Objective: To explore MRI and CSF findings in patients with herpes zoster (HZ) and to correlate the findings with clinical manifestations of the disease.
Methods: Fifty immunocompetent patients (mean age, 59 years; range, 17 to 84 years) with HZ of fewer than 18 days duration participated. None had clinical signs of meningeal irritation, encephalitis, or myelitis. In 42 patients (84%), the symptoms constituted pain and rash only. Six patients (12%) had motor paresis, and three patients (6%) had ocular complications. One to three CSF samples were obtained from 46 patients (the first sampling taken 1 to 18 days from onset of rash), and 16 patients (all with either trigeminal or cervical HZ) underwent MRI of the brain. The clinical follow-up continued at least 3 months.
Results: CSF was abnormal in 28/46 patients (61%): pleocytosis (range, 5 to 1,440 microL) was detected in 21, elevated protein concentration in 12, varicella zoster virus (VZV) DNA in 10, and immunoglobulin G antibody to VZV in 10. These changes were more common in patients with acute complications, although they did not predict development of postherpetic neuralgia (PHN). In 9/16 patients (56%), MRI lesions attributable to HZ were seen in the brainstem and cervical cord. At 3 months, 5/9 patients (56%) with abnormal MRI had PHN, whereas none of the 7 patients with no HZ-related lesions on MRI had any remaining pain.
Conclusions: Subclinical extension of viral inflammation into the CNS occurs commonly in HZ. This finding may have implications for treatment of HZ and prevention of various associated complications.