A Characterization of the Neurologic Manifestations in Zika Virus Infection

Neurologic manifestations associated with the Zika virus (ZIKV) encompass a large group of clinical neurologic manifestations, and a modified Rankin scale (mRS) score may help identify the risk for mechanical ventilation in certain patients with the virus, according to study results published in Neurology.

Patients from the University Hospitals of Guadeloupe and Martinique with a documented ZIKV infection and recent neurologic manifestations were included in the observational study (n=87). Only patients who presented during the French West Indies 2016 outbreak (January 6, 2016 to September 13, 2016) were included in the study. Following standardized neurologic examinations, patients were classified as having disease involving only the peripheral nervous system (PNS), only the central nervous system (CNS), or both (mixed disorders). An electromyogram was used in patients with clinical evidence of PNS involvement.

Hospitalization was required in 95% of cases, with Guillain-Barre ́ syndrome representing the most frequent manifestation in the cohort (46.0%). Other manifestations observed included encephalitis or encephalomyelitis (20.7%), isolated single or multiple cranial nerve palsies (9.2%), other peripheral manifestations (6.9%), and stroke (1.1%).

Approximately 16% of patients (n=14) developed a mixed disorder that involved the CNS and PNS. In 21 cases, mechanical ventilation was required. An mRS of 4 to 5 was associated with an increased risk for mechanical ventilation in the overall cohort (hazard ratio [HR], 6.25; 95% CI, 1.77–22.10; P =.004), as well as in patients with Guillain-Barre ́ syndrome (HR, 9.63; 95% CI, 1.26–73.73; P =.029).

In 76 patients with a median 14-month follow-up (interquartile range, 13 to 17 months), the researchers observed a residual disability in 25.0% of patients (n=17) as demonstrated by an mRS score  ≥2. Disability was considered severe in 7.9% of patients (n=6), based on an mRS score ≥4. There was a higher risk for either residual disability or death in patients with ZIKV RNA detected in one biologic fluid (odds ratio, 9.19; 95% CI, 1.12-75.22; P =.039).

Study limitations included the hospital-based sample, as well as the strict selection criteria leading to a small number of patients in the cohort.

“During an epidemic or in endemic regions,” the researchers wrote in response to their findings, “ZIKV testing in urine, plasma, and CSF [cerebrospinal fluid] should be considered in the diagnostic workup of peripheral, CNS and PNS, acute or subacute neurologic manifestations in both adults and children, including those with facial or multiple cranial nerve palsies.”

Reference

Lannuzel A, Fergé JL, Lobjois Q, et al. Long-term outcome in neuroZika: When biological diagnosis matters. Neurology. 2019;92(21):e2406-e2420.