👹 Radiculopathy

August 3, 2024

Neurosurgery, Core

Claudication, Foot Drop

Radiculopathy #

Introduction #

Radiculopathy is a symptom generated by pathology affecting the nerve roots.
Peripheral neuropathy is differentiated from radiculopathy by the distribution of the symptoms.

Anatomy #

The nerve roots ‘radiate’ from the spinal cord = radiculopathy.
The root traverses four zones:

the central canal (intrathecal);
the lateral recess (within the root sleeve);
the foramen; and
the extraforaminal space .

Pathology #

Due to both compression and inflammation - ‘chemical neuroradiculitis’.
nucleus pulposis herniation = Slipped disc
- Due both compression and inﬂammation
- Causes 90% of radiculopathy.
Most intervertebral disc prolapses are paracentral - zones 1 and 2.
- Irritation here can cause symptoms in the transiting root

Assessment #

The goals:

localize the level of the lesion
identify the nature of the lesion
- UMN vs LMN pathology
screen for emergency conditions
- Cauda equina syndrome
- Acute painful foot drop
screen for anaesthetic risk factors.
- Fitness for surgery

History #

Pain - Electric shock like severe pain increase when limb extended.
altered perianal sensation
urogenital symptoms - ‘autonomic dysfunction’
- insensate urinary incontinence
- i.e. retention and has overﬂow incontinence.

Examination #

Root tension manoeuvres (Lasegue and Braggard’s)
Tone and reﬂexes should be normal or reduced.
If hyperreﬂexia and hypertonia -> assess cervicothoracic spine.
Perianal sensory loss -> strong predictor of cauda equina compression

Feature	Bragard Test	Lasegue Test
Purpose	To evaluate nerve root compression and differentiate between a genuine and pseudo-Lasegue sign	To evaluate sciatic nerve irritation or lumbar nerve root irritation
Patient Position	Supine	Supine
Initial Movement	Examiner raises the patient’s leg while extended at the knee until pain is felt (Lasegue sign)	Examiner raises the patient’s leg while extended at the knee until pain is felt
Subsequent Movement	Examiner lowers the leg just until the pain subsides, then dorsiflexes the foot	None
Positive Test Indication	Pain reproduced upon dorsiflexion of the foot indicates nerve root compression	Pain in the back or along the sciatic nerve distribution indicates sciatic nerve irritation
Area of Concern	Nerve root compression, typically between L4 and S1 levels	Sciatic nerve or lumbar nerve roots
Mechanism of Pain Elicitation	Stretching of the sciatic nerve through dorsiflexion	Stretching of the sciatic nerve during leg raise

Imaging #

MRI imaging T2 within 6 months of onset of symptoms
CT myelogram - If patient with a old implantable devices.

Treatments #

Non-surgical #

The majority (90%) of radiculopathy are treated non-surgically.
1st line - Antineuropathics
- Eg: duloxetine
- ﬁrst-line treatment in radiculopathy without motor symptoms
2nd line pregabalin and gabapentin.
- Mechanism of action: works at the root and spinal cord level to reduce ascending pain ﬁbre neuronal discharge.

Steroid injection #

Peri-root steroid injection is an effective treatment.
reduces the production of inﬂammatory mediators.
Efﬁcacy rates are high, with 66% of patients with good relief at a year.

Surgery #

Microdiscectomy - remove the compressive disc extrusion
- 80% - 90% have relief of pain in the immediate postoperative period
- often motor and sensory symptoms respond less reliably and less immediately.
A small laminotomy allows for fenestration of the ligamentum ﬂavum.
Medial facetectomy allows lateral recess and proximal foraminal decompression of the nerve root.
Common complications:
- infection 3%
- recurrent disc prolapse 5%
- inadvertent durotomy (‘CSF leak’) 7%
- continuing radicular symptoms 10%.
Rare complications:
- 1% nerve injury resulting in urogenital, motor or sensory deﬁcits
- 1:4000 of iliac vessel injury during discectomy
- very rare risk of visual deﬁcit from prone positioning.

Warning
The outcome is that 75% of patients at 3 months and 95% of patients at 1 year will have recovered with conservative management.
the timing of the intervention is controversial, as many patients will improve without intervention. offer surgery or injection therapy after 3-6 months of failed conservative management.