Predictivity of plasma prolactin levels in differentiating epilepsy from pseudoseizures: a prospective study

Evidence-Based Practice for the Clinical Assessment of Psychogenic Nonepileptic Seizures: A Report From the American Neuropsychiatric Association Committee on Research

The American Neuropsychiatric Association's Committee on Research assigned the task of defining the most helpful clinical factors and tests in establishing the diagnosis of psychogenic nonepileptic seizures (PNES) during a neuropsychiatric assessment. A systematic review of the literature was conducted using three search engines and specified search terms for PNES and the predetermined clinical factors and diagnostic tests, followed by a selection process with specific criteria. Data extraction results from selected articles are presented for clinical factors (semiology, psychiatric comorbidities, medical comorbidities, psychological traits) and diagnostic tests (EEG, psychometric and neuropsychological measures, prolactin level, clinical neuroimaging, autonomic testing). Semiology with video EEG (vEEG) remains the most valuable tool to determine the diagnosis of PNES. With the exception of semiology, very few studies revealed the predictive value of a clinical factor for PNES, and such findings were isolated and not replicated in most cases. Induction techniques, especially when coupled with vEEG, can lead to a captured event, which then confirms the diagnosis. In the absence of a captured event, postevent prolactin level and personality assessment can support the diagnosis but need to be carefully contextualized with other clinical factors. A comprehensive clinical assessment in patients with suspected PNES can identify several clinical factors and may include a number of tests that can support the diagnosis of PNES. This is especially relevant when the gold standard of a captured event with typical semiology on vEEG cannot be obtained.

Serum GFAP level: A novel adjunctive diagnostic test in differentiate epileptic seizures from psychogenic attacks

PURPOSE

There has been increasing interest in the use of different biomarkers to help distinguish psychogenic from epileptic seizures, in patients presenting acutely with seizure-like events. In the present study, we measured serum glial fibrillary astrocytic protein (GFAP) levels in patients presenting with such events who were subsequently diagnosed as epileptic seizures (ESs) or psychogenic non-epileptic seizures (PNESs) and compared GFAP levels obtained with those found in healthy subjects.

METHODS

Sixty-three patients with seizures (43 with ES and 20 with PNES), and 19 healthy subjects participated in the study. Venous blood samples were obtained within the first 6 h after seizures and serum GFAP levels were measured by protein quantification (ELIZA kit) with an electrochemical luminescence immunoassay.

RESULTS

Serum GFAP levels were significantly higher in patients with ES compared to PNES or healthy controls. A cut-off point of 2.71 ng/ml was found optimally to differentiate ES from PNES (sensitivity 72%, specificity 59%).

CONCLUSION

Our study suggests that post-seizure serum GFAP levels could be used in future studies better to understand the underlying mechanism of seizures and may offer as an adjunctive diagnostic test in differentiating ES from PNES.

Recognizing Syncope: Pitfalls and Surprises

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 which may render the distinction from epileptic seizures difficult. Differential diagnosis is based on the specific features and not the mere presence of these phenomena. Recognition of syncope depends also on accurate information about precipitants, premonitory symptoms and postictal events: the absence of postictal confusion has been identified as the single most powerful factor discriminating syncope from epileptic seizures whereas incontinence and head injury are common in both conditions. Investigations such as electroencephalogram, tilt testing and postictal prolactin or creatine kinase levels may be helpful but are never diagnostic in isolation. Exceptionally, hypoxic and epileptic mechanisms interact within a single attack.

Biomarkers in the diagnosis and study of psychogenic nonepileptic seizures: A systematic review

OBJECTIVE

Video electroencephalography (vEEG) is the gold-standard method for diagnosing psychogenic nonepileptic seizures (PNES), but such assessment is expensive, unavailable in many centers, requires prolonged hospitalization, and many times is unable to capture an actual seizure episode. This paper systematically reviews other non-vEEG candidate biomarkers that may facilitate both diagnosis and study of PNES as differentiated from epileptic seizures (ES).

METHODS

PubMed database was searched to identify articles between 1980 and 2015 (inclusion: adult PNES population with or without controls, English language; exclusion: review articles, meta-analyses, single case reports).

RESULTS

A total of 49 studies were examined, including neuroimaging, autonomic nervous system, prolactin, other (non-prolactin) hormonal, enzyme, and miscellaneous marker studies. Functional MRI studies have shown PNES is hyperlinked with dissociation and emotional dysregulation centers in the brain, although conflicting findings are seen across studies and none used psychiatric comparators. Heart rate variability suggests increased vagal tone in PNES when compared to ES. Prolactin is elevated in ES but not PNES, although shows low diagnostic sensitivity. Postictal cortisol and creatine kinase are nonspecific. Other miscellaneous biomarkers (neuron specific enolase, brain derived neurotropic factor, ghrelin, leptin, leukocytosis) showed no conclusive evidence of utility. Many studies are limited by lack of psychiatric comparators, size, and other methodological issues.

CONCLUSION

No single biomarker successfully differentiates PNES from ES; in fact, PNES is only diagnosed via the negation of ES. Clinical assessment and rigorous investigation of psychosocial variables specific to PNES remain critical, and subtyping of PNES is warranted. Future investigational and clinical imperatives are discussed.

Biomarker identification in psychiatric disorders: from neuroscience to clinical practice

Patients with psychiatric disorders exhibit several neurobehavioral and neuropsychological alterations compared to healthy controls. However, signature endpoints of these behavioral manifestations have not yet been translated into clinical tests for diagnosis and follow-up measures. Recently, neuroproteomic approaches have been utilized to identify unique signature markers indicative of these disorders. Development of reliable biomarkers has the potential to revolutionize the diagnosis, classification, and monitoring of clinical responses in psychiatric diseases. However, the lack of biological gold standards, the evolving nosology of psychiatric disorders, and the complexity of the nervous system are among the major challenges that have hindered efforts to develop reliable biomarkers in the field of neuropsychiatry and drug abuse. While biomarkers currently have a limited role in the area of neuropsychiatry, several promising biomarkers have been proposed in conditions such as dementia, schizophrenia, depression, suicide, and addiction. One of the primary objectives of this review is to discuss the role of proteomics in the development of biomarkers specific to neuropsychiatry. We discuss and evaluate currently available biomarkers as well as those that are under research for clinical use in the future.

TIDAL WAVES: Network mechanisms in the neuroendocrine control of prolactin release

Neuroendocrine tuberoinfundibular dopamine (TIDA) neurons tonically inhibit pituitary release of the hormone, prolactin. Through the powerful actions of prolactin in promoting lactation and maternal behaviour while suppressing sexual drive and fertility, TIDA neurons play a key role in reproduction. We summarize insights from recent in vitro studies into the membrane properties and network behaviour of TIDA neurons including the observations that TIDA neurons exhibit a robust oscillation that is synchronized between cells and depends on intact gap junction communication. Comparisons are made with phasic firing patterns in other neuronal populations. Modulators involved in the control of lactation - including serotonin, thyrotropin-releasing hormone and prolactin itself - have been shown to change the electrical behaviour of TIDA cells. We propose that TIDA discharge mode may play a central role in tuning the amount of dopamine delivered to the pituitary and hence circulating prolactin concentrations in different reproductive states and pathological conditions.

Indicators for elevated risk factors for alcohol-withdrawal seizures: an analysis using a random forest algorithm

Alcohol-withdrawal seizures (AWS) are an important and relevant complication during detoxification in alcohol-dependent patients. Therefore, it is important to evaluate the individual risk for AWS. We apply a random forest algorithm to assess possible predictive markers in a large sample of 200 alcohol-dependent patients undergoing alcohol withdrawal. This analysis showed that the combination of homocysteine, prolactin, blood alcohol concentration on admission, number of preceding withdrawals, age and the number of cigarettes smoked may successfully predict AWS. In conclusion, the results of this analysis allow for origination of further research, which should include additional biological and psychosocial parameters as well as consumption behaviour.

Audio-induced psychogenic non-epileptic seizures

A 45-year-old woman presented with vague attacks, which consisted of headaches, confusion and sleepiness. An electroencephalograph was normal, but subsequent scans revealed the presence of a right-sided convexity meningioma. This was excised and complications led to the removal of an infected bone flap in a separate procedure the following year. Various types of 'seizures' resulted from the operation. These were described to involve both tonic-clonic and absence seizures. This continued for 18 years, unaffected by medication, until a specialist diagnosed pseudo-epilepsy, by fortune of a hospital fire alarm. The patient began a psychological intervention programme including cognitive-behavioural therapy, which has significantly reduced episodes. In conclusion, psychogenic non-epileptic seizures may develop after intracranial neurosurgery undertaken for indications other than the control of refractory epileptic seizures. A diagnosis of psychogenic non-epileptic seizures should be considered in patients who develop refractory seizures after neurosurgery and managed appropriately.

Psychogenic nonepileptic seizures: answers and questions

Psychogenic nonepileptic seizures (PNES) superficially resemble epileptic seizures, but are not associated with ictal electrical discharges in the brain. PNES constitute one of the most important differential diagnoses of epilepsy. However, despite the fact they have been recognized as a distinctive clinical phenomenon for centuries and that access to video/EEG monitoring has allowed clinicians to make near-certain diagnoses for several decades, our understanding of the etiology, underlying mental processes, and, subsequently, subdifferentiation, nosology, and treatment remains seriously deficient. Emphasizing the clinical picture throughout, the first part of this article is intended to "look and look again" at what we know about the epidemiology, semiology, clinical context, treatment, and prognosis of PNES. The second part is dedicated to the questions that remain to be answered. It argues that the most important reason our understanding of PNES remains limited is the focus on the visible manifestations of PNES or the seizures themselves. In contrast, subjective seizure manifestations and the biographic or clinical context in which they occur have been relatively neglected.

Elevated prolactin serum levels and history of alcohol withdrawal seizures

BACKGROUND

Prolactin has been discussed to be useful for differential diagnosis in epilepsia. Aim of the present study was to investigate the association between prolactin serum levels and previous alcohol withdrawal seizures.

METHODS

We assessed 118 male patients admitted for detoxification treatment. Previous withdrawal seizures were recorded and prolactin serum levels were measured using an enzymatic immunoassay.

RESULTS

Patients with a history of alcohol withdrawal seizures had significantly higher prolactin levels (17.8 ng/ml, SD=12.1) than patients without previous seizures (13.0 ng/ml, SD=8.1, p<0.05). Logistic regression revealed significant predictive qualities for prolactin serum levels (B=0.05, Wald=5.30, p=0.021, OR=1.06, 95%CI=1.01-1.11).

CONCLUSIONS

The present findings show an association between elevated prolactin serum levels and a history of withdrawal seizures. Hence, the results suggest that prolactin elevation at admission may be a clinical marker for an increased risk of withdrawal seizures.

Biological markers to predict previous alcohol withdrawal seizures: a risk assessment

Recent studies have shown that both, elevated homocysteine and prolactin plasma levels are associated with a higher risk of alcohol withdrawal seizures. The aim of this study was to evaluate the predictive qualities of a combined assessment of homocysteine and prolactin for previous alcohol withdrawal seizures. Therefore, 117 male patients suffering from alcohol dependency were included into the study. Homocysteine was measured directly at admission, prolactin the morning following admission for detoxification treatment. Pearson's chi(2)-test showed significant results for the combined assessment of both parameters (chi(2) = 14.71, p = 0.001). Multivariate logistic regression also revealed significant predictive qualities (p = 0.001, OR = 9.23, 95%CI = 2.36-36.05). A combination of both, homocysteine and prolactin, may help to assess the individual risk of alcohol withdrawal seizures in clinical practice.

Post-traumatic epilepsy: an overview

Post-traumatic epilepsy (PTE) is a recurrent seizure disorder secondary to brain injury following head trauma. PTE is not a homogeneous condition and can appear several years after the head injury. The mechanism by which trauma to the brain tissue leads to recurrent seizures is unknown. Cortical lesions seem important in the genesis of the epileptic activity, and early seizures are likely to have a different pathogenesis than late seizures. Anti-epileptic drugs available for treatment are phenytoin, sodium valproate, and carbamazepine. Newer anti-epileptics are helpful, particularly in patients with associated post-traumatic stress disorders; however, no randomized controlled studies are available to prove that one of these drugs is better than the other. Current evidence is that the treatment of early post-traumatic seizures does not influence the incidence of post-traumatic epilepsy. Routine preventive anticonvulsants are not indicated for patients with head injuries, and treatment in the acute phase does not reduce death or disability rates.

Sensitivity and specificity of procedures for the differential diagnosis of epileptic and non-epileptic seizures: a systematic review

OBJECTIVES

Non-epileptic seizures (NES) present a considerable challenge in clinical practice. This paper reviews published evidence for the reliability of a number of procedures for the differential diagnosis of NES and epilepsy.

METHODS

Papers identified from MEDLINE and PsychInfo Databases (1980-2001) and additional hand searches were independently reviewed using methods for evaluating evidence in systematic reviews [Liddle, J., Williamson, M. Irwig, L. Method for evaluating research guideline evidence. New South Wales Department of Health; 1996 [State Health publication no. (CEB) 96-204]; SIGN. An introduction to SIGN methodology for the development of evidence based clinical guidelines. Scottish Intercollegiate Network; 1999]. Included studies had to have an NES group and a control group of people with epilepsy (each n> or =10), allocated using EEG linked video-recording of concurrent behaviour, and sensitivity and specificity values had to be stated or be calculable.

RESULTS

Thirty-three papers were identified, of which 13 satisfied criteria. Excluded studies are briefly described. Those retained comprised a range of procedures [seizure induction, MMPI assessment, physiological assessment (prolactin, SPECT), pre-ictal pseudosleep, and ictal/post-ictal characteristics]. No procedure emerged with both high sensitivity and specificity and adequately replicated findings, although high levels of specificity were more commonly reported than high levels of sensitivity. This suggests that procedures were generally better at excluding a possible diagnosis.

CONCLUSIONS

No procedure attains reliability equivalent to EEG video-telemetry. Further rigorous evaluation, using standardised and replicable methodologies, is required. The range of symptoms presented in NES suggests that a multi-method approach may be required. This too would require evaluation.

Value of serum prolactin in the management of syncope

OBJECTIVE

A meta-analysis of studies of the usefulness of raised serum prolactin in diagnosing generalised tonic-clonic seizures (GTCS) in patients presenting to the accident and emergency (A&E) department after a single episode of syncope.

METHODS

A three part question was defined. Medline, EMBASE, PubMed, the Cochrane Library were searched to identify relevant studies. Studies were evaluated for eligibility and quality and data extracted to calculate sensitivity (SN), specificity (SP), and likelihood ratios (LR).

RESULTS

Of 13 relevant studies only three met the criteria for evaluation. If a serum prolactin concentration is greater than three times the baseline when taken within one hour of syncope, then in the absence of test "modifiers": (1) the patient is nine times more likely to have suffered a GTCS as compared with a pseudoseizure positive LR = 8.92 (95% CI (1.31 to 60.91)), SN = 0.62 (95% CI (0.40 to 0.83)), SP = 0.89 (95% CI (0.60 to 0.98)) and (2) five times more likely to have suffered a GTCS as compared with non-convulsive syncope positive LR 4.60 (95% CI (1.25 to 16.90)), SN = 0.71 (95% CI (0.49 to 0.87)), SP = 0.85 (95% CI (0.55 to 0.98)).

CONCLUSION

A positive test result is highly predictive of a GTCS, however a negative test result does not necessarily exclude a seizure. Serum prolactin should be measured in patients presenting to the A&E department within an hour of a syncopal episode, unless the cause is immediately obvious.

Serum prolactin levels for differentiation of nonepileptic versus true seizures: limited utility

Frequently occurring nonepileptic psychogenic seizures (PNES) are a cause of substantial morbidity. Differentiation of these from true seizures may sometimes be very difficult. Serum prolactin level estimation following the event has been described as a useful test for this purpose. We conducted this study to assess the role of this test in diagnosis of PNES. Serum prolactin was estimated from venous blood samples of 19 patients (13 females, 6 males) with PNES and 17 patients (5 females, 12 males) with true complex partial seizures with or without secondary generalization. The age range was 12-39 years in the PNES group and 9-42 years in the true seizure group. Five patients (all females) in the PNES group (26.3%) had raised prolactin levels, all of them having greater than twice normal levels. In the true seizure group, 10 of 17 (58.8%) patients had raised levels; only 3 (17.6%) of these had greater than twice normal levels. The difference in percentage of patients with abnormal prolactin levels between these groups was not found to be significant. We demonstrate that serum prolactin level estimation is not a useful method for differentiation of psychogenic nonepileptic from true epileptic seizures.

Psychogenic nonepileptic seizures: review and update

The population incidence of psychogenic nonepileptic seizures (PNES) may be only 4% that of epilepsy, but many patients with PNES have a tendency to seek medical attention, and PNES make up a larger share of the workload of neurologists and emergency and general physicians. Although a great number of publications describe how PNES can be distinguished from epileptic seizures, it usually takes several years to arrive at this diagnosis, and three-quarters of patients (with no additional epilepsy) are treated with anticonvulsants initially. However, the management of PNES as epileptic seizures can lead to significant iatrogenic harm. Moreover, the failure to recognize the psychological cause of the disorder detracts from addressing associated psychopathology and enhances secondary somatization processes. This review provides an overview of studies of the diagnosis, etiology, treatment, and prognosis of PNES. Physicians should always consider PNES in the differential diagnosis of a seizure disorder. If a diagnosis of PNES is possible, or a diagnosis of epilepsy in doubt, a clear diagnostic categorization should be sought. This should involve the assessment of the patient by a physician versed in the diagnosis of seizure disorders and, in many cases, the documentation of a typical seizure by video-EEG. Outcome may be improved if the diagnosis is more actively sought, made earlier, and communicated more convincingly.

Diagnosis of sudden unexplained death in epilepsy by immunohistochemical staining for prolactin in cerebral vessels

Sudden unexplained death in epilepsy occurs when epilepsy patients die suddenly and unexpectedly in the absence of recent tonic-clonic seizure activity. There is currently no known reliable indicator of acutely lethal seizure activity. Clinical studies record a relationship between recent (within 10-40 minutes) seizure activity and elevated serum prolactin levels, and postictal elevation of prolactin within peripheral vessels has proved clinically useful in determining recent seizure activity. The authors hypothesized that elevated prolactin could be detected in cerebral vessels by immunohistochemical stains, serving as a marker for sudden unexplained death in epilepsy. They conducted a retrospective study of individuals who died in their jurisdiction during the 14 years from 1986 through 1999. The study contained one group of individuals who died of sudden unexplained death in epilepsy, a group with epilepsy who died of some other cause, and a control group whose members died rapidly of a gunshot wound of the torso. Sections of hippocampus and neocortex were obtained and stained with a polyclonal prolactin antibody. No significant difference in the level of immunostaining for prolactin in cerebral vessels was found between the experimental and control groups. A review of the protocols used indicates that revision of certain aspects may provide better immunostaining and more conclusive results.

The role of quantitative ictal SPECT analysis in the evaluation of nonepileptic seizures

Nonepileptic seizures may represent difficult diagnostic problems. Identifying their presence and frequency is critical for determining appropriate treatment. The authors investigated the value of quantitative perfusion changes as measured by ictal single-photon emission tomography (SPECT) difference images in differentiating nonepileptic from epileptic seizures. Eleven patients with a clinical suspicion of nonepileptic events had ictal and interictal technetium-99m hexamethylpropylene amine SPECT scans during continuous audiovisual surface electroencephalogram (EEG) monitoring. The authors analyzed perfusion difference images based on registration, normalization, and subtraction of ictal and interictal SPECT images. The difference images were registered to each patient's magnetic resonance imaging scan to anatomically localize ictal perfusion changes. Three of 11 patients also carried the diagnosis of epilepsy and were taking antiepileptic medication. Five patients were taking antiepileptic drugs, but the diagnosis of epilepsy was not confirmed. In all patients, continuous video EEG monitoring revealed no ictal EEG findings. In nine of these patients, visual interpretation of ictal SPECT was suggestive of localized increased (n = 6) or decreased perfusion (n = 3). In all patients, however, no blood flow changes were noted on quantitative SPECT analysis with injections performed during the seizure-like event, suggesting the diagnosis of pseudoseizures. The authors' results suggest that quantitative ictal SPECT analysis is a useful tool in the diagnosis of nonepileptic seizures.

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.

Pseudoseizure "status"

Psychogenic pain, disturbances of gait and stance, sensory symptoms, dizziness, and psychogenic seizures have been found to be the most common conversion symptoms in neurology clinics. A retrospective analysis of 18 patients suffering from pseudoseizure "status" is presented in this study. All of the patients fulfilled the DSM-III-R criteria of conversion disorder. However, 5 of them had concomitant major depression, 6 suffered from bulimia nervosa, and 7 met the criteria for substance abuse. On Axis II, 10 cases of borderline personality disorder, 2 cases of antisocial personality disorder, and 3 cases of histrionic personality disorder were diagnosed. The majority of the patients had attempted suicide and other forms of self-destructive behavior. The findings suggest that patients with pseudoseizure "status" suffer from severe affective imbalances and disturbed impulse control.

Pseudoseizures and dissociative disorders: a common mechanism involving traumatic experiences

Patients with psychogenic non-epileptic seizures (pseudoseizures) have been diagnosed as having conversion disorder or dissociative disorder. Pseudoseizure patients frequently report a history of physical and sexual abuse, and traumatic experience is considered part of the mechanism for producing dissociation. Pseudoseizures may be a manifestation of dissociative disorder, especially when a history of sexual or physical abuse is documented. A common mechanism involving traumatic experience may be present in both pseudoseizures and dissociative disorders. A complete neurodiagnostic evaluation along with an awareness of this relationship is needed to provide appropriate care for this patient population.

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.

Epilepsy and prolactin in adults: a clinical review

Serum levels of prolactin may increase as a consequence of epileptic seizures. The hormone release is caused by the propagation of epileptic activity, usually from the temporal lobe to the hypothalamic-pituitary axis. Due to the intensity of the epileptic afterdischarge, a rise is seen in approximately 60% of complex partial seizures. Prolactin usually fails to rise after psychogenic seizures, therefore, postictal prolactin levels can be used to differentiate between epileptic and psychogenic seizures. However, a subclassification of epileptic seizures by means of prolactin measurement is not possible. In repetitive seizures, prolactin may show a decrease in its postictal release. This is more common in status epilepticus, probably as a result of a diminished propagation of ictal activity during the course of status epilepticus. The influence of chronic epileptic discharges and anticonvulsant medication on prolactin release is moderate.

Serum prolactin levels and neonatal seizures

To assess the effects of neonatal seizures on the hypothalamus and to test clinical use of prolactin as a neonatal seizure marker, we studied postictal and recovery baseline serum prolactin levels in 19 neonates whose seizures were classified according to their clinical and EEG features. Postictal prolactin levels were obtained 30 min after the seizure, and recovery levels were ascertained 2-4 days later. The ratio of postictal prolactin level to recovery baseline level (prolactin ratio) was used as an indicator of postictal prolactin increase. The specificity and sensitivity of a prolactin ratio of > 2 was compared with the current standard of diagnosis (seizure discharges recorded by ictal EEG). Infants with electroclinical seizures had significantly higher prolactin ratios than control infants or infants with seizures without EEG correlation. Marked prolactin increases were noted only in infants with focal tonic seizures and temporal electrode involvement. A prolactin ratio of > 2 had a specificity of 100% and a sensitivity of 40%. We conclude that neonatal seizures have variable effects on the hypothalamus and that the low sensitivity and the need to await recovery levels limit the clinical value of prolactin ratio as a neonatal seizure marker.