Visual evoked potentials show strong positive association with intracranial pressure in patients with cryptococcal meningitis

Abstract

Objective : To verify the relationship between intracranial pressure and flash visual evoked potentials (F-VEP) in patients with cryptococcal meningitis. Method The sample included adults diagnosed with cryptococcal meningitis admitted at a reference hospital for infectious diseases. The patients were subjected to F-VEP tests shortly before lumbar puncture. The Pearson’s linear correlation coefficient was calculated and the linear regression analysis was performed. Results : Eighteen individuals were subjected to a total of 69 lumbar punctures preceded by F-VEP tests. At the first lumbar puncture performed in each patient, N2 latency exhibited a strong positive correlation with intracranial pressure (r = 0.83; CI = 0.60 - 0.94; p < 0.0001). The direction of this relationship was maintained in subsequent punctures. Conclusion : The intracranial pressure measured by spinal tap manometry showed strong positive association with the N2 latency F-VEP in patients with cryptococcal meningitis.

Vision loss in an AIDS patient with cryptococcal meningitis

“…In our patient, the mechanism for vision loss may be due to direct infiltration of optic nerve or damage to the pathway, although this was not supported by the MRI scan. Studies suggested that the direct infection of the optic nerve with Cryptococcus can also result in rapidly progressing optic neuropathy and permanent damage to the optic nerve [3,10]. However, compared to other case reports, it is important to mention that our patient did not have visual pathway affection in the MRI scan nor papilledema on examination.…”

“…Also, inflammatory compression of optic never, adhesive arachnoiditis, cerebral vasculitis, intracranial hypertension, and amphotericin B toxicity can also lead to vision loss [[6], [7], [8], [9]]. Raised intracranial pressure leading to visual loss is considered the most common mechanism of vision loss [10,11]. Antifungal therapeutics may not be sufficient even with early detection of infection, necessitating aggressive interventions to lower the intracranial pressure to reduce the visual complications and may also prevent permanent visual loss [7].…”

Multimodality Monitoring in Neurocritical Care: Decision-Making Utilizing Direct And Indirect Surrogate Markers

“…(continued) Prospective study, 15 patients This study found that using flash visual evoked potentials (FVEPs) to monitor ICP is unreliable, as this method has a wide range of latency, amplitude, and waveform across normal participants and high intraindividual variability overtime. Vieira et al, 2015 48 Prospective study, 18 patients This study found FVEP N2 latency exhibits a strong positive correlation with intracranial pressure (r ¼ 0.83, CI ¼ 0.60-0.94; P < .0001).…”

“…18,47 Any dysfunction of this pathway can be monitored by changes in the waveforms of these visual - evoked potentials (VEPs). 18,48 With regard to ICP, research has shown that latency of N2 and P3 waves of the VEP waveform can indicate changes in ICP. 48,49 A linear relationship between ICP and the latency of P3 has also been indicated when using high-density electrode arrays and independent component analysis extraction.…”

Noninvasive methods of detecting increased intracranial pressure

“…Several studies have reported a positive correlation between ICP and F-VEP N2 wave latency with correlation coefficients ranging from 0.83 to 0.84 [89,90]. Similarly, Gumerlock et al found that a F-VEP N2 latency >80 ms linearly corresponded to an ICP > 20 cmH 2 O [91].…”