Exteroceptive suppression periods and pericranial muscle tenderness in chronic tension-type headache: effects of psychopathology, chronicity and disability

Abstract

We examined pericranial muscle tenderness and abnormalities in the second exteroceptive suppression period (ES2) of the temporalis muscle in chronic tension-type headache (CTTH; n = 245) utilizing a blind design and methods to standardize the elicitation and scoring of these variables. No ES2 variable differed significantly between CTTH sufferers and controls (all tests, P>0.05). We found no evidence that CTTH sufferers with daily or near daily headaches, a mood or an anxiety disorder, or high levels of disability exhibit abnormal ES2 responses (all tests, P>0.05). CTTH sufferers were significantly more likely than controls to exhibit pervasive tenderness in pericranial muscles examined with standardized (500 g force) manual palpation (P<0.005). Female CTTH sufferers exhibited higher levels of pericranial muscle tenderness than male CTTH sufferers at the same level of headache activity (P<0.0001). Elevated pericranial muscle tenderness was associated with a comorbid anxiety disorder. These findings provide further evidence of pericranial hyperalgesia in CTTH and suggest this phenomenon deserves further study. Basic research that better elucidates the biological significance of the ES2 response and the factors that influence ES2 assessments appears necessary before this measure can be of use in clinical research.

The Role of Muscles in Tension-Type Headache

“…Tenderness and hardness have been found to be increased on both days with and days without headache [6,12,17], indicating that these factors are of primary importance for the development of headache and not only a consequence of the headache.…”

“…Many studies consistently have shown that the pericranial myofascial tissues are considerably more tender in patients with TTH than in healthy patients, and that the tenderness is positively associated with both the intensity and the frequency of TTH [6,[12][13][14]. The tenderness is uniformly increased throughout the pericranial region in both individuals with episodic and those with chronic TTH [13,15,16].…”

Behavioral and psychologic aspects of the pathophysiology and management of tension-type headache

“…A dysfunction in supraspinal (limbic) pain modulation circuits also has been postulated to maintain pain by permitting or facilitating the transmission of nociceptive information [3,9]. However, research has failed to provide support for the latter possibility, at least when the putative dysfunction is indexed by abnormalities in the exteroceptive suppression of temporalis or masseter muscle activity [10][11][12][13].…”

“…In response to standardized pressure stimuli, pericranial muscle tenderness has been observed consistently in tension-type headache, particularly in CTTH, even when the patient is in a headache-free state [10][11][12]14,15]. From the shape of pressure-pain curves, Bendtsen et al [16] have concluded that this muscle tenderness results from a sensitization of second-order neurons in the trigeminal nucleus and dorsal horn [7•,8]; nitric oxide appears to be involved in this sensitization process at the molecular level [17].…”

Central mechanisms in tension-type headaches

“…They are induced by the activation of the same afferent axons, and mediated in the brainstem by separate oligo-(ES1) and multisynaptic (ES2) neural nets, activating brainstem interneurons that inhibit the motorneurons of jaw-closing muscles [31]. Several studies [32][33][34][35][36] have shown that the second temporalis exteroceptive silent period (ES2) can decrease in patients with CTTH; other studies have demonstrated that silent period remains normal [37][38][39][40][41]. For patients with ETTH, ES2 duration is normal [33,35,36].…”