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We examined frequency doubling (FD) illusion based automated perimetry (FDT) and dichoptic FD multifocal visual evoked potentials (FDmfVEPs) in Normal and multiple sclerosis (MS) subjects. Contrast thresholds were determined at 17 visual field locations using an FDT perimeter. The stimuli presented to each location were 0.25 cpd gratings presented with rapid (25 Hz) counterphase flicker and thus displayed the spatial FD illusion. Dichoptic mfVEPs were recorded by concurrently stimulating eight regions/eye with FD stimuli presented at 95% contrast. Recordings were obtained from 27 Normal subjects, 26 MS patients who had experienced Optic Neuritis (MSON) and 24 MS patients without a history of ON (MSNON). The FDT thresholds showed enhanced contrast sensitivity for MSON patients (P < 0.0001) but not for MSNON patients. Response amplitudes for the central four regions of the mfVEP stimulus were reduced in both patient groups (P < 0.005). A classification model based upon the FDT thresholds performed at a specificity of 96% for a sensitivity of 97% in MSON patients, but the accuracy (simultaneously largest sensitivities and specificities) was poor (∼60%) in MSNON patients. Discriminant models based on the FDT thresholds and FDmfVEPs were able to diagnose more that 90% MSON patients but performed poorly for MSNON patients.

Neurological syndromes occur in a significant number of patients with antiphospholipid antibodies. The optimal management for these patients however remains uncertain. Our study is a descriptive analysis looking retrospectively at 45 patients who presented to the principal tertiary referral centre in the Australian Capital Territory, with either cerebral arterial or venous thrombosis for which there was no obvious cause for their presentation when initially reviewed. The diagnosis was based on the clinical findings made by one of three neurologists attached to our centre. Radiological findings and the presence of either IgM or IgG anticardiolipin antibodies, IgG anti-beta-2 glycoprotein 1 antibodies or a lupus anticoagulant were then documented. In this group of patients three subgroups were identified: 1. Individuals that fulfilled the Sapporo Classification Criteria 2. Individuals with transiently positive antiphospholipid antibodies and 3. Individuals with persistently low positive antiphospholipid antibodies. The most interesting of these three groups are those individuals with transiently positive antiphospholipid antibodies. A potential cause for presentation was identified in only one patient of this group with documented infective endocarditis and bacteraemia. Comparison with the other two groups suggested that there was little in terms of clinical presentation, radiological findings or intercurrent risk factors for thrombotic disease to distinguish between them. With disappearance of antiphospholipid antibodies, the individuals within this group have not had further thrombotic events. Our observations emphasise the problems that continue to exist in relation to the occurrence of cerebrovascular disease in the context of antiphospholipid antibodies and the optimal management of these stratified groups. Our findings also raise an as yet unanswered question as to the signficance of these transiently positive antiphospholipid antibodies. In the absence of signi

We compared the diagnostic capabilities of contrast reversal and sparse pattern pulse stimulation for dichoptic multifocal visual evoked potentials (mfVEPs) measured in normal subjects and multiple sclerosis (MS) patients. Multifocal reponses were obtained from 27 normal subjects and 50 relapsing-remitting patients, 26 of whom had experienced optic neuritis (ON+). The patient groups were matched for length of disease and number of clinical attacks. Compared with the responses of normal subjects those of MS patients had significantly smaller response amplitudes, lower signal-to-noise ratios, more complex response waveforms, and longer response delays. The effects were larger for sparser stimuli. Sensitivities and specificities for the different stimulus types were estimated from receiver operator characteristic (ROC) plots. Bootstrap estimates of the accuracies of the ROCs for the most promising measure, the template delays, indicated the sparsest stimulus would deliver 92% sensitivity at a false-positive rate of 0%. In contrast, at 92% sensitivity the conventional mfVEP stimulus misdiagnosed more than 20% of the normal population. The results were similar for patients with no history of ON (ON-). In performing well in patients with no history of ON, the sparse mfVEPs seem to measure progressive damage associated with axon and gray matter losses rather than damage associated with a history of serious inflammation.