Characterising the Analgesic Effect of Different Targets for Deep Brain Stimulation in Trigeminal Anaesthesia Dolorosa.
Several deep brain stimulation (DBS) targets have been explored for the alleviation of trigeminal anaesthesia dolorosa. We aimed to characterise the analgesia produced from the periaqueductal grey (PAG) and centromedian-parafascicular (CmPf) nucleus using a within-subject design.



We report a case series of 3 subjects implanted with PAG and CmPf DBS systems for the treatment of anaesthesia dolorosa. At follow-up, testing of onset and offset times, magnitude, and thermal and mechanical sensitivity was performed.



The mean pain score of the cohort was acutely reduced by 56% (p < 0.05) with PAG and 67% (p < 0.01) with CmPf stimulation at mean time intervals of 38 and 16 min, respectively. The onset time was 12.5 min (p < 0.05) for PAG stimulation and 2.5 min (p < 0.01) for CmPf. The offset time was 2.5 min (p < 0.05) for PAG and 12.5 min (p < 0.01) for CmPf. The two targets were effective at different stimulation frequencies and were not antagonistic in effect.



The mechanisms by which stimulation at these two targets produces analgesia are likely to be different. Certain pain qualities may respond more favourably to specific targets. Knowledge of onset and offset times for the targets can guide optimisation of stimulation settings. The use of more than one stimulation target may be beneficial and should be considered in anaesthesia dolorosa patients.
North Bristol NHS Trust, Southmead Hospital, University of Bristol, Bristol, UK.
Hugh P
HP
Sims-Williams
Shazia
S
Javed
Anthony E
AE
Pickering
Nikunj K
NK
Patel
D000328:Adult; D000698:Analgesia / Q000379:methods; D059350:Chronic Pain / Q000601:surgery*; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D020646:Intralaminar Thalamic Nuclei / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010487:Periaqueductal Gray / Q000601:surgery*; D061221:Trigeminal Nerve Injuries / Q000601:surgery*