Low back pain neurologists perspectives

Low Back PainNeurologist’s perspectives

Dr.A.V.SrinivasanDr.A.V.Srinivasan

Back pain is a common cause of referral to Back pain is a common cause of referral to the neurology clinicthe neurology clinic

Pain experience is the result of a multitude Pain experience is the result of a multitude of processes, whereof the sensory input is of processes, whereof the sensory input is one, that interact in a proposed neural one, that interact in a proposed neural network, the neuromatrix.network, the neuromatrix.

Progress in Neurobiology August 2001; 64 (6): 613-637Best Practice & Research Clinical Rheumatology Vol. 21, No. 1, pp. 153e166, 2007

Low Back Pain is more common

Prevalence of chronic pain

Best Practice & Research Clinical Rheumatology Vol. 21, No. 1, pp. 153e166, 2007

Best Practice & Research Clinical Rheumatology Vol. 20, No. 4, pp. 707-720, 2006

Differential diagnosis of low back pain

Am Fam Physician 2007;75:1181-8, 1190-2

The lumbar disc herniation is the most The lumbar disc herniation is the most frequent disease of the spinal degenerative frequent disease of the spinal degenerative processes, and they cause of 30% to 80% of processes, and they cause of 30% to 80% of the low back pain casesthe low back pain cases

Medicina (Kaunas) 2007; 43(8)

Cauda equina syndrome Single or double-level compression of the lumbosacral Single or double-level compression of the lumbosacral

nerve roots located in the dural sac results in a polyradicular nerve roots located in the dural sac results in a polyradicular symptomatology clinically diagnosed as cauda equina symptomatology clinically diagnosed as cauda equina syndrome. syndrome.

The cauda equina nerve roots provide the sensory and motor The cauda equina nerve roots provide the sensory and motor innervation of most of the lower extremities, the pelvic floor innervation of most of the lower extremities, the pelvic floor and the sphincters. Therefore, in a fully developed cauda and the sphincters. Therefore, in a fully developed cauda equina syndrome, multiple signs of sensory disorders may equina syndrome, multiple signs of sensory disorders may appear such as appear such as low-back pain, saddle anesthesia, bilateral low-back pain, saddle anesthesia, bilateral sciatica, then motor weakness of the lower extremities or sciatica, then motor weakness of the lower extremities or chronic paraplegia and, bladder dysfunctionchronic paraplegia and, bladder dysfunction..

Progress in Neurobiology August 2001; 64 (6): 613-637

CES - Etiology Non-neoplastic compressive etiologiesNon-neoplastic compressive etiologies

Herniated lumbosacral discs Herniated lumbosacral discs Spinal stenosisSpinal stenosis Spinal neoplasms Spinal neoplasms

Non-compressive etiologiesNon-compressive etiologies Ischemic insultsIschemic insults Inflammatory conditionsInflammatory conditions Spinal arachnoiditis Spinal arachnoiditis Other infectious etiologies. Other infectious etiologies.

Orendacavo J et al. Progress in Neurobiology August 2001; 64 (6): 613-637

Failed Back Syndrome

• Failed back syndrome (FBS) is a well-Failed back syndrome (FBS) is a well-recognized complication of surgery of the recognized complication of surgery of the lumbar spine. It can result in chronic pain lumbar spine. It can result in chronic pain and disability, often with disastrous and disability, often with disastrous emotional and financial consequences to emotional and financial consequences to the patient. the patient.

• "spinal cripples""spinal cripples"

Onesti ST. Failed back syndrome. Neurologist 2004 Sep; 10(5): 259-64.

Consequences of Untreated & Under treated Acute Pain

Extensive and Persistent cascade of neurochemical mediators triggered by

tissue injury leads to a long-term, permanent, neurological change that can

lead to

SENSITIZATION

ALLODYNIA

HYPERALGESIA

MAY evolve into chronic pain

Progression of Acute Pain to Chronic Pain

Chronic pain appearsChronic pain appears

Because of an expression of the presence Because of an expression of the presence ofof

Central SensitizationCentral Sensitization

Sensitization

SensitizationSensitization is a phenomenon of is a phenomenon of inappropriate or disproportionate inappropriate or disproportionate

response to normal stimulusresponse to normal stimulus

Types of Sensitization

Peripheral & CentralPeripheral & Central

Peripheral Sensitization

Occurs at the site of injuryOccurs at the site of injury

Primary afferent neurons are involvedPrimary afferent neurons are involved

Exposure to prostaglandinsExposure to prostaglandins

Increased pain sensation at the site of injuryIncreased pain sensation at the site of injury

Central Sensitization

Increased excitability of pain neurons Increased excitability of pain neurons (nociceptor neurons) in the dorsal horn of the (nociceptor neurons) in the dorsal horn of the spinal cord.spinal cord.

Neurons detecting and transmitting pain display Neurons detecting and transmitting pain display ‘‘plasticity’plasticity’

• progressive increase in the response to repeated progressive increase in the response to repeated painful stimulipainful stimuli

• all contribute to altered sensitivity to painall contribute to altered sensitivity to pain

Clinical Implications of Central Sensitization

Increased response to a noxious stimulus Increased response to a noxious stimulus (Hyperalgesia)(Hyperalgesia)

Disproportionate response to pain syimulus Disproportionate response to pain syimulus (Allodynia)(Allodynia)

Prolonged / Persistent painProlonged / Persistent pain Referred painReferred pain

Central sensitization in low back pain

In back pain patients, both hypoalgesia and hyperalgesia to electrical cutaneous stimulation is reported (Wilder-Smith et al., 2002).

Hyperalgesia to pressure on the thumbnail was found in idiopathic chronic low-back pain patients compared to controls indicating generalized hyperalgesia (Giesecke et al., 2004).

European Journal of Pain 11 (2007) 415–420

The distribution of experimental pain in controls and chronic low back patients evoked by injection of hypertonic saline in infraspinatus and tibialis anterior muscles. The evoked pain areas were significantly larger in the patients for both muscles. Dark shading indicates overlapping pain areas among subjects. European Journal of Pain 11 (2007) 415–420

Central Sensitization & Tramadol

Why Tramadol is Superior

In patients with Central SensitizationIn patients with Central Sensitization

Tramadol An Atypical Centrally Acting Analgesic

NA uptake

inhibtion

5HT uptake inhibition

m-agonist

Role of Tramadol

TramadolTramadol• Centrally acting opioid analgesic, binds Centrally acting opioid analgesic, binds

to to µ µ opioid receptorsopioid receptors• Inhibits reuptake of NE and serotonin Inhibits reuptake of NE and serotonin

within pain pathways of CNSwithin pain pathways of CNS• Contribute to enhancing the descending Contribute to enhancing the descending

pain inhibitory pathwayspain inhibitory pathways

Role of Tramadol

Down regulation of central sensitisationDown regulation of central sensitisation hence an hence an ideal drug for Neuropathic painideal drug for Neuropathic pain

““Enhances” Enhances” descending inhibitory pathwaysdescending inhibitory pathways

Excellent Analgesic EfficacyExcellent Analgesic Efficacy

Tolerated well even in very high dosagesTolerated well even in very high dosages

Tramadol Most Logical Choice for a variety of Chronic Pain Most Logical Choice for a variety of Chronic Pain

Conditions where central sensitisation plays a major role:Conditions where central sensitisation plays a major role:

Our experience in INDIAOur experience in INDIA :: OA /RA Flare PainOA /RA Flare Pain Neuropathic Pain Neuropathic Pain Acute Radicular Back PainAcute Radicular Back Pain Chronic Back PainChronic Back Pain Fibromyalgia PainFibromyalgia Pain Cancer PainCancer Pain

Tramadol – Central Sensitization

Binds to Mu opiods

Mimicks the effects Enkephalins

Reduce the effects of Sub P

Reduce the intensity of the pain

Pain relief

Enhances descending inhibition

Inhibits reuptake of Serotonin and NE

More in qty at the synapse

Reduce the effects of Sub P

Reduce the intensity of the pain

Pain relief

Best Practice & Research Clinical Rheumatology Vol. 19, No. 4, pp. 609–621, 2005

Treatment choice Should be evidence based and tailored as much as possible Should be evidence based and tailored as much as possible

to suit the individual patient. to suit the individual patient. Acetaminophen (paracetamol), mild opioids and NSAIDs Acetaminophen (paracetamol), mild opioids and NSAIDs

are the first-line drugs for low back pain but there is no are the first-line drugs for low back pain but there is no evidence that one is more effective than the others. evidence that one is more effective than the others.

Tramadol is proposed to be the better choice due to its Tramadol is proposed to be the better choice due to its pharmacological profile and effect on pain in several pharmacological profile and effect on pain in several musculoskeletal disorders.musculoskeletal disorders.

Non-benzodiazepine muscle relaxants (with or without Non-benzodiazepine muscle relaxants (with or without pain medication) could be considered as second-line drugs pain medication) could be considered as second-line drugs in acute low back pain, and cyclic antidepressants in in acute low back pain, and cyclic antidepressants in chronic low back pain.chronic low back pain.

Strong opioids could be considered in musculoskeletal Strong opioids could be considered in musculoskeletal pain when other treatment options have failedpain when other treatment options have failed

Best Practice & Research Clinical Rheumatology Vol. 21, No. 1, pp. 153-166, 2007 Best Practice & Research Clinical Rheumatology Vol. 19, No. 4, pp. 609–621, 2005

Symptoms to be used to tailor choice of treatment


The benefits of medication in low back pain will The benefits of medication in low back pain will increase if:increase if: Medication is prescribed only for severe symptomsMedication is prescribed only for severe symptoms The choice of medication is targeted on the main The choice of medication is targeted on the main

symptomsymptom Patients understand the aim of the medication and how Patients understand the aim of the medication and how

long it should be used before evaluation can take placelong it should be used before evaluation can take place Medication should be taken on a time-contingent basis; Medication should be taken on a time-contingent basis;

this facilitates evaluationthis facilitates evaluation Evaluation is based on the aimEvaluation is based on the aim The type of drug has been tailored on individualThe type of drug has been tailored on individual basisbasis The dose has been tailored on individual basisThe dose has been tailored on individual basis..


Low back pain neurologists perspectives

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