044 - Frequency and evolution of brain MRI findings associated with congenital cytomegalovirus infection

Publication Number: 44.4680

Hajime Narita, Nagoya University Graduate School of Medicine, nagoya-shi, Aichi, Japan; Takako Suzuki, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan; Anna Shiraki, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan; Ayano Yanagisawa, Nagoya University Graduate School of Medicine, Honolulu, HI, United States; Misa Hashimoto, Nagoya University Graduate School of Medicine, nagoya, Aichi, Japan; Misae Yamada, Nagoya University, Nagoya, Aichi, Japan; Takamasa Mitsumatsu, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan; Yuji Ito, Nagoya University Hospital, Nagoya, Aichi, Japan; Hiroyuki Yamamoto, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan; Tomohiko Nakata, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan; Yuka Torii, Nagoya University Hospital, Nagoya, Aichi, Japan; Jun-ichi Kawada, Fujita Health University School of Medicine, Nagoya, Aichi, Japan; Yoshinori Ito, Aichi Medical University, Nagakute, Aichi, Japan; Hiroyuki Kidokoro, Nagoya University, Nagoya, Aichi, Japan; Jun Natsume, Nagoya University, Nagoya, Aichi, Japan

Background: Congenital cytomegalovirus (cCMV) infection is associated with characteristic brain MRI findings, including multifocal white matter abnormalities (WMAs), temporal-pole WMAs, and ventriculomegaly. These findings support the suspicion and treatment indication of cCMV. However, few studies have examined the longitudinal changes in these MRI findings.

Objective: This study aimed to clarify the frequency and evolution of MRI findings in patients with cCMV.

Design/Methods: We retrospectively reviewed 68 patients diagnosed with cCMV by PCR testing of urine samples within three weeks of birth or umbilical cord samples. Each patient underwent a brain MRI between December 2011 and May 2024. In the neonatal period, "symptomatic" was defined as the presence of any of the following: MRI abnormalities (ventriculomegaly, cortical malformation, or WMAs), auditory brainstem response abnormalities, or chorioretinitis. Two pediatric neurologists independently assessed the MR images, reaching a consensus after discussion.

Results: Among the 68 patients, 48 were symptomatic in the neonatal period, and 20 were asymptomatic. A total of 142 MRI scans were performed, with 114 scans for symptomatic patients and 28 for asymptomatic patients.
In symptomatic patients (48 patients), WMAs were observed in 29 patients (60%) , temporal-pole WMAs in 23 patients (48%), ventriculomegaly in 28 patients (58%), enlargement of the inferior horn of the lateral ventricles in 22 patients (46%), subependymal cysts in 22 patients (46%), ventricular septations in 7 patients (15%), cortical malformation in 5 patients (10%), and delayed myelination in 15 patients (31%) on initial MRI (Table 1). For patients with follow-up MRI scans (36 patients), the extent of WMAs decreased in 59% of cases with initial WMA findings (Figure 1A). Other findings also showed decreases or resolution over time (Figure 2).
In asymptomatic patients (20 patients), WMAs were observed in 4 patients (20%), enlargement of the inferior horn of the lateral ventricles in 1 patient (5%), subependymal cysts in 1 patient (5%), and ventricular septations in 1 patient (5%). WMAs presented as multifocal lesions, and the extent of WMAs decrease over time (Figure 1B).

Conclusion(s): Brain MRI findings in symptomatic patients with cCMV tend to decrease over time. It is important to consider the age-related evolution of MRI abnormalities in the management of cCMV. Since asymptomatic patients can also exhibit MRI abnormalities, brain MRI should be performed at the time of diagnosis.

Table 1: MRI findings in Symptomatic Patients
We examined the number of patients with findings observed on the initial MRI and the rates of decrease in cases that could be followed up. For the white matter abnormalities, we recorded the percentage decrease in the extent of lesions, while for other findings, we recorded the percentage of resolution. Although no decrease was observed in cortical malformations, other findings showed a trend toward resolution at follow-up.

Figure 1: Evolution of White Matter Abnormalities
We categorized the extent of white matter lesions into three groups and examined the evolution of these findings. In symptomatic cases, extensive lesions observed in neonates tended to decrease over time. In asymptomatic cases, only multifocal findings were noted, and the extent of the lesions also decreased over time.

Figure 2: Follow-up MRI in Symptomatic Patients
We compared the number of patients with findings other than white matter abnormalities between the initial MRI and the final follow-up images. A significant decrease was observed in findings other than cortical malformations.