Figure 1, Figure 2, and Figure 3. Demonstration of high-density lesions in the periventricular white matter, corpus callosum, internal capsule, basal ganglia, midbrain, and pons.
The diagnosis made was disseminated encephalomyelitis. His hospital stay was long and complex and included treatment with erythromycin ethylsuccinate for 10 days and acyclovir sodium for 21 days and high-dose steroids. Following treatment with acyclovir, the patient's balance, gait, and strength improved. Although his verbal level is still less than that of most 4 year olds, it has improved, and residual deficiencies are high-frequency hearing deficit in the left ear, impairment with problem solving, and short attention span.
Acute disseminated encephalomyelitis may develop late in the course of a viral illness, after a vaccination or bacterial infection such as mycoplasma. It is a monophasic, self-limiting disease similar to Guillian-Barré syndrome. Presenting symptoms include multifocal signs of central nervous system disease and are secondary to demyelinating lesions similar to those found in multiple sclerosis.1 Studies by Rabinowitz et al2 showed that there is sharing of antigenic determinants between the herpes virus and myelin basic protein, which results in cross-reaction in a host immune response. A temporary related central nervous system manifests as postinfections disseminated encephalomyelitis. Early detection and treatment is of paramount importance to restore neurologic function.3 Herpes simplex virus may be diagnosed and detected in cerebrospinal fluid via polymerase chain reaction and magnetic resonance imaging. These tests are rapid, specific, and highly sensitive.4 A combination of antiviral (acyclovir) and corticosteroid therapy given to 5 cases of "relapse" following herpes simplex encephalitis resulted in full recovery of 5 patients.5 The experience of Rudd et al6 indicates that long-term acyclovir therapy might prevent recurrent herpes simplex disease.
The diagnosis of acute disseminated encephalomyelitis may present a clinical dilemma to the medical practitioner. Early treatment is necessary if one is to prevent the devastating course of the illness. Our experience shows the importance of an early diagnosis of acute disseminated encephalomyelitis via polymerase chain reaction and magnetic resonance imaging. Early initiation of combination therapy of acyclovir and steroids has proven to be of immeasurable value regarding outcome.
Accepted for publication February 18, 1999.
Reprints: Hooshang Semnani, MD, FAAP, Northridge Hospital Medical Center, Pediatric Intensive Care Unit, 18300 Roscoe Blvd, Northridge, CA 91328.
Radiological Case of the Month. Arch Pediatr Adolesc Med. 2000;154(12):1270. doi: