PLAB 2 Neurology: Mastering Peripheral Neuropathy Guidelines for OSCE Success

As medical professionals aspiring to practice in the UK, mastering common neurological presentations is paramount for success in exams like PLAB 2. Peripheral neuropathy, a condition affecting the peripheral nerves, is a frequently encountered scenario in general practice and a high-yield topic for your OSCEs. This blog post aims to equip you with a comprehensive, guideline-based approach to confidently diagnose and manage peripheral neuropathy in the PLAB 2 setting.

Understanding Peripheral Neuropathy: A PLAB 2 Perspective

Peripheral neuropathy encompasses a range of conditions that result from damage to the peripheral nerves. These nerves connect the central nervous system (brain and spinal cord) to the rest of the body, including muscles, skin, and internal organs. Damage can lead to weakness, numbness, and pain, typically in the hands and feet. For PLAB 2, the focus is on a structured approach to identifying the condition, considering common causes, and initiating appropriate management.

Key Components for a PLAB 2 OSCE Station

In a PLAB 2 OSCE station, you'll likely face a patient presenting with symptoms suggestive of peripheral neuropathy. Your performance will be judged on your ability to gather a comprehensive history, perform a focused examination, formulate an initial management plan, and communicate effectively.

1. History Taking: The Diagnostic Compass

This is where you gather clues to the type and cause of neuropathy. Remember the 'SOCRATES' mnemonic for pain, and expand to other neurological symptoms:

• Onset & Progression: When did symptoms start? Were they sudden or gradual? Have they worsened? (e.g., acute onset suggests Guillain-Barré Syndrome, gradual suggests diabetic neuropathy).

• Symmetry: Are symptoms on one side (mononeuropathy) or both (polyneuropathy)? Symmetrical presentations are more common in systemic diseases.

• Nature of Symptoms:

  • Sensory: Numbness, tingling (pins and needles), burning, shooting pains, loss of sensation (glove-and-stocking distribution is classic).

  • Motor: Weakness, difficulty with fine motor tasks, muscle cramps, foot drop.

  • Autonomic: Dizziness (postural hypotension), bowel/bladder dysfunction, erectile dysfunction, abnormal sweating.

• Associated Symptoms: Fatigue, weight loss, fever, rashes.

• Past Medical History: Crucial for identifying common causes:

  • Diabetes Mellitus: Most common cause.

  • Thyroid disease, Renal disease, Liver disease.

  • Autoimmune conditions: Rheumatoid arthritis, SLE, Sjogren's syndrome.

  • Infections: HIV, Hepatitis C, Lyme disease.

  • Cancer: Paraneoplastic syndromes, chemotherapy-induced neuropathy.

• Medication History: Enquire about neurotoxic drugs (e.g., chemotherapy agents, isoniazid, amiodarone, metronidazole, phenyotin).

• Social History: Alcohol intake (alcoholic neuropathy), occupational exposures (heavy metals like lead, arsenic), travel history.

• Family History: Any family members with similar neurological conditions.

2. Focused Neurological Examination: Confirming the Diagnosis

Your examination should confirm nerve involvement and help localize the lesion.

• Inspection: Look for muscle wasting (especially small muscles of hands/feet), skin changes, trophic changes, foot deformities.

• Motor System:

  • Tone: May be normal or reduced.

  • Power: Test individual muscle groups, especially in the distal limbs. Look for patterns (e.g., foot drop).

  • Reflexes: Often diminished or absent, especially ankle jerks (AChilles reflex).

• Sensory System:

  • Light touch, Pinprick, Temperature: Assess in a 'glove-and-stocking' distribution.

  • Vibration: Use a 128 Hz tuning fork, compare distal to proximal.

  • Proprioception: Test joint position sense (especially great toe).

• Coordination: (Finger-nose test, heel-shin test) – may be affected if proprioception is impaired.

• Gait: Observe the patient's gait for ataxia or foot drop.

3. Investigations: Uncovering the Cause

In PLAB 2, you'll be expected to suggest relevant initial investigations. These are guided by your history and examination findings:

• Blood Tests:

  • FBC, ESR/CRP: Inflammation, systemic disease.

  • U&Es, LFTs, TFTs: Renal, liver, thyroid dysfunction.

  • HbA1c/Glucose: Screen for diabetes.

  • Vitamin B12 & Folate: Deficiency can cause neuropathy.

  • Autoimmune Screen: ANA, RF, ANCA (if suspicion of autoimmune vasculitis).

  • Serum electrophoresis: For paraproteinaemia (e.g., myeloma).

  • Infectious disease screen: HIV, Hepatitis serology (if indicated by history).

• Nerve Conduction Studies (NCS) & Electromyography (EMG): This is the definitive diagnostic test to confirm neuropathy, differentiate between demyelinating and axonal types, and localize nerve damage. You would refer for this.

• Imaging: MRI of the spine (if considering nerve root compression).

• Lumbar Puncture: If Guillain-Barré Syndrome or chronic inflammatory demyelinating polyneuropathy (CIDP) is suspected.

4. Management: Holistic and Patient-Centered

Your management plan should address the underlying cause, symptom control, and patient education.

• Treat the Underlying Cause: This is paramount. For example, strict glycaemic control in diabetes, alcohol cessation, vitamin supplementation for deficiencies, or managing autoimmune conditions.

• Symptomatic Management:

  • Neuropathic Pain: First-line medications include amitriptyline, gabapentin, pregabalin, or duloxetine. Start low and titrate slowly. Explain side effects like drowsiness.

  • Foot Care: Emphasize daily foot checks, appropriate footwear, and regular podiatry referrals, especially in diabetic patients, to prevent ulcers and infections.

  • Physiotherapy/Occupational Therapy: To maintain muscle strength, improve mobility, and provide aids (e.g., ankle-foot orthosis for foot drop).

• Patient Education & Lifestyle Advice:

  • Explanation of condition: Use clear, jargon-free language.

  • Prognosis: Be realistic but supportive.

  • Safety: Advise on avoiding falls, careful driving, checking bath water temperature, and protecting numb areas.

  • Healthy Lifestyle: Balanced diet, regular exercise, smoking cessation.

• Referrals:

  • Neurologist: For definitive diagnosis, complex cases, and management. Especially if NCS/EMG is needed.

  • Diabetologist/Endocrinologist: For diabetic neuropathy.

  • Pain Clinic: For refractory neuropathic pain.

  • Podiatry: Essential for foot care.

  • Physiotherapy/Occupational Therapy: For rehabilitation.

5. Communication Skills: Empathy and Clarity

Throughout the station, demonstrate excellent communication:

• Active listening: Pay attention to the patient's concerns.

• Empathy: Acknowledge their distress and impact on daily life.

• Clear explanations: Break down complex medical information.

• Shared decision-making: Involve the patient in their management plan.

• Safety netting: Explain what symptoms to look out for and when to seek urgent medical attention.

Conclusion

Peripheral neuropathy is a multifaceted condition that requires a systematic and patient-centered approach. By meticulously gathering history, performing a focused examination, requesting appropriate investigations, and formulating a comprehensive management plan, you'll not only excel in your PLAB 2 OSCEs but also provide excellent care to your future patients in the NHS. Practice these guidelines regularly, and you'll navigate these stations with confidence and competence. Good luck!