Combined Cingulate and Thalamic DBS for Chronic Refractory Chronic Pain

Treatment of Chronic Refractory Pain by Combined Deep Brain Stimulation of the Anterior Cingulum and Sensory Thalamus: a Feasibility and Safety Study

Deep brain stimulation (DBS) of the sensory thalamus has been proposed for 40 years to treat medically refractory neuropathic pain, but its efficacy remains partial and unpredictable. Recently, bilateral DBS of the dorsal anterior cingulate cortex (ACC), a brain region involved in the integration of the affective and cognitive aspects of pain, has been successively proposed to treat few patients suffering from refractory chronic pain, by decreasing the emotional impact of their chronic pain. ACC-DBS could be an alternative or complementary approach to thalamic DBS in these patients, but the consequences of chronic dACC-DBS on cognition and affects have not been studied specifically.

The primary objective is to evaluate the feasibility and safety of bilateral ACC-DBS combined with unilateral thalamic DBS in patients suffering from chronic unilateral pain, refractory to medical treatment. Secondary objective will evaluate the efficacy of this combined DBS compared to thalamic DBS only.

Chronic pain represents a major personal and societal burden, especially for medically resistant patients. Deep brain stimulation (DBS) of the sensory thalamus has been proposed for 40 years to treat medically refractory neuropathic pain, but its efficacy remains partial and unpredictable. Recently, bilateral DBS of the dorsal anterior cingulate cortex (ACC), a brain region involved in the integration of the affective, emotional and cognitive aspects of pain, has been successively proposed to treat few patients suffering from refractory chronic pain. In a pilot study, 16 patients treated by ACC-DBS experienced a significant improvement of their quality of life despite a slight decrease of their pain intensity, by improving the affective and emotional impacts of their chronic pain. ACC-DBS could be an alternative or complementary approach to thalamic DBS in these patients. However the consequences of chronic dACC-DBS on cognition and affects have not been studied specifically.

The primary objective of this study is to evaluate the feasibility and safety of bilateral ACC-DBS combined with unilateral thalamic DBS in patients suffering from chronic unilateral pain, refractory to medical treatment. Secondary objective will evaluate the efficacy of this combined DBS compared to thalamic DBS only

Inclusion Criteria:

• adult patients (age 18-70 years old) suffering from chronic (duration >1 year) unilateral neuropathic pain
• severe (VAS score >6/10)
• with high emotional impact (HAD subscores > 10) considered as resistant to medication specific to neuropathic pain at sufficient doses and durations (including at least antiepileptics and antidepressants) and not sufficiently improved by rTMS and relevant surgical solutions.

Non inclusion criteria:

• previous history of stroke,
• cognitive impairment (MMSE score <24),
• DSMIV axis I psychiatric disorder,
• contra-indication to surgery, anesthesia or MRI;
• patient responder to rTMS,