Dianne Feinstein's Shingles Complications Raise Concerns.

Senator Dianne Feinstein, 89, developed post-shingles encephalitis, a rare and potentially debilitating complication in which the brain swells, after recovering from shingles. The condition can cause headache, fever, sensitivity to light, vomiting, confusion, a stiff neck, or even seizures, and can leave patients with lasting problems such as memory or language trouble, sleep disorders, mood disorders, walking difficulty, and other cognitive problems. The condition is estimated to affect fewer than 1% of shingles patients, but precise rates are difficult to determine. Shingles can also contribute to cognitive decline in other ways, including by damaging blood vessels of the brain.