Evaluation of pattern-reversal visual evoked potential in patients with neuromyelitis optica.
BACKGROUND
The visual evoked potential (VEP) is used in the evaluation of multiple sclerosis (MS) patients, showing a delay in P100 wave latency with no changes in amplitude in 60-100% of cases. In the last decade, the recurrent form of neuromyelitis optica (NMO) has been recognized, and clinically characterized by acute events of transverse myelitis (TM) and optic neuritis (ON), differing from MS in clinical and laboratory criteria. Despite these differences, so far, the VEP parameters described in MS have been used in the evaluation of patients with NMO. The objective of this study was to investigate VEP responses in NMO.


METHODS
Patients with NMO underwent pattern-reversal visual stimulation. Nineteen patients were selected for the study.


RESULTS
Among the 38 eyes examined, 18 (47.4%) had no visual evoked responses and 13 (34.2%) had a reduction of P100 wave amplitude with normal latency. Only two (5.3%) had the pattern described in MS and five (13.2%) were normal.


CONCLUSIONS
Evaluation of VEP in patients with definite NMO revealed a pattern that is different from that of MS in 81.6% of eyes examined, characterized by the absence of responses, or decreased amplitude with normal latency.
Postgraduate Program in Neurology, Federal University of the State of Rio de Janeiro, Brazil.
Silvio P
SP
Neto
Regina M P
RM
Alvarenga
Claudia C F
CC
Vasconcelos
Marina P
MP
Alvarenga
Luiz C
LC
Pinto
Vera L R
VL
Pinto
D000293:Adolescent; D000328:Adult; D004185:Disability Evaluation; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000503:physiopathology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D014787:Vision Tests; D014792:Visual Acuity; D055815:Young Adult
D007074:Immunoglobulin G