Pain
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We report a woman who developed atypical cluster headache as the first manifestation of trigeminal dysfunction from leptomeningeal lymphoma. Progression to a complete trigeminal neuropathy led to resolution of her pain. The role of the trigeminal nerve in the expression of the signs and symptoms of cluster headache is discussed.
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Randomized Controlled Trial Clinical Trial
Management of injection pain in children.
Researchers have come to understand a great deal about pain mechanisms, especially in the past 30 years. This understanding has spawned the development of a number of psychological pain control strategies which have been extensively assessed for use with adults. Less is known about pain control strategies in children. ⋯ Age was found to be an important determinant of the success of distraction. Furthermore, age was found to be related to amount of pain reported by children regardless of type of treatment. The results of this study support the use of music distraction in the reduction of injection pain in children.
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Counterirritation, the phenomenon of one painful stimulus reducing pain caused by a second noxious stimulus, has been recognized clinically for decades. Recently a physiological mechanism to explain counterirritation was described and termed diffuse noxious inhibitory controls (DNICs). Nevertheless, few psychophysical studies have examined systematically the effects of a noxious conditioning stimulus on pain perception. ⋯ Similarly, the pain threshold was significantly increased from 45.7 degrees C to 47.3 degrees C while the hand was in cold water and this threshold remained elevated after the cold water was terminated. Since DNICs have been found to completely and selectively inhibit the activity of only one type of pain transmission neuron (wide dynamic range), our data suggest that these neurons are involved in the perception of pain intensity. However, the persistence of residual pain perception in the presence of noxious conditioning stimuli indicates the importance of other nociceptive pathways.
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The formalin test in mice is a valid and reliable model of nociception and is sensitive for various classes of analgesic drugs. The noxious stimulus is an injection of dilute formalin (1% in saline) under the skin of the dorsal surface of the right hindpaw. The response is the amount of time the animals spend licking the injected paw. ⋯ It is suggested that the early phase is due to a direct effect on nociceptors and that prostaglandins do not play an important role during this phase. The late phase seems to be an inflammatory response with inflammatory pain that can be inhibited by anti-inflammatory drugs. ASA and paracetamol seem to have actions independent of their inhibition of prostaglandin synthesis and they also have effects on non-inflammatory pain.
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Pressure threshold is the minimal pressure (force) which induces pain. The pressure threshold meter (PTM) is a force gauge with a rubber disc of 1 cm2 surface. The instrument has been proven to be useful in clinical practice for quantification of deep muscle tenderness. ⋯ Results serve as a reference for clinical diagnosis of abnormal tenderness and for documentation of treatment results. The sensitivity of individual muscles varies. Therefore the results presented should be kept in mind when diagnosis of pathological tenderness by palpation is attempted.