Detection of Neurological Manifestations Among Neonates With Sepsis

Neonatal sepsis remains a major global health problem and a leading cause of neonatal morbidity and mortality. Globally, an estimated 1.3-3.9 million cases occur annually, resulting in approximately 400,000-700,000 deaths each year. It is a life-threatening systemic inflammatory response to bacterial, viral, or fungal infections occurring during the first 28 days of life and may progress to multiorgan dysfunction and death.

Neonatal sepsis is classified into early-onset sepsis (EOS), occurring within the first 72 hours and usually related to vertical maternal transmission, and late-onset sepsis (LOS), occurring after 72 hours up to 28 days and commonly associated with postnatal or hospital-acquired infections.

Neonates are particularly susceptible to sepsis because of immature immune and barrier defenses. Neonatal polymorphonuclear leukocytes have impaired chemotaxis, adherence, and bactericidal activity. Humoral immunity depends largely on maternally derived IgG transferred during the last trimester, making preterm infants especially vulnerable due to reduced transplacental transfer. Immature skin and mucosal barriers further facilitate microbial invasion.

Sepsis results from a dysregulated systemic inflammatory response following failure to control the invading pathogen. Excessive release of cytokines such as IL-6 and TNF-α, together with vasoactive mediators including nitric oxide, prostaglandins, and leukotrienes, causes endothelial dysfunction, vasodilation, increased vascular permeability, hypotension, impaired tissue perfusion, and potentially multiorgan dysfunction.

The developing neonatal brain is particularly vulnerable to these systemic effects. Inflammatory and vasoactive mediators can disrupt the blood-brain barrier, while cerebral circulatory disturbances, endothelial injury, neurotransmitter dysregulation, and oxidative stress may contribute to central nervous system (CNS) injury. In addition, blood-brain barrier dysfunction may facilitate pathogen entry into the CNS, increasing the risk of meningitis and cerebral dysfunction. Systemic inflammation may also cause white matter injury through oligodendrocyte damage and impaired cerebral perfusion, particularly in preterm infants.

Neurological manifestations of neonatal sepsis may include altered consciousness, seizures, abnormal tone and reflexes, apnea, and feeding difficulties with risk of aspiration. Cohort studies, particularly in preterm infants, have also demonstrated an increased risk of adverse long-term neurodevelopmental outcomes following neonatal sepsis.