1. Mahdi Panah khahi, MD,FIPP
Neuropathic Pain
Mahdi Panah khahi, MD,FIPP
Assistant Professor of Anesthesiology & Pain
Pain Management Center, Sina Hospital, TUMS

2. و لقد خلقنا الانسان في كبد ......
آيه 4 ، سوره بلد

3. Everything is pain; Delivery is pain, disease is pain, aging is pain
Everything is pain; Delivery is pain, disease is pain, aging is pain.death is pain, to be away from your beloved is pain, even hatred is pain Budha

4. You can not control two sensations in the body;love and pain
David B. Morris; The Culture of Pain, 1991

5. درد یک تجربه ناخوشایند حسی و هیجانی مرتبط با آسیب بافتی واقعی یا بالقوه است , یا با عباراتی از این قبیل آسیب ها توصیف میشود.
درد یک تجربه ناخوشایند حسی و هیجانی مرتبط با آسیب بافتی واقعی یا بالقوه است , یا با عباراتی از این قبیل آسیب ها توصیف میشود.

7. PAIN is the most common symptom reported by physicians
More than 80 % of all patients who see physicians do so because of PAIN
It affects general health, psychological health, social and economical well – being
Pts in Chronic Pain use health services up to 5 times more frequently than the rest of the population

8. The cost of unrelieved chronic pain in USA is more than 50 billion $ /Y
More than 550 million workdays are lost every year because of chronic pain
Unrelieved or inadequately relieved pain in :
40% of all cancer patients
50% of nursing home patients
55% of postoperative patients
70% of patients with AIDS

10. بیمار شماره 1 آقای 43 ساله که با درد آرنج چپ مراجعه نموده بود.
از 17 سالگی، درد به دنبال ضربه به آرنج شروع و به تدریج افزایش یافته بود.
به خاطر درد ، 4 بار تحت جراحی قرار گرفته بود.
پس از هر جراحی درد تشدید یافته و پس از جراحی آخر دچار بی حسی در مسیر عصب اولنار چپ از آرنج به پایین گردیده بود.
بدنبال این عارضه، سه بار تزریق در ناحیه گردن در سه روز متوالی (در مطب پزشک) برایشان انجام شده بود.

11. بیمار شماره 1
پس از آن دچار عفونت شدید ریوی (مدیاستینیت) گردیده و به مدت 20 روز در بیمارستان بستری بود.
در موقع مراجعه به کلینیک ما:
درد وی سوزشی ، مداوم و اغلب 10-8 بوده و با هیچ یک از مسکن ها ( حتی مخدر ها) کاهش نیافته بود.
در قسمت داخلی آرنج چپ ، هیپرستزی و آلودینیا داشت و پوشیدن لباس هم برایشان مشکل و دردناک بود.
بی حسی در مسیر عصب اولنار چپ از آرنج تا انتهای انگشتان داشت.
خواب بیمار به شدت مختل بود

12. بیمار شماره 1
پس از مداخله درمانی و تجویز داروی مناسب در مراجعه پس از 6 هفته بهبودی بیش از90-80 % در درد اظهار نمود.
خواب وی بهبود یافته و فعالیت های روزمره وی به دنبال کاهش درد تغییر فاحش پیدا کرد.
در معاینه هیپرستزی و آلودینیا از بین رفته بود.

13. بیمار شماره 2
خانم 27 ساله به علت فرو رفتن مداوم ناخن انگشت شست پای راست در پوست آن ناحیه و درد ناشی از آن ، تحت جراحی ناخن قرار گرفته بود.
به علت عدم بهبود و تشدید درد ، ناچار به کشیدن ناخن در جراحی دوم شده بودند.
جراحی سوم هم به خاطر برداشتن نورینوم ، مثل دفعات قبل منجر به تشدید درد وی گردیده بود.
تزریق در ناحیه آسیب دیده هم نتیجه ای نداده بود.

14. بیمار شماره 2
انواع دارو های ضد درد تجویز شده درد وی را کاهش نداده بود.
در بدو مراجعه به کلینیک ما:
درد سوزشی شدید (10) که پس از آخرین مداخله درمانی در7 ماه پیش ، به تدریج رو به افزایش بوده و از اطراف انگشت شست در بدو شدوع، به تدریج به سمت مچ پا، ساق ،ران وکمر هم منتشر شده بود.
علارغم مراجعه به ده ها پزشک ، تغییری در شدت درد وی ایجاد نشده بود.

15. بیمار شماره 2
به شدت افسرده بود.
خواب به شدت مختل شده بود.
آلودینیای شدید داشت و هر گونه تماس و برخورد آب به این ناحیه درد شدید ایجاد می کرد.
اختلات شدید عملکردی در زندگی پیدا کرده بود.
از 7 ماه پیش تحت درمان با داروی گاباپنتین قرار گرفته بود.
با درمان مناسب ، در مراجعه بعدی پس از 2 ماه، آلودینیا صرفا ً محدود به یک نقطه در نوک انگشت شده بود.
خواب کاملا ً بهبود یافته بود.
افسردگی بیمار مرتفع شده بود.
3-2 بار در هفته استخر می رفت.
عملکرد وی کاملا ً بهبود یافته بود.

16. Pain is a more terrible lord of man than even death.
We must all die. But that I can save him from days of torture, that is what I feel as my great and ever new privilege.
Pain is a more terrible lord of man than even death.
Albert Schweitzer, 1875–1965

17. The type of pain
Acute Pain
Chronic Pain
Cancer Pain

18. More Definitions (Ashburn, Staats)
Acute pain = a normal response to tissue damage that resolves as the injured tissue heals or soon afterward
Chronic pain = pain that persists longer than the expected time frame for healing OR pain associated with progressive, nonmalignant disease
[+ Cancer-related pain]

19. The type of pain Somatic (arising from skin, muscle, bone)
Visceral (arising from organs within the chest and abdomen)
Neuropathic (caused by damage or dysfunction in the nervous system)
Patients often experience more than one type of pain

20. Neuropathic pain
Pain initiated or caused by a primary lesion or dysfunction in the nervous system.
Neuropathic pain syndromes can originate at any point or points along the somatosensory pathways, from the most distal nerve endings in the skin to the somatosensory cortex in the parietal lobe.

21. Types of Pain Nociceptive pain Neuropathic pain
Arises from somatic and/or visceral structures.
Usually well localized with limited duration.
Generally responsive to NSAIDS and opioids.
Neuropathic pain
Result of damage or inflammation to nerves or nerve fibers.
Often triggered by an injury but may or may not involve actual nervous system damage.
Two Categories of Pain
Nociceptive pain tends to be thought of as “normal” pain associated with injury or damage to somatic and/or visceral structures.
Neuropathic pain arises from nerve or nerve fiber damage or inflammation. Treatment usually includes adjuvant analgesics.
While both types of pain are distinctive, they are not mutually exclusive. Thus, pain is not always easily classified. Sometimes a patient presents with more than one pain problem over time.

22. Neuropathic Pain Syndromes
Central:
Central post stroke pain.
Multiple sclerosis pain
Parkinson disease pain
Spinal cord injury syndrome
Peripheral:
Complex regional pain syndrome
Phantom Limb Pain
Neuropathy due to tumour invasion
Painful diabetic neuropathy
Chemotherapy induced neuropathy
Post Herpetic Neuralgia
HIV sensory neuropathy
Post mastectomy pain
Trigeminal neuralgia

23. Painful neuropathies (Classified by major etiologic categories)
Toxic-metabolic
Endocrine
Chemotherapy and chemical exposure associated
Nutritional
Posttraumatic
Complex regional pain syndrome types I and II
Compressive
Nerve entrapment syndromes
Autoimmune
Vasculitic
Paraneoplastic
Para infectious
Infectious
Hereditary
Painful neuropathies can be classified by major etiologic categories: toxic-metabolic (endocrine, chemotherapy and chemical exposure associated, nutritional), posttraumatic (complex regional pain syndrome types I and II), compressive (nerve entrapment syndromes), autoimmune (vasculitic, paraneoplastic, para infectious), infectious, and hereditary .

24. Terms: Allodynia: pain due to normal non painful stimuli.
Hyperalgesia: increased response to normally painful stimuli.
Hyperaesthesia: increased sensitivity to stimulation.
Analgesia: diminished response to normally painful stimuli.
Dysesthesia: unpleasant abnormal sensations.
Paraesthesia: abnormal sensation that is not unpleasant.
May include itching, numbness, tingling, pins and needles

25. Pain Management Center in Sina Hospital
Acute Pain Service
Post Operative Pain Management
Chronic Pain Service
Multidisciplinary Pain Clinic
Pain Specialist
Pain Fellows
Psychologist
Physical Medicine Specialist
Other Medical Specialists
Pain Specialist Nurse
Anesthesiology Resident
Secretary
Cancer Pain Clinic

26. Pain Management Center
Treatment options :
Medical T.
Physical T.
Behavioral T.
Interventional T.
Alternative Medicine

28. Diagnostic Evaluation of Patients with Neuropathic Pain
History
Examination
Physical Examination in General
Neurological Examination
Sensory Examination
Diagnostic Testing
MRI
CT scan
EMG NCV

29. Features of neuropathic pain:
Most common descriptors:
Electric shock.
Burning.
Tingling.
Cold, pricking, tingling & itching.

30. Patient descriptors Paresthesias and dysesthesias Burning Shooting
Stabbing
electric-shock like
Throbbing
Crushing
like-toothache
like-sunburn
Pins and needles

31. Patient descriptors
Other physical signs associated with neuropathic pain may include:
changes in skin color and temperature
swelling of limbs

32. Pathophysiology of Neuropathic Pain
Peripheral mechanisms: (1)
Dysfunction or damage to the normal function of peripheral mechanisms can lead to increased sensitivity of peripheral sensory nerves which results in an increase in the level of stimulation (intensity) transmitted to the brain.
Ectopic discharges (or abnormal spontaneous activity):
This is commonly felt as paraesthesias (sodium channels)
Nociceptor (peripheral) sensitisation:
The nociceptors malfunction and become more receptive to noxious stimulation.
Ephaptic cross-talk:
This is the random cross-firing of impulses between adjacent peripheral nerve fibres.

33. Pathophysiology of Neuropathic Pain
Central mechanisms: (1,2)
Damage or dysfunction of central mechanisms can increase the sensitivity of central sensory nerves, which the brain interprets as pain.
Central mechanisms include:
Central disinhibition
This refers to the pathological loss of the central modulatory mechanisms

34. Mechanisms Of Neuropathic Pain
Neuropathic pain is usually extremely distressing, unremitting and responds poorly to standard analgesics such as NSAIDS

35. Mechanisms Of Neuropathic Pain
Neuropathic pain is usually extremely distressing, unremitting and responds poorly to standard analgesics such as NSAIDS

36. Mechanisms Of Neuropathic Pain
Automatic Firing of Damaged Nerves
Neuropathic pain is usually extremely distressing, unremitting and responds poorly to standard analgesics such as NSAIDS

37. Mechanisms Of Neuropathic Pain
De afferentation
Neuropathic pain is usually extremely distressing, unremitting and responds poorly to standard analgesics such as NSAIDS

38. Mechanisms Of Neuropathic Pain
Sympathetically mediated pain
Neuropathic pain is usually extremely distressing, unremitting and responds poorly to standard analgesics such as NSAIDS

39. Managing neuropathic pain
Multimodal approach
Steps in treatment:
Optimise analgesic therapy
Select the right drug.
Use the right route, titration and dosage.
Minimise side effects.
Use adjuvant or combination therapy.
Consider other treatment strategies
TENS, nerve blocks or surgery.
Psychological therapies.
Physiotherapy.
Complementary therapies.
Patient Support Groups.

40. Pharmacotherapy of Neuropathic Pain
Conventional analgesics:
NSAIDs (e.g. diclofenac, ibuprofen), opioids (e.g. morphine, fentanyl, tramadol), paracetamol
Antidepressants:
e.g. amitriptyline
Anticonvulsants:
e.g. NEURONTIN (gabapentin), carbamazepine, phenytoin
rubefacients (rubs): e.g. capsaicin
NMDA antagonists: e.g. ketamine
local anaesthetics and derivatives: e.g. lignocaine
centrally-acting antihypertensive drugs: e.g. clonidine
skeletal muscle relaxants: e.g. baclofen.

41. Interventional Pain Management

42. Stellate Ganglion Block

46. Lumbar Medial Branch Radiofrequency Ablation

47. Dorsal Column Stimulator Implant

48. Peripheral Nerve Stimulator

49. Intrathecal Drug Delivery Pumps

59. rheumatologists study joints orthopedists study bones
The problem…
inadequate professional and public awareness
rheumatologists study joints
orthopedists study bones
oncologists study cancer cells
... pain is typically viewed
as “just a symptom”