Relative sensory sparing in the diabetic foot implied through vibration testing

Area of Science:

• Neurology
• Diabetology
• Biomedical Engineering

Background:

• The dorsal aspect of the hallux is commonly used for vibration testing in diabetic patients.
• This study aimed to validate this preference by comparing vibration testing at the hallux and 5th metatarsal head.

Purpose of the Study:

• To compare vibration testing sensitivity at the hallux versus the 5th metatarsal head in diabetic patients with neuropathy.
• To validate the dorsal hallux as the optimal site for vibration testing in diabetic neuropathy.

Main Methods:

• Timed vibration testing (TVT) using a 128 Hz electronic tuning fork (ETF).
• Testing was conducted on 28 diabetic patients with neuropathy and 17 non-diabetic controls.
• Vibration sensitivity was measured at both the hallux and 5th metatarsal head in all participants.

Main Results:

• Diabetic patients exhibited reduced TVT values at both tested locations compared to controls.
• Significantly lower TVT values were observed at the hallux (P<0.001) compared to the 5th metatarsal head.
• This indicates greater sensory loss at the hallux in diabetic neuropathy.

Conclusions:

• The hallux is confirmed as the most appropriate site for vibration testing in diabetic neuropathy.
• The 5th metatarsal head may show relative sensory sparing, a novel finding in diabetic patients.
• These results refine clinical practice for assessing diabetic foot sensation.