are identified. Larger studies to determine the risk factors that iden-tify these prognostic factors are warranted.

doi:10.1016/j.jocn.2010.07.038

38. Neuropathy: An integral component of cerebellar ataxianeuropathy vestibular areflexia syndromeDavid J. Szmulewicz a, John A. Waterston a, Michael Halmagyi b,Stuart Mossman c, Andrew Chancellor d, Catriona A. McLean a, ElsdonStorey a

a The Alfred Hospital, VICb Royal Prince Alfred Hospital, NSWc Capital Coast Health, New Zealandd New Zealand

Aim: The syndrome of cerebellar ataxia with bilateral vestibulop-athy was delineated in 2004. Sensory neuropathy was mentioned in3 of the 4 patients described. We aimed to characterize and estimatethe frequency of neuropathy in this condition, and determine its typ-ical MRI features.

Methods: Retrospective review of 18 subjects (including 4 fromthe original description) who met the criteria for bilateral vestibu-lopathy with cerebellar ataxia.

Results: The reported age of onset range was 39–71, and symp-tom duration was 3–38 years. The syndrome was identified in onesibling pair, suggesting that this may be a late-onset recessive disor-der, although the other 16 cases were apparently sporadic. All 18 hadsensory neuropathy with absent sensory nerve action potentials,although this was not apparent clinically in two, and the presenceof neuropathy was not a selection criterion. In 5, the loss of pin-pricksensation was virtually global, mimicking a neuronopathy. However,findings in the other 11 with clinically manifest neuropathy sug-gested a length-dependent neuropathy. MRI scans showed cerebellaratrophy in 16, involving anterior and dorsal vermis, and hemisphericcrus I, while two were normal. The inferior vermis and brainstemwere spared.

Conclusions: Sensory neuropathy is an integral component of thissyndrome. It may result in severe sensory loss, which contributessignificanctly to the disability. The MRI changes are not specific,but, coupled with loss of sensory nerve action potentials, may aiddiagnosis. We propose a new name for the condition – CANVAS (Cer-ebellar Ataxia Neuropathy Vestibular Areflexia Syndrome).

doi:10.1016/j.jocn.2010.07.039

39. The greatest benefit to mankind; the virtues in clinical med-icine and beyondStephen Sergay

Tampa Neurology Associates, USA

Better quality science, education and clinical care, delivered mostcost effectively, can be the product of health care planning wheneconomic and structural health care planning intersect with themost intimate component of physician professionalism, the moralphilosophy of doctoring, more recently exemplified by the charactervirtues of the doctor. It is medicine’s responsibility to carry this mes-sage to the healthcare planning table. Our moral philosophy, whichis patient centered, has developed over centuries and carries with itour sense of responsibility and integrity. I will discuss how this ulti-mate source of appropriate physician motivation and behavior is

threatened by technology and the social and economic issues ofthe day and I will propose a solution to the profound challengeswe face.

doi:10.1016/j.jocn.2010.07.040

40. Large scale EEG recordings and seizure generationGreg Worrell

Mayo Clinic, USA

His research is integrated with a clinical practice focused onpatients with medically resistant epilepsy. The current focus of hisresearch is the use of large-scale system electrophysiology, brainstimulation, and data mining to identify and track electrophysiolog-ical biomarkers of epileptic brain and seizure generation.

Electrophysiology is an important clinical and research tool forinvestigation of human brain. It is now possible to probe neuralactivity across a wide range of spatiotemporal scales; from extracel-lular action potentials of single neurons, local field potentials of neu-ronal assemblies, to macroscale clinical EEG. To investigate thespatiotemporal scales characterizing the genesis of focal seizuresin humans, our group is performing wide bandwidth, continuous,long-term recordings in patients undergoing evaluation for epilepsysurgery. Here we report evidence that human epileptic brain is orga-nized on spatial scales not probed by clinical EEG. In epileptic brainseizure-like events, called microseizures, were isolated to singlemicroelectrodes, and not seen on macroelectrodes. Microseizuresexhibit a wide range of spectral dynamics and occur asynchronouslyin non-contiguous regions of brain. Microseizures were increased inbrain regions generating seizures and rare in brain regions not gen-erating seizures, and were absent in control brain from patientswithout a history of seizures. Based on these findings we proposethat epileptic brain is composed of pathological microcircuits gener-ating microseizures that may be an early electrographic signature ofictogenesis.

doi:10.1016/j.jocn.2010.07.041

41. Essential tremorDavid Williams

Alfred Hospital and Monash University, VIC

The earliest descriptions of essential tremor (ET) in the 19th cen-tury reported isolated tremor as a benign ‘‘constitutional property”of sufferers that was absolutely heritable. Contemporary expertsdebate most of these issues. ET is arguably the most prevalent move-ment disorder in the community, affecting up to 14% of people over65 years of age. It is most often benign and to a large extent hered-itary, but despite this no monogenetic causes of ET have been iden-tified. A proportion of patients with ET have cognitive slowing,cerebellar signs or parkinsonism, suggesting an association withbroader neurological dysfunction than isolated tremor. Most cer-tainly in a small proportion of patients tremor can become entirelydisabling, requiring full assistance in daily care needs. Therapeuticoptions are no longer limited to primidone and propranolol, withtopiramate and gabapentin emerging as modern treatment options.Deep brain stimulation does effectively provide curative treatmentfor those with disabling tremor, even in those older than 80. Theconcept of benign tremor is further challenged by recent associationsof ET with post-mortem cerebellar neurodegeneration and an

1622 Abstracts / Journal of Clinical Neuroscience 17 (2010) 1610–1638