Bases científicas de la analgesia acupuntural

Revista Médica del Uruguay

versión On-line ISSN 1688-0390

Rev. Méd. Urug. vol.21 no.4 Montevideo dic. 2005

Bases científicas de la analgesia acupuntural

Dra. Emma Gubitosi Moya*

Servicio de Acupuntura del Hospital Policial "Insp. Gral. Uruguay Genta", Dirección Nacional de Sanidad Policial, Ministerio del Interior. Montevideo, Uruguay

Resumen

En esta revisión bibliográfica se realiza una síntesis de aportes de los trabajos que consideramos más relevantes en el tema realizados en laboratorios o institutos de investigación dependientes de universidades extranjeras hasta setiembre de 2005 en base de datos Medline, Lilacs y Cochrane.

La acupuntura, terapéutica médica con comprobación científica, es eficaz en el tratamiento del dolor: contribuye a su alivio y al del componente emocional que lo acompaña. Es técnica refleja, reguladora. Produce respuestas reflejas mediadas por centros superiores de control central y por los sistemas endocrino e inmunológico.

En las últimas décadas han adquirido importancia los estudios destinados a conocer los mecanismos de neuromodulación de la nocicepción y los niveles centrales de acción de la acupuntura. Empleando métodos neurofisiológicos, neurofarmacológicos, neuroquímicos y neuroimagenológicos, equipos de investigadores citados coinciden en que la estimulación acupuntural activa fibras aferentes de nervios periféricos generando impulsos nerviosos que ascienden hacia el cerebro vía el fascículo ventrolateral de la médula espinal. Concluyen que la neuromodulación comprende: eventos periféricos; mecanismos espinales, "puerta de entrada"; mecanismos supraespinales, a través de vías inhibidoras descendentes, mecanismo inhibitorio nociceptivo difuso, sistema nervioso autónomo, eje hipotálamo-hipófiso-adrenal y mecanismos corticales. Participan ciertos núcleos cerebrales: caudado, arcuato, accumbens, sustancia gris periacueductal, núcleos del rafe y áreas del sistema límbico; moduladores peptídicos; neurotransmisores: serotonina, noradrenalina, acetilcolina y hormonas.

Diferentes investigadores sugieren que activa la expresión de los genes de los precursores de los péptidos opioides endógenos: beta endorfinas, encefalinas y dinorfinas.

Durante intervenciones quirúrgicas, los autores consultados recomiendan seleccionar adecuadamente los parámetros de electroacupuntura y complementarla con el uso de fármacos si fuera necesario.

Palabras clave: ANALGESIA POR ACUPUNTURA.

NOCICEPCIÓN - neuromodulación.

* Médica acupunturista. Algóloga. Posgrado de Fisiatría.

Jefe de Servicio de Acupuntura de la Dirección Nacional de Sanidad Policial. Ministerio del Interior. Montevideo, Uruguay.

Correspondencia: Dra. Emma Gubitosi Moya

Br. Artigas 808 Ap. 501. Montevideo, Uruguay

E-mail: emmagubitosi@hotmail.com

Presentado: 23/11/04.

Reenviado al autor: 20/8/05.

Corregido por el autor: 7/10/05.

Aceptado: 13/10/05.

Introduction

Acupuncture is a reflex, regulatory technique that stimulates the regulation and healing systems of the organism. It acts on three levels of the central nervous system: spinal, brainstem and diencephalic (1-3). It produces reflex responses, both local and systemic, nonspecific and general, mediated by higher centers of central control and by the endocrine and immune systems (4-6). It has undergone changes in recent decades: advances in the understanding of the mechanisms of regulation and modulation of pain, both anatomical and humoral, of musculoskeletal pathology and the clarification of some of its main mechanisms of action, allow us to affirm today that this age-old form of medical treatment is a scientifically proven therapy (1,5,7). It is effective in the treatment of pain, in palliative care and in neurological functional rehabilitation. The most frequent uses are: musculoskeletal pain, dysfunction of the locomotor system and systemic regulation (2,5).

In a recent meta-analysis review of acupuncture in low back pain (randomized controlled trials) authored by Manheimer, White, Berman, Forys, Ernest (2005), it is concluded that it is an effective therapy in the treatment of chronic low back pain; they found no evidence that it is more effective than other therapies (8). It lacks the unwanted effects of drugs, reduces their use or makes them unnecessary. It helps to reduce institutional costs.

The results of studies in animal models and in man on the neurological and endocrine effects of acupuncture and electroacupuncture between the late 1960s and the early 1970s, already initiated in China, confirmed the effectiveness of analgesia acupuncture The discovery of the relationship with neurochemicals, especially endorphins, began to provide the scientific basis to understand their mechanisms (7). Omura (1975-1978) (9) studied the beneficial effects of acupuncture, including the analgesic, and states that they occur during the phase of vasodilation that is the third of three phases (vasoconstriction, quasi-control and vasodilation).

The Consensus Development Conference on Acupuncture, National Institute of Health, Bethesda, Md (1997) (10), after evaluating the scientific-medical works of acupuncture carried out during the last three decades on uses, risks and benefits, suggests that it is effective in different conditions, including conditions that occur with pain. One of the advantages it presents is that the documented adverse effects were minimal.

Cao (2002) (7), from the National Key Laboratory of Medical Neurobiology of the Medical College of Fudan University, Shanghai, China, states that the analgesic effect of acupuncture has neurophysiological bases. Acupunctural stimulation activates antinociceptive systems and produces psychophysiological and autonomic responses (11). It can inhibit some "noxious sensory impulses" by acting on the three central levels and, in addition, regulates some internal functions. The autonomic nervous system maintains the homeostasis of the internal environment and regulates functions of visceral organs: respiratory, cardiovascular and renal through autonomic reflexes according to changes in the external environment. Acupuncture would normalize autonomic dysfunctions (2). Li, Wu, Arita, Hanaoka (2002) (12), suggest that acupuncture can inhibit renal somato-sympathetic reflexes in anesthetized rat models acting at the level of the same spinal segment by central mechanisms and by activating the endogenous control system of the pain.

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