Klinik und Poliklinik für Neurologie, Universität Leipzig,
Leipzig, Germany; Translational Centre for Regenerative Medicine (TRM-Leipzig),
Universität Leipzig, Leipzig, Germany.
ObjectiveVisual evoked potentials (VEP) may be suitable
surrogate outcome measures in multiple sclerosis (MS) remyelination trials. The
extent of spontaneous changes of subclinically delayed VEP is unknown, whereas
VEP improve after acute optic neuritis (ON).MethodsIn all, 124 patients with
three VEP recordings at least 3 months apart: 71 patients with MS who had never
suffered clinical ON; 53 patients with ON (isolated ON or ON as an attack of MS
at first recording). Latencies of P100 were analyzed by multivariate analysis of
variance.ResultsEyes of patients with MS had a mean P100 latency of 110.2 ms,
worsening mildly over time (n = 104 eyes, P = 0.022). MS patients' eyes with
subclinical demyelination (delayed P100 latency at first recording >116 ms)
showed no significant evidence of remyelination (n = 24 eyes, P = 0.27). By
contrast, in ON patients' affected eyes, mean P100 latency decreased (P =
0.001), whereas unaffected eyes remained stable (P = 0.26). Clinically
non-affected eyes from both diagnostic groups with subclinically prolonged
latencies remained stable (n = 32: mean P100 at 124.8 +/- 10.7, 123.5 +/- 13.6,
and 122.8 +/- 13.1 ms; P = 0.57), whereas non-affected eyes with normal latency
at baseline deteriorated slightly (P = 0.001). A subgroup with more
homogeneously defined follow-up periods confirmed this observation. Non-affected
eyes selected for stability (difference <5 ms) between first and second
recording deteriorated (normal baseline, n = 66 eyes, P = 0.013) or remained
stable (prolonged baseline, n = 18 eyes, 95% confidence interval of change -5.42
to +6.89 ms, P = 0.805).ConclusionProlonged P100 latencies in eyes never
affected by clinical ON remain stable and thus can be used as surrogate outcome
measure for remyelination trials.
PMID: 18701569 [PubMed - as supplied by publisher]
