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Versace V, Campostrini S, Dezi S, Sebastianelli L, Ortelli P, Saltuari L, Valls-Solé J, Kofler M. Conscious agency vs. pre-conscious sensory filtering: Disparate suppression of trigeminal blink reflex by self-stimulation and by prepulses. Psychophysiology 2023; 60:e14190. [PMID: 36166649 DOI: 10.1111/psyp.14190] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 08/19/2022] [Accepted: 09/06/2022] [Indexed: 01/25/2023]
Abstract
Modulation of the blink reflex (BR) to supraorbital nerve (SON) stimulation by a weak somatosensory prepulse (sPP) consists of inhibition of R2 and facilitation of R1. Similar BR changes occur with self-stimulation. Our aim was to compare neurophysiological processes underlying both effects. We assessed BR parameters in 18 healthy participants following right SON stimulation either performed by an experimenter (experiment 1A) or following self-stimulation (experiments 1B, 1C). In experiments 1A and 1C, sPPs to digit 2 preceded SON stimuli by 40, 100, 200 and 500 ms. In experiment 1B: self-stimulation was delayed by 40, 100, 200, and 500 ms. In experiment 2, BRs were elicited by an experimenter randomly during a 2-s period before participants applied self-stimulation. In experiment 1, as expected, sPPs caused facilitation of R1 and inhibition of R2, which peaked at 100 ms ISI, similarly in experiments 1A and 1C. Self-stimulation caused a decrease of R2, which was evident in a broad range of time intervals. In experiment 2, R2 was already inhibited at the onset of the 2-s period, while R1 began to rise significantly 1.4 s before self-stimulation. Both effects progressively increased until self-triggering. The results concur with a time-locked gating mechanism of prepulses at brainstem level, whereas self-stimulation modulates BR in a tonic manner, reflecting a cognitive influence due to self-agency.
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Affiliation(s)
- Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy.,Lehrkrankenhaus der Paracelsus Medizinischen Privatuniversität, Salzburg, Austria
| | - Stefania Campostrini
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy.,Lehrkrankenhaus der Paracelsus Medizinischen Privatuniversität, Salzburg, Austria
| | - Sabrina Dezi
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy.,Lehrkrankenhaus der Paracelsus Medizinischen Privatuniversität, Salzburg, Austria
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy.,Lehrkrankenhaus der Paracelsus Medizinischen Privatuniversität, Salzburg, Austria
| | - Paola Ortelli
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy.,Lehrkrankenhaus der Paracelsus Medizinischen Privatuniversität, Salzburg, Austria
| | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno (SABES-ASDAA), Vipiteno-Sterzing, Italy.,Lehrkrankenhaus der Paracelsus Medizinischen Privatuniversität, Salzburg, Austria
| | - Josep Valls-Solé
- IDIBAPS (Institut d'Investigació August Pi i Sunyer), Facultat de Medicina, University of Barcelona, Barcelona, Spain
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
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2
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Bologna M, Valls-Solè J, Kamble N, Pal PK, Conte A, Guerra A, Belvisi D, Berardelli A. Dystonia, chorea, hemiballismus and other dyskinesias. Clin Neurophysiol 2022; 140:110-125. [PMID: 35785630 DOI: 10.1016/j.clinph.2022.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/12/2022] [Accepted: 05/24/2022] [Indexed: 11/30/2022]
Abstract
Hyperkinesias are heterogeneous involuntary movements that significantly differ in terms of clinical and semeiological manifestations, including rhythm, regularity, speed, duration, and other factors that determine their appearance or suppression. Hyperkinesias are due to complex, variable, and largely undefined pathophysiological mechanisms that may involve different brain areas. In this chapter, we specifically focus on dystonia, chorea and hemiballismus, and other dyskinesias, specifically, levodopa-induced, tardive, and cranial dyskinesia. We address the role of neurophysiological studies aimed at explaining the pathophysiology of these conditions. We mainly refer to human studies using surface and invasive in-depth recordings, as well as spinal, brainstem, and transcortical reflexology and non-invasive brain stimulation techniques. We discuss the extent to which the neurophysiological abnormalities observed in hyperkinesias may be explained by pathophysiological models. We highlight the most relevant issues that deserve future research efforts. The potential role of neurophysiological assessment in the clinical context of hyperkinesia is also discussed.
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Affiliation(s)
- Matteo Bologna
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy
| | - Josep Valls-Solè
- Institut d'Investigació Biomèdica August Pi I Sunyer, Villarroel, 170, Barcelona, Spain
| | - Nitish Kamble
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Bengaluru, India
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health & Neurosciences (NIMHANS), Bengaluru, India
| | - Antonella Conte
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy
| | | | - Daniele Belvisi
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy
| | - Alfredo Berardelli
- Department of Human Neurosciences, Sapienza University of Rome, Italy; IRCCS Neuromed, Pozzilli (IS), Italy.
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Gowen CL, Khwaounjoo P, Cakmak YO. EMG-Free Monitorization of the Acoustic Startle Reflex with a Mobile Phone: Implications of Sound Parameters with Posture Related Responses. SENSORS 2020; 20:s20215996. [PMID: 33105890 PMCID: PMC7660167 DOI: 10.3390/s20215996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/14/2020] [Accepted: 10/14/2020] [Indexed: 11/16/2022]
Abstract
(1) Background: Acute acoustic (sound) stimulus prompts a state of defensive motivation in which unconscious muscle responses are markedly enhanced in humans. The orbicularis oculi (OO) of the eye is an easily accessed muscle common for acoustic startle reaction/response/reflex (ASR) investigations and is the muscle of interest in this study. Although the ASR can provide insights about numerous clinical conditions, existing methodologies (Electromyogram, EMG) limit the usability of the method in real clinical conditions. (2) Objective: With EMG-free muscle recording in mind, our primary aim was to identify and investigate potential correlations in the responses of individual and cooperative OO muscles to various acoustic stimuli using a mobile and wire-free system. Our secondary aim was to investigate potential altered responses to high and also relatively low intensity acoustics at different frequencies in both sitting and standing positions through the use of biaural sound induction and video diagnostic techniques and software. (3) Methods: This study used a mobile-phone acoustic startle response monitoring system application to collect blink amplitude and velocity data on healthy males, aged 18–28 community cohorts during (n = 30) in both sitting and standing postures. The iPhone X application delivers specific sound parameters and detects blinking responses to acoustic stimulus (in millisecond resolution) to study the responses of the blinking reflex to acoustic sounds in standing and sitting positions by using multiple acoustic test sets of different frequencies and amplitudes introduced as acute sound stimuli (<0.5 s). The single acoustic battery of 15 pure-square wave sounds consisted of frequencies and amplitudes between 500, 1000, 2000, 3000, and 4000 Hz scales using 65, 90, and 105 dB (e.g., 3000 Hz_90 dB). (4) Results: Results show that there was a synchronization of amplitude and velocity between both eyes to all acoustic startles. Significant differences (p = 0.01) in blinking reaction time between sitting vs. standing at the high intensity (105 dB) 500 Hz acoustic test set was discovered. Interestingly, a highly significant difference (p < 0.001) in response times between test sets 500 Hz_105 dB and 4000 Hz_105 dB was identified. (5) Conclusions: To our knowledge, this is the first mobile phone-based acoustic battery used to detect and report significant ASR responses to specific frequencies and amplitudes of sound stimulus with corresponding sitting and standing conditions. The results from this experiment indicate the potential significance of using the specific frequency, amplitude, and postural conditions (as never before identified) which can open new horizons for ASR to be used for diagnosis and monitoring in numerous clinical and remote or isolated conditions.
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Affiliation(s)
- Christopher L. Gowen
- Department of Anatomy, School of Biomedical Sciences, University Of Otago, Po Box 56, Dunedin 9054, New Zealand; (C.L.G.); (P.K.)
| | - Prashanna Khwaounjoo
- Department of Anatomy, School of Biomedical Sciences, University Of Otago, Po Box 56, Dunedin 9054, New Zealand; (C.L.G.); (P.K.)
- Medtech Core, Auckland 1010, New Zealand
| | - Yusuf O. Cakmak
- Department of Anatomy, School of Biomedical Sciences, University Of Otago, Po Box 56, Dunedin 9054, New Zealand; (C.L.G.); (P.K.)
- Medtech Core, Auckland 1010, New Zealand
- Brain Health Research Centre, Dunedin 9054, New Zealand
- Centre for Health Systems and Technology, Dunedin 9054, New Zealand
- Correspondence: ; Tel.: +64-03-479-4030
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4
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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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Garcia-Rill E, Saper CB, Rye DB, Kofler M, Nonnekes J, Lozano A, Valls-Solé J, Hallett M. Focus on the pedunculopontine nucleus. Consensus review from the May 2018 brainstem society meeting in Washington, DC, USA. Clin Neurophysiol 2019; 130:925-940. [PMID: 30981899 PMCID: PMC7365492 DOI: 10.1016/j.clinph.2019.03.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 03/15/2019] [Accepted: 03/22/2019] [Indexed: 12/12/2022]
Abstract
The pedunculopontine nucleus (PPN) is located in the mesopontine tegmentum and is best delimited by a group of large cholinergic neurons adjacent to the decussation of the superior cerebellar peduncle. This part of the brain, populated by many other neuronal groups, is a crossroads for many important functions. Good evidence relates the PPN to control of reflex reactions, sleep-wake cycles, posture and gait. However, the precise role of the PPN in all these functions has been controversial and there still are uncertainties in the functional anatomy and physiology of the nucleus. It is difficult to grasp the extent of the influence of the PPN, not only because of its varied functions and projections, but also because of the controversies arising from them. One controversy is its relationship to the mesencephalic locomotor region (MLR). In this regard, the PPN has become a new target for deep brain stimulation (DBS) for the treatment of parkinsonian gait disorders, including freezing of gait. This review is intended to indicate what is currently known, shed some light on the controversies that have arisen, and to provide a framework for future research.
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Affiliation(s)
- E Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - C B Saper
- Department of Neurology, Division of Sleep Medicine and Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - David B Rye
- Department of Neurology, Division of Sleep Medicine and Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - M Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - J Nonnekes
- Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Rehabilitation, Nijmegen, the Netherlands
| | - A Lozano
- Division of Neurosurgery, University of Toronto and Krembil Neuroscience Centre, University Health Network, Toronto, Canada
| | - J Valls-Solé
- Neurology Department, Hospital Clínic, University of Barcelona, IDIBAPS (Institut d'Investigació Biomèdica August Pi i Sunyer), Barcelona, Spain
| | - M Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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Abstract
Dystonia can be seen in a number of different phenotypes that may arise from different etiologies. The pathophysiological substrate of dystonia is related to three lines of research. The first postulate a loss of inhibition which may account for the excess of movement and for the overflow phenomena. A second abnormality is sensory dysfunction which is related to the mild sensory complaints in patients with focal dystonias and may be responsible for some of the motor dysfunction. Finally, there are strong pieces of evidence from animal and human studies suggesting that alterations of synaptic plasticity characterized by a disruption of homeostatic plasticity, with a prevailing facilitation of synaptic potentiation may play a pivotal role in primary dystonia. These working hypotheses have been generalized in all form of dystonia. On the other hand, several pieces of evidence now suggest that the pathophysiology may be slightly different in the different types of dystonia. Therefore, in the present review, we would like to discuss the neural mechanisms underlying the different forms of dystonia to disentangle the different weight and role of environmental and predisposing factors.
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Affiliation(s)
- Angelo Quartarone
- Department of Biomedical, Dental Sciences and Morphological and Functional Images, University of Messina, Messina, Italy.,IRCCS Centro Neurolesi "Bonino Pulejo", Messina, Italy
| | - Diane Ruge
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Dortmund, Germany
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7
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Brainstem reflexes are hyperactive in patients with drug-induced akathisia. Neurol Sci 2017; 38:1683-1689. [DOI: 10.1007/s10072-017-3038-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 06/17/2017] [Indexed: 10/19/2022]
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8
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Öztürk O, Gündüz A, Kızıltan ME. Deficient median nerve prepulse inhibition of the blink reflex in cervical dystonia. Clin Neurophysiol 2016; 127:3524-3528. [PMID: 27815976 DOI: 10.1016/j.clinph.2016.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 08/31/2016] [Accepted: 09/07/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We analyzed prepulse inhibition (PPI) of the blink reflex (BR) in patients with cervical dystonia (CD) to examine the sensory modulation of the motor system. METHODS This study enrolled 22 consecutive patients with idiopathic CD and 25 age- and gender-matched healthy subjects. Prepulse inhibition of the BR was recorded after stimulating the median nerve at the wrist using an electrical stimulus twice at a perception threshold 100ms before a test stimulus to the supraorbital nerve. RESULTS The R2 area and amplitude were significantly reduced and the R2 latency delayed after the conditioned stimulus in patients with CD. The R1 latency and amplitude did not differ between trials in patients with CD. In healthy subjects, the R1 amplitude was higher, whereas the R2 latency was delayed and the R2 amplitude and area were reduced after the conditioned stimulus. However, there was significantly less R2 and R2c area suppression in patients compared with healthy subjects. ANOVA showed that reduction of R2 area after conditioned stimulus (F=6.620, p=0.003) and percentage change of R2 area (F=5.217, p=0.009) were lower in patients with and without sensory tricks compared with healthy subjects, whereas the reduction in PPI was pronounced in patients without a sensory trick compared with healthy subjects. CONCLUSIONS Patients with CD show significantly less prepulse R2 inhibition than healthy subjects, but this occurred without R1 facilitation. The absence of a sensory trick leads to the more pronounced reduction of PPI. SIGNIFICANCE The modulatory effects of sensory inputs are lost in patients with CD without sensory tricks.
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Affiliation(s)
- Oya Öztürk
- Bakırköy Prof. Dr. Mazhar Osman Mental Health and Neurological Diseases Training and Research Hospital, Department of Neurology, Turkey
| | - Ayşegül Gündüz
- Department of Neurology, Cerrahpaşa School of Medicine, Istanbul University, Turkey.
| | - Meral E Kızıltan
- Department of Neurology, Cerrahpaşa School of Medicine, Istanbul University, Turkey
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9
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Kiziltan ME, Gunduz A, Apaydın H, Ertan S, Kiziltan G. Auditory startle reflex and startle reflex to somatosensory inputs in generalized dystonia. Clin Neurophysiol 2015; 126:1740-5. [DOI: 10.1016/j.clinph.2014.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 10/13/2014] [Accepted: 11/03/2014] [Indexed: 11/25/2022]
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10
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Colosimo C, Suppa A, Fabbrini G, Bologna M, Berardelli A. Craniocervical dystonia: clinical and pathophysiological features. Eur J Neurol 2010; 17 Suppl 1:15-21. [PMID: 20590803 DOI: 10.1111/j.1468-1331.2010.03045.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Blepharospasm, oromandibular, lingual, laryngeal and cervical dystonia are common forms of adult-onset dystonia. Each condition may appear in isolation or manifest along with other forms of craniocervical dystonia. Although the various craniocervical dystonias typically present with involuntary muscle spasms causing abnormal postures, they differ for some clinical features. Neurophysiologic and neuroimaging studies have shown a number of motor and sensory abnormalities at cortical and subcortical levels, probably reflecting a dysfunction in the basal ganglia-thalamo-cortical circuits. The best treatment for craniocervical dystonia is botulinum toxin injected into the overactive muscles.
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Affiliation(s)
- C Colosimo
- Department of Neurological Sciences, Sapienza University of Rome, Rome, Italy
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11
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Carlsen AN, Maslovat D, Lam MY, Chua R, Franks IM. Considerations for the use of a startling acoustic stimulus in studies of motor preparation in humans. Neurosci Biobehav Rev 2010; 35:366-76. [PMID: 20466020 DOI: 10.1016/j.neubiorev.2010.04.009] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 04/27/2010] [Accepted: 04/29/2010] [Indexed: 11/25/2022]
Abstract
Recent studies have used a loud (> 120 dB) startle-eliciting acoustic stimulus as a probe to investigate early motor response preparation in humans. The use of a startle in these studies has provided insight into not only the neurophysiological substrates underlying motor preparation, but also into the behavioural response strategies associated with particular stimulus-response sets. However, as the use of startle as a probe for preparation is a relatively new technique, a standard protocol within the context of movement paradigms does not yet exist. Here we review the recent literature using startle as a probe during the preparation phase of movement tasks, with an emphasis on how the experimental parameters affect the results obtained. Additionally, an overview of the literature surrounding the startle stimulus parameters is provided, and factors affecting the startle response are considered. In particular, we provide a review of the factors that should be taken into consideration when using a startling stimulus in human research.
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Affiliation(s)
- Anthony N Carlsen
- School of Human Kinetics, University of British Columbia, Vancouver, Canada.
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12
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Bakker MJ, Boer F, van der Meer JN, Koelman JH, Boerée T, Bour L, Tijssen MA. Quantification of the auditory startle reflex in children. Clin Neurophysiol 2009; 120:424-30. [DOI: 10.1016/j.clinph.2008.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 09/23/2008] [Accepted: 11/03/2008] [Indexed: 10/21/2022]
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13
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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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14
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15
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Laterality of auditory startle responses in humans. Clin Neurophysiol 2008; 119:309-14. [DOI: 10.1016/j.clinph.2007.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 10/30/2007] [Accepted: 11/11/2007] [Indexed: 11/23/2022]
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16
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Putzki N, Graf K, Stude P, Diener HC, Maschke M. Habituation of the Auditory Startle Response in Cervical Dystonia and Parkinson’s Disease. Eur Neurol 2008; 59:172-8. [DOI: 10.1159/000114038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Accepted: 08/17/2007] [Indexed: 11/19/2022]
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17
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Müller J, Rinnerthaler M, Poewe W, Kofler M. Auditory startle reaction in primary blepharospasm. Mov Disord 2007; 22:268-72. [PMID: 17149731 DOI: 10.1002/mds.21270] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Primary dystonia is associated with abnormal brainstem function, as shown by abnormalities of the blink reflex in blepharospasm (BSP) and of the auditory startle reaction in cervical dystonia. We examined the auditory startle reaction--a brainstem reflex elicited by an unexpected loud stimulus--in patients with primary BSP to expand knowledge on brainstem pathophysiology in primary focal dystonia. Thirteen patients with primary BSP were included and 13 age- and sex-matched healthy volunteers served as controls. Auditory startle responses (ASRs) were elicited by binaural high-intensity auditory stimuli, and reflex electromyographic activity was recorded simultaneously with surface electrodes bilaterally from masseter, orbicularis oculi, sternocleidomastoid, and biceps brachii muscles. Patients with BSP showed higher ASR probabilities (masseter, sternocleidomastoid, biceps brachii), shorter ASR onset latencies (masseter, orbicularis oculi, sternocleidomastoid), and larger ASR area-under-the-curve (masseter, sternocleidomastoid) as compared with normal controls. Habituation of ASRs did not differ significantly between patients and controls. These results corroborate previous findings of increased brainstem excitability in primary BSP but point to a different pattern of brainstem dysfunction compared to cervical dystonia, indicating that different pathophysiological mechanisms are involved in the two types of focal dystonia.
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Affiliation(s)
- Jörg Müller
- Department of Neurology, Medical University Innsbruck, Austria
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Neurophysiology of basal ganglia diseases. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s0072-9752(07)83003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Siegelaar SE, Olff M, Bour LJ, Veelo D, Zwinderman AH, van Bruggen G, de Vries GJ, Raabe S, Cupido C, Koelman JHTM, Tijssen MAJ. The auditory startle response in post-traumatic stress disorder. Exp Brain Res 2006; 174:1-6. [PMID: 16525797 DOI: 10.1007/s00221-006-0413-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2005] [Accepted: 01/24/2006] [Indexed: 10/24/2022]
Abstract
Post-traumatic stress disorder (PTSD) patients are considered to have excessive EMG responses in the orbicularis oculi (OO) muscle and excessive autonomic responses to startling stimuli. The aim of the present study was to gain more insight into the pattern of the generalized auditory startle reflex (ASR). Reflex EMG responses to auditory startling stimuli in seven muscles rather than the EMG response of the OO alone as well as the psychogalvanic reflex (PGR) were studied in PTSD patients and healthy controls. Ten subjects with chronic PTSD (>3 months) and a history of excessive startling and 11 healthy controls were included. Latency, amplitude and duration of the EMG responses and the amplitude of the PGR to 10 auditory stimuli of 110 dB SPL were investigated in seven left-sided muscles. The size of the startle reflex, defined by the number of muscles activated by the acoustic stimulus and by the amplitude of the EMG response of the OO muscle as well, did not differ significantly between patients and controls. Median latencies of activity in the sternocleidomastoid (SC) (patients 80 ms; controls 54 ms) and the deltoid (DE) muscles (patients 113 ms; controls 69 ms) were prolonged significantly in PTSD compared to controls (P < 0.05). In the OO muscle, a late response (median latency in patients 308 ms; in controls 522 ms), probably the orienting reflex, was more frequently present in patients (56%) than in controls (12%). In patients, the mean PGR was enlarged compared to controls (P < 0.05). The size of the ASR response is not enlarged in PTSD patients. EMG latencies in the PTSD patients are prolonged in SC and DE muscles. The presence of a late response in the OO muscle discriminates between groups of PTSD patients with a history of startling and healthy controls. In addition, the autonomic response, i.e. the enlarged amplitude of the PGR can discriminate between these groups.
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Affiliation(s)
- S E Siegelaar
- Department of Neurology H2-222 and Clinical Neurophysiology, Academic Medical Centre, PO Box 22660, 1100 DD, Amsterdam, The Netherlands
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Kofler M, Müller J, Valls-Solé J. Chapter 19 Auditory startle responses as a probe of brainstem function in healthy subjects and patients with movement disorders. SUPPLEMENTS TO CLINICAL NEUROPHYSIOLOGY 2006; 58:232-48. [PMID: 16623335 DOI: 10.1016/s1567-424x(09)70072-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Markus Kofler
- Department of Neurology, Hospital HochZirl, A-6170 Zirl, Austria.
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Currà A, Bagnato S, Berardelli A. Chapter 21 Recent findings in cranial and cervical dystonia: how they help us to understand the pathophysiology of dystonia. ACTA ACUST UNITED AC 2006; 58:257-65. [PMID: 16623337 DOI: 10.1016/s1567-424x(09)70074-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Affiliation(s)
- Antonio Currà
- Dipartimento di Scienze Neurologiche, Università degli Studi di Roma "La Sapienza", 00185 Rome, Italy.
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