Blink reflex and BAEPs in detection of subclinical involvement of 5th, 7th and 8th cranial nerves in N-IDDM

Abstract EN

We studied 30 non-insulin dependent diabetic (NIDDM) patients for the presence of subclinical neuropathy of the trigeminal (5th), facial (7th) and cochlear (8th) nerves, using the blink reflex and brain stem auditory evoked potentials (BAEPs).

A routine motor and sensory nerve conduction study for the peripheral nerves was performed as well.

We found that the facial nerve was involved in 5 patients (16.66 %), the trigeminal in one (3.33 %) and the cochlear in another patient (3.33 %).

The efferent pathway of the blink reflex (facial nerve) showed extracranial involvement in 4 patients and intracranial involvement in one patient.

Only one patient showed absence of wave III on his right side in BAEPs.

Six out of the 30 (20 %) patients had clinical symptoms and/or signs of peripheral neuropathy.

All patients with manifested clinical symptoms and signs had abnormal nerve conduction (NC) studies while 13 out of the remaining 24 (54.2 %) who had no clinical manifestations had abnormal NC studies.

Four of the 6 patients with clinical peripheral neuropathy showed subclinical involvement of the 7th (3 patients) and 5th (one patient) cranial nerves.

Thus, the blink reflex and BAEPs are good diagnostic techniques to detect subclinical abnormalities of the 5th, 7th and 8th cranial nerves, and to be recommended for follow up of NIDDM patients.