TY - JOUR
T1 - Reduced habituation of the retinal ganglion cell response to sustained pattern stimulation in multiple sclerosis patients
AU - Fadda, Antonello
AU - Di Renzo, Antonio
AU - Martelli, Francesco
AU - Marangoni, Dario
AU - Batocchi, Anna Paola
AU - Giannini, Daniela
AU - Parisi, Vincenzo
AU - Falsini, Benedetto
PY - 2013/8
Y1 - 2013/8
N2 - Objective: Sustained pattern stimulation in normal subjects induces adaptive changes in pattern electroretinogram (PERG), an effect that has been interpreted as a response of glial cells and retinal ganglion cells (RGC). The aim of this study was to compare the effect in normal subjects and in multiple sclerosis patients without previous optic neuritis. Methods: PERGs were elicited by a 7.5. Hz pattern stimulus, presented continuously over 152. s. Response cycles were averaged in 20 packets of 60 events each and amplitude and phase of the 2nd harmonic response was measured. Adaptive changes are expressed as amplitude reduction over the full examination time. Results: In normal subjects PERG amplitude declined progressively to a plateau (dA. =. -0.46. μV, SE. =. 0.09. μV); in patients the effect size was severely reduced (dA. =. -0.20. μV, SE. =. 0.04. μV). No significant difference was found in mean amplitude. Conclusions: The results show reduced RGC habituation in patients, suggesting an abnormal gain and sensitivity control in the inner retina, even in absence of clinical optic neuritis. Recent findings in astrocyte biology and indications drawn from a mathematical model point to a key role of glial cells in this process. Significance: The proposed methodology may have implications in the assessment of MS patients and in understanding the pathophysiology of neurological and retinal disorders.
AB - Objective: Sustained pattern stimulation in normal subjects induces adaptive changes in pattern electroretinogram (PERG), an effect that has been interpreted as a response of glial cells and retinal ganglion cells (RGC). The aim of this study was to compare the effect in normal subjects and in multiple sclerosis patients without previous optic neuritis. Methods: PERGs were elicited by a 7.5. Hz pattern stimulus, presented continuously over 152. s. Response cycles were averaged in 20 packets of 60 events each and amplitude and phase of the 2nd harmonic response was measured. Adaptive changes are expressed as amplitude reduction over the full examination time. Results: In normal subjects PERG amplitude declined progressively to a plateau (dA. =. -0.46. μV, SE. =. 0.09. μV); in patients the effect size was severely reduced (dA. =. -0.20. μV, SE. =. 0.04. μV). No significant difference was found in mean amplitude. Conclusions: The results show reduced RGC habituation in patients, suggesting an abnormal gain and sensitivity control in the inner retina, even in absence of clinical optic neuritis. Recent findings in astrocyte biology and indications drawn from a mathematical model point to a key role of glial cells in this process. Significance: The proposed methodology may have implications in the assessment of MS patients and in understanding the pathophysiology of neurological and retinal disorders.
KW - Electroretinography
KW - Glia
KW - Multiple sclerosis
KW - Retinal ganglion cell
UR - http://www.scopus.com/inward/record.url?scp=84880176395&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84880176395&partnerID=8YFLogxK
U2 - 10.1016/j.clinph.2013.03.001
DO - 10.1016/j.clinph.2013.03.001
M3 - Article
C2 - 23571090
AN - SCOPUS:84880176395
VL - 124
SP - 1652
EP - 1658
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
SN - 1388-2457
IS - 8
ER -