Ultrasound-Guided Botulinum Toxin Injections for Hand Spasticity: A Technical Guide for the Dorsal Approach

Abstract: Spasticity often occurs following neurological disorders such as traumatic brain injury, cerebral palsy, and stroke. Botulinum toxin (BTX) injections, especially when paired with rehabilitation, are among the most effective interventions for these patients. Various techniques for administering BTX injections to the upper limb muscles have been described. However, a standardized method for ultrasound-guided injections in the intrinsic muscles of the hand remains quite scant in the literature. The authors suggest a novel dorsal approach to treat the most common abnormal postural patterns in hand spasticity, thumb-in-palm, and intrinsic plus. This approach facilitates access to the muscles while minimizing patient discomfort, as it avoids the need to open forcibly the spastic hand. The adductor pollicis, flexor pollicis brevis, lumbrical, and interosseus muscles have been identified as primary anatomical targets to improve hand posture and function. Standardized sonographic scans are leveled with anatomical illustrations and probe/patient positioning images for interventional procedures. Additionally, tips and techniques for promptly identifying vascular bundles are included to enhance the safety of the procedures. This technical report aims to provide an easy and ready-to-use tool in clinical practice for injecting intrinsic hand muscles in spastic patients, utilizing a novel dorsal approach.