Referred Pain Elicited by Manual Exploration of the Lateral Rectus Muscle in Chronic Tension-Type Headache

Abstract Purpose and background Recently, we found that maximal medial rectus recession and lateral rectus resection in patients with complete lateral rectus paralysis resulted in a partial restoration of abduction. In an attempt to understand some of the mechanisms involved with this effect we examined gene expression profiles of lateral recti from these patients, with our focus being directed to genes related to myogenesis. Materials and methods Lateral recti resected from patients with complete lateral rectus paralysis and those from concomitant esotropia (controls) were collected. Differences in gene expression profiles between these two groups were examined using microarray analysis and quantitative Reverse-transcription PCR (qRT-PCR). Results A total of 3056 differentially expressed genes (DEGs) were identified between these two groups. Within the paralytic esotropia group, 2081 genes were up-regulated and 975 down-regulated. The results of RT-PCR revealed that PAX7, MYOG, PITX1, SIX1 and SIX4 showed higher levels of expression, while that of MYOD a lower level of expression within the paralytic esotropia group as compared with that in the control group (p < 0.05). Conclusion The decreased expression of MYOD in the paralytic esotropia group suggested that extraocular muscle satellite cell (EOMSCs) differentiation processes were inhibited. Whereas the high expression levels of PAX7, SIX1/4 and MYOG, suggested that the EOMSCs were showing an effective potential for differentiation. The stimulation resulting from muscle surgery may induce EOMSCs to differentiate and thus restore abduction function.

Download Full-text

Exteroceptive Suppression of Temporalis Muscle Activity: Findings in Headache

Cephalalgia ◽

10.1046/j.1468-2982.1993.1301011.x ◽

1993 ◽

Vol 13 (1) ◽

pp. 11-14 ◽

Cited By ~ 16

Author(s):

Thomas-Martin Wallasch ◽

Hartmut Göbel

Keyword(s):

Muscle Activity ◽

Silent Period ◽

Tension Type Headache ◽

Temporalis Muscle ◽

Pharmacological Agents ◽

Chronic Tension Type Headache ◽

Exteroceptive Suppression ◽

Headache Diagnosis ◽

Secondary Phenomenon ◽

Type Headache

Exteroceptive suppression of temporalis muscle activity was proposed by Schoenen and co-workers in 1987 as a tool in headache diagnosis and research. Their finding of a decreased or abolished second silent period (ES2) in chronic tension-type headache sufferers has been confirmed by several independent laboratories during the last five years. Temporalis silent periods have also been studied in various other types of headaches. Their modulation by neuropsychological factors and pharmacological agents has also been investigated as well as their retest reliability. The pathophysiological concept of muscle contraction in tension-type headache has been challenged by studies using temporalis silent periods. The exterocepfive suppression of temporalis muscle activity points unequivocally towards a central pathogenetic mechanism, although it remains unclear whether the abnormalities of temporalis ES2 represent the primary dysfunction or a secondary phenomenon in chronic tension-type headache.

Download Full-text