Comparison of brain MRI findings between microcephalic and normocephalic infants with congenital Zika syndrome
| MRI Findings | Microcephaly | Without Microcephaly (n = 3) | P1 | P2 | P3 | P4 | |
|---|---|---|---|---|---|---|---|
| At Birth (n = 9) | Postnatally (n = 7) | ||||||
| Reduced brain volume | 8 (88.9%) | 5 (71.4%) | 0 (0.0%) | .018a | .550 | .141 | .021a |
| Brain stem hypoplasia | 6 (66.7%) | 1 (14.3%) | 0 (0.0%) | .182 | .060 | .020a | .263 |
| Cerebellum hypoplasia | 3 (33.3%) | 0 (0.0%) | 0 (0.0%) | .509 | .213 | .087 | 1.000 |
| Malformations of cortical developmentb | |||||||
| Simplified gyral pattern | 6 (66.7%) | 0 (0.0%) | 0 (0.0%) | .182 | .028a | .009a | .515 |
| Pachygyria | 6 (66.7%) | 4 (66.7%) | 0 (0.0%) | .182 | 1.000 | .637 | .069 |
| Polymicrogyria | 0 (0.0%) | 4 (66.7%) | 2 (66.7%) | .045a | .011a | .009a | .245 |
| Normal cortex | 1 (11.1%) | 0 (0.0%) | 1 (33.3%) | .455 | 1.000 | 1.000 | .314 |
| Brain calcifications | |||||||
| Cortico-subcortical white matter junction | 8 (88.9%) | 7 (100.0%) | 3 (100.0%) | 1.000 | 1.000 | .474 | 1.000 |
| Calcifications at other sites | 7 (77.8%) | 0 (0.0%) | 0 (0.0%) | .046a | .003a | .001a | .263 |
| Basal ganglia | 4 (44.4%) | 0 (0.0%) | 0 (0.0%) | .491 | .103 | .082 | 1.000 |
| Thalamus | 3 (33.3%) | 0 (0.0%) | 0 (0.0%) | .509 | .229 | .206 | 1.000 |
| Periventricular | 3 (33.3%) | 0 (0.0%) | 0 (0.0%) | .509 | .229 | .206 | 1.000 |
| Brain stem | 4 (44.4%) | 0 (0.0%) | 0 (0.0%) | .491 | .103 | .082 | 1.000 |
| Cerebellum | 2 (22.2%) | 0 (0.0%) | 0 (0.0%) | 1.000 | .475 | .471 | 1.000 |
| Corpus callosum abnormalities | 9 (100.0%) | 2 (28.6%) | 0 (0.0%) | .005a | .005a | .001a | .058 |
| Moderate-to-severe ventriculomegaly | 8 (88.9%) | 2 (28.6%) | 0 (0.0%) | .018a | .035a | .005a | .087 |
| Enlarged extra-axial CSF space | 9 (100.0%) | 3 (42.9%) | 0 (0.0%) | .005a | .019a | .003a | .036a |
| Enlarged cisterna magna | 9 (100.0%) | 4 (57.1%) | 0 (0.0%) | .005a | .063 | .008a | .021a |
| Delayed myelinationb | 7 (77.8%) | 2 (33.3%) | 2 (66.7%) | 1.000 | .136 | .335 | 1.000 |
| Symmetry of abnormalities | 8 (88.9%) | 3 (42.9%) | 1 (33.3%) | .127 | .106 | .057 | .523 |
Note:—P indicates Fisher exact test; P1, microcephaly at birth vs without microcephaly; P2, microcephaly at birth vs microcephaly postnatally; P3, microcephaly at birth vs without microcephaly at birth (microcephaly postnatally + without microcephaly); P4, microcephaly (microcephaly at birth + microcephaly postnatally) vs without microcephaly. Microcephaly postnatally vs without microcephaly yielded no statistically significant results.
↵a Statistically significant results.
↵b Not assessed in Infant 14 (without MRI). For myelination assessment, infant 15 was considered born at term.