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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The exteroceptive suppression (ES) of electrical activity in the temporal muscle is an inhibitory antinociceptive brain-stem reflex. We investigated whether aspirin can significantly modulate latencies or durations of the early (ES1) and late (ES2) exteroceptive suppression periods of electrical activity in the temporal muscle. Participating in the randomized double-blind crossover study were 20 patients with migraine without aura, 20 patients with tension-type headache, and 20 healthy subjects. ES1 and ES2 elicited by an electrical stimulus of 20 mA lasting 0.2 msec were recorded during maximal voluntary contraction of the mastication muscles before and 30 min after medication. In a randomized and double-blind fashion half of the subjects were given 1200 mg of aspirin in the form of an effervescent solution and the other half were given an identically tasting solution without aspirin. One week later the experiment was repeated with the substances exchanged in crossover fashion. The administration of placebo as well as aspirin caused a highly significant increase in ES1 duration (P less than or equal to 0.001). While aspirin caused a highly significant increase in ES2 duration (P less than or equal to 0.001) the taking of placebo showed no significant effect on ES2 duration. In giving aspirin as opposed to the placebo, there was a significant interaction between groups and drug effect on the latency of ES1; whereas in migraine patients and in patients with tension-type headache the latency of ES1 was reduced by administration of aspirin, it was increased in healthy subjects (P less than or equal to 0.05). Neither aspirin nor placebo significantly varied the ES2 latency.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Acetylsalicylic acid activates antinociceptive brain-stem reflex activity in headache patients and in healthy subjects. 158 37

EMG analysis of the late exteroceptive suppression period of the temporal muscle activity is discussed as comparative methodology in the assessment of patients suffering from chronic tension-type headache and from migraineurs. After electrical perioral trigeminal nerve stimulation during maximum voluntary jaw occlusion, early (ES1) and late (ES2) exteroceptive suppression periods can be registered above the temples using surface EMG recordings. In patients suffering from chronic tension-type headache the duration of the late suppression period is shortened (p less than 0.001) compared to migraineurs or controls. However, patients suffering from episodic tension-type headache display late suppression periods of temporal muscle activity of differing lengths.
Cephalalgia 1991 May
PMID:EMG analysis of the late exteroceptive suppression period of temporal muscle activity in episodic and chronic tension-type headaches. 186 Jan 31

In 18 normal subjects and 36 patients with chronic headache (3 cluster headache, 18 maigraine and 15 muscle contraction headache), exteroceptive suppression in the temporalis, masseter and trapezius muscles was examined. In the temporalis and masseter muscles, early and late phases (ES1 and ES2) were observed. In the present study, late response (ES2) was examined. Patients with muscle contraction headache showed an obvious decrease of exteroceptive suppression in duration and degree. Patients with common migraine showed slight reduction of exteroceptive suppression in duration and amount, when compared with normal subjects. Patients with classic migraine or cluster headache elicited almost normal exteroceptive suppression. Exteroceptive suppression in the trapezius muscle consisted of one or two suppressive phase(s). Early phase was small and unstable. In the present study, late response with latency of about 45 ms was examined. In the trapezius muscle, migraine and patients with muscle contraction headache elicited the reduction of the exteroceptive suppression in degree. There might be the failure of the inhibitory interneuron mediating the pathway of exteroceptive suppression not only in patients with muscle contraction headache, but also in patients with migraine, especially in patients with common migraine.
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PMID:[Exteroceptive suppression after mental nerve stimulation in patients with chronic headache]. 235 Sep 23

Early (ES1) and late (ES2) exteroceptive suppression periods elicited by electrical stimulation of the labial commissure during teeth-clenching were recorded over the temporalis muscle in 45 headache patients (25 tension headaches and 20 migraines) and 22 controls. Mean duration of ES2 for single shocks was significantly reduced in tension headache when compared with migraine or controls. At a stimulation rate of 2 Hz, ES2 was abolished in 40% of tension headache sufferers, but in none of the migraineurs. EMG analysis of temporalis late exteroceptive suppression might be a helpful diagnostic tool in functional headaches. Reduction of ES2 suggests that there is deficient activation or excessive inhibition of pontobulbar inhibitory interneurons which receive a strong input from limbic structures. ES2 might thus represent an interface between psychogenic and myogenic factors putatively involved in the pathogenesis of tension headache.
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PMID:Exteroceptive suppression of temporalis muscle activity in chronic headache. 368 73

In 26 patients suffering from temporomandibular dysfunction (TMD) the silent period (ES), which consists of an early (ES1) and a late (ES2) inhibition which interrupts the voluntary electromyographic activity after an electrical stimulus, was recorded from the masseter muscles. Several different patterns were identified: in 8 patients (group I) the ES was normal; in 1 patient (group II) the ES was entirely absent; in 11 patients (group III) only the ES2 was absent and in 6 patients (group IV) ES1 and ES2 were combined. Such results can be explained by hypothesizing several functional states: normal excitability in group I, absolute (group II) or relative (group III) inexcitability and hyperexcitability in group IV. A central origin of TMD can be related either to a "dysregulation" of circuits located in the brainstem which give rise to the ES or to the centers, probably located in the basal ganglia, which control the circuits of the brainstem.
Headache 1994 Sep
PMID:Is temporomandibular dysfunction a cranial dystonia? An electrophysiological study. 796 Jul 32

The brainstem mediated inhibitory reflex of the m. temporalis was investigated on average 3 days after the accident in 61 patients (f = 36; m = 25; mean age = 28 years +/- 9 SD) who presented an acute cervico-cephalic syndrome with posttraumatic headache and neck pain following acute whiplash injury but without neurological deficits, bone injury of the cervical spine or combined direct head trauma. We postulated a disturbed reflexive temporalis muscle inhibition in patients with 'whiplash cephalalgia', as has previously been reported for classical muscle tension headache. Latencies and durations of the early and late exteroceptive EMG suppression (ES1 and ES2) and the interposed EMG activity (IE) of the voluntarily contracted right temporalis muscle following ipsilateral stimulation of V/2 + 3 afferents were recorded. The reflex data were compared to a cohort of 69 age and sex matched normal subjects (f = 37; m = 32; mean age = 28 years +/- 7 SD). The following significant reflex changes were found in patients: a shortened duration of ES2 with delayed onset and premature ending, a slight prolongation of ES1 and IE, a delayed onset of IE and a diminished ratio of ES2:ES1 and ES2:IE. We conclude that the abnormality of the antinociceptive reflex is based on a transient dysfunction of the brainstem mediated reflex circuit following the acceleration trauma, which can be considered a neurophysiological correlate of the posttraumatic cervico-cephalic pain syndrome and may be useful as a 'biological marker' in monitoring the time course of recovery from pain.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Pathological jaw opening reflex after whiplash injury]. 801 31

We compared the early (ES1) and late (ES2) exteroceptive suppression (ES) periods of temporalis muscle activity in 18 migraine patients during both the migraine interval and migraine attack and investigated the effect of sumatriptan and placebo on ES parameters. The measurements were performed in a balanced sequence at four different times on each patient, twice during the migraine interval and once in each of two migraine attacks. First ES1 and ES2 were measured (stimulus intensity 20 mA, stimulus duration 0.2 ms, stimulation frequency 2 Hz, averaging of 10 responses), then the medication was given on a double-blind basis with an autoinjector using either 6 mg sumatriptan or a placebo solution. Thirty minutes after application the measurements were repeated. No significant differences were found in early and late exteroceptive suppression latencies and durations between baseline measurements. Treatment did not affect the latencies of ES1 and ES2. While sumatriptan caused a significant increase in ES1 duration (p < or = 0.05) both during the migraine interval and during the migraine attack, placebo showed no significant effect on ES1 duration. Treatment with sumatriptan during the migraine attack was accompanied by a significant increase in the duration of ES2 (p < or = 0.05), but no significant changes in the durations of the late suppression periods were observed under any other conditions. The results do not support the assumption that under the experimental conditions chosen migraine attacks are accompanied by a paroxysmal change in the brain-stem mechanisms involved in the modulation of the ES parameters.(ABSTRACT TRUNCATED AT 250 WORDS)
Cephalalgia 1994 Apr
PMID:Exteroceptive suppression of temporalis muscle activity during migraine attack and migraine interval before and after treatment with sumatriptan. 806 53

The exteroceptive suppression period (ES) of the temporalis muscle activity is a trigemino-trigeminal brain stem reflex. It will be elicited most when stimulating trigeminal sensory afferents by painful stimuli and typically leads to a biphasic interruption of voluntary muscle activity. The first phase of decreased voluntary activity is called the early exteroceptive suppression period (ES1), the second, the late exteroceptive suppression period (ES2). Between these two suppression periods a phase of increased muscle activity, the so-called facilitation period (FP), can be seen. This phenomenon can be modulated by different stimulating parameters and usually, in healthy subjects, this normal pattern of the exteroceptive suppression can be elicited regularly. The reflex answer may occur at low non-painful stimulus intensities; typically, however, it appears to be most pronounced with high-intensity stimuli. Because of the obvious relationship between stimulus intensity, pain perception and reflex, the reflex is regarded as an antinociceptive reaction. The absence of an inhibition of motor activity can be visualized, for example, in hemimasticatory spasm or dystonic disorders. However, above all the ES nowadays attracts most attention as a tool to analyse different pain syndromes. One main advantage of this method in man is the ability to evaluate certain antinociceptive brain stem mechanisms functionally by means of a simple noninvasive technique. A large number of results have been obtained showing that chronic pain syndromes such as chronic tension-type headache and migraine cause changes within the normal ES recording pattern. Furthermore, some substances used in pain therapy, such as serotonin agonists or antagonists, acetylsalicylic acid or naloxone, may also alter the general appearance of the ES. This review will summarize different parameters that influence the ES reflex answer. Furthermore, the diagnostic value of changes in the ES for pathophysiological processes regarding pain perception and processing in certain pain syndromes will be discussed.
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PMID:[Exteroceptive suppression of activity of the temporal muscle. Principles and applications]. 903 58

We studied the inhibition of voluntary temporalis muscle activity after stimulations of extracephalic cutaneous or mixed nerves in 23 healthy volunteers, 29 patients suffering from migraine without aura, 24 from episodic and 42 from chronic tension-type headache. Two successive EMG suppressions were induced bilaterally after stimulating at 40 mA the index finger or the median nerve, but not after stimulations of the sural or peroneal nerves. They differed from those obtained after labial commissure stimulation at 20 mA, i.e. the classic temporalis silent periods ES1 and ES2. Overall prevalence of index- (3%) and median nerve-induced (16%) early suppression was much lower than that of labial-induced ES1 (100%); prevalence of index-induced late suppression (index-"ES2") was 62% and that of median-"ES2" 48%, compared with 97% for labial-ES2. Latency and duration of index-/median-"ES2" were not significantly different between groups. Index-"ES2" occurred significantly more often in migraineurs (83%) than in controls (48%) suggesting that the spino-bulbar pathways involved in index-/median-"ES2" are hyperexcitable in migraine.
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PMID:Suppression of voluntary temporalis muscle activity by peripheral limb stimulations in healthy volunteers, migraineurs and tension-type headache sufferes. 907 11

Brain stem interneuronal excitability can be assessed by recording the recovery cycle of the blink reflex and exteroceptive suppression of temporalis muscle activity. Abnormal endogenous pain control mechanisms due to disturbed brain stem interneuronal activity have been implicated in the pathogenesis of tension-type headaches. The blink reflex, exteroceptive suppression of temporalis muscle activity, and the recovery curve of both the R2 component of the blink reflex and the ES2 component of the exteroceptive suppression of the temporalis muscle activity were studied in 20 patients with migraine without aura, 32 patients with tension-type headache, and 20 normal controls. In our study, the blink reflex was elicited by stimulation of the supraorbital nerve; the exteroceptive suppression of the temporalis muscle activity was elicited by applying electrical shocks to the labial commissure, both on the lower and upper sides. The recovery cycle was established by delivering paired shocks at different interstimulus intervals. Comparisons were made between normal control subjects, patients with migraine without aura, and patients with tension-type headache. The latency of R1, R2, and R2', the amplitude and size of the R2 and R2' components of the blink reflex, the latency and duration of the ES1 and ES2 components, and the recovery curve of the ES2 component of the temporalis muscle activity did not differ between groups. However, the recovery curve of the R2 component of the blink reflex diminished in patients with tension-type headache compared with the other groups. Our findings indicate reduced excitability of the brain stem interneurons in patients with tension-type headache.
Headache 2001 Feb
PMID:Recovery cycle of the blink reflex and exteroceptive suppression of temporalis muscle activity in migraine and tension-type headache. 1125 98


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