THE EFFECT OF PAIN ON THE DIURNAL PATTERN OF PLASMA CORTICOID LEVELS

Osteoporotic Mechanisms

Osteogenic cells are derived from sinusoid vessel walls. When conditions are favourable—a supply of energy, correct concentrations of oxygen and carbon dioxide, the hormone balance on the anabolic and anticatabolic side, the osteogenic factor present—osteogenic precursor cells differentiate to osteoblasts and osteocytes. When the balance is on the catabolic side precursor cells coalesce to form osteoclasts. When catabolic conditions persist osteoclastic activity continues until all the precursor cells are used up.

Phagocytic cells can also enlarge and coalesce to form osteoclasts. Parathyroid hormone is needed for coalescence. The formation of these osteoclasts is stimulated by an increased marrow pressure or exposure of dead bone tissue. Corticosteroids prevent initial enlargement of cells. Excess parathyroid hormone stimulates the production and activity of extra phagocytic osteoclasts.

The hormone balance may approach the catabolic during later stages of pregnancy and after childbirth, after the menopause, during and after the general hormonal decline in old age, when corticosteroids are given for therapeutic purposes, or as a result of the action of contraceptive agents. The effects of stress (caused by the unpleasant emotions, fear, apprehension frustration, jealousy, anxiety, etc, as well as serious illness or trauma) include a rise in blood cortisol levels. A combination of factors may result in corticosteroid levels exceeding the threshold for thrombus formation. This threshold depends on the other chemicals affecting the pituitary-adrenal system that are present. It is abnormally low for contraceptive agents.

These mechanisms of bone formation and removal account for the main types of osteoporosis. A lowered blood flow arises from a decrease or cessation of muscle activity, the effect of catabolic compounds on muscle fibres, or thrombi lodged in vessels supplying muscles and bone. A build-up of pressure stimulates the formation of phagocytic osteoclasts, while until the flow is increased again there is insufficient stimulus for new bone formation.

When catabolic conditions prevail, osteogenic precursor cells coalesce to osteoclasts, and when anticatabolic conditions return, more precursor cells are formed that may proceed to osteoblast and bone formation before the next catabolic episode. With an unfortunate timing of alternations this results in considerable bone loss. In pregnancy the loss is temporary, but after the menopause and in old age there may be a permanent decrease of bone tissue. This type of osteoporosis may also be caused by contraceptive agents. It leads to backache, the increased number of fractured wrists in older women, and intracapsular hip fractures.

Small thrombi cause irreversible osteoporosis. Blood flow through bone is decreased, and vessels in cortical bone blocked. Bone served by these vessels dies, and with prolonged catabolic conditions a considerable amount of dead bone tissue may be present. After phagocytic removal it is not usually replaced. This type of ‘senile’ osteoporosis, which can cause extracapsular hip fractures, is common in old age. It is also the main mechanism of osetoporosis caused by contraceptive agents.

There are racial variations. Negroes are the least susceptible and the Japanese the most susceptible.

In elderly people senile osteoporosis is part of a more generalized condition. The liver and brain are also affected—there are considerable individual variations, but symptoms often include depression and sometimes pyschotic episodes. Like diabetes and thyroid deficiency, an anticatabolic deficiency requires continuous therapy. The anticatabolic agent chosen should be one that reverses corticosteroid effects on bone, liver and brain efficiently, and at the same time has a high Cortisol threshold for thrombus formation.

Hormone testing and treatment enters pain care

A number of factors have recently coalesced to bring hormone testing and treatment to the field of pain care. Uncontrolled, severe pain as well as opioid drugs have a profound impact on the endocrine system. Because pain is a potent stressor, it initially causes pituitary, adrenal, and gonadal hormones to elevate in the serum. If severe pain goes uncontrolled for too long, however, hormone levels deplete in the serum. The finding of abnormal (too high or low) serum hormone levels serve as biomarker of endocrinopathies, which helps inform the clinician that enhanced analgesia as well as hormone replacement may be necessary. Adequate, physiologic levels of some specific hormones are necessary for optimal analgesia, neuroprotection, and neurogenesis. Although not a substitute for opioids, some hormone replacements may minimize their use. We know that the central nervous system produces a group of hormones called neurohormones whose natural function is neuroprotection and neurogenesis. Their clinical use in centralized pain states is new, and early reports indicate that they may have considerable benefit for treatment.

The physiologic effects of pain on the endocrine system

Severe pain has profound physiologic effects on the endocrine system. Serum hormone abnormalities may result and these serve as biomarkers for the presence of severe pain and the need to replace hormones to achieve pain control. Initially severe pain causes a hyperarousal of the hypothalamic-pituitary-adrenal system which results in elevated serum hormone levels such as adrenocorticotropin, cortisol, and pregnenolone. If the severe pain does not abate, however, the system cannot maintain its normal hormone production and serum levels of some hormones may drop below normal range. Some hormones are so critical to pain control that a deficiency may enhance pain and retard healing.

Normalization of serum cortisol concentration with opioid treatment of severe chronic pain

Serum cortisol concentrations may be altered in severe, chronic pain due to excess stimulation of the hypothalamic-pituitary-adrenal axis. Among 40 consecutive patients with severe, chronic pain 26 (65.0%) demonstrated abnormal serum cortisol concentration. After 90 days of treatment, only 7 (17.5%; p<0.01) continued to show abnormal serum cortisol concentration indicating that serum cortisol and other serologic abnormalities may serve as biologic markers of severe, chronic pain.

Hormonal changes in headache patients

Seventy-three patients with headache underwent serum and cerebrospinal fluid (CSF) radioimmunoassays of follicle-stimulating hormone (FSH), luteinizing hormone (LH), cortisol and prolactin. Serum FSH showed significant increases in all headache patients while serum LH increased only in females. Such a rise of serum FSH and LH is attributed to disturbances of the sleep-wake cycle. On the other hand, serum cortisol was significantly decreased in the male headache patients, probably due to altered circadian rhythm. Serum prolactin remained within normal limits. CSF prolactin, FSH and LH showed detectable levels in all headache sufferers compared to undetectable levels in control subjects, while CSF cortisol was significantly reduced.

Clinical characteristics of patients with idiopathic pain syndromes. Depressive symptomatology and patient pain drawings

The frequency of depressive symptomatology as estimated by means of self-rating on a visual analogue scale and the pain drawings by patients were compared between healthy volunteers, patients with neurogenic pain syndromes and patients with idiopathic pain syndromes. All patients with chronic pain syndromes had significantly more depressive symptomatology than the healthy volunteers. Patients with idiopathic pain syndromes had significantly more inhibition symptoms--memory disturbances and concentration difficulties--than patients with neurogenic pain syndromes. In the pain drawings, estimated by means of the technique suggested by Margolis et al. [10], the idiopathic pain patients had significantly higher scores on both raw scores and weighted body surface scores than the patients with neurogenic pain syndromes. Thus, both self-rating of depressive symptomatology and pain drawings can be of some help in the difficult clinical delineation between patients with idiopathic and neurogenic pain syndromes, respectively, but used as single measures, both methods have low discriminative power.

Circadian secretion of cortisol and melatonin in cluster headache during active cluster periods and remission

The cyclic nature of cluster headache warranted a study of the 24-hour rhythms of serum cortisol and melatonin. They were both altered during cluster periods as compared with periods of remission and healthy controls. The 24-hour mean and maximal cortisol levels were higher and the timing of the cortisol minimum was delayed as compared to the same patients in remission. Although there was no relation between the cortisol and melatonin levels and headaches, the rise of cortisol following many attacks might in part represent an adaptive response to pain. The nocturnal melatonin maximum was lower during cluster periods than in remission. This finding, and the dysautonomic signs during attacks, may reflect a change of the vegetative tone in a hyposympathetic direction.

Discrimination of idiopathic pain syndromes from neurogenic pain syndromes and healthy volunteers by means of clinical rating, personality traits, monoamine metabolites in CSF, serum cortisol, platelet MAO and urinary melatonin

The aim of the present study was to investigate the discriminative power of a series of variables (including determination of depressive symptomatology by means of a visual analogue scale, determination of personality traits by means of the Karolinska Scales of Personality, determination of monoamine metabolites in CSF, platelet MAO activities, serum cortisol before and after dexamethasone suppression and urinary melatonin) in differentiating chronic pain patients from healthy subjects, and patients with idiopathic pain syndromes from patients with neurogenic pain syndromes. Separately each of the measures gave a significant but often low contribution to the discrimination, while a combination of several measures gave a complete discrimination both between healthy subjects and patients with chronic pain syndromes and between patients with idiopathic and neurogenic pain syndromes, respectively.

Neuroendocrine responses in psychiatric and pain patients with major depression

Basal and postdexamethasone concentrations of cortisol and prolactin were studied in three groups of male patients: chronic pain patients with no psychiatric diagnosis (n = 12), chronic pain patients with coexisting major depression by Research Diagnostic Criteria (RDC) (n = 24), and pain-free psychiatric patients meeting RDC criteria for major depression (n = 28). Basal cortisol concentrations were significantly higher in pain-major depression and psychiatric-major depression patients compared to pain patients without psychiatric illness. The frequency of cortisol nonsuppression after dexamethasone was significantly greater in pain patients with major depression (41.7%) compared to pain patients without psychiatric disorder (8.3%), and was comparable to that of psychiatric patients (21.4%). Prolactin concentrations, but not cortisol levels, were significantly correlated with observer-rated severity of depression in pain patients. These findings suggest that cortisol and prolactin abnormalities in chronic pain may be related to psychiatric disorder rather than to pain per se, at least in male patients, and may indicate a role for cholinergic mechanisms in the interface of pain and depression.

Basal and post-dexamethasone cortisol and prolactin concentrations in depressed and non-depressed patients with chronic pain syndromes

To assess the behavior of two putative neuroendocrine markers of depression in chronic pain, the authors determined plasma cortisol and prolactin concentrations before and after dexamethasone in 52 hospitalized male chronic pain patients. Their psychiatric diagnoses by Research Diagnostic Criteria (RDC) were: major depression (N = 24; 44.2%), minor depression (N = 10; 19.2%), another RDC diagnosis (N = 7; 13.5%) and not mentally ill (N = 12; 21.6%). Failure to suppress cortisol after dexamethasone (a positive DST) occurred in 43.5% of those with major depression, 20% of those with minor depression, 42.8% of those with other psychiatric diagnoses and in 8.3% of patients without a psychiatric disorder. The frequency of non-suppression was significantly different only for patients with major depression compared to those without diagnosable psychiatric disorder. Mean basal cortisol concentrations at 08.00, 16.00 and 23.00 h did not differ among psychiatric diagnostic groups of pain patients, or between these groups and healthy volunteers. Levels of prolactin, but not cortisol, were significantly correlated with the severity of mood disturbances. These findings suggest strategies using multiple endocrine markers to distinguish pain from depression should be explored.

Is chronic pain a variant of depressive illness? A critical review

A critical review of the literature on the association of chronic pain of obscure origin and depression suggests the following: the nosological confusion in defining these two commonly occurring symptom complexes; poor sampling methods and widely ranging selection criteria; occasional lack of appropriate controls and use of unreliable instruments to measure pain and depression; and the frequently erroneous assumption that response of the pain to "antidepressant" medications implies that pain is masquerading some form of depression. All of the above observations lead to incomparable and sometimes opposing conclusions regarding the nature of the association between these two common symptom complexes. Some widespread recurring clinical features of the various studies include; a premorbid history of perfectionistic traits, an apparently minor precipitating event; and pain involving the head, face and musculoskeletal system. Otherwise, chronic pain of obscure origin appears to be a multifactorial and multifaceted problem, with each patient requiring a complete physical and psychosocial evaluation. Further understanding of this group of disorders requires studies of specific chronic pain syndromes using proper controls.

Dysesthesias and self-mutilation in humans and subhumans: a review of clinical and experimental studies

The chronic deafferentation syndrome includes a complex pattern of abnormal self-directed behavior and a stress response. Subhuman self-mutilation is a secondary consequence of the chronic deafferentation syndrome. The evidence indicates that the chronic deafferentation syndrome in subhumans is a valid model for the induced and the spontaneous dysesthesias in humans. Objective criteria for the definition of subhuman dysesthesias have been derived from independent sources of evidence, in neurally intact subjects; those criteria are then found to match the subhuman syndrome of deafferentation. Support for the validity of the inference of subhuman dysesthesias derives from the parallels with the various facts of the human dysesthesias. The credibility of this argument is significantly strengthened by reports of morphological and excitatory physiological abnormalities, in central somatosensory structures, in response to deafferentation. There is no independent subhuman evidence in support of alternate interpretations of the deafferentation syndrome, and those interpretations seem to be inadequate in several aspects. Doubts concerning the validity of this animal model have been allayed by reports of dysesthesias in humans with spinal posterior rhizotomies or ganglionectomies, and also those with congenital analgesia. Moreover, the occurrence of this syndrome in hypoalgesic areas as a consequence of anterolateral cordotomy in monkeys, can best be interpreted as a reflection of dysesthesias. This syndrome is released by neuropathological or neurosurgical lesions in the peripheral or central nervous system; lesions which involve small caliber peripheral afferents or the spinothalamic tract. Variability in the release of this syndrome has been associated with several different factors. So far, the chronic syndrome is intractable. Evidence relates the abnormalities of this syndrome to pathophysiological foci in central relays of the somatosensory system, and suggests that the chronic abnormalities of this syndrome can be sustained at brain levels.

The dexamethasone suppression test as a biologic marker of depression in chronic pain

The relationship between chronic pain and depression has become enmeshed in the literature. In an attempt to unravel the relationship between chronic pain and depression, the authors studied a uniform group of 80 chronic back pain patients with and without depression using the dexamethasone suppression test (DST). The DST examines the hypothalamic response to an exogenously administered steroid (dexamethasone) challenge. In normal subjects and patients without major depression, the dexamethasone suppresses the release of cortisol from the adrenal glands. In 40% of patients with major depression, there is an early escape of cortisol from dexamethasone suppression. We found that 40% of patients with a DSM-III major depression (dysphoric mood, appetite and sleep changes, loss of energy and interest, decreased concentration, suicidal ideation, and feelings of self-reproach) were non-suppressors and none of the patients without major depression showed this abnormality. These findings suggest that the concept of chronic pain as a variant of depression might be an oversimplification.

Stress, cortisol, interferon and "stress" diseases. I. Cortisol as the cause of "stress" diseases

An attempt is made to define a biochemical formula for stress, as an overproduction of cortisol +/- impaired interferon response. The behavior Type A individual under stress, would exhibit elevated levels of cortisol with normal interferon response, whereas the Type C individual, would exhibit elevated levels of cortisol and impaired interferon responses. Evidence is presented that elevated levels of cortisol manufactured chronically under the affect of stress, and regardless of the type of individual affected, are a cause or the cause of chronic diseases, and not the result of same. This evidence would show that: Elevated levels of cortisol precede certain diseases, and do not follow them, when cortisol is checked out for this purpose in pre-disease conditions. When elevations of cortisol levels are induced through long-term corticosteroids therapy, in patients suffering of diseases requiring this type of treatment, conditions mimicking chronic diseases, would appear. When corticosteroids therapy would be discontinued, the "chronic diseases" mentioned above would disappear. When pharmaceuticals with potential cortisol antagonistic capabilities, were used in diseases totally unrelated, but having in common, elevated levels of cortisol, alleviation of symptoms and/or diseases would occur.

Plasma cortisol concentrations in patients with different circadian pain rhythm

Plasma cortisol concentration was measured 4 times in a 24 h period in 4 groups of patients. Thirty of them complained of pain with different circadian rhythmicity (nocturnal pain, diurnal pain, continuous pain) and 10 were pain-free and served as a control group. The mean plasma cortisol concentration was significantly higher in pain patients as compared with healthy, pain-free subjects at the time of the highest pain intensity. There is a positive correlation between the intensity of pain and increased plasma cortisol level and this disagrees with previous reports of a relationship of pain and lower blood cortisol levels.

Prolactin and cortisol in cerebrospinal fluid: sex-related associations with clinical and psychological characteristics of patients with low back pain

Clinical and psychological characteristics of 33 patients with low back pain were correlated with prolactin and cortisol concentrations in cerebrospinal fluid (CSF). A significant sex difference was found in CSF prolactin levels: women secreted more prolactin into the CSF than did men. High CSF cortisol levels were associated with a rhizographically-demonstrable abnormality, suggesting a relationship between cortisol and an 'organic' origin of pain symptoms. Impairment-disability indices also were associated with CSF hormone levels. Moreover, the two hormones had dissociated psychological correlates. Prolactin was related to depression and anxiety, whereas cortisol was related to somatization. Sex differences were observed in the cortisol response to the symptoms of chronic low back pain, especially in the presence of anxiety and somatization. The sex differences in psychoneuroendocrine and emotional responses suggest that male and female pain patients have different coping mechanisms.

Circadian rhythms of plasma cortisol in migraine

Diurnal rhythm of plasma cortisol, of psychological state, and of pain was measured for two days in 25 migraine patients and eight control subjects. Fourteen of the migraine patients and none of the controls displayed either consistently high plasma cortisol or an occasional aberrant peak. Abnormal psychological findings, particularly depression, were found in the Minnesota Multiphasic Personality Inventory only in migraine patients with abnormal plasma cortisol levels. Neither psychological abnormality nor pain seemed the single cause of elevation of plasma cortisol.

Endorphins in chronic pain. I. Differences in CSF endorphin levels between organic and psychogenic pain syndromes

A series of 37 patients with chronic pain was investigated with regard to neurologic and psychiatric variables. Twenty of the patients were classified as having mainly organic (= somatogenic) pain syndromes while 17 patients were rather suffering from psychogenic pain syndromes. Samples of lumbar cerebrospinal fluid (CSF) were obtained from the patients and analyzed for the presence of opiate receptor-active material, here called endorphins. Patients classified as having mainly organic pain syndromes were found to have significantly lower endorphin levels than patients with predominantly psychogenic pain syndromes. In the total group of patients as well as in the two subgroups, there was a significant correlation between CSF endorphin levels and the depth of depressive symptomatology as reported by the patients. On the other hand, there was no correlation between CSF endorphin levels and extent of anxiety or motor retardation. It is concluded that CSF endorphins reflect central processes involved in chronic pain syndromes.

Plasma 11-hydroxycorticosteroid and growth hormone levels in acute medical illnesses

Adrenal cortical response in acute medical illness has been studied by measuring the plasma 11-hydroxycorticosteroid (11-OHCS) concentration in 178 patients. Those with unbalanced diabetes, acute infections, and severe myocardial infarction had high levels. The results obtained suggest that in a patient with a severe infection and hypotension a plasma 11-OHCS level of less than 15 mug./100 ml. indicates an inadequate adrenal cortical response, and one patient with septicaemia and temporary adrenal cortical insufficiency is described. Growth hormone levels were increased in patients with severe diabetic ketosis but not in those with hyperosmolar non-ketotic diabetic coma.