Oliver Summ - Academia.edu (original) (raw)
Papers by Oliver Summ
Klinische Neurophysiologie, 2012
Brain, 2016
A single pulse of transcranial magnetic stimulation has been shown to be effective for the acute ... more A single pulse of transcranial magnetic stimulation has been shown to be effective for the acute treatment of migraine with and without aura. Here we aimed to investigate the potential mechanisms of action of transcranial magnetic stimulation, using a transcortical approach, in preclinical migraine models. We tested the susceptibility of cortical spreading depression, the experimental correlate of migraine aura, and further evaluated the response of spontaneous and evoked trigeminovascular activity of second order trigemontothalamic and third order thalamocortical neurons in rats. Single pulse transcranial magnetic stimulation significantly inhibited both mechanical and chemically-induced cortical spreading depression when administered immediately post-induction in rats, but not when administered preinduction, and when controlled by a sham stimulation. Additionally transcranial magnetic stimulation significantly inhibited the spontaneous and evoked firing rate of third order thalamocortical projection neurons, but not second order neurons in the trigeminocervical complex, suggesting a potential modulatory effect that may underlie its utility in migraine. In gyrencephalic cat cortices, when administered post-cortical spreading depression, transcranial magnetic stimulation blocked the propagation of cortical spreading depression in two of eight animals. These results are the first to demonstrate that cortical spreading depression can be blocked in vivo using single pulse transcranial magnetic stimulation and further highlight a novel thalamocortical modulatory capacity that may explain the efficacy of magnetic stimulation in the treatment of migraine with and without aura.
The Journal of Headache and Pain, Oct 1, 2010
Cephalalgia
Objectives To study the effects of the potent and selective brain penetrant TRPV1 receptor antago... more Objectives To study the effects of the potent and selective brain penetrant TRPV1 receptor antagonist A-993610 on dural nociceptive and facial mechanical input to the trigeminocervical complex (TCC). Introduction It has been proposed that TRPV1 receptors may play a role in modulating in trigeminal sensory processing. We used a model of trigeminovascular nociceptive activation to test this in the rat. Methods Male Sprague Dawley rats (N = 9) were anesthetized with pentobarbitone (60 mg/kg) and cannulated for monitoring and drug administration. The anesthesia was then maintained by propofol (20–25 mg/kg/h). After appropriate surgical preparation wide-dynamic-range neurons, identified by noxious pinch, and innocuous brush, responding to electrical stimulation of the middle meningeal artery/dura mater (MMA; stimulation parameters: 0.5 Hz, 0.3–0.4 ms,12.6–18 V), were identified and recorded using electrophysiological techniques. A-993610, dissolved in polyethylene glycol 300 (8 mg/ ml), ...
The Journal of Headache and Pain, 2010
Klinische Neurophysiologie, 2011
Cephalalgia, 2014
Exploding head syndrome (EHS) is characterized by attacks of a sudden noise or explosive feeling ... more Exploding head syndrome (EHS) is characterized by attacks of a sudden noise or explosive feeling experienced in the head occurring during the transition from wake to sleep or from sleep to wake. We present six new cases extending the clinical experience with the syndrome. We also reviewed all available cases from the scientific literature and evaluated the typical features of EHS. The female to male ratio is 1.5 to 1. The median age at onset is 54. In average, one attack per day to one attack per week occurs. Some patients suffer from several attacks per night. In about half of all patients, a chronic time course can be observed but episodic or sporadic occurrence is also common. The most frequent accompanying symptoms beside the noise are fear and flashes of light. Polysomnographic studies do not reveal any specific sleep pattern associated with EHS. Tricyclic antidepressants are helpful in some patients. However, most patients do not need treatment because of the benign nature of the syndrome. EHS is a well-defined disease entity with a benign nature.
Klinische Neurophysiologie, 2011
Current Pain and Headache Reports, 2013
Indomethacin, as a member of the non-steroidal anti-inflammatory drug class, plays a special role... more Indomethacin, as a member of the non-steroidal anti-inflammatory drug class, plays a special role in the treatment of headaches. By definition, it is completely efficacious in the treatment of the primary headache disorders paroxysmal hemicrania and hemicrania continua. Therefore, indomethacin is also used as a tool for differential diagnosis in headache clinics. Indomethacin has a clear action as a cyclooxygenase inhibitor. Additional mechanisms and interactions with cell signaling pathways and inflammatory pathways are considered in this article. However, it is not known what mechanism or interaction with pathophysiological mechanisms is the key to indomethacin's specific pharmacology in headache therapy. Focusing on headache therapy, we summarize the current knowledge of pharmacology, treatment options, and recommendations for the use of indomethacin in primary headaches. New findings from the field of headache research, as well as from Alzheimer's disease and cancer research on the pharmacological actions of indomethacin and their potential implications on the pathophysiology of indomethacin sensitive headaches, are discussed.
Cephalalgia, 2011
It has been proposed that TRPV1 receptors may play a role modulating trigeminal sensory processin... more It has been proposed that TRPV1 receptors may play a role modulating trigeminal sensory processing. We used models of trigeminovascular nociceptive activation to study the involvement of TRPV1 receptors in the rat. Due to a possible role of TRPV1 receptors in cortical spreading depression (CSD), an experimental phenomenon sharing many features with migraine aura, we also utilized a model of mechanically induced CSD. Male Sprague Dawley rats (N = 39) were anesthetized and cannulated for monitoring and drug administration to study the effects of the TRPV1 receptor antagonist A-993610 (8 mg kg(-1) IV). Wide-dynamic-range neurons, responding to electrical stimulation of the middle meningeal artery (MMA)/dura mater were identified and recorded using electrophysiological techniques. Intravital microscopy was used to study neurogenic dural vasodilation (NDV) of the MMA comparing capsaicin and electrical stimulation, and the effect of A-993610 on mechanically induced CSD was examined. Administration of A-993610 had no significant effect on trigeminal firing of A- or C-fibers elicited by electrical stimulation of the MMA. It also showed no effect on NDV whilst blocking vasodilation due to intravenous capsaicin injection. The mechanically induced CSD response could not be altered by A-993610 administration. Although there is evidence that TRPV1 receptors play an important role in sensory processing in general, the new data do not support a role in the treatment of acute migraine.
Expert Review of Neurotherapeutics, Mar 1, 2010
Klinische Neurophysiologie, 2012
Brain, 2016
A single pulse of transcranial magnetic stimulation has been shown to be effective for the acute ... more A single pulse of transcranial magnetic stimulation has been shown to be effective for the acute treatment of migraine with and without aura. Here we aimed to investigate the potential mechanisms of action of transcranial magnetic stimulation, using a transcortical approach, in preclinical migraine models. We tested the susceptibility of cortical spreading depression, the experimental correlate of migraine aura, and further evaluated the response of spontaneous and evoked trigeminovascular activity of second order trigemontothalamic and third order thalamocortical neurons in rats. Single pulse transcranial magnetic stimulation significantly inhibited both mechanical and chemically-induced cortical spreading depression when administered immediately post-induction in rats, but not when administered preinduction, and when controlled by a sham stimulation. Additionally transcranial magnetic stimulation significantly inhibited the spontaneous and evoked firing rate of third order thalamocortical projection neurons, but not second order neurons in the trigeminocervical complex, suggesting a potential modulatory effect that may underlie its utility in migraine. In gyrencephalic cat cortices, when administered post-cortical spreading depression, transcranial magnetic stimulation blocked the propagation of cortical spreading depression in two of eight animals. These results are the first to demonstrate that cortical spreading depression can be blocked in vivo using single pulse transcranial magnetic stimulation and further highlight a novel thalamocortical modulatory capacity that may explain the efficacy of magnetic stimulation in the treatment of migraine with and without aura.
The Journal of Headache and Pain, Oct 1, 2010
Cephalalgia
Objectives To study the effects of the potent and selective brain penetrant TRPV1 receptor antago... more Objectives To study the effects of the potent and selective brain penetrant TRPV1 receptor antagonist A-993610 on dural nociceptive and facial mechanical input to the trigeminocervical complex (TCC). Introduction It has been proposed that TRPV1 receptors may play a role in modulating in trigeminal sensory processing. We used a model of trigeminovascular nociceptive activation to test this in the rat. Methods Male Sprague Dawley rats (N = 9) were anesthetized with pentobarbitone (60 mg/kg) and cannulated for monitoring and drug administration. The anesthesia was then maintained by propofol (20–25 mg/kg/h). After appropriate surgical preparation wide-dynamic-range neurons, identified by noxious pinch, and innocuous brush, responding to electrical stimulation of the middle meningeal artery/dura mater (MMA; stimulation parameters: 0.5 Hz, 0.3–0.4 ms,12.6–18 V), were identified and recorded using electrophysiological techniques. A-993610, dissolved in polyethylene glycol 300 (8 mg/ ml), ...
The Journal of Headache and Pain, 2010
Klinische Neurophysiologie, 2011
Cephalalgia, 2014
Exploding head syndrome (EHS) is characterized by attacks of a sudden noise or explosive feeling ... more Exploding head syndrome (EHS) is characterized by attacks of a sudden noise or explosive feeling experienced in the head occurring during the transition from wake to sleep or from sleep to wake. We present six new cases extending the clinical experience with the syndrome. We also reviewed all available cases from the scientific literature and evaluated the typical features of EHS. The female to male ratio is 1.5 to 1. The median age at onset is 54. In average, one attack per day to one attack per week occurs. Some patients suffer from several attacks per night. In about half of all patients, a chronic time course can be observed but episodic or sporadic occurrence is also common. The most frequent accompanying symptoms beside the noise are fear and flashes of light. Polysomnographic studies do not reveal any specific sleep pattern associated with EHS. Tricyclic antidepressants are helpful in some patients. However, most patients do not need treatment because of the benign nature of the syndrome. EHS is a well-defined disease entity with a benign nature.
Klinische Neurophysiologie, 2011
Current Pain and Headache Reports, 2013
Indomethacin, as a member of the non-steroidal anti-inflammatory drug class, plays a special role... more Indomethacin, as a member of the non-steroidal anti-inflammatory drug class, plays a special role in the treatment of headaches. By definition, it is completely efficacious in the treatment of the primary headache disorders paroxysmal hemicrania and hemicrania continua. Therefore, indomethacin is also used as a tool for differential diagnosis in headache clinics. Indomethacin has a clear action as a cyclooxygenase inhibitor. Additional mechanisms and interactions with cell signaling pathways and inflammatory pathways are considered in this article. However, it is not known what mechanism or interaction with pathophysiological mechanisms is the key to indomethacin's specific pharmacology in headache therapy. Focusing on headache therapy, we summarize the current knowledge of pharmacology, treatment options, and recommendations for the use of indomethacin in primary headaches. New findings from the field of headache research, as well as from Alzheimer's disease and cancer research on the pharmacological actions of indomethacin and their potential implications on the pathophysiology of indomethacin sensitive headaches, are discussed.
Cephalalgia, 2011
It has been proposed that TRPV1 receptors may play a role modulating trigeminal sensory processin... more It has been proposed that TRPV1 receptors may play a role modulating trigeminal sensory processing. We used models of trigeminovascular nociceptive activation to study the involvement of TRPV1 receptors in the rat. Due to a possible role of TRPV1 receptors in cortical spreading depression (CSD), an experimental phenomenon sharing many features with migraine aura, we also utilized a model of mechanically induced CSD. Male Sprague Dawley rats (N = 39) were anesthetized and cannulated for monitoring and drug administration to study the effects of the TRPV1 receptor antagonist A-993610 (8 mg kg(-1) IV). Wide-dynamic-range neurons, responding to electrical stimulation of the middle meningeal artery (MMA)/dura mater were identified and recorded using electrophysiological techniques. Intravital microscopy was used to study neurogenic dural vasodilation (NDV) of the MMA comparing capsaicin and electrical stimulation, and the effect of A-993610 on mechanically induced CSD was examined. Administration of A-993610 had no significant effect on trigeminal firing of A- or C-fibers elicited by electrical stimulation of the MMA. It also showed no effect on NDV whilst blocking vasodilation due to intravenous capsaicin injection. The mechanically induced CSD response could not be altered by A-993610 administration. Although there is evidence that TRPV1 receptors play an important role in sensory processing in general, the new data do not support a role in the treatment of acute migraine.
Expert Review of Neurotherapeutics, Mar 1, 2010