Articles: neuralgia.
-
One of the physiological changes accompanying neuropathic pain from nerve injury is the spontaneous firing of primary afferent fibers. At least some of this activity is thought to arise from the dorsal root ganglion. We have investigated whether this activity is resident in the cell bodies of dorsal root ganglion neurons and if it is retained in vitro. ⋯ Spontaneous resting potential fluctuations (up to 10 m V peak-to-peak) occurred in both control and CCI neurons, and triggered the spontaneous, random action potentials in neurons from CCI rats. Spontaneously firing neurons exhibited more negative action potential threshold (-34.8 mV) when compared to quiescent neurons from ganglia either after CCI (-18.7 mV) or controls (-20.5 mV). These findings show that spontaneous action potential activity after CCI is a property residing in the cell bodies of dorsal root ganglion neurons and is amenable to more detailed analysis using such an in vitro system, allowing better understanding of the cellular changes underlying neuropathic pain from nerve injury.
-
Glossopharyngeal neuralgia is a rare disease characterized by severe paroxysmal attacks of pain in the distribution of the 9th cranial nerve. The most important differential diagnosis is trigeminal neuralgia. ⋯ Autonomic disturbances may occur during pain attacks in some patients. We describe a patient suffering from glossopharyngeal neuralgia with transitory unconsciousness due to cardiac asystole and arterial hypotension accompanying the attack of pain.
-
Randomized Controlled Trial Clinical Trial
Lidocaine patch: double-blind controlled study of a new treatment method for post-herpetic neuralgia.
Post-herpetic neuralgia (PHN) is a common and often intractable neuropathic pain syndrome predominantly affecting the elderly. Topical local anesthetics have shown promise in both uncontrolled and controlled studies. Thirty-five subjects with established PHN affecting the torso or extremities completed a four-session, random order, double-blind, vehicle-controlled study of the analgesic effects of topically applied 5% lidocaine in the form of a non-woven polyethylene adhesive patch. ⋯ The highest blood lidocaine level measured was 0.1 micrograms/ml, indicating minimal systemic absorption of lidocaine. Patch application was without systemic side effect and well tolerated when applied on allodynic skin for 12 h. This study demonstrates that topical 5% lidocaine in patch form is easy to use and relieves post-herpetic neuralgia.
-
In the syndrome of post-herpetic neuralgia (PHN), the nature of the sensory disturbance and its relationship both to the severity and cause of the pain is controversial. To address these issues, sensory mapping and quantitative thermal sensory testing was carried out four times in separate sessions on 35 subjects with established PHN. All subjects had pain affecting the torso or extremities and brush-evoked allodynia. ⋯ This implies that there is no simple relationship between loss of peripheral nerve function and spontaneous or evoked pain. Rather, the preservation of several sensory modalities in their area of maximal pain suggests that in some PHN patients, activity in primary afferent nociceptors that remain connected to both their peripheral and central targets contributes significantly to ongoing pain. Although other mechanisms are likely to contribute to the pain, the demonstrated responsivity of PHN to topical agents including local anaesthetics, capsaicin, and non-steroidal anti-inflammatory drugs, supports this proposed mechanism of pain generation.