Delayed facial palsy following uneventful middle ear surgery: a herpes simplex virus type 1 reactivation?

In rare cases, a facial palsy appears a few days after uneventful middle ear surgery. The reason for this delayed palsy is unclear. One hypothesis is that it results from a reactivation of herpes simplex virus type 1 (HSV-1) in the geniculate ganglion of the facial nerve. From 1987 to 1996, in the course of over 1,800 middle ear operations, we observed 7 ipsilateral delayed facial palsies and investigated 5 of them using immunologic and virologic methods, including the polymerase chain reaction (PCR). We could detect HSV-1 genome with the nested primer PCR in the tongue swabs of 4 of the 5 examined patients with delayed facial palsy. The immunologic changes in these palsies are also compatible with a reactivation of HSV-1. We conclude that minimal stimulation of the facial nerve during middle ear surgery could result in a reactivation of HSV-1 in the geniculate ganglion, which may in turn lead to a facial palsy.