ABSTRACT
Researches on more economical and practical methods for the differential diagnosis of seizures are required. Prolactin is the most specific neurohormone that is elevated after seizures in adults and children. The possibility that serum prolactin could be used as an epileptic marker in neonates is attractive because an ictal EEG recording is not always available. Therefore, this study aimed at determination of the clinical usefulness of serum prolactin as a diagnostic aid in neonatal convulsions and its relation to etiology, type and duration of seizures. The present study was conducted on 35 term neonates with neonatal convulsions [patients group] recruited from the NICU of Obstetric and Gynecology Department, Ain Shams University. Their mean birth weight was 3.45 +/- 0.42 kg and their mean gestational age was 38.63 +/- 1.29 weeks. Thirty-five healthy neonates were chosen to serve as a control group. Each neonate in the patients group had at least one clinically observed seizure. Seizures were diagnosed clinically and EEG confirmation was not required. Postictal serum prolactin levels were obtained at 30 minutes, 24 hours and 72 hours [recovery level] after the seizures using ELISA technique. The ratio of 30 minutes postictal prolactin level to recovery level [prolactin ratio] was used as an indicator of postictal prolactin increase. The results of the current study showed that etiologic diagnoses included were hypoxic-ischemic encephalopathy [HIE] [40%] followed by neonatal sepsis [31.4%], intracranial hemorrhage [ICH] [14%], hypoglycemia [8.6%] and hypocalcemia [6%]. Serum prolactin level was significantly higher [P<0.01] at 30 minutes postictally in the patients with seizures than in control group and this value started to decline after 24 hours and became insignificant at 72 hours postictally. Additionally, postictal serum prolactin levels were significantly higher in tonic and clonic convulsions and in seizures due to hypoxia as compared to controls. Moreover, 24 hours postictal serum prolactin level was significantly higher than 30 minutes postictal level in both tonic and myoclonic convulsions. Postictal serum prolactin levels correlated negatively with Apgar score at 5 minutes and the mean prolactin ratio in the patients group was 2.41 +/- 1.80 denoting a marked postictal prolactin elevation. In conclusion, postictal serum prolactin levels increased significantly during the 24 hours following seizures in neonatal seizures especially with tonic and clonic types and mostly due to hypoxia. Therefore, postictal serum prolactin level may be helpful in the differentiation of seizures as well as providing important information about their etiology particularly when continuous EEG monitoring is not possible. In addition, prolactin ratios may be used to assess more accurately the phenomenon of postictal hyperprolactinemia