Epidemiology and Impact on Quality of Life of Postherpetic Neuralgia and Painful Diabetic Neuropathy :

A prospective survey study was performed in patients with painful diabetic polyneuropathy (PDN) to assess the nature and scope of their pain. Pain associated with diabetic neuropathy is commonly encountered in clinical practice. Yet, little is known regarding the pain experience and impact on quality of life in persons with painful diabetic neuropathy. These 105 patients noted an average of 6/10 pain, most often described as 'burning', 'electric', 'sharp', and 'dull/ache', which, for most, is worse at night time and when tired or stressed. On average, patients reported that the pain caused substantial interference in sleep and enjoyment of life and moderate interference in recreational activities, normal work, mobility, general activity, social activities, and mood. Unexpectedly, a potential genetic predisposition to the development of painful neuropathy was suggested by the fact that a majority (56%) reported a family member with PDN. Thus, this study found that pain associated with diabetic neuropathy is a significant medical issue that has a substantial impact on the quality of life of many people with this condition.

There is little information on the incidence and natural history of neuropathy in patients with non-insulin-dependent diabetes mellitus (NIDDM). We studied patients with newly diagnosed NIDDM and control subjects both at base line and 5 and 10 years later. Polyneuropathy was diagnosed on the basis of clinical criteria (pain and paresthesias) and electrodiagnostic studies (nerve conduction velocity and response-amplitude values). We investigated the relation between metabolic variables (results of oral glucose-tolerance tests, serum lipid and insulin concentrations, and glycosylated hemoglobin values) and the development of polyneuropathy. In 10 years, 36 patients with NIDDM and 8 control subjects died; 86 patients and 121 control subjects completed the study. When the study ended, 18 percent of the patients were being treated only with diet, 59 percent with oral hypoglycemic drugs alone, 12 percent with insulin alone, and 11 percent with both insulin and oral hypoglycemic agents. At base line the prevalence of definite or probable polyneuropathy among the patients with NIDDM was 8.3 percent, as compared with 2.1 percent among the control subjects. These values 10 years later were 41.9 percent and 5.8 percent, respectively. The number of patients with NIDDM who had nerve-conduction abnormalities in the legs and feet increased from 8.3 percent at base line to 16.7 percent after 5 years and to 41.9 percent after 10 years. The decrease in sensory and motor amplitudes, indicating axonal destruction, was more pronounced than the slowing of the nerve conduction velocities, which indicates demyelination. Among the patients with NIDDM, those with polyneuropathy had poorer glycemic control than those without. Low serum insulin concentrations before and after the oral administration of glucose were associated with the development of polyneuropathy, regardless of the degree of glycemia. The prevalence of polyneuropathy among patients with NIDDM increases with time, and the increase may be greater in patients with hypoinsulinemia.

Herpes zoster (HZ) strikes millions of older adults annually worldwide and disables a substantial number of them via postherpetic neuralgia (PHN). Key age-related clinical, epidemiological, and treatment features of zoster and PHN are reviewed. HZ is caused by renewed replication and spread of varicella-zoster virus (VZV) in sensory ganglia and afferent peripheral nerves in the setting of age-related, disease-related, and drug-related decline in cellular immunity to VZV. VZV-induced neuronal destruction and inflammation causes the principal problems of pain, interference with activities of daily living, and reduced quality of life in elderly patients. Recently, attempts to reduce or eliminate HZ pain have been bolstered by the findings of clinical trials that antiviral agents and corticosteroids are effective treatment for HZ and that tricyclic antidepressants, topical lidocaine, gabapentin, and opiates are effective treatment for PHN. Although these advances have helped, PHN remains a difficult condition to prevent and treat in many elderly patients.