Objectives

To present long-term outcomes of ventral tegmental area (VTA) deep brain stimulation (DBS) for medically refractory, chronic trigeminal autonomic cephalalgias 

Introduction

VTA DBS has been proven to be a safe and effective therapy for chronic cluster headache (CCH) and short-lasting unilateral neuralgiform headache attacks (SUNHA) in relatively small patient cohorts. The mechanism of action is not fully understood but is likely to involve the neuromodulation of the trigeminal parasympathetic reflex, which is triggered during attacks. To our knowledge, this is the largest series of patients that have undergone this procedure in a single centre.

Methods

Between 2009 and 2019, 71 patients (39 male and 32 female with an average age of 53 years [SD=13]) were treated with VTA DBS for chronic, medically refractory CCH (n=43) and SUNHA (n=28). Fifty-four patients underwent unilateral implantation (33 right), and 17 underwent bilateral implantations. Patients were assessed pre- and post-operatively by a specialist multidisciplinary team including headache neurologists, specialist nurses and functional neurosurgeons.

Results

The average follow-up was six years (SD=3.2). Response was set at 50% improvement in attack frequency. Forty-nine patients (69%) were responders with a mean improvement of 78% (SEM=2.7, SD=19.1, CL95%=5.5) and a median of 83%. In responders, headache severity on the verbal rating score (VRS) improved by a mean of 40% (SEM=5.2, SD=36.7, CL95%=10.5) and a median of 30% (3 points out of 10 in the CCH responders and 4.5 points in the SUNHA group). Attack duration in the responders improved by a mean of 37% (SEM=8, SD=56.1, CL95%=16.1) and a median of 50% from 120 to 45 minutes per attack in CCH and from 2 to 0.35 minutes in the SUNHA group. The headache load (HAL); a composite score encompassing frequency, severity, and duration of attacks improved by a mean of 73% (SEM=7.7, SD=52, CL95%=15) and a median of 89% in clinical responders.

Two thirds of patients (73% of responders and 48% of non-responders) had a stun effect during the postoperative period, which consisted in either complete symptom relief or in clinically significant reduction of the frequency, duration, or severity of the headaches. The mean length of the stun effect was 28 days (SEM=5.5, S=37.4, CL95%=11) and a median of 17 days. 

Four non-responders had the DBS system explanted, two of them secondary to infection and one due to post-surgical neuropathic pain around the head wound site. Two patients had the stimulation turned off due to absence of benefit. Four patients died due to unrelated conditions.

Conclusions

This open label study provides class IV evidence that VTA-DBS is a safe and effective long-term therapy for CCH and SUNHA.

Dr M Matharu and Mr H Akram contributed equally to this submission as co-senior authors