The present study aims to compare directly the efficacy of two noninvasive neurostimulation techniques : repetitive transcranial magnetic stimulation and transcranial direct electrical current of the motor cortex in patients with chronic lumbar radiculopathy on pain intensity.

The present study ims to compare directly the efficacy of two noninvasive neurostimulation techniques : repetitive transcranial magnetic stimulation (rTMS) and transcranial direct electrical current (tDCS) of the motor cortex in patients with chronic lumbar radiculopathy on average pain intensity. This will be a sham controlled crossover design : patients will be randomized to receive either active rTMS or tDCS during 3 consecutive days followed by the alternative treatment within 3 weeks apart, or sham rTMS or tDCS during 3 consecutive dats followed by the alternative treatment within 3 weeks apart. The investigator will be blind to the treatment. Assessments will be performed before each treatment, then 1 hour after the end of the third day session, then 2 days and 1 week after the stimulation. Assessments will include pain questionnaires, quality of life, anxiety and depression, catastrophizing and evaluation of treatment effect on experimental pain using Quantitative sensory testing.

Inclusion Criteria:

Patients aged more than 18 years and less than 60 years, males of females Lumbosciatica or lumbocruralgia with predominant neuropathic components with DN4 score ≥ 4/10 Chronic pain with an intensity of at least 4/10 Stable analgesic treatment for at least 15 days before inclusion Able to speak and understand French Social security

Exclusion Criteria:

Work accident or litigation Contraindication to rTMS (sismotherapy in the preceding month, epilepsia, past head trauma, intracranial hypertension, metallic clip, pace maker, pregnancy or lactation Major depressive episode Intermittent pain Consent refusal Impossible to follow up during the duration of the study Pain more severe than neuropathic pain