Steroid-dependent postvaricella encephalomyelitis

Varicella-zoster virus: atypical presentations and unusual complications

Varicella-zoster virus (VZV) is the etiologic agent of varicella (primary infection) and herpes zoster (reactivation of latent infection). Although varicella is most often a relatively benign and self-limited childhood illness, the disease can be associated with a variety of serious and potentially lethal complications in both immunocompetent and immunocompromised persons. One complication of varicella that appears to be increasing in frequency is serious bacterial soft tissue infections caused by group A streptococci. Issues related to management of varicella become especially complex when varicella involves pregnant women or susceptible neonates. Herpes zoster can be associated with a variety of neurologic complications, including a syndrome of delayed contralateral hemiparesis. Neurologic complications of herpes zoster, including chronic encephalitis, occur with increased frequency in AIDS patients. VZV retinitis is a potentially sight-threatening complication that occurs in both immunocompetent and immunocompromised persons. Current knowledge regarding pathogenesis and antiviral therapy is reviewed.

Encephalitis related to primary varicella-zoster virus infection in immunocompetent children

INTRODUCTION

Encephalitis is a rare complication of primary varicella-zoster virus (VZV) infection in immunocompetent children.

METHODS

The clinical and laboratory findings of two girls with VZV-related encephalitis are reported.

RESULTS

Both children presented with focal epileptic seizures, corresponding to cortical/subcortical as well as white matter lesions. The first showed a typical vesicular skin rash. She was easily diagnosed and made a rapid recovery during acyclovir and steroid treatment. In the second girl, a preceding measles-mumps-rubella virus vaccination and the absence of skin vesicles were misleading with respect to the diagnosis, which was finally proven by IgG seroconversion and intrathecal synthesis of IgG antibodies to VZV. She developed left parieto-occipital tissue necrosis and recovered only transiently during initial acyclovir/steroid treatment. Eight weeks after onset, progressive white matter demyelination and the occurrence of erythema nodosum in the lower limbs necessitated a second 4-month course of oral steroids. The VZV PCR from cerebrospinal fluid was negative in both children.

CONCLUSIONS

Primary VZV infection may cause severe encephalitis that may occur without skin vesicles and lead to a chronic course with systemic vasculitis. The coincidence of vaccination and neurologic diseases offers no proof per se of a causal relationship.

ADEM: literature review and case report of acute psychosis presentation

Acute disseminated encephalomyelitis is a monophasic, immune-mediated disorder that produces multifocal demyelinating lesions within the central nervous system. It is characterized clinically by the acute onset of neurologic abnormalities, including varying degrees of mental state changes ranging from drowsiness to coma. It is unusual for the illness to present as an isolated acute psychosis. The case of a 14-year-old female with biopsy-confirmed acute disseminated encephalomyelitis, who was initially diagnosed with an acute psychiatric disorder, is presented, and published reports on this unusual manifestation are reviewed. A Medline database search was performed from 1965 to 1999, using the terms acute disseminated encephalomyelitis, postvaccinal encephalomyelitis, postinfectious encephalomyelitis, and measles encephalomyelitis, combined with the terms psychosis, psychiatric disorder, and behavioral disorder. Selected cross-referenced reports were also reviewed. Nine patients were identified who presented with acute psychosis. We conclude that, although rare, acute disseminated encephalomyelitis can present as an acute psychosis. This immune-mediated condition should be included in the differential diagnosis of neurologic disorders presenting as a psychiatric illness.

An 11-year-old girl with syndrome of inappropriate antidiuretic hormone secretion

An 11-year-old girl presented with a syndrome of inappropriate antidiuretic hormone secretion, which was transitory and, initially, of obscure origin. Subsequently, the patient's hypothalamic disorder emerged as a component of a steroid-responsive relapsing encephalomyelitis with cerebral pathology restricted to the basal ganglia and brainstem. Where such a disorder fits in the spectrum from acute disseminating encephalomeylitis to multiple sclerosis is discussed.