the aim of this study is to present a case of successful relief of bilateral occipital neuralgia ( on ) using unilateral occipital nerve stimulation ( ons ) and to discuss the possible underlying mechanisms . we present the case of a 59-year - old female patient with severe bilateral on treated with unilateral ons . we systematically reviewed previous studies of ons for on , discussing the possible mechanisms of ons in the relief of on . the patient reported complete pain relief after consistent unilateral ons during the follow - up period . the underlying mechanisms may be linked to the relationship between pain and several brain regions , including the pons , midbrain , and periaqueductal gray . future studies will be required to clarify the mechanisms by which unilateral occipital stimulation provided relief for bilateral neuralgia in this case . occipital neuralgia ( on ) is the third most common headache syndrome following migraine and tension - type headaches . on is characterized by severe sharp , shooting , or electric shock pain at the distribution of the occipital nerve . any stretching or entrapment of the occipital nerve from the second cervical vertebra ( c2 ) to the outlet of the nerve out of the occipital muscle can evoke chronic pain . several studies with small samples have reported that at least one - third of on patients exhibit bilateral dysfunction.1,2 occipital nerve stimulation ( ons ) has been used to relieve severe pain caused by on when conservative medical treatments and block procedures are ineffective.3 ons is a type of neuromodulation , using a spinal cord stimulation device to stimulate the corresponding occipital nerve to treat various types of neuralgia . we present a case in which a patient with refractory bilateral on was successfully treated with unilateral ons . in addition , we review previous studies of ons for treating on . finally , we discuss the possible mechanisms by which unilateral ons relieves bilateral on . a 59-year - old female presented with severe shooting pain at the distribution of the right occipital nerve 6 months ago . the pain could not be relieved , and the medicines were changed gradually to baclofen 20 mg three times daily , lamotrigine 100 mg two times daily and pregabalin 150 mg two times daily . this medical treatment had been administered for 1 month , and the patient was still suffering from severe pain without any relief . moreover , the pain spread from the left side , gradually becoming bilateral on with vas 910 . percocet 330 mg was then administered every 8 hours , combined with baclofen , lamotrigine , and pregabalin , as described earlier . bilateral occipital block procedures were able to relieve the pain to vas 2 , but relief lasted not > 24 hours . the long - term pain negatively affected the patient s daily functioning and her body weight decreased by 20 kg over 6 months . the patient was referred to the department of neurosurgery , first affiliated hospital of pla general hospital , and ons therapy was recommended . the patient provided written informed consent to have this case and any companying images published . was inserted percutaneously from the right side to the left , perpendicular to the bilateral occipital nerve course at c1 ( figure 1 ) . the trial stimulation only successfully produced paresthesia covering the left occipital area and did not result in any sensation in the right occipital area under the 1.04.0 v amplitude range . when the amplitude was increased above 5.0 v , only local scalp pain was reported by the patient . an incorrect placement of the lead covering the right occipital nerve was suspected . however , unilateral stimulation still produced bilateral pain relief , to vas 24 , and a lead adjustment procedure was refused by the patient . after 7 days of trial stimulation , a permanent ipg ( medtronic primeadvanced ) was implanted subcutaneously in the upper right chest area . when the ipg was switched on , the patient experienced a tickling - like sensation , which substantially relieved the pain . only the contacts of the electrode covering the left occipital area were used with a pulse width of 120 ms , a frequency of 60 hz , and an amplitude of 3.0 v. at 3-year follow - up , the patient reported long - lasting pain relief with vas 0 and no side effects . the precise mechanisms underlying on are currently unclear , but various studies have suggested that whiplash injury , compression of the c2 nerve , and compression of the upper cervical roots due to arthritic changes in the spine are the leading possible causes.2,4 moreover , everyday activities that compress the occipital nerve have been reported to cause on.2 long - term compression of the c2 nerve has been reported to produce a series of reactions at the dorsal root ganglion and spinal cord , including inflammation , microglia proliferation , neurotransmitter changes , cytokine responses , and ionic channel changes , which eventually induce chronic pain.5,6 when pharmacotherapeutic methods for on patients are unable to relieve pain , surgical interventions are considered an appropriate option . surgical methods include neurectomy,7 c2c3 decompression,8 partial posterior rhizotomy,9 radiofrequency ablation,10 and peripheral nerve stimulation ( pns).1 among these methods , pns has the advantages of minimal invasion , adjustability , reversibility , and a low likelihood of complications . in a literature search of pubmed using the keywords  occipital neuralgia  , we obtained a total of 359 articles from january 1960 to august 2014 . a supplemental search was performed manually based on the references of several review articles.11,12 upon review by the authors , 45 articles relating to pns or neuromodulation were identified . the reviewers assessment yielded 19 review articles , 10 case reports , 10 retrospective case series , 5 technical reports , and 1 prospective case series . excluding 19 review articles and 12 articles regarding pns for trigeminal neuralgia , migraine , and other chronic headaches , the remaining 14 articles involved 77 patients suffering from on or cervical originating headache treated with pns ( table 1).1,3,1324 among the 78 patients in these 14 studies , most of those receiving permanent implants experienced pain relief of at least 50% . lead migration and infection were the two leading causes of ons - related complications,11 and no other severe complications were reported . due to the high efficacy and low risk of pns , it may be appropriate for use in patients with poor health . chaiban et al14 reported the successful treatment of an 86-year - old on patient with a pacemaker . bartsch and goadsby25 demonstrated that neurons in the c2 spinal dorsal horn receive input from the ipsilateral and contralateral occipital nerves . in addition to direct connections between the occipital nerve and the upper cervical spinal cord , a review of brain imaging and ons research by bari and pouratian26 reported that the function of many pain - related brain regions can be affected when occipital nerves are stimulated . one study using 3-tesla magnetic resonance imaging reported activation in the hypothalamus , thalamus , orbitofrontal cortex , prefrontal cortex , periaqueductal gray , inferior parietal lobule , and cerebellum during ons in a single healthy volunteer.27 in addition , deactivation was observed in primary cortices , including primary motor area , visual area , auditory area , and somatosensory area , the amygdala , paracentral lobule , hippocampus , secondary somatosensory cortex , and supplementary motor area , in the same subject.27 one positron emission tomography study reported changes in regional cerebral blood flow in the pons , anterior cingulate cortex , cuneus , and left pulvinar after bilateral ons.28 another study using 18-fluorodeoxyglucose - positron emission tomography in a group of chronic cluster headache patients reported decreased metabolism in the anterior cingulate cortex , midcingulate , left visual cortex , left pulvinar , cerebellum , midbrain , and left lower pons , as well as increased metabolism in the bilateral senso - rimotor cortices , when long - term ons was applied.29 these studies indicate that ons may have widespread effects on the central nervous system , resulting in pain relief . continuous stimulation of the occipital nerves may produce diverse functional and metabolic changes in many brain regions . in addition , changes in the pons , midbrain , and periaqueductal gray may be involved in bilateral pain relief after unilateral ons . ons is an effective treatment for on , with very low risk and a high success rate . ons may be applicable for other types of headache , including migraine , cluster headaches , and tri - geminal neuralgia . this study described a case of unilateral ons providing effect relief of bilateral on , indicating that ons may have widespread effects in the brain and upper spinal cord .
objectivesthe aim of this study is to present a case of successful relief of bilateral occipital neuralgia ( on ) using unilateral occipital nerve stimulation ( ons ) and to discuss the possible underlying mechanisms.materials and methodswe present the case of a 59-year - old female patient with severe bilateral on treated with unilateral ons . 
 we systematically reviewed previous studies of ons for on , discussing the possible mechanisms of ons in the relief of on.resultsthe patient reported complete pain relief after consistent unilateral ons during the follow - up period . 
 the underlying mechanisms may be linked to the relationship between pain and several brain regions , including the pons , midbrain , and periaqueductal gray.conclusionons is an effective and safe option for treating on . 
 future studies will be required to clarify the mechanisms by which unilateral occipital stimulation provided relief for bilateral neuralgia in this case .