A middle aged man has developed numbness and tingling in his toes and feet, and more recently his fingertips. He also complains that he trips up more frequently.
Clinical Approach: This man has distal sensory symptoms and motor symptoms. Here it is important to decide whether this is due to a peripheral cause , central or a combination of both.
Clinical History :
1. Is this an urgent case? Ask about the duration of symptoms and rate of progression. Any worrying associated symptoms like loss of sphincter control or difficulty in breathing.
2. Differentiating between peripheral and central nervous system dysfunction:
A peripheral nervous system dysfunction is characterized by
- tingling, numbness and burning in feet.
- Numb fingers.
- Foot drop
- Difficulty in rising from a chair
- Difficulty in going up and down stairs.
A spinal cord lesion is characterized by
- Legs and feet feeling stiff and heavy.
- Clumsy stiff hands
- Sphincter disturbances.
3. Duration of symptoms may help determine the cause of neuropathy.
4. Any associated pain.
Past History: Ask specifically about:
- Diabetes mellitus
- Alcohol intake
- Current medications
- Dietary history
- Pernicious anemia
- Weight loss
- Neck trauma
- Rheumatoid arthritis.
1. Signs in case of peripheral nervous system disorder
- Distal weakness
- Absent ankle reflexes
- Stocking distribution sensory loss
- Muscle wasting (if severe)
2. Signs in case of central nervous system disorder
- Spastic tone
- Weakness both proximal and dismally, but predominantly in leg flexor
- Brisk reflexes
- Extensor plantars
- Possible sensory level
3. Is is important to check if the signs are symmetrical?
- Asymmetry in the context of an upper motor neurone syndrome would represent a Brown-Sequard syndrome with loss of proprioception ispilateral to the weak leg, and loss of pain and temperature sensation contralateral to the weak leg.
- Asymmetric lower motor neurone findings suggest mononeuritis multiplex or entrapment neuropathic..
4. Check for associated cranial nerve pansies
- Deafness in CN VIII
- Bilateral facial weakness in Guillain-Barre syndrome and Sarcoidosis
- Malignant infiltration of the basal meninges may lead to multiple cranial nerve palsies.
5. General Examination :
Look and check if the patient is systemically well?
- Cachexia may suggest malignancy or alcoholism
- Vasculitic rash in systemic vasculitis
- Look for signs of hypothyroidism