Extracephalic tenderness and pressure pain threshold in children with headache

Background Sensitisation of the pain detection system has been suggested to be involved in the pathogenesis of recurrent headache. In adults, increased sensitivity to pain has been found in patients with chronic tension type headache. Children with migraine or with unspecific headache report non‐headache pains and interictal pericranial muscular tenderness more often than headache‐free children. Objective To study if children with different types of headache report non‐headache pain more often than children with no headache and if extracephalic muscular tenderness is different in children with headache in comparison to headache‐free children. To find out if interval to the headache episode has influence on the extracranial muscular tenderness. Design A population‐based sample of 13‐year‐old children with migraine (n = 48), episodic tension type headache (61) or no headache (59) were interviewed for the occurrence and characteristics of headache and fulfilled a questionnaire on non‐headache pain. A structured manual palpation test on muscular tenderness and a pain threshold measurement were done on seven cephalic and three extracephalic points. Results Children with migraine reported other pains, especially stomach pain and limb pain more often than children with episodic tension type or no headache. There were no significant differences in the extracephalic muscular tenderness or in the pressure pain thresholds between the three groups. Conclusions Children with migraine experience more non‐headache pains than children with episodic tension type headache and with no headache. However, neither children with migraine nor children with episodic tension type headache show increased interictal extracephalic muscular sensitivity for palpation.     

Cephalic muscle tenderness and pressure pain threshold in a general population.

Tenderness and pain thresholds in pericranial muscles were studied in a general population. A random sample of 1000 adults aged 25-64 years was drawn as part of the Glostrup Population Studies, and 740 adults were examined. This study was part of a multifacetted, epidemiological study of different headache disorders according to the new headache classification. Manual palpation and pressure pain threshold with an electronic pressure algometer were performed by observers blinded to other information such as the person's history of headache, previous illness and mental state. The muscles most commonly tender to manual palpation were the lateral pterygoid (55%), the trapezius (52%), and the sternocleido-mastoid muscles (51%). Females were more tender than men in all the muscles examined by manual palpation. In total, the young age group was more tender than the old age group (P = 0.03). Pressure pain thresholds on temporal muscles showed lower thresholds in women than in men (P less than 10(-3)), and in the total population thresholds increased with age (P less than 0.05). No side-to-side difference in tenderness by manual palpation was found, while the right side showed increased pain thresholds in right-handed individuals (P less than 10(-4)). No side-to-side difference was found in left-handed persons. This study provides data about the normal population and forms the necessary basis for evaluating the importance of muscle tenderness in headache subjects and other selected groups.     

Autonomic function and pressure pain threshold following thoracic mobilization in asymptomatic subjects: A randomized controlled trial

Objective

To compare the effects of two different mobilization techniques and a placebo intervention applied to the thoracic spine on heart rate variability (HRV) and pressure pain threshold (PPT) in asymptomatic individuals.

Acute pain threshold in subjects with chronic pain following spinal cord injury.

Studies of pain perception in patients with chronic pain have yielded contradictory results. While several studies found that acute pain threshold is raised in chronic pain subjects, others showed that these subjects exhibit a decreased pain threshold compared to pain free subjects. The aim of this study was to further examine this topic by studying pain perception in subjects with chronic pain following partial or complete spinal cord injury (SCI). We found a significant elevation of heat-pain threshold (measured above the level of lesion) in complete SCI subjects with chronic pain (CSCIP) as opposed to complete SCI subjects without pain, incomplete SCI subjects with (ISCIP) and without chronic pain and normal controls. This elevation of pain threshold was completely reversed following a complete relief of the chronic pain by DREZ lesion. Moreover, the CSCIP exhibited significantly higher scores in the McGill pain questionnaire compared to ISCIP, indicative of a more intense chronic pain perceived by these subjects. In addition, the chronic pain below the level of spinal lesion, reported by CSCIP originated from a significantly larger body area than that of ISCIP. These results indicate that a critical level of chronic pain must be perceived in order to induce an elevation in acute pain threshold.     

Increased pericranial tenderness, decreased pressure pain threshold, and headache clinical parameters in chronic tension-type headache patients

OBJECTIVE: The aim was to investigate whether increased pericranial tenderness or decreased pressure pain threshold (PPT) was related to headache intensity, duration, and frequency in chronic tension-type headache (CTTH). METHODS: Twenty-five CTTH patients and 25 matched controls were studied. A headache diary was kept for 4 weeks to substantiate the diagnosis and record the pain history. Three tenderness (total, cephalic, and neck) scores and PPT at both cephalic and neck points were objectively and blinded assessed. Bodily pain perceived by the patients was assessed with the Short Form-36 questionnaire. RESULTS: CTTH patients showed decreased PPT and increased tenderness as compared with controls (P<0.001). Negative correlations were found between PPT on each point and their respective tenderness scores. Within the CTTH group, neither increased tenderness nor decreased PPT seemed to directly influence headache intensity, frequency or duration; or vice versa. DISCUSSION: Increased tenderness may predispose the patients to other perpetuating factors in inducing headache attacks. Further research is needed to clearly define the role of pericranial tender tissues or other factors in the genesis and maintenance of CTTH.     

Reproducibility indices applied to cervical pressure pain threshold measurements in healthy subjects

OBJECTIVES: To apply various statistical indices for reproducibility analysis of pressure pain threshold measurements and to derive a preferred pressure pain threshold measurement protocol based on these indices. METHODS: The pressure pain threshold of 3 pairs of right and left homologous cervical region sites were measured in 20 healthy subjects (10 women, 10 men) using a hand-held pressure algometer. Measurements took place on 2 occasions (test 1 and test 2) separated by a mean interval of 1 week. On each testing session, the site-related pressure pain thresholds were measured 3 times each according to 2 different protocols. Protocol A consisted of a repetitive order, namely 3 consecutive measurements at each site before proceeding to the next, whereas protocol B consisted of an alternate order in which 3 consecutive rounds of all individually tested sites took place. For test 1, protocol A was followed by protocol B with an hour interval. For test 2, the reverse order took place. RESULTS: The findings revealed no significant differences between the two protocols and indicated a significant rise (P < 0.0001) in the absolute scores from test 1 to test 2 in both protocols. Absolute values (mean +/-SD) derived from the entire sample of pressure pain threshold sites ranged from 140 +/- 60 to 198.7 +/- 95 kPa (1.60 +/- 0.6 to 1.99 +/- 0.95 kg/cm, respectively). No significant gender or side differences were noted. Pearson r as well as the intraclass correlation coefficient revealed good to excellent reproducibility for both protocols and for all sites measured: r = 0.79-0.94 and intraclass correlation coefficient(3,3) = 0.85-0.96, respectively. To define site-specific cutoff values indicating change at the 95% confidence level, 1.96*SEM was calculated, and its values ranged from 31.6 to 58.2 kPa, which correspond to 16.8% to 32.8% of the absolute mean values. In addition, the limits of agreement, which depict the individual test-retest differences relative to their mean, indicated a heteroscedastic trend. DISCUSSION: The two protocols yielded very similar results. However, on the grounds of patient's comfort and compliance as well as facility of application, protocol B stands out as the more preferred between the two.     

Measurement of reported pain of childbirth: a comparison between Australian and Italian subjects

A group of 22 Australian-born mothers, 10 mothers born in Italy and 8 born in Australia of Italian parents, were tested using the Present Pain Index, the Pain Rating Index (Ranking) and the Number of Words Chosen index from the McGill Pain Questionnaire. This questionnaire consists of words that can be used to describe and measure the intensity of the pain by using weighted words that have a sensory, an evaluative and an affective component. The subjects were mothers in the same maternity ward of a suburban public hospital. No statistically significant results were obtained.     

Chronic pain in spinal cord injury: comparison between inpatients and outpatients

Chronic pain is a common clinical finding in spinal cord injury (SCI), with a reported incidence of between 45% and 90%. This figure was obtained by using nonstandardized pain evaluation and for mostly inpatient populations. Because of the shortcomings of previous investigations and the wide range of reported incidence, a study was conducted using self-rating pain measurement, an activity check list, and a drug-use rating scale. Pain in 40 hospitalized SCI patients (19 quadriplegics and 21 paraplegics) was evaluated according to the self-rating pain scale and for physical activities. The medical record of each of these patients was then reviewed to evaluate use of pain medications. Using the same method, 24 outpatients (12 with quadriplegia and 12 with paraplegia) in the Hospital Based Home Care Program were studied. Statistical analysis showed an incidence of chronic pain and decreased activity of 60% among inpatients and of 16.6% in outpatients. The drug-use rating scale was also significantly higher among inpatients while outpatients had a higher level of physical activity than inpatients. Whether these differences are causally related to the patient's hospitalization is difficult to determine.     

The initial effects of different rates of lumbar mobilisations on pressure pain thresholds in asymptomatic subjects

Lumbar mobilisations are commonly used in clinical practice to reduce pain and increase function. Mobilisations to the cervical spine have been shown to reduce pain using pressure pain thresholds (PPTs). Yet there is no evidence to confirm that this happens in the lumbar spine. Furthermore little is known about the effects of different treatment doses on the amount of hypoalgesia produced. It is unknown if changing the rate of application of mobilisations has an effect on hypoalgesia. The aim of this study was to investigate the immediate effects of lumbar posteroanterior mobilisations performed at different rates on PPT and the extent of the hypoalgesia.A repeated measures, single blind, randomised-trial was conducted on 30 asymptomatic subjects. PPTs were measured at 4 sites in the upper and lower quadrants, before and after the application of lumbar posteroanterior mobilisations performed at 2 Hz, 1 Hz and quasi-static. The results demonstrated an immediate and significant improvement in PPT measures (P = 0.000) irrespective of the rate or site tested. The effects were both local and widespread. There was no significant difference in PPT between the rates of mobilisations.This study provides new experimental evidence that lumbar posteroanterior mobilisations produce an immediate and significant widespread hypoalgesic effect, regardless of the rates of mobilisation in asymptomatic subjects.     

The effect of soft tissue deloading tape on thoracic spine pressure pain thresholds in asymptomatic subjects

The application of tape to deload soft tissue is used in the management of thoracic spine pain. A reported clinical feature of this treatment is reduced tenderness of the spine during postero-anterior mobilizations. A randomized, single blind, placebo controlled, repeated measures design study was employed to investigate the effects of deloading tape on pressure pain threshold measurements at the level of the T7 spinous process in an asymptomatic group of 24 subjects. Pressure pain thresholds were assessed prior to and following the application of deloading tape, placebo sham tape and no-tape control conditions. All subjects received all three conditions in a randomized order on three separate days. Differences between the pre- and post-measurements were used as indicators of change in a subject's pressure pain threshold. No significant change in pressure pain threshold measurements was found between conditions. In summary, this study demonstrated that deloading tape applied to the level of the T7 spinous process did not significantly change pressure pain threshold measurements in asymptomatic subjects, raising the possibility that any pain relieving effect may well be conditional upon pain being present.     

Beat-to-beat blood pressure response in asymptomatic IDDM subjects

Nine insulin-dependent diabetic (IDDM) patients (aged 25-37 yr) with no symptoms of autonomic neuropathy and 15 healthy control subjects (aged 26-39 yr) were studied at rest and during tests of Valsalva maneuver, deep breathing, cold pressor, and postural change from sitting to standing. Continuous (beat-to-beat) measures were taken of heart rate, systolic blood pressure, diastolic blood pressure, and skin conductance. The diabetic patients were differentiated from the control group by the following: less variability in diastolic blood pressure during deep breathing, failure to exhibit diastolic blood pressure decreases during recovery from a cold pressor stimulus, a flatter blood pressure response pattern when changing from sitting to standing, and a smaller standing ratio (maximum/minimum) for R-R interval. Among the patients, age was negatively correlated with systolic and diastolic standing ratios and diastolic blood pressure variability during deep breathing. By use of the tracking cuff, a method of continuously recording blood pressure noninvasively, we have been able to assess subtle blood pressure changes, thereby revealing signs of sympathetic dysfunction in a group of relatively young diabetic patients with no symptoms of neuropathy. The tracking-cuff method of recording blood pressure has potential in further research on autonomic functioning in diabetic patients.     

Neuromuscular function: comparison of symptomatic and asymptomatic polio subjects to control subjects

The purpose of this study was to determine if there were any differences between symptomatic and asymptomatic polio survivors by history of acute poliomyelitis illness, electromyographic evidence of terminal motor unit reorganization, and neuromuscular function of the quadriceps femoris muscle. Thirty-four symptomatic postpolio subjects, 16 asymptomatic postpolio subjects, and 41 controls were studied. A questionnaire assessed polio history. Peak knee extension torque was measured isokinetically and isometrically. Endurance (time to exhaustion) was measured at 40% of maximal isometric torque. Work capacity was determined as the product of torque and duration. Recovery of isometric strength was measured at regular intervals for ten minutes after exhaustion. Quantitative electromyography was also performed on the quadriceps to determine motor unit action potential duration and amplitude. It was found that symptomatic subjects had evidence of more severe original polio involvement by history (documented electromyographically), were weaker and capable of performing less work than asymptomatic subjects, and recovered strength less readily than controls.     

Algometry. Measuring pain threshold, method and characteristics in healthy subjects.

A pressure algometer was tested using a specially designed protocol in 28 healthy adult males and females. Two observers examined the pressure threshold (PT) of local tenderness at the joints of the wrists, elbows, knees, ankles, and at the paravertebral tissues. Several characteristics of the instrument were found. There were no significant differences in PT's between the same points on either side of the body (r = 0.738-0.934). A large source of variance was the measurement of one area within short time intervals. No significant differences in means were found between the two observers for the paravertebral points, while significant differences were found at the peripheral joints. Male subjects had significantly higher PT's than females. The PT's of the paravertebral tissues decreased in a cranial direction, while PT's of the peripheral joints showed similar levels. There was no significant influence on observing PT's on different dates or in a different order.     

Local decrease of pressure pain threshold in nummular headache

BACKGROUND: Nummular headache (NH) is a primary disorder presenting with localized pain that is circumscribed to a coin-shaped area of the head surface. METHODS: In 12 patients with NH (3 men and 9 women, 21 to 67 years old), we measured the pressure pain threshold (PPT) in several points while they were headache-free. The following cephalic and extracephalic points were explored: the symptomatic cranial area, a symmetrical point on the nonsymptomatic side, and 3 standardized pairs of symmetrical points (anterior part of the temporal muscle, upper trapezius muscle, and distal dorsal part of the second finger). Three consecutive PPT readings were obtained with an algometer on each point, and the repeatability of these measurements was always high (ICC: 0.93 to 0.97). RESULTS: Mean PPT was lower in the symptomatic cranial area than in the contra-lateral symmetrical point (1.8 +/- 0.6 kg/cm(2) vs 2.4 +/- 0.6 kg/cm(2); P < .001), whereas in the remaining reference points PPT was almost equal on both sides. CONCLUSIONS: According to these data, NH seems to be associated with a local increase of pain sensitivity to mechanical stimulation.     

Comparison between the reliability levels of manual palpation and pressure pain threshold in children who reported orofacial pain

The aim of this study was to compare the intra- and inter-rater reliability of pressure pain threshold (PPT) and manual palpation (MP) of orofacial structures in symptomatic and symptom-free children for temporomandibular disorders (TMD). Fourteen children reporting pain in masticatory muscles or the temporomandibular joint and 16 symptom-free children were randomly assessed on three different occasions: by rater-1 in the first and third session and by rater-2 in the second session. The trained raters applied algometry and MP as recommended by the Research Diagnostic Criteria for TMD. Intraclass correlation coefficients and the Kappa statistic were used to assess the levels of reliability of PPT and MP, respectively. Excellent intra- and inter-rater reliability levels were observed for PPT values at most of the examined sites for symptom-free children and excellent and moderate reliability levels for children reporting pain. For MP, moderate and poor intra-rater and inter-rater reliability levels were observed for most sites in both groups. Algometry showed higher reliability levels for both groups of children and is recommended for pain assessment in children in association with MP.     

Gender differences in pressure pain threshold in healthy humans

AIMS OF INVESTIGATION: To quantify the magnitude of putative gender differences in experimental pressure pain threshold (PPT), and to establish the relevance of repeated measurements to any such differences. METHODS: Two separate studies were undertaken. A pressure algometer was used in both studies to assess PPT in the first dorsal interosseous muscle. Force was increased at a rate of 5 N /s. In study 1, two measurements were taken from 240 healthy volunteers (120 males, 120 females; mean age 25 years) giving a power for statistical analysis of beta=0.80 at alpha=0.01. In study two, 30 subjects (15 males, 15 females mean age 28 years) were randomly selected from study one. Fourteen repeated PPT measurements were recorded at seven, 10 min intervals. Mean PPT data for gender groups, from both studies, were analysed using analysis of covariance with repeated measures, and age as the covariate. RESULTS: The mean PPT for each of the two measurements in study one showed a difference between gender of 12.2 N (f=30.5 N, m=42.7 N) and 12.8 N (f=29.5 N, m=42.3 N), respectively, representing a difference of 28% with females exhibiting a lower threshold. In study two, the mean difference calculated from 14 PPT repeated measurements over a 1h period was comparable to that in study one at 12.3N (range 10.4-14.4 N) again females exhibited the lower threshold. The differences in mean PPT values between gender were found to be significant in both study one, at (P<0.0005, F=37.8, df=1) and study two (P=0.01, F=7.6, df=1). No significant differences were found in either study with repeated measurement (P=0.892 and P=0.280), or on the interaction of gender and repeated measurement after controlling for age (P=0.36 and P=0.62). CONCLUSION: Healthy females exhibited significantly lower mean PPTs in the first dorsal interosseous muscle than males, which was maintained for fourteen repeated measures within a 1 h period. This difference is likely to be above clinically relevant levels of change, and it has clear implications for the use of different gender subjects in laboratory based experimental designs utilising PPT as an outcome measure.     

Patterns of hip rotation range of motion: a comparison between healthy subjects and patients with low back pain

The purpose of this study was to characterize and classify the prevalence of passive hip rotation range-of-motion (ROM) asymmetry in healthy subjects (n = 100) and in patients with low back dysfunction (n = 50). We categorized the subjects of both groups as having one of three patterns of hip rotation. Pattern IA existed when all ROM measurements were equal (within 10 degrees). Pattern IB existed when total medial and lateral rotation were equal, but one or more of the individual measurements were unequal. Pattern II existed when total medial rotation ROM was greater than total lateral rotation ROM. Those subjects with total lateral rotation ROM greater than total medial rotation ROM demonstrated pattern III. The distribution of subjects among the ROM pattern categories was significantly different in the patient and healthy subject groups. The frequency of occurrence of pattern III was greater in the patient group than in the healthy subject group. These results suggest an association between hip rotation ROM imbalance and the presence of low back pain.     

Pressure pain threshold evaluation of the effect of spinal manipulation in the treatment of chronic neck pain: a pilot study

Nine subjects with chronic mechanical neck pain syndromes were evaluated for pressure pain threshold (PPT) over standardized tender points in the paraspinal area surrounding a manipulable spinal lesion. The subjects were then allocated randomly to an intervention consisting of either an oscillatory mobilization of the cervical spine (n = 4), which was designated as the control procedure, or a rotational manipulation of the cervical spine (n = 5). An assessor-blinded re-evaluation of the pressure pain threshold levels was conducted after 5 min. In the group receiving a manipulation the mean increases in pressure pain threshold ranged from 40-56% with an average of 45%. In the control group no change in any of the pressure pain thresholds was found. These results were analyzed using ANOVA and were found to be statistically significant (p less than 0.0001). This study confirms that manipulation can increase local paraspinal pain threshold levels. The use of the pressure pain threshold meter allows for the determination of such a beneficial effect in the deeper tissues.