POST-TRAUMATIC HEADACHE. CURRENT VIEWS ON PATHOPHYSIOLOGICAL MECHANISMS OF DEVELOPMENT AND CLINICAL SPECIFICS (REVIEW).

Headache after craniocerebral injury is an urgent problem due to its frequent occurrence, tendency towards chronization, and strong patient disadaptation effect. Despite the significant incidence of post-traumatic headache (the PTHA) and related socioeconomic factors, many fundamental aspects of this problem have not been considered adequately. Therefore, the aim of our review is to highlight key points regarding the pathogenetic mechanisms of development, key clinical features, and strategies for optimal management of PTHA. A literature review was performed using the Pubmed database by selecting articles about post-traumatic headache (PTHA) over 10 years (from 2010 to 2020).The search was performed in English, Russian, and Ukrainian using the following key words and terms: post-traumatic headache, post-traumatic cephalalgia, headache after brain injury, and post-concussion syndrome. All articles with information on etiology, pathogenesis, clinic, diagnosis, differential diagnosis, neuroimaging, pathomorphological evaluation, and treatment strategies for this pathology were included in the analysis. After identifying all the articles that met the inclusion criteria and deleting duplicate data, 46 literature sources on PTHA were selected. According to the International Headache Classification, PTHA is a secondary cephalalgia associated with head and/or neck injury, which develops within 7 days of a craniocerebral injury. A distinction is made between acute and persistent PTHA associated with mild, moderate, and severe injury. To diagnose persistent PTHA, it is sufficient to establish a causal link between the fact of head injury and the duration of pain for 3+ months. It is interestingly that individuals with mild craniocerebral injury have both higher incidence and higher duration and intensity of PTHA compared to those with severe injury. Despite the absence of specific characteristics, several clinical phenotypes of PTHA are distinguished, the most common of which are migraine-like and tensor types. The pathogenetic mechanisms of PTHA development are complex and diverse. Since recently, special attention has been paid to activation of the trigemino-vasculo-thalamic system, central sensitization, and GCRP-associated mechanisms that probably play an important role in the PTHA pathogenesis. Modern neuroimaging methods using diffusion-tensor and functional MRI are important in the PTHA diagnosis and differential diagnosis. PTHA treatment requires a multidisciplinary approach and includes a combination of drug and drug-free methods. Despite a long history of PTHA research, the issues concerning diagnostic criteria, pathogenetic mechanisms, clinical features, and strategies, in particular in patients who suffered severe craniocerebral injury, have not been considered properly. The above data indicate the need to clarify many aspects of the studied problem.