1. The efficiency of neuropathic pain removing using different methods of neurostimulation
N.A. Sapon
Restorative Neurosurgery Department, Romodanov Neurosurgery Institute, Kiev, Ukraine

2. The objective of research – is to evaluate efficacy of different methods of neurostimulation at abatement of neuropathic pain (NP).
Materials and methods
26 patients with consequences of injury of peripheral nerves of extremities combined with NP
neurolysis, autografting or nerve suture + +
12 patients
14 patients
Temporary (3–10 days) neurostimulation (TNS)
Chronic (up to 1 year) neurostimulation (CNS)
Implantation of graphitic electrodes with further stimulation of neural structures
Implantation of silicon-covered electrodes with further stimulation of neural structures with external neurostimulation device “NeySi-3M”

3. Neurostimulator «NeySi-3M»
The neurostimulation system «NeySi-3M» is the neurostimulator designed and manufactured in Ukraine, a partially implanted electrostimulative device, the area of its application is neurosurgery, this device is developed to provide chronic electrostimulation of peripheral nerves and plexuses, spinal cord, regions of cerebrum, in order to reduce neuropathic pain and other pain syndromes, to restore proper functional status of damaged structures of central and peripheral NS (nerves, plexuses, cerebrum and spinal cord).
Eternal device: 1 — external aerial wire, 2 — unit that generates electrical impulses;
Internal device (implanted):
3 — internal aerial wire, 4 — electrodes.

4. The internal aerial wire is already implanted into patient’s body and the electrodes are attached to proper neural target which is meant to be stimulated. During the course of neurostimulation the external aerial wire is placed directly upon the skin projection of implanted internal aerial wire.
The stimulation starts on 2nd or 3rd day after the surgical implantation. Surgeon himself defines proper regiment and settings of stimulation, instructs the patient on how to properly apply the device.
One carried out 3-4 procedures of stimulation a day, each single procedure of stimulation lasted 5-10 min.
One proceeded stimulation until the proper result is obtained (during 1 year or more).

5. Distribution of patients with NPS in dependence on terms and efficacy of neurostimulation (1 month post-op)
Decrease of NPS severity in dependence on type of neurostimulation applied post-op
NB! High efficacy of surgery – decrease in pain severity and intensity up to 3 or less points on VAS scale; Low efficacy of surgery – decrease of pain severity and intensity more then 3 points on VAS scale.
CONCLUSIONS. The probability of reduction of pain syndrome in patients after CNS of damaged nerve is notably statistically higher then in those patients after TNS OR=1,67 (CI=0,33-9,10; р=0,05).

6. Injury of upper trunk (C5-C6) of brachial plexus
Pre-op
Post-op, 7 months after the chronic electrostimulation

7. Based upon literature reviews
Neurogenic pain
Neuropathic pain =
Our opinion
Neurogenic
pain
Neuropathic pain ≠

8. 3 major types of pain syndromes (PS)
Somatogenic PS
Neurogenic PS
Psycogenic PS
neurogenic
neuropathic
Differences: pathogenesis, manifestation, treatment strategies

9. Neurogenic pain
Neuropathic pain
The type of pain which arises due to /or exactly after the pathogenic factor affected any structure of NS without further sensitization of segmental and suprasegmental apparatus of NS
Directly after this factor is reduced the pain syndrome disappears.
The type of pain which arises due to/ or exactly after the pathogenic factor affected any structure of NS with further sensitization of segmental and suprasegmental apparatus of NS
Directly after this factor is reduced the PS transforms but does not reduce completely.
In order to reduce PS one has to apply additional methods to influence segmental and suprasegmental levels (neuromodulation, pharmacological therapy).

10. neurogenic pain syndrome to neuropathic pain syndrome
Pathways of development of PS after the nerve injury
Transformation of
neurogenic pain syndrome
to neuropathic pain syndrome
Neurogenic pain
Surgical decompression and restoration of anatomical continuity of damaged nerve if
Sensitization of segmental and suprasegmental levels
Neurogenic pain
Neuropathic pain
Neuropathic pain
Pain reduces
Pain persists

11. Clinical criteria of neuropathic pain syndrome:
1. Presence of stimuli-independent pain.
2. Permanent pain with positive sensory phenomena (allodynia, hyperpathia).
3. Multifactorial influence on increase of pain severity (emotions, weather, motion).
4. Psycho-emotional changes of identity (depression, anxiety)
5. Low efficacy of standard pharmacological therapy.
6. Reduction of factor that caused appearance of PS, usually, does not reduce pain.
7. In order to reduce neuropathic pain syndrome one has to apply additional methods of treatment (neuromodulation, pharmacological therapy).

12. Clinical criteria of neurogenic pain syndrome:
1. Severity and duration of pain depends on terms and intensity of impact of pathogenic factor on structures of NS.
2. Reduction of pathogenic factor leads to pain reduction and does not require further application of other treatment methods.
3. Lack of severe psycho-emotional changes of identity.

13. Conclusions
1. Neurogenic and neuropathic pain syndromes are completely different clinical statuses, have different pathological ground, mechanisms of development, have clinical features that require different diagnostics and treatment strategies.
2. Statistically proved risks of development of chronic pain syndrome require “as soon as possible” neurosurgical treatment in order to prevent transformation of neurogenic pain into neuropathic one.
3. Patients with permanent severe pain syndrome after the injury of nerves of extremities, which does not reduce after application of standard surgical procedures, require application of CNS.
4. In order to prevent formation and reduce currently existing neuropathic pain syndrome, to prevent formation of psycho-emotional changes of patient’s identity from the risk group (female, elderly persons, injuries of nerves of extremities, postponed surgeries a.o.) one should apply anticonvulsant-based and antidepressant-based therapy pre- and post-op.

14. Thank You for Your attention!
Leonardo da Vinci, Hands, 1474
Royal Library of Windsor Castle, Great Britain
N.A.Sapon