga RM, Fu R, Seemungal BM, et al., 2013, Separating auditory and visual attention networks using eye tracking, 19th Annual Meeting of the Organization for Human Brain Mapping, Seattle, USA
Fu RZ, Hassan S, Geoghegan O, et al., 2013, Quality improvement exercise on external ventricular drain (EVD) access technique in a London neurosurgical department, International Forum on Quality and Safety in Health Care, London, UK
Wong PY, Benjamin P, Fu R, et al., 2013, Audit of handover practice in neurosurgery, International Forum on Quality and Safety in Health Care, London, UK
Braga RM, Fu R, Seemungal BM, et al., 2013, The visual components of auditory top-down attention, British Neuroscience Association 2013 Biennial Meeting, London
Fu R, 2013, Neurosurgery: Course Review: Operative Skills In Neurosurgery, Core Surgery Journal, Vol: 3, Pages: 52-54, ISSN: 2046-0198
Fu RZ, Laban JT, Minhas PS, et al., 2012, Intrathecal vancomycin prophylaxis for external ventricular drains (EVDs): a two-year observational study, The 2012 Autumn meeting of the Society of British Neurological Surgeons, Pages: 629-629, ISSN: 0268-8697
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