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The Photoparoxysmal Response Reflects Abnormal Early Visuomotor Integration in the Human Motor Cortex.
Brain Stimul. 2015 Nov-Dec; 8(6):1151-61.BS

Abstract

BACKGROUND

Visual-paired associative stimulation (V-PAS) is a transcranial magnetic stimulation (TMS) technique able to investigate long-term potentiation (LTP) and depression (LTD)-like plasticity in the primary motor cortex (M1) arising through early visuomotor integration.

OBJECTIVE/HYPOTHESIS

Abnormal early visuomotor integration might contribute to the pathophysiology of intermittent photic stimulation (IPS)-induced photoparoxysmal response (PPR).

METHODS

We applied V-PAS in 25 healthy subjects (HS), 25 PPR-positive patients, with and without idiopathic generalized epilepsy (IGE), and 8 PPR-negative patients with IGE. V-PAS consisted of primary visual area activation achieved by visual evoked potentials coupled with TMS-induced M1 activation at 100 ms interstimulus interval (ISI) (V-PAS100). Before and after V-PAS, we measured changes in motor evoked potentials (MEPs). We compared MEPs after 1 Hz repetitive TMS (rTMS) and 0.25 Hz-V-PAS100. To examine possible V-PAS-induced after-effects at other ISIs, we delivered V-PAS at 40 (V-PAS40) and 140 ms ISIs (V-PAS140). To clarify whether V-PAS100 increases parieto-/premotor-to-M1 connectivity, before and after V-PAS100, we examined MEPs evoked by paired-pulse techniques.

RESULTS

V-PAS100 increased MEPs more in PPR-positive patients than in HS. PPR-negative patients had normal response to V-PAS100. 1 Hz-rTMS, 0.25 Hz-V-PAS100 and V-PAS40 elicited similar responses in HS and PPR-positive patients, whereas V-PAS140 induced stronger after-effects in PPR-positive patients than HS. After V-PAS, MEPs elicited by facilitatory paired-pulse protocols decreased similarly in HS and PPR-positive patients. Conversely, MEPs elicited by inhibitory protocols decreased in HS, whereas in PPR-positive patients, they turned from inhibition to facilitation.

CONCLUSION

We suggest that abnormal early visuomotor integration contributes to the pathophysiology of PPR.

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    Authors+Show Affiliations

    Suppa A
    IRCCS Neuromed Institute, 86077 Pozzilli, IS, Italy.
    Rocchi L
    Department of Neurology and Psychiatry, "Sapienza" University of Rome, 00185 Rome, Italy.
    Li Voti P
    Department of Neurology and Psychiatry, "Sapienza" University of Rome, 00185 Rome, Italy.
    Papazachariadis O
    Department of Physiology and Pharmacology, "Sapienza" University of Rome, 00185 Rome, Italy.
    Casciato S
    Department of Neurology and Psychiatry, "Sapienza" University of Rome, 00185 Rome, Italy.
    Di Bonaventura C
    Department of Neurology and Psychiatry, "Sapienza" University of Rome, 00185 Rome, Italy.
    Giallonardo AT
    Department of Neurology and Psychiatry, "Sapienza" University of Rome, 00185 Rome, Italy.
    Berardelli A
    IRCCS Neuromed Institute, 86077 Pozzilli, IS, Italy; Department of Neurology and Psychiatry, "Sapienza" University of Rome, 00185 Rome, Italy. Electronic address: alfredo.berardelli@uniroma1.it.

    MeSH

    AdolescentAdultCase-Control StudiesEpilepsies, MyoclonicEpilepsy, GeneralizedEvoked Potentials, MotorEvoked Potentials, VisualFemaleHumansMaleMiddle AgedMotor CortexPhotic StimulationPhotosensitivity DisordersTranscranial Magnetic StimulationVisual CortexYoung Adult

    Pub Type(s)

    Journal Article
    Research Support, Non-U.S. Gov't

    Language

    eng

    PubMed ID

    26138028

    Citation

    Suppa, A, et al. "The Photoparoxysmal Response Reflects Abnormal Early Visuomotor Integration in the Human Motor Cortex." Brain Stimulation, vol. 8, no. 6, 2015, pp. 1151-61.
    Suppa A, Rocchi L, Li Voti P, et al. The Photoparoxysmal Response Reflects Abnormal Early Visuomotor Integration in the Human Motor Cortex. Brain Stimul. 2015;8(6):1151-61.
    Suppa, A., Rocchi, L., Li Voti, P., Papazachariadis, O., Casciato, S., Di Bonaventura, C., Giallonardo, A. T., & Berardelli, A. (2015). The Photoparoxysmal Response Reflects Abnormal Early Visuomotor Integration in the Human Motor Cortex. Brain Stimulation, 8(6), 1151-61. https://doi.org/10.1016/j.brs.2015.05.013
    Suppa A, et al. The Photoparoxysmal Response Reflects Abnormal Early Visuomotor Integration in the Human Motor Cortex. Brain Stimul. 2015;8(6):1151-61. PubMed PMID: 26138028.
    * Article titles in AMA citation format should be in sentence-case
    TY - JOUR T1 - The Photoparoxysmal Response Reflects Abnormal Early Visuomotor Integration in the Human Motor Cortex. AU - Suppa,A, AU - Rocchi,L, AU - Li Voti,P, AU - Papazachariadis,O, AU - Casciato,S, AU - Di Bonaventura,C, AU - Giallonardo,A T, AU - Berardelli,A, Y1 - 2015/06/11/ PY - 2014/10/01/received PY - 2015/04/23/revised PY - 2015/05/22/accepted PY - 2015/7/4/entrez PY - 2015/7/4/pubmed PY - 2016/7/9/medline KW - Epilepsy KW - Paired associative stimulation KW - Photoparoxysmal response KW - Primary motor cortex KW - Visuomotor integration SP - 1151 EP - 61 JF - Brain stimulation JO - Brain Stimul VL - 8 IS - 6 N2 - BACKGROUND: Visual-paired associative stimulation (V-PAS) is a transcranial magnetic stimulation (TMS) technique able to investigate long-term potentiation (LTP) and depression (LTD)-like plasticity in the primary motor cortex (M1) arising through early visuomotor integration. OBJECTIVE/HYPOTHESIS: Abnormal early visuomotor integration might contribute to the pathophysiology of intermittent photic stimulation (IPS)-induced photoparoxysmal response (PPR). METHODS: We applied V-PAS in 25 healthy subjects (HS), 25 PPR-positive patients, with and without idiopathic generalized epilepsy (IGE), and 8 PPR-negative patients with IGE. V-PAS consisted of primary visual area activation achieved by visual evoked potentials coupled with TMS-induced M1 activation at 100 ms interstimulus interval (ISI) (V-PAS100). Before and after V-PAS, we measured changes in motor evoked potentials (MEPs). We compared MEPs after 1 Hz repetitive TMS (rTMS) and 0.25 Hz-V-PAS100. To examine possible V-PAS-induced after-effects at other ISIs, we delivered V-PAS at 40 (V-PAS40) and 140 ms ISIs (V-PAS140). To clarify whether V-PAS100 increases parieto-/premotor-to-M1 connectivity, before and after V-PAS100, we examined MEPs evoked by paired-pulse techniques. RESULTS: V-PAS100 increased MEPs more in PPR-positive patients than in HS. PPR-negative patients had normal response to V-PAS100. 1 Hz-rTMS, 0.25 Hz-V-PAS100 and V-PAS40 elicited similar responses in HS and PPR-positive patients, whereas V-PAS140 induced stronger after-effects in PPR-positive patients than HS. After V-PAS, MEPs elicited by facilitatory paired-pulse protocols decreased similarly in HS and PPR-positive patients. Conversely, MEPs elicited by inhibitory protocols decreased in HS, whereas in PPR-positive patients, they turned from inhibition to facilitation. CONCLUSION: We suggest that abnormal early visuomotor integration contributes to the pathophysiology of PPR. SN - 1876-4754 UR - https://www.unboundmedicine.com/medline/citation/26138028/The_Photoparoxysmal_Response_Reflects_Abnormal_Early_Visuomotor_Integration_in_the_Human_Motor_Cortex_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1935-861X(15)00968-7 DB - PRIME DP - Unbound Medicine ER -