RESUMO
BACKGROUND: We describe a new method to study the sensibility of the nipple-areola complex of the breast with faradic electricity delivered through an electromyographic device used to monitor peripheral nerve conduction. METHODS: The objective results of faradic pulses (2-50 mA per pulse) delivered to the nipple-areola complex of the breast through a Nihon-Kohden II machine (Evoked potential/Electromyographs, Nihon-Kohden Co., Japan) were evaluated in normal volunteers to get a basal measure that was defined by the patient as "a soft electric discharge." The measures were recorded and their output discharges averaged (at least 5 to each complex). RESULTS: Twenty-eight volunteers with normal breasts, 28 patients with breast hypertrophy before and after breast reduction, and 28 patients before and after breast augmentation were studied. The faradic pulses were perceived from 1.5 to 3.5 mA in the areola and from 3 to 5.5 mA in the nipple in the control group and from 4.5 to 7.0 mA in the areola and from 6.5 to 9.5 mA in the nipple in the breast hypertrophy group with no significant changes before and after surgery. In the breast augmentation group the faradic pulses were very similar to the volunteers that had normal breasts, but 13 months after breast augmentation with silicone gel prosthesis, a difference was found because all the patients had a higher threshold and three cases had lost sensibility of the nipple-areola complex. CONCLUSION: In normal breasts the areola had a lower threshold for faradic pulses compared to the nipple. Hypertrophic breasts had a higher threshold to the faradic stimulation than normal subjects in the pre- and postoperative period. Hypoplastic breasts before breast augmentation had a perception threshold similar to that of the normal volunteers but after breast augmentation this perception was much higher.
Assuntos
Diagnóstico por Computador , Eletromiografia/métodos , Mamilos/inervação , Limiar Sensorial/fisiologia , Adulto , Mama/inervação , Mama/cirurgia , Estudos de Coortes , Eletrodos , Eletromiografia/instrumentação , Feminino , Humanos , Japão , Mamoplastia/efeitos adversos , Mamoplastia/métodos , Pessoa de Meia-Idade , Percepção/fisiologia , Período Pós-Operatório , Cuidados Pré-Operatórios , Probabilidade , Valores de Referência , Sensibilidade e EspecificidadeRESUMO
Changes in breast sensibility after reduction mammaplasty remain a controversial subject and most previous studies report only qualitative results. There is more accurate measuring of the sensibility of the skin with the Pressure-Specified Sensory Device (PSSD), which measures the pressure perception of the skin in grams per square millimeter. The evaluation of breast sensibility before and after reduction mammaplasty using the upper medial pedicle technique was undertaken in 25 patients. The PSSD was used to measure one dynamic point threshold in nine points of the breast during the preoperative period and 6 months after surgery. After surgery all patients had decreased sensation in all points studied, and this was significant. There are few reports of breast sensibility after mammaplasty using the PSSD, and the discrepancy in results reported using other methods of evaluation could be related to precision in evaluation.
Assuntos
Mama , Mamoplastia , Sensação , Pele/inervação , Tato , Adolescente , Adulto , Feminino , Humanos , Mamilos/inervação , Limiar SensorialRESUMO
Electrical stimulation of the XIII thoracic nerve (the 'mammary nerve') causes milk ejection and the release of prolactin and other hormones. We have analysed the route of the suckling stimulus at the level of different subgroups of fibres of the teat branch of the XIII thoracic nerve (TBTN), which innervates the nipple and surrounding skin, and assessed the micromorphology of the TBTN in relation to lactation. There were 844 +/- 63 and 868 +/- 141 (S.E.M.) nerve fibres in the TBTN (85% non-myelinated) in virgin and lactating rats respectively. Non-myelinated fibres were enlarged in lactating rats; the modal value being 0.3-0.4 micron 2 for virgin and 0.4-0.5 micron 2 for lactating rats (P greater than 0.001; Kolmogorov-Smirnov test). The modal value for myelinated fibres was 3-6 micron 2 in both groups. The compound action potential of the TBTN in response to electrical stimulation showed two early volleys produced by the A alpha- and A delta-subgroups of myelinated fibres (conduction velocity rate of 60 and 14 m/s respectively), and a late third volley originated in non-myelinated fibres ('C') group; conduction velocity rate 1.4 m/s). Before milk ejection the suckling pups caused 'double bursts' of fibre activity in the A delta fibres of the TBTN. Each 'double burst' consisted of low amplitude action potentials and comprised two multiple discharges (33-37 ms each) separated by a silent period of around 35 ms. The 'double bursts' occurred at a frequency of 3-4/s, were triggered by the stimulation of the nipple and were related to fast cheek movements visible only by watching the pups closely. In contrast, the A alpha fibres of the TBTN showed brief bursts of high amplitude potentials before milk ejection. These were triggered by the stimulation of cutaneous receptors during gross slow sucking motions of the pup (jaw movements). Immediately before the triggering of milk ejection the mother was always asleep and a low nerve activity was recorded in the TBTN at this time. When reflex milk ejection occurred, the mother woke and a brisk increase in nerve activity was detected; this decreased when milk ejection was accomplished. In conscious rats the double-burst type of discharges in A delta fibres was not observed, possibly because this activity cannot be detected by the recording methods currently employed in conscious animals.(ABSTRACT TRUNCATED AT 400 WORDS)