Mononeuropathy
OtherOverview
Mononeuropathy is a disorder affecting a single peripheral nerve, causing weakness, numbness, or pain in the distribution of that nerve. Common sites include the median nerve (carpal tunnel), ulnar nerve (cubital tunnel), and radial nerve (radial tunnel syndrome). The condition results from compression, trauma, or inflammation of the affected nerve and requires careful clinical assessment to identify the specific nerve involved and underlying cause.
Pathophysiology
Mononeuropathy develops when a single peripheral nerve experiences compression, stretch, ischemia, or direct trauma that disrupts axonal conduction. Mechanical compression (e.g., at anatomical sites of natural narrowing) causes demyelination and axonal injury, leading to impaired nerve conduction velocity. Inflammatory responses and edema within the nerve's fascicles further compromise blood flow and nutrient delivery. Chronic compression can result in permanent axonal loss if the offending mechanism is not relieved. The severity of symptoms correlates with the degree of nerve fiber involvement and duration of compression.
Patient Education
Early diagnosis and conservative management of nerve compression syndromes can prevent permanent nerve damage; identifying and modifying the mechanical cause is essential to recovery.
Typical Presentation
Site
Specific nerve distribution; common sites include median nerve (palm, thumb, index and middle fingers), ulnar nerve (ring and little fingers, medial hand), radial nerve (dorsal thumb and hand), peroneal nerve (lateral lower leg, dorsum of foot), and femoral nerve (anterior thigh)
Quality
Burning, tingling, pins-and-needles (paresthesia), numbness, electric shock-like sensations, or aching pain along nerve distribution
Intensity
Mild to moderate paresthesia in early stages; severe pain or weakness in advanced compression; typically progressive if untreated
Aggravating
Repetitive activity involving the affected nerve, sustained postures that compress the nerve, direct pressure on the nerve pathway, prolonged gripping or fine motor tasks, nighttime (especially in carpal tunnel syndrome)
Relieving
Rest, immobilization or splinting of the affected area, ice application, elevation, nerve gliding exercises, activity modification, anti-inflammatory medication
Associated
Weakness in muscles innervated by the affected nerve, muscle atrophy with chronic compression, loss of sensation in the nerve's cutaneous distribution, reduced grip strength, clumsiness with fine motor tasks, symptoms worse at night or upon waking
Orthopaedic Tests
Phalen's Test (Wrist Flexion Test)
Procedure
Patient rests both elbows on a table with the forearms vertical and lets the wrists drop into full flexion under gravity. Hold for up to 60 seconds without forcing.
Positive Finding
Numbness or paraesthesia in the median nerve distribution within 60 seconds.
Sensitivity / Specificity
Reference: Dabbagh A, MacDermid JC, Yong J, Packham TL, Grewal R, Boutsikari EC. Diagnostic Test Accuracy of Provocative Maneuvers for the Diagnosis of Carpal Tunnel Syndrome: A Systematic Review and Meta-Analysis. Phys Ther. 2023;103(6).
Interpretation
Tests the commonest mononeuropathy, carpal tunnel syndrome. A positive test supports it, but on its own changes the probability only a little; combine it with the history and sensory testing. Figures are pooled from a 2023 meta-analysis that excluded studies using healthy controls. Individual studies varied widely (sensitivity 12–92%, specificity 30–95%), so no single study figure should be quoted.
Tinel's Sign
Procedure
Tap gently along the course of the suspected nerve, starting distally and moving towards the suspected site of compression or injury.
Positive Finding
Tingling spreading into the territory of that nerve when a particular point is tapped.
Interpretation
Suggests irritation or regrowth of the nerve at the tapping point and helps locate the lesion. After a nerve injury, a Tinel's sign that moves further along the nerve over weeks suggests regeneration. It does not confirm a mononeuropathy on its own.
Upper Limb Tension Test (ULTT) – Median Nerve Bias
Procedure
Patient supine. Stabilise the shoulder girdle, then add shoulder abduction, wrist and finger extension, forearm supination, shoulder lateral rotation and elbow extension. Then add cervical side-flexion away from and towards the tested side.
Positive Finding
Reproduction of the familiar arm or hand symptoms that changes with cervical side-flexion and differs from the other side.
Interpretation
Shows that the median nerve is irritable somewhere along its course but does not locate the problem. It is also often positive with cervical radiculopathy.
Straight Leg Raise (SLR) / Lower Limb Tension Test
Procedure
Patient supine. Lift the symptomatic leg with the knee straight until symptoms appear, then add ankle dorsiflexion.
Positive Finding
Reproduction of the familiar leg symptoms, increased by ankle dorsiflexion.
Interpretation
Tests tension on the sciatic nerve and the lower lumbar roots. A positive test suggests a neural source but cannot tell a nerve-root problem from a problem further along the sciatic nerve; the neurological examination and nerve studies do that. The SLR tests lumbar nerve-root tension. Its published accuracy is for disc herniation causing leg pain, not for a single-nerve (mononeuropathy) problem, so no figure is shown here.
Electromyography (EMG) and Nerve Conduction Studies (NCS)
Procedure
Performed by a neurophysiologist or specialist. Nerve conduction studies measure how fast and how strongly nerves conduct; EMG uses a fine needle to record muscle activity.
Positive Finding
Slowed conduction or a block at one site, reduced response size, or signs of muscle denervation in the territory of one nerve.
Interpretation
Confirms a mononeuropathy, locates the lesion and shows how severe it is (loss of myelin versus loss of nerve fibres), which guides management and surgical decisions. Results can be normal early in an injury or in mild compression.
Froment's Sign (Adductor Pollicis Function)
Procedure
Ask the patient to hold a piece of paper between the thumb and the side of the index finger with both hands while you pull it away.
Positive Finding
The thumb tip bends (interphalangeal joint flexion) to hold the paper on the affected side.
Interpretation
Shows weakness of adductor pollicis (ulnar nerve), compensated by flexor pollicis longus (median nerve). Supports an ulnar nerve lesion at the elbow or wrist; the sensory pattern and other ulnar muscles help locate the level.
⚠ Red Flags
- •Rapidly progressive neurological deficit suggesting acute nerve compression or trauma requiring urgent decompression
- •Complete sensory loss or paralysis indicating severe axonal damage
- •Symptoms following significant trauma or fracture with possible nerve transection
- •Bilateral mononeuropathies or polyeuropathy suggesting systemic disease (diabetes, vasculitis, infection)
- •Constitutional symptoms (fever, weight loss, night sweats) suggesting underlying infection or malignancy compressing the nerve
- •Signs of complex regional pain syndrome with significant edema, skin changes, and vasomotor instability
- •Progressive weakness with atrophy unresponsive to conservative management over 8-12 weeks
⚡ Yellow Flags
- •Significant psychological distress, catastrophizing, or fear avoidance limiting engagement with rehabilitation
- •Prominent anxiety or depression concurrent with symptom onset
- •Secondary gain or compensation-seeking behavior associated with work-related nerve injury
- •Poor medication compliance or resistance to activity modification despite clear mechanical trigger
- •High perceived disability disproportionate to objective neurological findings
- •Work-related psychosocial stressors or job dissatisfaction in occupational nerve compression syndromes
Osteopathic Techniques
Region
Proximal nerve pathway (cervical spine, brachial plexus, or lumbosacral plexus as appropriate)
Technique
Rationale
Releases muscular tension and fascia surrounding nerve roots and plexuses, reducing proximal compression and improving neural mobility; addresses trigger points in muscles that may refer symptoms or contribute to entrapment
Region
Site of nerve entrapment (e.g., carpal tunnel, cubital tunnel, fibular head)
Technique
Rationale
Gentle soft tissue mobilization and myofascial release at the entrapment site reduces local inflammation, swelling, and muscular guarding; improves tissue compliance and reduces direct pressure on the nerve
Region
Affected peripheral nerve pathway
Technique
Rationale
Positions the affected nerve in a shortened or pain-free position to reduce tension and mechanical irritation; facilitates neural gliding and reduces protective muscle splinting
Region
Joints proximal and distal to entrapment site (wrist, elbow, shoulder, or ankle/knee as appropriate)
Technique
Rationale
Gentle mobilization restores normal joint mechanics and reduces compensatory tension patterns that may contribute to nerve compression; improves overall segmental mobility
Region
Cervical or lumbosacral spine (depending on nerve origin)
Technique
Rationale
Muscle energy techniques release tension in muscles with myofascial attachments affecting the nerve's proximal path; restores cervical or lumbar segmental mobility to reduce proximal nerve root compression
Region
Tissues surrounding affected nerve
Technique
Rationale
Enhances lymphatic drainage to reduce local edema and inflammatory mediators compressing the nerve; improves tissue perfusion and nutrient delivery to compromised nerve segments
Rehabilitation Exercises
Nerve Gliding Exercises for Median Nerve
Ulnar Nerve Gliding Sequence
Gentle Wrist Extension Stretch (Carpal Tunnel Syndrome)
Upper Limb Nerve Tension Mobilization (Slump Stretch Variant)
Intrinsic Hand Muscle Activation (Lumbrical Exercises)
Progressive Grip Strengthening with Therapy Putty
Forearm Pronation and Supination Strengthening (Radial Nerve)
Ergonomic Posture Training for Workstation
Shoulder and Cervical Postural Correction
Single-Leg Balance Training (for Lower Limb Mononeuropathies)
Ankle and Foot Mobilization (for Peroneal Nerve Compression)
Gentle Walking Program with Proper Footwear
Referral Criteria
- •Rapidly progressive neurological deficit unresponsive to conservative management within 2-4 weeks
- •Severe weakness or paralysis requiring urgent surgical decompression evaluation by neurologist or orthopedic surgeon
- •Diagnosis uncertain or atypical presentation requiring electromyography (EMG) and nerve conduction studies (NCS) performed by neurologist
- •Suspected systemic disease (diabetes, vasculitis, infection) causing mononeuropathy; refer to internal medicine or infectious disease specialist
- •Failure to improve after 8-12 weeks of conservative management; consider surgical consultation for decompression
- •Signs of complex regional pain syndrome with disproportionate pain and dysfunction; refer to pain management specialist or physiotherapist specializing in CRPS
- •Significant psychological distress, anxiety, or depression limiting rehabilitation participation; refer to mental health professional
- •Suspected malignancy or tumor compressing the nerve; refer for imaging and oncology consultation
- •Post-traumatic nerve injury with evidence of nerve transection; refer urgently to surgeon for possible nerve repair
- •Bilateral mononeuropathies or evidence of polyeuropathy; refer to neurologist to investigate underlying systemic cause