Correction to: Acta Acta Neurochirurgica (2019) 161:1589–1598

https://doi.org/10.1007/s00701-019-03981-7

Correct figure 3 is shown below:

Fig. 3
figure 1

a Normal arachnoid as seen in an rightside MVD surgery for TN. The arachnoid while present and touching the surrounding structures is not adhesive to them, is delicate and transparent and the structures are easily seen through it. b Intraoperative image illustrating a case of arachnoiditis. The arachnoid membranes are thick and they are particularly adhesive to the trigeminal nerve and superior cerebellar artery. -Rightside MVD for TN. IV, trochlear nerve; V, trigeminal nerve; SCA, superior cerebellar artery; *thickened coalescing arachnoiditis between the SCA and the trigeminal nerve