The long-term effects of antiepileptic drugs on the visual system in rats: Electrophysiological and histopathological studies

Yoshinobu Goto, Takayuki Taniwaki, Junya Shigematsu, Shozo Tobimatsu

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Objective: We quantified the long-term effects of antiepileptic drugs (AEDs) on the visual system of rats using electroretinograms (ERGs) and visual evoked potentials (VEPs). Methods: Twenty adult Sprague-Dawley rats were divided into 4 groups (n = 5). Each animal was treated by monotherapy of phenytoin (PHT), valproic acid (VPA), zonisamide (ZNS) or physiological saline as control. The AEDs were injected intraperitoneally daily for 180 days. ERGs and VEPs were recorded before the medication and on Days 30 and 180. Results: There were no significant changes in the 4 groups on Day 30. On Day 180, the amplitudes of a- and b-waves of dark-adapted (DA) ERGs were reduced in the PHT group compared with those of the control group. In the VPA group, the amplitudes of the DA ERG a- and b-waves, light-adapted ERG b-wave and the DA VEP were reduced. No significant changes were observed in the ZNS group. There were no histopathological changes of the retina and visual cortex in all groups. Conclusions: Our results indicate that neurons along the visual pathways have different sensitivity to each AED. This may result from the differential pharmacological actions of each AED on visual neurons. Significance: Our findings suggest that epileptic patients on long-term use of AEDs might have subclinical influences to the visual systems.

Original languageEnglish
Pages (from-to)1395-1402
Number of pages8
JournalClinical Neurophysiology
Volume114
Issue number8
DOIs
Publication statusPublished - Aug 1 2003

Fingerprint

zonisamide
Anticonvulsants
Visual Evoked Potentials
Valproic Acid
Phenytoin
Neurons
Visual Pathways
Visual Cortex
Sprague Dawley Rats
Retina
Pharmacology
Light
Control Groups

All Science Journal Classification (ASJC) codes

  • Sensory Systems
  • Neurology
  • Clinical Neurology
  • Physiology (medical)

Cite this

The long-term effects of antiepileptic drugs on the visual system in rats : Electrophysiological and histopathological studies. / Goto, Yoshinobu; Taniwaki, Takayuki; Shigematsu, Junya; Tobimatsu, Shozo.

In: Clinical Neurophysiology, Vol. 114, No. 8, 01.08.2003, p. 1395-1402.

Research output: Contribution to journalArticle

@article{e48d5fd999ab469e9deabe808ce5d372,
title = "The long-term effects of antiepileptic drugs on the visual system in rats: Electrophysiological and histopathological studies",
abstract = "Objective: We quantified the long-term effects of antiepileptic drugs (AEDs) on the visual system of rats using electroretinograms (ERGs) and visual evoked potentials (VEPs). Methods: Twenty adult Sprague-Dawley rats were divided into 4 groups (n = 5). Each animal was treated by monotherapy of phenytoin (PHT), valproic acid (VPA), zonisamide (ZNS) or physiological saline as control. The AEDs were injected intraperitoneally daily for 180 days. ERGs and VEPs were recorded before the medication and on Days 30 and 180. Results: There were no significant changes in the 4 groups on Day 30. On Day 180, the amplitudes of a- and b-waves of dark-adapted (DA) ERGs were reduced in the PHT group compared with those of the control group. In the VPA group, the amplitudes of the DA ERG a- and b-waves, light-adapted ERG b-wave and the DA VEP were reduced. No significant changes were observed in the ZNS group. There were no histopathological changes of the retina and visual cortex in all groups. Conclusions: Our results indicate that neurons along the visual pathways have different sensitivity to each AED. This may result from the differential pharmacological actions of each AED on visual neurons. Significance: Our findings suggest that epileptic patients on long-term use of AEDs might have subclinical influences to the visual systems.",
author = "Yoshinobu Goto and Takayuki Taniwaki and Junya Shigematsu and Shozo Tobimatsu",
year = "2003",
month = "8",
day = "1",
doi = "10.1016/S1388-2457(03)00128-7",
language = "English",
volume = "114",
pages = "1395--1402",
journal = "Clinical Neurophysiology",
issn = "1388-2457",
publisher = "Elsevier Ireland Ltd",
number = "8",

}

TY - JOUR

T1 - The long-term effects of antiepileptic drugs on the visual system in rats

T2 - Electrophysiological and histopathological studies

AU - Goto, Yoshinobu

AU - Taniwaki, Takayuki

AU - Shigematsu, Junya

AU - Tobimatsu, Shozo

PY - 2003/8/1

Y1 - 2003/8/1

N2 - Objective: We quantified the long-term effects of antiepileptic drugs (AEDs) on the visual system of rats using electroretinograms (ERGs) and visual evoked potentials (VEPs). Methods: Twenty adult Sprague-Dawley rats were divided into 4 groups (n = 5). Each animal was treated by monotherapy of phenytoin (PHT), valproic acid (VPA), zonisamide (ZNS) or physiological saline as control. The AEDs were injected intraperitoneally daily for 180 days. ERGs and VEPs were recorded before the medication and on Days 30 and 180. Results: There were no significant changes in the 4 groups on Day 30. On Day 180, the amplitudes of a- and b-waves of dark-adapted (DA) ERGs were reduced in the PHT group compared with those of the control group. In the VPA group, the amplitudes of the DA ERG a- and b-waves, light-adapted ERG b-wave and the DA VEP were reduced. No significant changes were observed in the ZNS group. There were no histopathological changes of the retina and visual cortex in all groups. Conclusions: Our results indicate that neurons along the visual pathways have different sensitivity to each AED. This may result from the differential pharmacological actions of each AED on visual neurons. Significance: Our findings suggest that epileptic patients on long-term use of AEDs might have subclinical influences to the visual systems.

AB - Objective: We quantified the long-term effects of antiepileptic drugs (AEDs) on the visual system of rats using electroretinograms (ERGs) and visual evoked potentials (VEPs). Methods: Twenty adult Sprague-Dawley rats were divided into 4 groups (n = 5). Each animal was treated by monotherapy of phenytoin (PHT), valproic acid (VPA), zonisamide (ZNS) or physiological saline as control. The AEDs were injected intraperitoneally daily for 180 days. ERGs and VEPs were recorded before the medication and on Days 30 and 180. Results: There were no significant changes in the 4 groups on Day 30. On Day 180, the amplitudes of a- and b-waves of dark-adapted (DA) ERGs were reduced in the PHT group compared with those of the control group. In the VPA group, the amplitudes of the DA ERG a- and b-waves, light-adapted ERG b-wave and the DA VEP were reduced. No significant changes were observed in the ZNS group. There were no histopathological changes of the retina and visual cortex in all groups. Conclusions: Our results indicate that neurons along the visual pathways have different sensitivity to each AED. This may result from the differential pharmacological actions of each AED on visual neurons. Significance: Our findings suggest that epileptic patients on long-term use of AEDs might have subclinical influences to the visual systems.

UR - http://www.scopus.com/inward/record.url?scp=0042346368&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0042346368&partnerID=8YFLogxK

U2 - 10.1016/S1388-2457(03)00128-7

DO - 10.1016/S1388-2457(03)00128-7

M3 - Article

C2 - 12888021

AN - SCOPUS:0042346368

VL - 114

SP - 1395

EP - 1402

JO - Clinical Neurophysiology

JF - Clinical Neurophysiology

SN - 1388-2457

IS - 8

ER -