Computed tomography in young children with herpes simplex virus encephalitis

Abstract

Computed tomographic (CT) scans were obtained from eight infants and young children with herpes simplex virus encephalitis. In two cases the initial scan showed diffuse edematous changes as a mass effect without laterality. Unilateral localized low attenuation in the initial scan was evident 4 days after the onset in one patient, and high attenuation in the initial scan appeared on the 6th day in another patient, but in general, it was not possible to establish an early diagnosis of herpes simplex virus encephalitis from CT scan. In the longitudinal study the calcification with ventriculomegaly appeared in 3 of 5 survivors, and gyriform calcification in 2 of 3 patients, respectively. The appearance of multicystic encephalomalacia was evident in one patient 6 months after the onset of neonatal herpes simplex encephalitis. It is shown that the CT findings of neonates and young children with herpes simplex encephalitis are different from those of older children and adults, and the importance of longitudinal CT studies was stressed in clarifying the pathophysiology of the central nervous system involvement in survivors.

Neonatal herpes simplex virus infections: HSV DNA in cerebrospinal fluid and serum

“…13 However, EEG lesions do not develop until a few days after first symptoms of central nervous system involvement 510 11 The same is true for lesions visible on computed tomography 12. Lesions on MRI are seen earlier, but only after 1–3 days 13…”

“…Accurate and rapid aetiological diagnosis is required for adequate handling and evaluation of therapeutic strategies. Before the introduction of PCR the diagnosis of neonatal herpes simplex virus infections was based on virus isolation from peripheral lesions or brain9 and serological methods, together with the demonstration of characteristic or suggestive EEG changes5 10 11 and neuroradiological lesions in clinically suspected cases 1213 However, EEG lesions do not develop until a few days after first symptoms of central nervous system involvement 5…”

Neuroimaging of herpesvirus infections in children

“…In the correct setting, this is a fairly specific pattern [5,32] and is iatrogenic, the sequela of retained iodinated contrast agent rather than hemorrhage or calcification [37,38]. Several months later, there is true gyriform calcification of the cortex, seen in concert with cortical thinning, white matter atrophy, and multicystic encephalomalacia [5,39,40].…”

Computed tomography (CT) in children with herpes simplex encephalitis

“…The calcification was limited to the grey matter and was similar to the calcification encountered in Sturge-Weber syndrome, but this condition, however, is almost always unilateral. CT findings, such as calcification in HSE, are even rarer being found in only three reported cases [5,6]. Progressive cortical calcification on plain skull radiography is also known to occur in a newborn infected with HSE [7].…”