Occipital Nerve Stimulation for Medically Refractory Hypnic Headache

Objective: Hypnic headache is a rare, primary headache disorder that exclusively occurs regularly during sleep. We present a case of hypnic headache successfully managed with occipital nerve stimulation. Materials and Methods: A 64‐year‐old female presented with a four‐year history of a right occipital headache that regularly awakened her from sleep. The headache, which was dull and throbbing, would awaken her regularly at 4:00 am , five hours after bedtime at 11:00 pm . No photophobia, nausea or vomiting, lacrimation, or other autonomic symptoms were present. The headache was refractory to various medical treatments, including indomethacin, flunarizine, propranolol. She underwent a trial of occipital nerve stimulation with a lead electrode using a medial approach. Results: During the ten‐day trial stimulation, she reported almost complete relief from hypnic headache. Chronic occipital nerve stimulation replicated the trial results. The attacks of hypnic headache recurred in one year with loss of stimulation‐induced paresthesia; a subsequent x‐ray showed electrode migration. After revision of the electrode to the original location, the effectiveness of the occipital nerve stimulation against hypnic headache was achieved again, and this effect has been consistent through 36 months of follow‐up. Conclusion: Occipital nerve stimulation was effective in a patient with chronic, refractory hypnic headache.     

Spinal canal surrogate for testing intradural implants

We have designed, built and tested an anthropomorphic-scale surrogate spinal canal, for use in preliminary evaluations of the performance characteristics of a novel intradural spinal cord stimulator. The surrogate employs a silicone mock spinal cord with semi-major and semi-minor diameters of 10 and 6?mm, respectively, commensurate with those of actual thoracic-level spinal cord. The axial restoring force provided by the 300 µm thick silicone denticulate ligament constructs on the mock cord is ~ 0.32 N mm^?1 over a 1.5?mm range of displacement, which is within a factor of 2 of that measured by others in human cadaver specimens. Examples of testing protocols of prototype intradural stimulators that employ this device are discussed.     

Sacral Neuromodulation for the Treatment of Chronic Functional Anorectal Pain: A Single Center Experience

Introduction:   Treatment of functional anorectal pain disorders remains a challenge. The purpose of this study is to describe a single center experience with sacral neuromodulation for the treatment of chronic functional anorectal pain.
Methods:   This is a retrospective study based on prospectively collected data of patients treated with sacral neuromodulation for functional anorectal pain from April 2005 to August 2008. Symptoms were analyzed using a visual analog scale pain score (0 to 10). A 7-point Likert scale was used to rate global perceived effect. All patients had a percutaneous nerve evaluation and subsequent test stimulation to assess sacral neuromodulation outcome prior to permanent implantation. Patients were eligible for permanent sacral neuromodulation in case of a pain score <3 during test stimulation and/or >50% decrease in the pain score compared to baseline.
Results:   Nine patients (2 males) were included in this study. Mean age was 53.8 years (27.6 to 74.0). Four patients (1 male) had successful test stimulation and were eligible for permanent implantation. Median pain score decreased from 8.0 (6.0 to 9.0) to 1.0 (0 to 2.0). All patients experienced a lasting improvement during the follow-up till 24 months. Global perceived effect in successful patient was 1 (completely recovered) in one patient and 2 (much improved) in three patients.
Conclusion:   This study showed that sacral neuromodulation can be a successful treatment for functional anorectal pain not responding to other treatments. Improvement obtained during test stimulation is a good predictor (diagnostic) for sustained success of permanent sacral neuromodulation.