Radiculopathies; Sciatica; Generalised Back Pain Flashcards
What is meant by a radiculopathy? [1]
Radiculopathies are disorders affecting spinal nerves or nerve roots, leading to pain, numbness, weakness or difficulty controlling specific muscles.
They can occur in any part of the spine
In general, what causes radiculopathy in the cervical, thoracic and lumbar vertabrae? [3]
Cervical:
- degenerative changes that narrow the space where nerve roots exit the spine
Lumbar:
- herniated disc
Thoracic:
- variety of conditions including herpes zoster; DM; disc hernation; infectionl tumours
Describe the basic overview pathophysiology of radiculopathies [+]
Mechanical compression or inflammation of the nerve root due to herniated intervertebral discs, spinal stenosis or direct trauma.
This leads to oedema which further increases pressure on nerve root, causing neuronal damge
Get ectopic dishcarges in the demyelinated regions of the neurons
Demyelination also causes ephaptic transmission (abnormal cross-talk between sensory fibres that normally carry non-painful stimuli and painful stimuli)
The neuronal injury and subsequent inflammation lead to activation of nociceptors - sensory receptors that respond to potentially damaging stimuli by sending “possible threat” signals to the spinal cord and brain. This process is termed peripheral sensitisation
Continued nociceptive input to the central nervous system can induce changes in the dorsal horn neurons leading to an increased response to peripheral stimuli. This is referred to as central sensitisation and it results in heightened pain sensitivity (hyperalgesia) or pain response from normally non-painful stimuli (allodynia).
Describe the sensory [4] and motor [3] symptoms of radiculopathies
Sensory:
- Pain: sharp, shooting, or electric-like and follows a dermatomal distribution - hallmark symptom
- Paresthesia
- Numbness
- Hypersensitivity
Motor SymptomsL:
- Muscle Weakness: Depending on which nerve root is compressed, patients may experience weakness in specific muscle groups
- Muscle Atrophy: In chronic cases where there has been ongoing nerve compression
- Fasciculations/Twitching
In clinical practice, the most common radiculopathies are those affecting the lumbosacral nerves between []
In clinical practice, the most common radiculopathies are those affecting the lumbosacral nerves between L1-S4
Describe the presentation for each lumbosacral radiculopathy (L1; L2-4; L5; S1)
L1:
- sensory changes in the inguinal region
L2-4:
- acute back pain that radiates around the anterior thigh
- sensory changes may be present over the anterior thigh and medial lower leg
L5:
- acute back pain that radiates down the lateral aspect of the leg to the foot
- sensory changes may be present over the lateral aspect of the lower leg and dorsum of the foot.
- Motor weakness is seen in foot dorsiflexion, big toe extension, and foot inversion/eversion
S1:
- acute back pain that radiates down the posterior aspect of the leg into the foot.
- sensory changes may be present over the posterior leg and lateral foot.
- weakness may be present in hip extension and knee flexion. There may be a loss of the ankle reflex
Several manoeuvres can be completed to determine whether the pain is radicular in origin (L1-S1), which includes [2]
Straight leg raise for L5/S1 radiculopathy:
- worsening radicular pain on raising the leg with the knee extended. Pain should be relieved if the knee is flexed
Reverse straight leg raise for L2-4 radiculopathy:
- worsening radicular pain on extending the leg with the patient prone
Why are thoracic radiculopathies rare? [1]
Thoracic radiculopathies are uncommon because the movement of the thoracic vertebrae is limited by the rib cage.
Describe the clinical presentation of thoracic radiculopathies [1]
Thoracic radiculopathy is characterised by radicular pain that starts in the back and radiates around the chest in a linear pattern; paraesthesia and anaesthesia (i.e. sensory loss) may be experienced in the same dermatomal distribution.
Describe the classic presentation of C5-C8 radiculopathie
C5 radiculopathy:
- associated with pain in the neck, shoulder, and scapula.
- sensory loss is usually seen in the lateral aspect of the upper arm
- weakness in shoulder abduction. Biceps and brachioradialis reflexes may be affected
C6 radiculopathy:
- associated with pain in the neck, shoulder, scapula, and lateral arm, forearm, and hand.
- Sensory loss in the lateral forearm, thumb, and finger (pointing a gun).
- Weakness may be seen in elbow flexion and supination/pronation. Biceps and brachioradialis reflexes may be affected
C7 radiculopathy:
- associated with pain in the neck, shoulder, hand, and middle finger.
- sensory loss in the palm, middle, and index finger.
- weakness is usually seen in elbow and wrist extension. Triceps reflex may be affected
C8 radiculopathy:
- associated with pain in the neck, shoulder, medial forearm, hand, and 4th/5th fingers.
- sensory loss in the medial forearm, hand, and 4th/5th digits
- weak finger movements
TOMTIP: [] radiculopathy is often discussed alongside cervical radiculopathies.
T1 radiculopathy is often discussed alongside cervical radiculopathies.
There are several important signs may be present that are suggestive of the involvement of the cervical cord (i.e. cervical myelopathy). What are they? [4]
Lhermitte phenomenon:
- shock-like paraesthesia radiating down the spine and towards the legs that occur on neck flexion
Gait disturbance
Upper motor neuron signs in the lower limbs (e.g. increased tone, weakness, clonus, upgoing plantar)
Bladder/bowel dysfunction
How do you investigate radiculopathies? [+]
Imaging:
- MRI: first line as gives high-resolution images of the spinal cord, nerve roots, and surrounding structures
- CT
- X-ray - can reveal osteophytes causing compression
Nerve conduction: assess the speed at which nerves transmit signals.
EMG: measures electrical activity within muscle fibres, providing insights into how well muscles respond to nerve stimulation.
Lab tests:
- Serology - if vasculitis or Lyme disease the cause
- CSF analysis
How do you differentiate between radiculopathies and peripheral neuropathies? [2]
Peripheral neuropathies typically present with symmetrical symptoms in a ‘stocking-glove’ distribution, whereas radiculopathy usually presents with asymmetrical symptoms in a dermatomal pattern.
Peripheral neuropathy does not usually have an accompanying localised spinal pain
How do you differentiate between radiculopathies and myelopathies? [3]
- Magnetic resonance imaging (MRI) of the spine remains the gold standard for distinguishing between these two conditions.
- Myelopathic signs are generally more diffuse, while radicular symptoms follow specific dermatomes or myotomes.
- Upper motor neuron signs such as spasticity and hyperreflexia suggest a myelopathy rather than a radiculopathy which is characterised by lower motor neuron signs like flaccidity and hyporeflexia.
Describe the management plan for radiculopathies
Pharmalogical treatment:
* NSAIDs are the first-line treatment for pain relief
* Corticosteroids may be used orally or via epidural injections in cases resistant to NSAIDs - this is both diagnostic and therapeutic. If this works to relieve pain, then know its the correct cause of pain
* Gabapentinoids, tricyclic antidepressants or selective serotonin reuptake inhibitors (SSRIs) can be considered for neuropathic pain
Physical Therapy
Lifestyle Modifications
Surgical Interventions:
* Open discectomy or microdiscectomy
* Disc fusion
* Laminectomy
What are general causes of mechanical back pain [6]
- Muscle or ligament sprain
- Facet joint dysfunction
- Sacroiliac joint dysfunction
- Herniated disc
- Spondylolisthesis (anterior displacement of a vertebra out of line with the one below)
- Scoliosis (curved spine)
- Degenerative changes (arthritis) affecting the discs and facet joints
What are general causes of neck pain [4]
- Muscle or ligament strain (e.g., poor posture or repetitive activities)
- Torticollis (waking up with a unilaterally stiff and painful neck due to muscle spasm)
- Whiplash (typically after a road traffic accident)
- Cervical spondylosis (degenerative changes to the vertebrae
Which factors / presenting features would indicate the following causes of back pain: [5]
- Spinal fracture
- Cauda equina
- Spinal stenosis
- Anky spond
- Spinal infection
Spinal fracture (e.g., major trauma)
Cauda equina (e.g., saddle anaesthesia, urinary retention, incontinence or bilateral neurological signs)
Spinal stenosis (e.g., intermittent neurogenic claudication)
Ankylosing spondylitis (e.g., age under 40, gradual onset, morning stiffness or night-time pain)
Spinal infection (e.g., fever or a history of IV drug use)
The spinal nerves [] – [] come together to form the sciatic nerve.
Describe the path of sciatic nerve [3]
The spinal nerves L4 – S3 come together to form the sciatic nerve.
Pathway:
- sciatic nerve exits the posterior part of the pelvis through the greater sciatic foramen, in the buttock area on either side
- It travels down the back of the leg.
- At the knee, it divides into the tibial nerve and the common peroneal nerve.
Where does the sciatic nerve supply sensation to? [2]
Where does the sciatic nerve supply motor function to? [3]
The sciatic nerve supplies sensation to the lateral lower leg and the foot.
It supplies motor function to the posterior thigh, lower leg and foot.
Describe the pain experienced in sciatica [1]
What other symptoms might be present? [2]
Sciatica causes unilateral pain from the buttock radiating down the back of the thigh to below the knee or feet. It might be described as an “electric” or “shooting” pain.
Other symptoms are paraesthesia (pins and needles), numbness and motor weakness.
Reflexes may be affected depending on the affected nerve root.
What are the three main causes of sciatica? [3]
Herniated disc
Spondylolisthesis (anterior displacement of a vertebra out of line with the one below)
Spinal stenosis
Bilateral sciatica is a red flag for []
Bilateral sciatica is a red flag for cauda equina syndrome.
Describe a test can perform to diagnose sciatica [1]
The sciatic stretch test:
- The patient lies on their back with their leg straight.
- The examiner lifts one leg from the ankle with the knee extended until the limit of hip flexion is reached (usually around 80-90 degrees).
- Then the examiner dorsiflexes the patient’s ankle.
- Sciatica-type pain in the buttock/posterior thigh indicates sciatic nerve root irritation.
- Symptoms improve with flexing the knee.
TOM TIP: It is worth remembering the main cancers that metastasise to the bones. A history of these in an exam patient presenting with back pain should make you think of possible cauda equina or spinal metastases. You can remember them with the [] mnemonic:
You can remember them with the PoRTaBLe mnemonic:
Po – Prostate
R – Renal
Ta – Thyroid
B – Breast
Le – Lung
What is the STarT Back Screening Tool? [1]
How does this tool inform management plans? [3]
Tool used to stratify the risk of a patient presenting with acute back pain developing chronic back pain.
This helps guide the intensity of the initial interventions (e.g., referral for group exercises, physiotherapy and cognitive behavioural therapy).
- Low risk patients: can be managed with reassurance and encouragement to remain active, early managed return to work and simple analgesia
- Medium risk patients: should be managed as per low risk in addition to offering a referral to physiotherapy
- High risk patients: should be referred to psychologically informed physiotherapy.
What might indicat back pain is malignant in origin? [2]
The pain is typically worse at night and may wake the patient from sleep.
There may be associated constitutional symptoms such as weight loss or night sweats.
How do you differentiate back pain from spinal stenosis? [1]
The cardinal symptom is neurogenic claudication
- unilateral or bilateral leg pain, numbness and weakness that worsens on walking and is relieved by sitting or forward flexion.
How do you manage generalised back pain? [+]
First line analgesia:
- NSAIDS (+PPI)
- Codeine / dihydrocodeine/ tramadol
Other management strategies
For patients at higher risk of poor outcome, NICE recommends considering the following:
* Referral to a group exercise programme
* Referral to physiotherapy for manual therapy
* Referral for CBT as part of a treatment package including exercise +/- manual therapy
Radiofrequency denervation
NICE advises consider referral for radiofrequency denervation in patients with chronic back pain where:
* The patient has failed to respond to non-surgical treatment
* The main source of pain is thought to be related to structures supplied by the medial branch nerve
* The pain is rated as 5 or more on a visual analogue scale or equivalent
What is the managment plan if muscle spasms are thought to be the primary issue causing back pain? [1]
A short course (2-5 days) of diazepam may be used. Initially this should be 2mg diazepam to be taken as required up to three times a day. The dose can be titrated up to 5mg tds if required.
Describe the management plan of sciatica [3]
NSAIDS first line
Codeine / dihydocodeine
Amitriptyline or Duloxetine (but not gabapentin or pregabalin)
