Psychogenic (nociplastic) pain: Current state of diagnosis, treatment options, and potentials of neurosurgical management.

Classification of pain syndromes is quite multifaceted. However, pathogenetic classification by which chronic pain syndromes are usually divided into nociceptive, neuropathic and psychogenic, is crucial in choosing treatment tactics. In modern classifications, psychogenic pain is distinguished from nociceptive pain (associated with direct tissue injury or damage) and neuropathic pain (in which lesion can only be determined morphologically). Mental disorders play a leading role in psychogenic pain. Here, somatic/neurological disorders, if any, are of no pathogenetic significance in the dynamics of pain syndrome. There are certain algorithms (though not yet fully developed) and even guidelines for diagnosing and treating nociceptive and neuropathic pain, whereas psychogenic pain has been and still is almost out of sight for a long time. Despite its considerable prevalence, attitude towards it is still uncertain. Until now, it has no single classification, nor any strategy with regards to diagnosis, treatment and prevention.

Four-dimensional ultrasound guidance during epidural anaesthesia.

BACKGROUND: Four-dimensional (4D) ultrasound scanning (3D real-time mode) can improve the orientation of the anatomy of the area of interest and navigation by controlling the needle position. The objectives of this study were to identify the optimal technique for navigation and to assess clinically the efficacy of 4D ultrasound navigation for epidural anaesthesia at lower thoracic and lumbar levels. DESIGN: Single-centre case series study was performed. METHODS: Sixteen patients were included. First, conventional 2D scanning was performed, followed by 4D reconstruction, and the basic tissues with high acoustic impedance (bone structures) and available acoustic windows were determined. Movement of the needle was controlled on the sagittal plane in 2D mode and at the same time in 4D mode (3D real-time mode). To improve the visibility of the needle, the 3D reconstruction was rotated during manipulation. RESULTS: The 4D scanning mode provided 100 % visibility of compact bone tissues and 93 % visibility of the posterior complex. Needle visualisation strongly depended on the rotation of the reconstructed image with the sensor remaining motionless. The needle was redirected in one patient (7 %) because it was in contact with the vertebral lamina. Dilation of the epidural space during saline injection was observed in five patients (36 %). A change in the puncture level was not required any patients; no complications associated with epidural puncture were observed. CONCLUSIONS: Ultrasound navigation in 4D could improve epidural anaesthesia due to the enhanced spatial orientation of the operator. The technique of "position contrast" should be used for reliable needle visualisation.