Congenital insensitivity to pain with anhidrosis: a case report.
Congenital insensitivity to pain with anhidrosis (CIPA) is a very rare genetic disorder of the peripheral nervous system characterized by recurrent episodes of unexplained fever, generalized anhidrosis, insensitivity to pain and temperature, and accompanied by self-mutilating behavior and mental retardation. We report on a 16 month-old boy with CIPA who exhibited these characteristic clinical features. A sural nerve biopsy revealed markedly reduced numbers of unmyelinated and small myelinated fibers, consistent with the characteristic features of CIPA. (+info)
Dorsal rhizotomy changes the spontaneous neuronal activity of nuclei in the medial thalamus.
The aim of this study was to examine the influence of unilateral dorsal root section at the cervicothoracic level of the spinal cord on the spontaneous neuronal activity of medial thalamic nuclei in the rat. Single unit extracellular recordings from thalamic nuclei, nc. parafascicularis and nc. centralis lateralis, were obtained with glass micropipettes. The abnormal bursting activity of these nuclei following deafferentation was registered, although a correlation between the occurrence of this activity and the degree of autotomy behavior was not found. Such bursts were never observed in the studied thalamic nuclei of control rats. (+info)
Deliberate self-harm and antidepressant drugs. Investigation of a possible link.
BACKGROUND: It is not clear if the frequency of deliberate self-harm (DSH) is the same in patients taking different pharmacological classes of antidepressant drugs. AIMS: To compare the frequency of DSH in patients who had been prescribed a tricyclic antidepressant (TCA) or a selective serotonin reuptake inhibitor (SSRI) prior to the DSH event. METHOD: This was a prospective study in 2776 consecutive DSH cases attending an accident and emergency department. The incidence of DSH in TCA-treated cases and SSRI-treated cases is expressed as number of DSH events per 10 000 prescriptions of each antidepressant. RESULTS: Significantly more DSH events occurred following the prescription of an SSRI than that of a TCA (P<0.001). The occurrence of DSH was highest with fluoxetine and lowest with amitriptyline. CONCLUSIONS: Merely prescribing safer-in-overdose antidepressants is unlikely to reduce the overall morbidity from DSH. (+info)
Axotomy- and autotomy-induced changes in the excitability of rat dorsal root ganglion neurons.
The spontaneous, ectopic activity in sensory nerves that is induced by peripheral nerve injury is thought to contribute to the generation of "neuropathic" pain in humans. To examine the cellular mechanisms that underlie this activity, neurons in rat L(4)-L(5) dorsal root ganglion (DRG) were first grouped as "large," "medium," or "small" on the basis of their size (input capacitance) and action potential (AP) shape. A fourth group of cells that exhibited a pronounced afterdepolarization (ADP) were defined as AD-cells. Whole cell recording was used to compare the properties of control neurons with those dissociated from rats in which the sciatic nerve had been sectioned ("axotomy" group) and with neurons from rats that exhibited self-mutilatory behavior in response to sciatic nerve section ("autotomy" group). Increases in excitability in all types of DRG neuron were seen within 2-7 wk of axotomy. Resting membrane potential (RMP) and the amplitude and duration of the afterhyperpolarization (AHP) that followed the AP were unaffected. Effects of axotomy were greatest in the small, putative nociceptive cells and least in the large cells. Moderate changes were seen in the medium and AD-cells. Compared to control neurons, axotomized neurons exhibited a higher frequency of evoked AP discharge in response to 500-ms depolarizing current injections; i.e., "gain" was increased and accommodation was decreased. The minimum current required to discharge an AP (rheobase) was reduced. There were significant increases in spike width in small cells and significant increases in spike height in small, medium, and AD-cells. The electrophysiological changes promoted by axotomy were intensified in animals that exhibited autotomy; spike height, and spike width were significantly greater than control for all cell types. Under our experimental conditions, spontaneous activity was never encountered in neurons dissociated from animals that exhibited autotomy. Thus changes in the electrical properties of cell bodies alone may not entirely account for injury-induced spontaneous activity in sensory nerves. The onset of autotomy coincided with alterations in the excitability of large, putative nonnociceptive, neurons. Thus large cells from the autotomy group were much more excitable than those from the axotomy group, whereas small cells from the autotomy group were only slightly more excitable. This is consistent with the hypothesis that the onset of autotomy is associated with changes in the properties of myelinated fibers. Changes in Ca2+ and K+ channel conductances that contribute to axotomy- and autotomy-induced changes in excitability are addressed in the accompanying paper. (+info)
Axotomy- and autotomy-induced changes in Ca2+ and K+ channel currents of rat dorsal root ganglion neurons.
Sciatic nerve section (axotomy) increases the excitability of rat dorsal root ganglion (DRG) neurons. The changes in Ca2+ currents, K+ currents, Ca2+ sensitive K+ current, and hyperpolarization-activated cation current (I(H)) that may be associated with this effect were examined by whole cell recording. Axotomy affected the same conductances in all types of DRG neuron. In general, the largest changes were seen in "small" cells and the smallest changes were seen in "large" cells. High-voltage-activated Ca2+ channel current (HVA-I(Ba)) was reduced by axotomy. Although currents recorded in axotomized neurons exhibited increased inactivation, this did not account for all of the reduction in HVA-I(Ba). Activation kinetics were unchanged, and experiments with nifedipine and/or omega-conotoxin GVIA showed that there was no change in the percentage contribution of L-type, N-type, or "other" HVA-I(Ba) to the total current after axotomy. T-type (low-voltage-activated) I(Ba) was not affected by axotomy. Ca2+ sensitive K+ conductance (g(K,Ca)) appeared to be reduced, but when voltage protocols were adjusted to elicit similar amounts of Ca2+ influx into control and axotomized cells, I(K,Ca)(s) were unchanged. After axotomy, Cd2+ insensitive, steady-state K+ channel current, which primarily comprised delayed rectifier K+ current (I(K)), was reduced by about 60% in small, medium, and large cells. These data suggest that axotomy-induced increases in excitability are associated with decreases in I(K) and/or decreases in g(K,Ca) that are secondary to decreased Ca2+ influx. Because I(H) was reduced by axotomy, changes in this current do not contribute to increased excitability. The amplitude and inactivation of I(Ba) in all cell types was changed more profoundly in animals that exhibited self-mutilatory behavior (autotomy). The onset of this behavior corresponded with significant reduction in I(Ba) of large neurons. This finding supports the hypothesis that autotomy, that may be related to human neuropathic pain, is associated with changes in the properties of large myelinated sensory neurons. (+info)
Punishment of self-injurious behavior using aromatic ammonia as the aversive stimulus.
Punishment with aromatic ammonia was used to eliminate self-injurious behavior of an autistic woman during experimental sessions. The effects were reversible but were limited to experimental sessions until staff used the ammonia on the ward at all times. (+info)
Dental transfigurements in Borneo.
Dental transfigurement, formerly termed dental mutilation, has been practised by many societies worldwide. This article gives many of the forms that have been attributed to the indigenes of the island of Borneo. The method has been performed by review of anthropological books, sparse dental references, Borneo research literature, and popular writing. (+info)
Self-inflicted injury: a follow-up study of 43 patients.
Forty-three patients, 38 women and 5 men, with self-inflicted skin lesions were studied. Thirty-three were followed up for up to 22 years. In most cases dermatitis artefacta was only one incident in a long history of psychogenic illness. Of the 43 patients, 13 (30%), 12 women and one man, continued to produce lesions or were disabled with other psychiatric disorders more than 12 years after the onset of symptoms. Prognosis was difficult but recovery seemed to occur when the patient's life circumstances changed rather than as a result of treatment. (+info)