Post-Herpetic Neuralgia (PHN)
Post-herpetic neuralgia (PHN), [4] possibly the most severe shingles complication, is far more likely to strike elderly people than younger people. According to a 2009 study, it plays a significant role in disability later in life.
PHN is a case of chronic nerve pain in the region where the rash first appeared. According to the CDC, between 10 and 18% of patients with shingles go on to develop PHN.
Stroke
According to a 2014 study, older persons with shingles have a higher risk of stroke for at least six months following their diagnosis and a stroke risk that is more than three times higher if they also have ocular herpes zoster.
People who took antiviral drugs had a decreased risk of stroke than people who did not take any medication.