Neuropathy, in a basic, practical, and somewhat literal sense means “nerve-ending suffering.” The idea is that the patient’s suffering is from the damaged nerve ending and not from something that is stimulating that nerve ending. In other words, a neuropathic stinging sensation might be arising from misfiring of the sensory nerve ending all by itself, and not in response to, for example, an actual bee sting.
Motor neuropathy involves muscle-supplying nerve fibers. Motor nerve endings insert into muscle to allow them to contract. Thus, nerve ending damage would cause weakness. A person with peripheral neuropathy of the motor (movement) nerves to the lower legs might, for example, develop a slapping walking sound or unsteadiness.
Sensory neuropathy involves damage to nerve endings that provide sensation. The result can be any number of sensations that all originate in the nerve itself, rather than from an external stimulus. The person might feel pain, tingling, burning, itching, pins and needles, tickling, and so forth. The variety of sensations possible likely relates partly to the degree of damage, and also to the many kinds of sensory receptors found in the body. Different sensory nerve endings are designed to detect pain, change of temperature, vibration, touch, pressure, and so forth.
Neuropathy can follow injury, viral illness, alcoholism, endocrine disorders, certain chemotherapy drugs, diabetes, Herpes zoster (shingles), and other more elusive and undiagnosable causes. When the cause cannot be found to direct treatment, the disorder is called idiopathic. General symptomatic treatments are as described below for sensory neuropathic cough.
A special kind of neuropathy is becoming better known in the medical community—Sensory Neuropathic Cough or SNC. The idea here is that nerve endings supplying sensation to the lining of the mouth, throat, larynx (voicebox), and trachea (windpipe) are neuropathic. The resulting neuropathic tickle, dry sensation, pinprick, itching, pressure, or dripping sensation initiates a spectrum of responses, depending on urgency of the sensation. As for that spectrum of responses: If the sensation is subtle, the individual might only clear the throat or cough once or twice. When extremely urgent, the sensation might initiate a violent attack of coughing lasting up to several minutes. The most severe attacks are often associated with turning red, tearing of the eyes, running of the nose, retching or actual vomiting, and even leakage of urine or worse. In some, laryngospasm (sudden locking shut of the throat making breathing difficult and noisy for 30 to 60 seconds) may occur on occasion. After a particularly bad attack of SNC, the individual may feel exhausted; chest wall may hurt. Public instances of this kind of coughing are humiliating. Thankfully, many do not cough at night, but some unfortunate people are awakened several times every night to cough, and may be come sleep-deprived and “zombified.”
Treatment of Neuropathy
Treatment of neuropathy in general, and SNC in particular, is always first directed at any known ongoing cause of the neuropathy. Otherwise, the standard of care involves use of what we call colloquially “nerve ending medicines.” These typically come from two general classes of drugs: seizure medications and those used for depression. Common ones in use are amitriptyline, desipramine, gabapentin or pregabalin, citalopram, effexor, capsaicin spray, and so forth. Often, physicians help patients work their way through a list of such medications, looking for the one that works best. Successful treatment may mean dramatic reduction of symptoms, but not necessarily that they are completely abolished. Some persons must remain on medication indefinitely; others whose cough is virtually abolished for at least a month may successfully taper off medication. Even in this latter group, a subsequent URI may again “waken the monster” and necessitate resuming medication.