Occipital neurostimulation-induced muscle spasms: implications for lead placement.

BACKGROUND For many headache types, occipital peripheral nerve stimulation (ONS) provides significant relief of chronic, frequent, and severe headaches. Though rarely reported, ONS may cause painful muscle spasms that make stimulator use impractical. The classic description of the technique advocates placement of the leads transversely at the level of the arch of C1 or at C1-2. At that level, the greater occipital nerve (GON) infrequently pierces the superficial fascia of the neck muscles to become superficial. However, important anatomic variability exists. OBJECTIVE To report placement of leads higher at the nuchal line rather than the classically recommended C1 level to avoid ONS-induced muscle spasm. METHODS Four interventional pain physicians independently revised ONS leads due to painful muscle stimulation. Five case reports of surgical ONS lead revision for management of ONS-induced muscle spasms are described and discussed. RESULTS Placement of peripheral neurostimulator leads at or above the nuchal line in these 5 cases provided good paresthesiae without causing neck muscle spasm. CONCLUSION Lead placement at the level of C1 or C1-2 may cause some patients to have intolerable neck/occipital spasm during neurostimulation. This is the first known published report of technical variation in the location of lead placement, at the nuchal line in a transverse fashion, for ONS. Placing ONS leads at the level of the occipital protuberance appears to eliminate ONS-induced muscle spasm while allowing good paresthesia coverage. LIMITATIONS Stimulation parameters vary, thus posting parameters may be misleading as muscle spasms occurred despite multiple reprogramming attempts and were a function of lead position, not program settings.