BACKGROUND AND PURPOSE:Although microcephaly is the most prominent feature of congenital Zika syndrome, a spectrum with less severe cases is starting to be recognized. Our aim was to review neuroimaging of infants to detect cases without microcephaly and compare them with those with microcephaly.

Background Congenital arthrogryposis (CA) consists of congenital joint contractures that affect at least two joints in different parts of the body. Approximately, 80% of CA cases are neurogenic, with changes to the formation, structure or functioning of the central and/or peripheral nervous systems. Most abnormalities are triggered either by motoneurons decreased activation in the corticospinal tract or by direct motoneurons injury. There had been few reports in the literature correlating congenital infection in humans with arthrogryposis until 2015. CA has recently been described associated with congenital Zika syndrome (CZS). Methods The objective of this study was to investigate and describe accurately the arthrogrypotic alterations in infants diagnosed with CZS and thus, suggest a possible pattern of orthopedic impairment. A total of 198 medical records of infants with CZS were evaluated. According to inclusion and exclusion criteria, 17 infants were included in the present study. Arthrogrypotic joints were orthopedically evaluated in four segments: right, left, upper, and lower limbs. All the four segments were assessed independently. Results Flexed wrists were the most frequently observed manifestation, associated with ulnar deviation (35.29%). Deformities were also commonly found in the third and fourth fingers (64.70%). Hip dislocation was found in 58.82% of the patients and talipes equinovarus and equinovalgus ankles were found in 29.41 and 23.52%. Conclusion There was a particular pattern of joint impairment related to CZS and arthogrypotic alterations of infants evaluated in this study.

Introduction:Congenital Zika virus syndrome is a distinct pattern of birth defects in fetuses infected by the Zika virus. It presents a broad clinical spectrum that includes occurrences of microcephaly, hypertonia, dysphagia, hyperexcitability, seizures, and arthrogryposis. Imaging findings show neuronal migration disorders.Methodology:Case reports have suggested that arthrogryposis has a neurogenic cause. We analyzed needle electromyography and nerve conduction examinations on 77 patients aged 2–24 months presenting highly probable congenital Zika virus syndrome, with or without arthrogryposis.Results:All those with arthrogryposis presented with chronic muscle denervation in the electromyography examination. Similarly, children with single or reversible joint abnormalities at birth showed the same findings. Denervation in the paravertebral musculature was found in all of the children with diaphragmatic paralysis or thoracic deformities.Conclusions:We propose that congenital contractures associated with congenital Zika virus syndrome are caused by the malformation of upper and lower motor neurons during embryogenesis.