Nerve injuries associated with nerve blocks: clinic and incidence

Persistent nerve injuries in context of peripheral nerve blocks are uncommon. Previous surveys and prospectively designed studies have specified neurological dysfunctions in different ways, which may cause the variability of data about incidence; so it has to be reckoned with about 5% after 1 week, 1% after 1 month and 0,01% after 6 months. Amongst the different locations interscalene blocks with their associated surgical procedures seem to have the highest incidence. Establishing the correlation between disabilities and the performed block technique often constitutes difficulties, especially when other reasons like patient positioning techniques, tractions, ischemia and surgery related nerve injuries have to be considered. Dysfunctions manifest as numbness, parasthesia, tingling sensation and/or amyasthenia. Fortunately long-term lesions, caused by nerve blocks are a rarity.