Pupillary disturbances in multiple sclerosis: correlation with MRI findings.

UNLABELLED: Autonomic nervous system disturbances such as pupillary abnormalities have rarely been evaluated in multiple sclerosis (MS). However, pupillary impairment is not uncommon in MS and its origin is still unclear. The aim of this study was to investigate pupillary disturbances in MS and to try to correlate pupillary defects with spinal cord and brainstem magnetic resonance imaging (MRI) findings. We prospectively studied 45 MS patients and 30 normal subjects. METHODS: The pupillary contraction latency and the amplitude of contraction were recorded by pupillometry. We also determined afferent and efferent pathway defects by comparing the direct and consensual pupillary reflexes. We evaluated brainstem and spinal cord demyelinating lesions and spinal cord cross-sectional area on MRI. At least one pupillometric parameters were significantly impaired in 60% of patients and in none of the controls. We did not find any correlation between pupillary defect and demyelinating lesions on MRI. The most frequent abnormality was efferent pathway shift and this was correlated with spinal cord atrophy (P<0.02). These results confirm that the autonomic nervous system, and especially pupillary function, is frequently impaired in MS. The parasympathetic system is most commonly affected and this is most likely linked to axonal loss (demonstrated by spinal cord atrophy) rather than to demyelinating lesions.

Do visual-evoked potentials and spatiotemporal contrast sensitivity help to distinguish idiopathic Parkinson's disease and multiple system atrophy?

A large number of patients with Parkinson's disease were reported to have abnormal visual-evoked potentials (VEPs) and spatiotemporal contrast sensitivity (STCS) suggesting dopaminergic deficiency in the visual pathway, probably the retina. Until now, VEPs and STCS have not been studied in multiple system atrophy (MSA). We investigated 12 patients with idiopathic Parkinson's disease (IPD) and 12 patients with MSA. The age medians were 64.5 years for IPD and 63.5 years for MSA. None of the patients showed any ocular disease that could interfere with the results. Checkboard VEPs and STCS measurements to horizontal sinusoidal gratings were evaluated. Statistical analysis was performed, including Student's t test and two- or three-way analysis of variance. A significant interocular difference in spatial contrast sensitivity was observed in IPD, which was not present in MSA. VEPs were not delayed in MSA, whereas latency of the major component and the second negative deflection were increased in IPD. VEPs and STCS measurements might provide useful help for distinguishing IPD from MSA.