To investigate the clinical value of pattern reversal visual evoked potential (P-VEP) in early diagnosis and assessment of optic nerve injury caused by neurosyphilis.

Total of 21 neurosyphilis patients with abnormal P100 wave latency and with P-VEP examination in Beijing Ditan Hospital, Capital Medical University from January 2016 to December 2019 were collected and the P-VEP results, clinical manifestations, characteristics of cerebrospinal fluid and serum indicators were analyzed, respectively.

Among the 21 patients with abnormal P-VEP, most were male (76%, 16/21). The mean age was (45.0 ± 11.5) years old. There were 17 patients with positive ocular symptoms and 4 patients with negative ocular symptoms. All patients with abnormal P-VEP neurosyphilis had optic nerve damage, whether symptomatic or asymptomatic. The abnormality of P-VEP was mainly manifested as prolonged latency of P100 wave. Of the abnormal eyes of P100 latency [(135.16 ± 22.21) ms] was significantly longer than that of normal eyes [(92.75 ± 8.26) ms], with significant difference (t =-2.813, P = 0.007). Patients with positive ocular symptoms had a longer latency of P100 wave [(137.94 ± 23.12) ms] than patients without ocular symptoms [(120.33 ± 5.50) ms], with significant difference (t = 1.28, P = 0.217). There was no correlation between P100 wave latency and white blood cells (r = 0.349, P = 0.155) and protein (r = 0.240, P = 0.323) of cerebrospinal fluid. The clinical data of 8 reexamined patients were analyzed and the changes of P100 wave latency were not consistent with the biochemical manifestations of serum and cerebrospinal fluid (all P > 0.05). Five of the eyes presented P100 wave absence, which did not improve during 6 months after treatment. P100 wave deletion may indicate that the optic nerve damage was irreversible.

Prolonged latency of P100 wave or absence of waveforms in patients with neurosyphilis may indicate optic nerve damage. The absence of a P100 wave form may indicate severe and irreversible optic nerve damage. Abnormal P-VEP may indicate neurosyphilis optic nerve damage earlier than clinical symptoms. It provides a basis for determining the optic nerve damage and the degree of damage in patients with neurosyphilis.