Increases in serum prolactin levels associated with syncopal attacks

Clinical utility of serum prolactin and lactate concentrations to differentiate epileptic seizures from non-epileptic attacks in the emergency room

PURPOSE

To evaluate the diagnostic utility of serum prolactin (PRL) and lactate (LAC) concentrations for patients presenting with either or both convulsions and transient loss of consciousness (TLOC) in the emergency room (ER).

METHODS

This was a retrospective single-center study conducted in a tertiary care hospital ER. Medical records of consecutive patients who presented with convulsions or TLOC between January 2018 and December 2020 were reviewed. Patients with an ER diagnosis of epileptic seizures, psychogenic non-epileptic seizure (PNES), and syncope were selected for analysis. Serum PRL and LAC concentrations were measured within 3 h of the event and compared between groups.

RESULTS

Among the 440 eligible patients, 173 (39.3%) were included for analysis. Serum PRL concentration was significantly higher in patients with epileptic seizures with convulsions than in those with PNES with convulsions (p < 0.001) and convulsive syncope (p = 0.023). Serum LAC concentration was not significantly elevated in patients with convulsive syncope. Using a PRL cut-off value of 24.0 ng/mL, serum PRL concentration had 100.0% sensitivity and 82.9% specificity for differentiating between PNES and other attacks without convulsions.

CONCLUSION

Elevated serum PRL with normal serum LAC concentration in patients who have attacks with convulsions suggests convulsive syncope. Serum PRL concentration is useful in the diagnosis of PNES with convulsions. However, serum LAC concentration is not useful as a routine screening test for attacks without convulsions in the ER.

Serum prolactin levels after seizure and syncopal attacks

Loss of consciousness and falling are the key features of syncope. Common accompaniments include tonic and myoclonic muscle activity, eye deviations, automatisms, vocalizations and hallucinations that may render the distinction from epileptic seizures difficult. The frequently increased levels of serum prolactin (SPRL) were observed immediately after generalized and complex partial seizures. Presumably, the hormone release is caused by the propagation of epileptic activity, usually from the temporal lobe to the hypothalamic pituitary axis. Numerous reports have demonstrated that the post-ictal SPRL level may be used to differentiate between epileptic and syncopal, non-epileptic attacks. In order to confirm the hypothesis, the SPRL levels were measured in patients with complex partial seizures (CPS) and patients with vaso-vagal syncopal attacks (VVS). The SPRL levels were prospectively measured for each patient as soon as possible after the event (within 1 hour), then 1 hour after the first determination and finally blood was sampled 24 hours later. During the study period (18 months), 18 patients with CPS and 15 patients with VVS were investigated in total. The mean values of SPRL levels in both groups were increased immediately after the event (CPS group: 1142 +/- 305 mIU/l; VVS group: 874 +/- 208 mIU/l). The elevated SPRL levels were found in 14 (78%) patients immediately after CPS and in 9 (60%) patients immediately after VVS. After examining the results of the present study we conclude that the elevated serum prolactin level after an epileptic attack is of no significant value in differential diagnosis between epileptic and vaso-vagal syncopal attacks.

Using age-appropriate prolactin levels to diagnose children with seizures in the emergency department

OBJECTIVE

To assess the utility of serum and cerebrospinal fluid (CSF) prolactin levels for identifying children who have experienced seizures.

METHODS

A prospective cohort study was performed in a pediatric ED at an urban children's hospital. A convenience sample of children underwent blood and CSF analyses in the ED over a 2-year period.

RESULTS

Thirty-five children (aged 3 months-15 years) with generalized tonic-clonic seizures and 48 ill control patients were studied. Both groups included febrile and afebrile patients. The patient characteristics in the seizure and control groups were similar with respect to age, fever, current medications, and blood, urine, and CSF cultures. When serum prolactin levels were assigned age-adjusted dichotomous values of "elevated" or "normal," the rates of elevation between the seizure and control patients were different (p < 0.001). The positive and negative predictive values of these age-adjusted levels were 68% (95% CI 47-85%) and 76% (95% CI 61-87%), respectively. The mean CSF prolactin levels of the seizure and control groups were not significantly different. In addition, there was no single threshold CSF prolactin level that could delineate seizure patients from control patients.

CONCLUSIONS

Age-adjusted serum prolactin levels are useful only as an adjunct in the prospective evaluation of the individual pediatric patient for epileptic seizure activity. CSF prolactin levels are not useful in the diagnosis of generalized seizures in children in the acute care setting.

Potential role of serum prolactin measurement in the diagnosis of late posttraumatic seizures. A case report

Posttraumatic seizures are an important medical complication after traumatic brain injury. However, the diverse clinical presentation of posttraumatic seizures, combined with the cognitive and behavior deficits frequently seen in this patient population, can make the diagnosis of posttraumatic seizures particularly challenging. Electroencephalography and imaging studies are often abnormal and nonspecific. It has been reported that serum prolactin levels frequently rise after epileptic seizures. This case report describes the use of prolactin measurement to confirm two suspected posttraumatic seizure episodes in a 42-yr-old male with severe traumatic brain injury. Each episode lasted less than 1 min and involved conspicuously altered postural tone and respiratory pattern, followed by a change in verbal and motor responsiveness. No rhythmic extremity movements were observed. Diagnostic evaluation included electroencephalography and imaging studies, which demonstrated nonspecific abnormalities. Serum prolactin levels obtained within 20 to 40 min were markedly elevated and two to three times greater than the baseline level. The use of prolactin levels in the diagnosis of posttraumatic seizures is reviewed, accompanied by discussion of pertinent aspects of normal and abnormal states of prolactin secretion and regulation.