Pain physician
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Hydrogen sulfide (H2S) is a malodorous gas which functions as an endogenous gasotransmitter in humans. It is becoming appreciated that H2S may be involved in a wide variety of processes including nociceptive processes. The molecular mechanisms responsible for many of the activities of H2S remain uncertain, however, H2S increases cAMP levels in neuronal and glial cell lines and primary neuron cultures with hyperpolarization. ⋯ A secondary contribution to the facilitation of pronociceptive processes may come from H2S-induced activation. It would appear that much like other gasotransmitters (e.g. nitric oxide), endogenous H2S may be involved in multiple physiologic processes and its effects remain complex, difficult to predict, and may vary depending on the specific environment/circumstances/location where it is generated. A greater understanding of the clinically significant human physiology of H2S and hydrogen sulfide's effects on modulating nociceptive processes may potentially lead to novel targets for improving analgesia.
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Atypical chest pain is a common complaint among Complex Regional Pain Syndrome (CRPS) patients with brachial plexus involvement. Anatomically, the intercostobrachial nerve (ICBN) is connected to the brachial plexus and innervates the axilla, medial arm and anterior chest wall. By connecting to the brachial plexus, the ICBN could become sensitized by CRPS spread and become a source of atypical chest pain. ⋯ The results of this study support the idea that chest pain is greater in CRPS patients than normal controls. The ICBN could be the source of this sensitization by CRPS spread from the brachial plexus.
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For many headache types, occipital peripheral nerve stimulation (ONS) provides significant relief of chronic, frequent, and severe headaches. Though rarely reported, ONS may cause painful muscle spasms that make stimulator use impractical. The classic description of the technique advocates placement of the leads transversely at the level of the arch of C1 or at C1-2. At that level, the greater occipital nerve (GON) infrequently pierces the superficial fascia of the neck muscles to become superficial. However, important anatomic variability exists. ⋯ Stimulation parameters vary, thus posting parameters may be misleading as muscle spasms occurred despite multiple reprogramming attempts and were a function of lead position, not program settings.
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Case Reports
Chronic regional pain syndrome after subtalar arthrodesis is not prevented by early hyperbaric oxygen.
Subtalar arthrodesis was performed on a 48-year-old, non-insulin-dependent diabetic with a history of chronic ankle instability and lateral ankle pain. In the early post-operative period he presented as an emergency with an infection at the operative site. This was treated with 2 returns to the operating theatre for washout and debridement. ⋯ Symptoms and signs at this time were compatible with a diagnosis of chronic regional pain syndrome (CRPS). There is published evidence to suggest that HBO therapy may be a useful modality in the treatment of established CRPS. Here, we seek to publicize a case in which early treatment with HBO for another indication did not prevent the simultaneous development of CRPS Type 1.
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Case Reports
Successful treatment of meralgia paresthetica with pulsed radiofrequency of the lateral femoral cutaneous nerve.
Meralgia paresthetica is a rarely encountered sensory mononeuropathy characterized by paresthesia, pain or sensory impairment along the distribution of the lateral femoral cutaneous nerve caused by entrapment or compression of the nerve as it crosses the anterior superior iliac spine and runs beneath the inguinal ligament. ⋯ The patient had experienced long-standing pain that was recalcitrant to conservative/pharmacologic therapy and multiple nerve blocks with local steroid instillations. A single treatment with pulsed radiofrequency resulted in complete and sustained cessation of pain. No side effects were evident. Pulsed radiofrequency of the LFCN may offer an effective, low risk treatment in patients with meralgia paresthetica who are refractory to conservative medical management or are unwilling or unfit to undergo surgery.