To the Editor:—
The apparent sensitivity of some cranial nerves to ingested or injected substances is a unique vulnerability, not generally appreciated. A careful study might reveal the cause of some cranial nerve syndromes of unknown etiology such as tic douloureux, Bell's palsy, facial hemispasm, certain types of deafness, tinnitus, vertigo, glossopharyngeal neuralgia, and spasmodic torticollis.The first (olfactory) nerve is susceptible to nasal or viral infections which can cause transitory and occasionally permanent loss of smell. The second nerve (optic) is sensitive to methanol, optochin, cortisone and cortisone-like substances, tobacco (nicotine), quinine, ethylene glycol (Prestone), aspidium, and other substances.The third, fourth, and sixth cranial nerves (oculomotor, trochlear, and abducens) are often involved in diabetes and syphilis. They are occasionally affected following spinal anesthesia.The trigeminal nerve (fifth) is involved in tic douloureux, a syndrome of unknown etiology. This nerve is affected by stilbamidine, diphenylhydantoin sodium, trichloroethylene, and carbamazepine