Anatomical and Clinical Characteristics of Scalp Acupuncture Systems: a Scoping Review and Synthesis

Scalp acupuncture is an acupuncture therapeutic modality that involves inserting needles into the scalp to treat various medical conditions, including pain and neurological and psychological disorders. This form of acupuncture has significant potential for the treatment of neurological conditions and has been developed since the 1950s in China, combining knowledge from traditional Eastern medicine with modern Western anatomy and neuroscience. The importance of this field has grown, especially considering that neurological dysfunctions are one of the leading causes of disability worldwide and that effective treatments are constantly being sought.

The objective of this research was to systematically identify and analyze the different scalp acupuncture systems available in the English-language literature, mapping their general and anatomical characteristics and clinical applications. The investigators conducted a comprehensive scoping review, using rigorous methodology based on the Joanna Briggs Institute guidelines. They performed extensive searches in several medical databases, including PubMed, the Cochrane Library, and other acupuncture-specialized sources, between December 2020 and January 2021. The selection process involved the analysis of more than 47,000 records, of which 270 publications were examined in detail.

The final analysis included 87 publications that provided detailed information on 19 distinct scalp acupuncture systems. The data were analyzed using theoretical framework synthesis principles, with the International Standard Scalp Acupuncture Nomenclature as the reference.

The results revealed an impressive diversity of scalp acupuncture systems, each with unique characteristics. The investigators identified 19 main systems, including the International Standard System, Jiao's Scalp Acupuncture, Yamamoto New Scalp Acupuncture, and systems based on neuroimaging, among others. The analysis showed that these systems differ significantly in their theoretical foundations, ranging from those based exclusively on traditional Chinese medicine to systems grounded entirely in modern neuroscience. Some systems integrate both approaches, combining traditional theories with contemporary knowledge of neuroanatomy and neurophysiology.

The most common clinical indications include the treatment of motor and sensory dysfunctions, problems with vision, hearing, and balance, as well as cognitive, mental, and emotional disorders such as insomnia, depression, and anxiety.

For patients and healthcare professionals, these findings have important implications. The diversity of systems offers multiple therapeutic options but also presents significant challenges. The variability among systems can make it difficult for patients and clinicians to choose the most appropriate treatment for specific conditions. For practitioners of acupuncture, the results highlight the need to understand the differences between systems and to choose appropriately based on the patient's condition and the available evidence.

The research also suggests that scalp acupuncture may be particularly promising for neurological conditions such as sequelae of stroke, cerebral palsy, and other central nervous system disorders. For patients, it is important to understand that different practitioners may use different systems, and that clear communication about which system is being used can be relevant to treatment.

However, the study identified important limitations that affect the quality of the evidence and the clinical application of scalp acupuncture. The main limitation identified was inconsistency in the anatomical localization of treatment points across different systems. Varied measurement methods and a lack of consensus on cranial anatomical landmarks create significant imprecision in the positioning of treatment areas. This variability can have serious consequences, given that central nervous system dysfunctions are the main areas of application for scalp acupuncture.

In addition, the language barrier significantly limited the analysis, as detailed information in English was not available for 14 of the 33 systems initially identified. The heterogeneity of systems also hinders the synthesis of evidence and secondary analyses, delaying the inclusion of scalp acupuncture in evidence-based health policies and its consolidation as a therapeutic intervention recognized by Western medicine.

In conclusion, although scalp acupuncture demonstrates considerable potential for the treatment of neurological conditions, its high systemic variability represents a significant obstacle to the advancement of the field. The investigators emphasize that discussions and consensus on the anatomical characteristics of scalp acupuncture are fundamental to improving the efficacy and safety of treatments, as well as supporting the standardization needed for future high-quality research. The implementation of precise measurement methods for the positioning of acupuncture points on the scalp emerges as an essential priority. Future research should focus on creating conceptual frameworks based on the theoretical foundations of the systems and on incorporating non-English literature to facilitate a more comprehensive understanding of the scalp acupuncture phenomenon.