Reduced gray matter volume in the frontotemporal cortex of patients with early subacute sclerosing panencephalitis

Association Between Clinical Severity, Neuroimaging, and Electroencephalographic Findings in Children with Subacute Sclerosing Panencephalitis

BACKGROUND

Children diagnosed with subacute sclerosing panencephalitis (SSPE) display a range of neuroimaging abnormalities during different stages of the disease, but their exact clinical significance remains unclear.

METHODS

In this retrospective cohort study, our objective was to examine magnetic resonance imaging (MRI) abnormalities in the brains of patients aged 18 years or younger with subacute sclerosing panencephalitis. We aimed to correlate these MRI abnormalities with clinical severity, sociodemographic variables, electroencephalographic (EEG) abnormalities, and cerebrospinal anti-measles antibody titers.

RESULTS

The study included 112 cases of subacute sclerosing panencephalitis (mean age at onset: 8.9 ± 2.6 years). MRI analysis at the time of presentation revealed the following abnormalities: subcortical white matter signal changes (n = 95), periventricular white matter signal changes (n = 76), splenium of corpus callosum involvement (n = 39), diffuse corpus callosum involvement (n = 27), cerebral atrophy (n = 35), basal ganglia involvement (n = 10), and brain stem involvement (n = 2). Notably, subcortical white matter involvement, periventricular white matter involvement, diffuse corpus callosum involvement, and basal ganglia involvement were more prevalent in patients with stage III and IV subacute sclerosing panencephalitis (P < .05 for all). Cerebral atrophy was also significantly more common in patients with stage III compared to those with stage IV subacute sclerosing panencephalitis (P < .0001). However, no substantial positive or negative associations were found between MRI findings and EEG abnormalities, other sociodemographic/clinical variables, and cerebrospinal fluid measles-specific antibody titers (P > .05).

CONCLUSION

Early in the disease progression of subacute sclerosing panencephalitis, the temporoparietal and parietooccipital regions of the subcortical white matter are affected. Neuroimaging abnormalities exhibit a stronger association with Jabbour's clinical staging, but do not show significant associations with other clinical, sociodemographic, and EEG features.

Association between cytomegalovirus infection, reduced gray matter volume, and resting-state functional hypoconnectivity in major depressive disorder: a replication and extension

Human cytomegalovirus (HCMV) is a neurotropic herpes virus known to cause neuropathology in patients with impaired immunity. Previously, we reported a reduction in the gray matter volume (GMV) of several brain regions in two independent samples of participants who were seropositive for HCMV (HCMV+) compared to matched participants who were seronegative for HCMV (HCMV-). In addition to an independent replication of the GMV findings, this study aimed to examine whether HCMV+ was associated with differences in resting-state functional connectivity (rsfMRI-FC). After balancing on 11 clinical/demographic variables using inverse probability of treatment weighting (IPTW), GMV and rsfMRI-FC were obtained from 99 participants with major depressive disorder (MDD) who were classified into 42 HCMV+ and 57 HCMV- individuals. Relative to the HCMV- group, the HCMV+ group showed a significant reduction of GMV in nine cortical regions. Volume reduction in the right lateral orbitofrontal cortex (standardized beta coefficient (SBC) = -0.32, [95%CI, -0.62 to -0.02]) and the left pars orbitalis (SBC = -0.34, [95%CI, -0.63 to -0.05]) in the HCMV+ group was also observed in the previous study. Regardless of the parcellation method or analytical approach, relative to the HCMV- group, the HCMV+ group showed hypoconnectivity between the hubs of the sensorimotor network (bilateral postcentral gyrus) and the hubs of the salience network (bilateral insula) with effect sizes ranging from SBC = -0.57 to -0.99. These findings support the hypothesis that a positive HCMV serostatus is associated with altered connectivity of regions that are important for stress and affective processing and further supports a possible etiological role of HCMV in depression.

Subacute sclerosing panencephalitis (SSPE) the story of a vanishing disease

Subacute sclerosing panencephalitis (SSPE), is a devastating "slow virus" brain disease which affects young children who had measles some 6-7 years earlier. Although, the pandemic of SSPE during 1960-1980's was almost eradicated due to mass immunization, the disease is still taking the life of young children in countries where measles immunization is incomplete and in world regions where genetic polymorphism to this particular infection is present. The present review was written for the fortunate young generation of pediatricians and pediatric neurologists who probably have not seen a case of SSPE during their career, and for those who work in counties where the disease has not been eradicated. It is also a reminder that with full coverage of measles immunization this devastating disease can be fully eradicated.

Measles virus and associated central nervous system sequelae

Worldwide, measles remains one of the most deadly vaccine-preventable diseases. In the United States, enrollment in the public schools requires that each child receives 2 doses of measles-containing vaccine before entry, essentially eliminating this once endemic disease. Recent outbreaks of measles in the United States have been associated with importation of measles virus from other countries and subsequent transmission to intentionally undervaccinated children. The central nervous system complications of measles can occur within days or years of acute infection and are often severe. These include primary measles encephalitis, acute postinfectious measles encephalomyelitis, measles inclusion body encephalitis, and subacute sclerosing panencephalitis. These measles-associated central nervous system diseases differ in their pathogenesis and pathologic effects. However, all involve complex brain-virus-immune system interactions, and all can lead to severe and permanent brain injury. Despite better understanding of the clinical presentations and pathogenesis of these illnesses, effective treatments remain elusive.

Imaging of central nervous system viral diseases

Viral infections of the central nervous system (CNS) are commonly encountered and there has been continued emergence of new neurotropic viruses which are being frequently recognized. These may present clinically as encephalitis, meningitis, encephalomyelitis, and encephalomyeloradiculitis. The clinical manifestations are usually nonspecific and diagnosis is usually based on the laboratory investigations. Imaging plays a role in its early detection and at times suggests the specific diagnosis that may help in early institution of appropriate therapy. In this review, we summarize the pathology, clinical, and imaging features of the common viral infections that affect the CNS.

Correlation of quantitative diffusion tensor tractography with clinical grades of subacute sclerosing panencephalitis

BACKGROUND AND PURPOSE

SSPE is a persistent infection of the central nervous system caused by the measles virus. The correlation between the clinical staging and conventional MR imaging is usually poor. The purpose of this study was to determine whether tract-specific DTI measures in the major white mater tracts correlate with clinical grades as defined by the Jabbour classification for SSPE.

MATERIALS AND METHODS

Quantitative DTT was performed on 20 patients with SSPE (mean age, 9 years) and 14 age- and sex-matched controls. All patients were graded on the basis of the Jabbour classification into grade II (n=9), grade III (n=6), and grade IV (n=5) SSPE. The major white matter tracts quantified included the CC, SLF, ILF, CST, CNG, SCP, MCP, ICP, ATR, STR, and PTR.

RESULTS

Although a successive decrease in mean FA values was observed in all the fiber tracts except for the SCP and ICP, moving from controls to grade IV, a significant inverse correlation between clinical grade and mean FA values was observed only in the splenium (r=-0.908, P<.001), CST (r=-0.663, P=.013), SLF (r=-0.533, P=.050), ILF (r=-0.776, P=.001), STR (r=-0.538, P=.047), and PTR (r=-0.686, P=.035) fibers. No significant correlation of mean MD values from these white matter tracts was observed with clinical grades of the disease.

CONCLUSIONS

We conclude that the grade of encephalopathy correlates inversely with the tract-specific mean FA values. This information may be valuable in studying the disease progression with time and in assessing the therapeutic response in the future.