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Gunduz A, Kofler M, Aktan Suzgun M, Tutuncu M, Karaali-Savrun F, Uzun N, E Kızıltan M. Cutaneous silent period in patients with spinal muscular atrophy type 2 and type 3. Neurophysiol Clin 2020; 50:353-359. [PMID: 32951956 DOI: 10.1016/j.neucli.2020.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/04/2020] [Accepted: 09/04/2020] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The aim of this study was to examine cutaneous silent periods (CSPs) in spinal muscular atrophy (SMA) type 2 and type 3 patients. METHODS Fourteen patients with SMA and 14 healthy subjects were included. CSPs were recorded from thenar muscles after painful stimulation of the index finger during slight thumb abduction. CSP parameters (including onset latency, duration, index of suppression, long-loop reflex, and post-inhibitory rebound activity) were measured. All parameters were compared between SMA patients and healthy subjects using the Mann-Whitney U test. We then correlated CSP parameters to Hammersmith Functional Motor Scale Expanded (HFMSE) scores in SMA patients by Spearman-rho testing. RESULTS No CSP parameter except E3% (i.e., the post-inhibitory rebound activity relative to pre-stimulus baseline) differed significantly between SMA patients and healthy subjects. E3% was significantly smaller in patients than healthy individuals. HFMSE scores of SMA patients correlated negatively with CSP duration and positively with E3%. DISCUSSION Smaller E3%, correlating with longer CSP duration, in SMA patients with more severe clinical findings and therefore more marked motoneuron loss suggests that the E3 component following the CSP is directly affected by motoneuron loss.
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Affiliation(s)
- Aysegul Gunduz
- Istanbul University- Cerrahpaşa, Cerrahpaşa School of Medicine, Department of Neurology, Istanbul, Turkey.
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Merve Aktan Suzgun
- Istanbul University- Cerrahpaşa, Cerrahpaşa School of Medicine, Department of Neurology, Istanbul, Turkey
| | - Melih Tutuncu
- Istanbul University- Cerrahpaşa, Cerrahpaşa School of Medicine, Department of Neurology, Istanbul, Turkey
| | - Feray Karaali-Savrun
- Istanbul University- Cerrahpaşa, Cerrahpaşa School of Medicine, Department of Neurology, Istanbul, Turkey
| | - Nurten Uzun
- Istanbul University- Cerrahpaşa, Cerrahpaşa School of Medicine, Department of Neurology, Istanbul, Turkey
| | - Meral E Kızıltan
- Istanbul University- Cerrahpaşa, Cerrahpaşa School of Medicine, Department of Neurology, Istanbul, Turkey
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Gündüz A, Ayas S, Kofler M, Aydın Ş, Kızıltan ME. Modulation of the excitatory phase following the cutaneous silent period by vibration. Neurol Sci 2020; 42:633-637. [PMID: 32648049 DOI: 10.1007/s10072-020-04557-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 07/02/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION The post-inhibition excitatory phase (E3) of the cutaneous silent period (CSP) is attributed to the resynchronization of motoneuron activity following the inhibitory period but there is also evidence that a somatosensory startle reflex may contribute to this phase. We hypothesized that the startle reflex component contained in E3 will decrease during vibration. METHODS Sixteen healthy individuals were included in the study. CSP was recorded from slightly contracted right thenar muscles after painful index finger stimulation, before, during, and immediately after vibration. The values of the percentage change of E3 relative to pre-stimulus baseline (E3%) were compared before, during, and after vibration for each individual. RESULTS There was a reduction in E3% during vibration and the values returned to normal immediately after vibration (153.1 ± 43.5%, 115.2 ± 30.2%, 154.9 ± 68.2%, respectively; p = 0.030). DISCUSSION E3 is reduced during vibration in healthy individuals, presumably due to suppression of a reflex component, which is superimposed upon the known resynchronization of motoneurons.
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Affiliation(s)
- Ayşegül Gündüz
- Department of Neurology, Cerrahpasa School of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Selahattin Ayas
- Department of Neurology, Cerrahpasa School of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey.
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Şenay Aydın
- Department of Neurology, Cerrahpasa School of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Meral Erdemir Kızıltan
- Department of Neurology, Cerrahpasa School of Medicine, Istanbul University-Cerrahpasa, Istanbul, Turkey
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Gündüz A, Aydın Ş, Kızıltan M. Cutaneous silent period: A literature review. NEUROL SCI NEUROPHYS 2020. [DOI: 10.4103/nsn.nsn_38_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Kofler M, Leis A, Valls-Solé J. Cutaneous silent periods – Part 1: Update on physiological mechanisms. Clin Neurophysiol 2019; 130:588-603. [DOI: 10.1016/j.clinph.2019.01.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 12/28/2018] [Accepted: 01/08/2019] [Indexed: 12/14/2022]
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Versace V, Campostrini S, Sebastianelli L, Saltuari L, Kofler M. Modulation of exteroceptive electromyographic responses in defensive peripersonal space. J Neurophysiol 2019; 121:1111-1124. [PMID: 30811266 DOI: 10.1152/jn.00554.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The cutaneous silent period (CSP) to noxious finger stimulation constitutes a robust spinal inhibitory reflex that protects the hand from injury. In certain conditions, spinal inhibition is interrupted by a brief burst-like electromyographic activity, dividing the CSP into two inhibitory phases (I1 and I2). This excitatory component is termed long-loop reflex (LLR) and is presumed to be transcortical in origin. Efficient defense from environmental threats requires sensorimotor integration between multimodal sensory afferents and planning of defensive movements. In the defensive peripersonal space (DPPS) immediately surrounding the body, we interact with objects and persons with increased alertness. We investigated whether CSP differs when the stimulated hand is in the DPPS of the face compared with a distant position. Furthermore, we investigated the possible role of vision in CSP modulation. Fifteen healthy volunteers underwent CSP testing with the handheld either within 5 cm from the nose (near) or away from the body (far). Recordings were obtained from first dorsal interosseous muscle following index (D2) or little finger (D5) stimulation with varying intensities. A subgroup of subjects underwent CSP recordings in near and far conditions, both with eyes open and with eyes closed. No inhibitory CSP parameter differed between stimulation in near and far conditions. LLRs occurring following D2 stimulation were significantly larger in near than far conditions at all stimulus intensities, irrespective of subjects seeing their hand. Similar to the hand-blink reflex, spinally organized protective reflexes may be modulated by corticospinal facilitatory input when the hand enters the DPPS of the face. NEW & NOTEWORTHY The present findings demonstrate for the first time that a spinally organized protective reflex, the cutaneous silent period (CSP), may be modulated by top-down corticospinal facilitatory input when the stimulated hand enters the defensive peripersonal space (DPPS) of the face. In particular, the cortically mediated excitatory long-loop reflex, which may interrupt the CSP, is facilitated when the stimulated hand is in the DPPS, irrespective of visual control over the hand. No spinal inhibitory CSP parameter differs significantly in or outside the DPPS.
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Affiliation(s)
- Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno/Sterzing and Research Unit for Neurorehabilitation of South Tyrol, Sterzing, Italy
| | - Stefania Campostrini
- Department of Neurorehabilitation, Hospital of Vipiteno/Sterzing and Research Unit for Neurorehabilitation of South Tyrol, Sterzing, Italy
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno/Sterzing and Research Unit for Neurorehabilitation of South Tyrol, Sterzing, Italy
| | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno/Sterzing and Research Unit for Neurorehabilitation of South Tyrol, Sterzing, Italy.,Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
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Aydın Ş, Kofler M, Bakuy Y, Gündüz A, Kızıltan ME. Effects of vibration on cutaneous silent period. Exp Brain Res 2019; 237:911-918. [PMID: 30659303 DOI: 10.1007/s00221-018-05463-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 12/21/2018] [Indexed: 12/14/2022]
Abstract
Suppression of an ongoing muscle contraction following noxious digital stimulation is called cutaneous silent period (CSP) which is under the influence of several physiological factors. In this study, we aimed to evaluate the influence of group Ia afferents on the cutaneous silent period (CSP) by applying 2-min vibration. CSP was obtained from abductor pollicis brevis muscle after stimulating index finger. The recordings were repeated three times-before, during and after vibration-which was applied over the tendon of flexor carpi radialis muscle. Onset latency, duration and magnitude of total CSP, inhibitory phases I1 and I2, and of the long-loop reflex were measured and compared. Suppression indices of CSP, I1 and I2 increased significantly during and after vibration, indicating significantly less exteroceptive EMG suppression outlasting the time of vibration. Vibration also caused mild shortening of I2 end latency (p = 0.048) and I2 duration (p = 0.019). Our findings indicate that vibration exerts a powerful influence on CSPs and causes reduction in the magnitude of exteroceptive EMG suppression during and after vibration. Although vibration is known to activate Ia afferents, we cannot exclude contribution of other afferents, e.g. mechanoreceptors, as well as pre- or postsynaptic inhibitory effects on ensuing interneurons, or enhanced vibration-related excitatory influence.
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Affiliation(s)
- Şenay Aydın
- Department of Neurology, Yedikule Chest Diseases and Chest Surgery Training and Research Hospital, Istanbul, Turkey. .,Department of Neurology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey.
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Yeliz Bakuy
- Department of Neurology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Ayşegül Gündüz
- Department of Neurology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
| | - Meral E Kızıltan
- Department of Neurology, Cerrahpasa Medical Faculty, Istanbul University-Cerrahpasa, Istanbul, Turkey
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Kofler M, Valls-Solé J, Vasko P, Boček V, Štetkárová I. Influence of limb temperature on cutaneous silent periods. Clin Neurophysiol 2014; 125:1826-33. [PMID: 24555925 DOI: 10.1016/j.clinph.2014.01.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 01/16/2014] [Accepted: 01/26/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The cutaneous silent period (CSP) is a spinal inhibitory reflex mediated by small-diameter afferents (A-delta fibers) and large-diameter efferents (alpha motoneurons). The effect of limb temperature on CSPs has so far not been assessed. METHODS In 27 healthy volunteers (11 males; age 22-58 years) we recorded median nerve motor and sensory action potentials, median nerve F-wave and CSPs induced by noxious digit II stimulation in thenar muscles in a baseline condition at room temperature, and after randomly submersing the forearm in 42 °C warm or 15 °C cold water for 20 min each. RESULTS In cold limbs, distal and proximal motor and sensory latencies as well as F-wave latencies were prolonged. Motor and sensory nerve conduction velocities were reduced. Compound motor and sensory nerve action potential amplitudes did not differ significantly from baseline. CSP onset and end latencies were more delayed than distal and proximal median nerve motor and sensory latencies, whereas CSP duration was not affected. In warm limbs, opposite but smaller changes were seen in nerve conduction studies and CSPs. CONCLUSION The observed CSP shift "en bloc" towards longer latencies without affecting CSP duration during limb cooling concurs with slower conduction velocity in both afferent and efferent fibers. Disparate conduction slowing in afferents and efferents, however, suggests that nociceptive EMG suppression is mediated by fibers of different size in the afferent than in the efferent arm, indirectly supporting the contribution of A-delta fibers as the main afferent input. SIGNIFICANCE Limb temperature should be taken into account when testing CSPs in the clinical setting, as different limb temperatures affect CSP latencies more than large-diameter fiber conduction function.
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Affiliation(s)
- Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria.
| | | | - Peter Vasko
- Department of Neurology, Charles University, Third Faculty of Medicine, Prague, Czech Republic
| | - Václav Boček
- Department of Neurology, Charles University, Third Faculty of Medicine, Prague, Czech Republic
| | - Ivana Štetkárová
- Department of Neurology, Charles University, Third Faculty of Medicine, Prague, Czech Republic
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Barraza-Sandoval G, Casanova-Mollá J, Valls-Solé J. Neurophysiological assessment of painful neuropathies. Expert Rev Neurother 2014; 12:1297-309; quiz 1310. [DOI: 10.1586/ern.12.93] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Cutaneous silent period in human FDI motor units. Exp Brain Res 2010; 205:455-63. [DOI: 10.1007/s00221-010-2380-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 07/21/2010] [Indexed: 10/19/2022]
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Kumru H, Opisso E, Valls-Solé J, Kofler M. The effect of a prepulse stimulus on the EMG rebound following the cutaneous silent period. J Physiol 2008; 587:587-95. [PMID: 19064615 DOI: 10.1113/jphysiol.2008.164186] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The cutaneous silent period (CSP) is a spinal inhibitory reflex mediated by Adelta fibres. The postinhibitory rebound of electromyographic (EMG) activity following the CSP has been mainly attributed to resynchronization of motoneurons, but the possibility of startle reflex activity contributing to the EMG burst has also been suggested. Several types of reflexes may be suppressed by a preceding weak stimulus--a phenomenon called prepulse inhibition (PPI). Our aim was to study whether PPI would diminish the EMG rebound, thereby providing further evidence for excitatory reflex activity contained within the postinhibitory EMG rebound following the CSP. Ten healthy subjects underwent CSP testing following noxious digit II stimulation in two conditions, with and without a prepulse applied to digit III. Rectified surface EMG recordings were obtained from right orbicularis oculi, sternocleidomastoid and thenar muscles of the dominant hand during thumb abduction with 25% of maximum force. The area of the EMG rebound and the EMG reflex responses in orbicularis oculi and sternocleidomastoid were significantly smaller in recordings where a prepulse stimulus was applied 100 ms before the stimulus as compared to control responses without prepulse. CSP onset and end latency, CSP duration, and the degree of EMG suppression were not influenced. Prepulses significantly reduced subjective discomfort as based on visual analog scale scores. Inhibition of the EMG rebound by prepulse stimulation supports the hypothesis that the excitatory EMG activity following the CSP contains not only resynchronization of motoneuronal firing, but also an excitatory reflex component. The most probable type of reflex seems to be a somatosensory startle reflex, a defence reaction which is generated in structures located in the caudal brainstem following an unexpected intense stimulus. Reduction of the discomfort associated with high-intensity electrical fingertip stimulation by a prepulse without affecting CSP parameters underlines the utility of PPI in the context of CSP testing.
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Affiliation(s)
- H Kumru
- Department of Neurology, Instituto Guttmann, Hospital de Neurorehabilitació, Camí de Can Ruti S/N, Badalona, Spain
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Sensory modulation of voluntary and TMS-induced activation in hand muscles. Exp Brain Res 2008; 188:399-409. [DOI: 10.1007/s00221-008-1372-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 04/02/2008] [Indexed: 11/26/2022]
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Kofler M, Kumru H, Stetkarova I, Schindler C, Fuhr P. Muscle force up to 50% of maximum does not affect cutaneous silent periods in thenar muscles. Clin Neurophysiol 2007; 118:2025-30. [PMID: 17644035 DOI: 10.1016/j.clinph.2007.06.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2007] [Revised: 05/28/2007] [Accepted: 06/10/2007] [Indexed: 12/23/2022]
Abstract
OBJECTIVE The cutaneous silent period (CSP) is a spinal inhibitory reflex mediated by A-delta fibers. The amount of muscle contraction has been reported to influence CSPs, but this has not been confirmed in studies applying clinically feasible stimulus parameters. METHODS Fourteen healthy subjects underwent comparison of CSPs while contracting the target muscle at different levels ranging from 10% to 50% of the maximum force, which was continuously monitored with a force transducer. Rectified surface electromyographic (EMG) recordings were obtained from abductor pollicis brevis muscle following ipsilateral recurrent noxious digit 2 and digit 5 stimulation. RESULTS Group average CSP onset and end latency, CSP duration, and the magnitude of EMG suppression were not influenced by volitional muscle contraction ranging from 10% to 50% of the maximum. In contrast, background EMG levels increased significantly with the amount of muscle force. CONCLUSIONS CSPs prove to be robust nociceptive cutaneomuscular reflexes, which are - in contrast to previous reports - not significantly influenced by clinically easily applicable amounts of muscle force. SIGNIFICANCE Non-dependence on the amount of volitional target muscle activation over a range from 10% to 50% of individual maximum force levels renders CSPs particularly suitable for clinical use in patients with peripheral and spinal disorders affecting the A-delta fiber system.
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Affiliation(s)
- Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria.
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Lo YL, Tan YE, Fook-Chong S, Boolsambatra P, Yue WM, Chan LL, Tan SB. Role of Spinal Inhibitory Mechanisms in Whiplash Injuries. J Neurotrauma 2007; 24:1055-67. [PMID: 17600520 DOI: 10.1089/neu.2006.0222] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Whiplash injury, commonly encountered in road traffic accidents, is a major cause of morbidity. Its pathophysiology is not well understood, and diagnosis remains clinical. Imaging and electrophysiological methods have not provided objective diagnostic evidence. Availability of a sensitive and specific diagnostic method would be of high clinical interest. We studied 20 consecutive patients with chronic whiplash injury. Despite persistent symptoms, most had minimal neurological findings. Cutaneous silent period (CSP), a nociceptive spinal inhibitory electromyographic reflex, showed 90% sensitivity and 90% specificity for its diagnosis. In contrast, only two patients (10%) had abnormal transcranial magnetic stimulation findings, and another two (10%) showed abnormal electromyography. Magnetic resonance imaging (MRI) showed cervical cord abnormalities in only two of 20 (10%) patients. None of the patients had abnormal somatosensory evoked potential studies. Our findings suggest that neurological dysfunction of whiplash may occur at several possible spinal cord localities in the CSP functional pathway. The use of this simple, quick, and sensitive method is advocated in the diagnostic work up of whiplash injury.
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Affiliation(s)
- Yew-Long Lo
- Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore.
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