Process Study 24-Month Results October 1, 2008 (abridged)

2 | MDT Confidential Study Design for Primary Endpoint (≥ 50% Reduction in Leg Pain (VAS) at 6 Months)

3 | MDT Confidential PROCESS Study Summary of ITT Results Until 6 Months (Kumar K et al. Pain 2007) Patients in the SCS and CMM groups were: –Well matched –Representative of patients with FBSS, suffering from neuropathic pain predominantly in the legs Significantly better outcomes were observed in the SCS group in terms of: –Pain relief (leg and back VAS) – the primary outcome 48% patients reaching ≥ 50% leg pain relief vs. 9% in CMM group 64% patients reaching ≥ 30% leg pain relief vs. 18% in CMM group –Disability (Oswestry Disability Index) –Quality of life (SF-36 and EQ-5D) –Patient satisfaction –Occurrence rate of SCS-related events comparable to literature

4 | MDT Confidential 24-month Analysis SCS-continue Group The 24 month analysis focuses on the SCS+CMM-continue group –i.e. patients randomised to SCS who remained on SCS until 24 months The following analyses have been limited to the primary outcome only (vs. CMM): –Revised ITT (where all patients requesting crossover are considered as having < 50% pain relief at 24 months) –Per treatment analyses (based on the treatment the patient is receiving at the 24 months visit)

5 | MDT Confidential Rationale For Focusing on the SCS Continue Group High and uneven crossover after 6 months –4 / 46 (9%) SCS+CMM patients with a 24m visit had crossed to CMM –30 / 41 (73%) CMM patients with a 24m visit had crossed to SCS+CMM other analyses no longer relevant AnalysesReason for non relevance Per ITTthe treatments received were very different from those to which the group was randomized (especially for the CMM group) Per treatmentThis analysis would mix patients with 24-months of treatment (i.e. patients who continued on their treatment) with patients with 12–18 months of treatment (i.e. those who switched post 6 months) SCS vs. CMM continue groups The small number of CMM-continue patients (n=11) implies that: The CMM-continue group would no longer be representative of the initial group Even if statistical tests were performed to compare SCS vs. CMM or changes from baseline, it is very unlikely that these would show significance

6 | MDT Confidential Patient Flow Through 24 Months

7 | MDT Confidential Leg Pain Relief in SCS+CMM-continue Group Over 24 Months Significant Reduction in Leg Pain VAS Over 24 Months

8 | MDT Confidential Primary Outcome: ≥ 50% Leg Pain Relief at 24 Months Continued Greater Effect with SCS in the Per Treatment/ITT Analyses Over 24 Months

9 | MDT Confidential Leg Pain Relief in SCS+CMM-continue Group at 24 Months ≥ 30% Leg Pain Relief Maintained in the Majority of Patients Over 24 Months

10 | MDT Confidential QoL in SCS+CMM-continue Group at 24 Months Significant Improvement in 7/8 Domains of QoL (SF-36) Over 24 Months

11 | MDT Confidential Quality of Life in SCS+CMM-continue Group Over 24 Months Significant Increase in QoL (EQ-5D) Over 24 Months

12 | MDT Confidential Function in SCS+CMM-continue Group Over 24 Months Significant Improvement in Function (Oswestry Disability Index) Over 24 Months

13 | MDT Confidential Satisfaction in SCS+CMM-continue Group Over 24 Months High Patient Satisfaction Maintained Over 24 Months “Are you satisfied with the pain relief provided by your treatment?” “Based on your experience so far, would you have agreed to this treatment?”

14 | MDT Confidential SCS-related Complications in SCS-continue Patients: 24 Months 19 (45%) Patients Had Total 34 Complications, 13 (31%) Patients Required Surgery IPG: implantable pulse generator; * 1) Case of suboptimal connection of extension to IPG, leading to intermittent stimulation; 2) Lead implanted anteriorly, leading to patient receiving shocks; 3) lead cut during implant SCS-related adverse event at 24 months Number of events Patients with ≥1 event Patients requiring surgery Number (%) Hardware related1410 (24)8 (19) Lead migration96 (14) Lead/extension fracture/ torqued contacts43 (7)1 (2) IPG migration11 (2) Loss of therapeutic effect, lost or unpleasant paresthesia55 (12)2 (5) Technique*32 (5) Biological129 (21)3 (7) Infection / wound breakdown44 (10)2 (5) Pain at IPG incision site / Pocket inflammation55 (12)1 (2) IPG pocket fluid collection32 (5)0 (0)

15 | MDT Confidential PROCESS Study Summary of Results at 24 Months In ITT and per treatment analyses, significantly more SCS patients achieved the primary outcome of ≥ 50% leg pain relief. Significant difference from baseline achieved in the SCS-continue group in main outcomes: –Leg pain relief (p < ) –Quality of life (SF-36 and EQ-5D, p ≤ 0.01) –Disability (ODI, p = ) No significant change in drug and non drug treatments Complications in line with the literature –45% of patients had ≥ 1 complications, 31% of patients required surgery High patient satisfaction, increasing number of patients return to work Sustained effect of SCS over 24 months

16 | MDT Confidential Thank You to the Participating Centers! UC EN