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 and motor 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.
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.
