Polyneuropathy

Procedure

Apply a 10g monofilament perpendicular to the skin at standardized sites (dorsum of foot, plantar surface, toes) with enough pressure to bend the filament. Patient indicates when contact is felt with eyes closed.

Positive Finding

Inability to perceive the 10g monofilament at one or more sites, indicating loss of protective sensation

Sensitivity / Specificity

86–92% / 81–89%

Feng et al., 2014, PLOS ONE (meta-analysis); Rencken et al., 1992, Diabetes Care

Interpretation

Positive result suggests distal sensory neuropathy, particularly in lower limbs; widely used to screen for diabetic peripheral neuropathy and predict foot ulceration risk

Procedure

Strike a 128 Hz tuning fork and place on bony prominences (medial malleolus, anterior tibial crest, great toe). Patient indicates when vibration is no longer felt.

Positive Finding

Loss of vibration perception or marked reduction compared to unaffected control side, particularly distally

Sensitivity / Specificity

75–85% / 78–88%

Martina et al., 1998, Neurology; Perkins et al., 2001, Diabetes Care

Interpretation

Suggests large fibre dysfunction; impaired vibration sense correlates with demyelinating and axonal neuropathies; high risk for falls and proprioceptive loss

Procedure

Using a sterile pin or neurological pin wheel, apply gentle punctate pressure in a stocking-glove distribution (distal to proximal). Patient identifies whether stimulus is sharp or dull with eyes closed.

Positive Finding

Loss of sharp sensation or inability to discriminate sharp from dull in distal limbs, often in a stocking-glove pattern

Sensitivity / Specificity

68–78% / 80–89%

See current literature; standard clinical bedside test validated across multiple neuropathy types

Interpretation

Positive result indicates small fibre dysfunction (C and Aδ fibres); suggests pain/temperature sensory loss characteristic of many peripheral neuropathies

Procedure

Patient rises from a standard chair, walks 3 metres at comfortable pace, turns around, returns, and sits. Time is recorded.

Positive Finding

Time >12 seconds or significant unsteadiness, loss of balance, or use of upper limbs for support

Sensitivity / Specificity

75–84% / 72–81%

Podsiadlo & Richardson, 1991, Journal of the American Geriatrics Society; Franchignoni et al., 2013, BJSM

Interpretation

Identifies fall risk and functional gait impairment in neuropathy; correlates with distal sensory loss and proprioceptive dysfunction affecting balance

Procedure

Patient stands with feet together, hands at sides, eyes open for 30 seconds, then eyes closed. Assess for loss of balance or need for support.

Positive Finding

Inability to maintain balance with eyes closed, significant sway, or requirement to open eyes or use support within 30 seconds

Sensitivity / Specificity

68–76% / 72–85%

See current literature; widely used in neuropathy assessment but sensitivity varies with neuropathy type and severity

Interpretation

Positive result indicates proprioceptive/vestibular dysfunction; suggests impaired joint position sense common in large fibre neuropathies; high fall risk

Procedure

Patient seated or prone with knee slightly flexed. Strike the Achilles tendon with a reflex hammer and observe for plantarflexion response.

Positive Finding

Absent or significantly diminished reflex bilaterally compared to upper limb reflexes

Sensitivity / Specificity

74–82% / 80–87%

Perkins et al., 2001, Diabetes Care; Kamenov et al., 2016, Neurology International

Interpretation

Absent ankle reflex is hallmark of large fibre/axonal neuropathy; indicates demyelination or axonal loss affecting motor and sensory fibres; common early sign in diabetic neuropathy