Postictal serum creatine kinase for the differential diagnosis of epileptic seizures and psychogenic non-epileptic seizures: a systematic review

Dissimilar Changes in Serum Cortisol after Epileptic and Psychogenic Non-Epileptic Seizures: A Promising Biomarker in the Differential Diagnosis of Paroxysmal Events?

The hypothalamic-pituitary-adrenal axis is known to be involved in the pathogenesis of epilepsy and psychiatric disorders. Epileptic seizures (ESs) and psychogenic non-epileptic seizures (PNESs) are frequently differentially misdiagnosed. This study aimed to evaluate changes in serum cortisol and prolactin levels after ESs and PNESs as possible differential diagnostic biomarkers. Patients over 18 years with ESs (n = 29) and PNESs with motor manifestations (n = 45), captured on video-EEG monitoring, were included. Serum cortisol and prolactin levels as well as hemograms were assessed in blood samples taken at admission, during the first hour after the seizure, and after 6, 12, and 24 h. Cortisol and prolactine response were evident in the ES group (but not the PNES group) as an acute significant increase within the first hour after seizure. The occurrence of seizures in patients with ESs and PNESs demonstrated different circadian patterns. ROC analysis confirmed the accuracy of discrimination between paroxysmal events based on cortisol response: the AUC equals 0.865, with a prediction accuracy at the cutoff point of 376.5 nmol/L 0.811 (sensitivity 86.7%, specificity 72.4%). Thus, assessments of acute serum cortisol response to a paroxysmal event may be regarded as a simple, fast, and minimally invasive laboratory test contributing to differential diagnosis of ESs and PNESs.

Brivaracetam-Associated Rhabdomyolysis Requiring Renal Replacement Therapy: A Case Report and Review of the Literature

Rhabdomyolysis is a rare adverse reaction that has a previously established association with levetiracetam use, which selectively binds the synaptic vesicle glycoprotein 2A (SV2A). Its structural analogue, brivaracetam, is a new third-generation antiseizure medication that has a higher affinity for SV2A, and current data suggests it provides a more favorable adverse event profile. Here, however, we report a case of rhabdomyolysis requiring dialysis in which serum creatine kinase level increased rapidly for several days until brivaracetam was discontinued. The delayed creatine kinase peak, rapid decline upon discontinuation of brivaracetam, and prior association of rhabdomyolysis with levetiracetam strongly suggest a causal relationship. To date, there are three reported cases of brivaracetam-associated rhabdomyolysis in the food and drugs administration adverse event reporting system (FAERS). Despite its favorable side effects profile, the use of brivaracetam may be associated with life-threatening rhabdomyolysis.

Peripheral inflammatory biomarkers as predictive tools for HyperCKemia risk assessment post-seizures

BACKGROUND

This study evaluates the potential of inflammatory biomarkers, especially the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), for early detection of hyperCKemia after seizures. Addressing the challenge of delayed hyperCKemia diagnosis, which can escalate to rhabdomyolysis, this research emphasizes the use of these accessible biomarkers.

METHODS

Conducted retrospectively, data from October 1, 2022, and October 1, 2023, were extracted from electronic medical records. Following univariate analysis (P-value < 0.05 for selection), Spearman's rank correlation and binary logistics regression were employed to examine the relationship between hyperCKemia and various clinical variables. Receiver operating characteristic curves (ROCs) defined the cut-off values for seizure-related hyperCKemia.

RESULTS

Among 98 seizure patients, 31 (31.63 %) developed hyperCKemia. Notable differences in leukocytes, neutrophils, CRP, and NLR levels were observed between hyperCKemia and normal CK groups (P < 0.05). Leukocytes, NLR, and CRP correlated with hyperCKemia, exhibiting odds ratios of 1.24 (95 % CI: 1.11-1.39, P < 0.001), 1.03 (95 % CI: 1.01-1.05, P = 0.001), and 1.22 (95 % CI: 1.09-1.35, P = 0.017). The optimal cut-off values were established as 9.78 × 10^9/L for leukocytes, 32.40 mg/L for CRP, and 7.35 for NLR.

CONCLUSION

Elevated levels of leukocytes, CRP, and NLR post-seizure are strong indicators of hyperCKemia risk, with significant implications for enhancing clinical decision-making and patient care strategies.

The role of creatine kinase in distinguishing generalized tonic-clonic seizures from psychogenic non-epileptic seizures (PNES) and syncope: a retrospective study and meta-analysis of 1300 patients

BACKGROUND/AIM

As the clinical differentiation between epileptic seizures, psychogenic non-epileptic seizures (PNES), and syncope depends mainly on a detailed report of the event, which may not be available, an objective assessment of a potential biochemical analysis is needed. We aimed to investigate whether serum creatine kinase (CK) could be used to differentiate epileptic seizure from PNES and syncope and to assess the strength of evidence present.

METHODS

We directed a retrospective cohort study coupled with a systematic review and meta-analysis of studies that measured CK in patients with epilepsy, PNES, syncope, and healthy controls.

RESULTS

The cohort study, which traced 202 patients, showed that the CK level was significantly higher 48 h after the event in the epilepsy group versus patients with syncope (p < 0.01) Along with 1086 patients obtained through a database search for meta-analysis, CK level compared to different types of seizures from PNES was higher in epileptic seizure patients with a mean difference of 568.966 mIU/ml (95% CI 166.864, 971.067). The subgroup analysis of CK showed that it was higher in GTCS compared to syncope with a mean difference of 125.39 mIU/ml (95% CI 45.25, 205.52).

DISCUSSION

Increased serum levels of CK have been associated mainly with epileptic seizures in relation to non-epileptic events. However, further studies would try to explore the variation in measurements and any other potential diagnostic marker.

CONCLUSION

The cohort study shows that the CK level in epilepsy seizures is higher after 48 h from the event compared to syncope. Moreover, the meta-analysis results show the present diagnostic utility of CK and its importance to be used in accordance with a detailed report of the event.

Characteristics and treatments of patients with significantly elevated creatine kinase levels induced by seizures: Case report and literature review

Motor signs accompanying seizures have been considered to result in overexertion of muscles and have the ability to cause elevated levels of serum creatine kinase (CK). There were no previous studies on the treatment of seizure-induced elevated CK. We summarized the characteristics and treatments of six patients with significant elevation of CK after seizure onset. There were four males and two females, the age range was 16-68 years. The CK levels were greater than 5000 U/L in five of the six patients and the highest CK level was 39,300 U/L. All patients exhibited an estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73m2. No patient developed renal failure or required continuous renal replacement therapy. We determined that serial assessment of CK, myoglobin, eGFR, and electrolytes should be performed in patients following seizures. Furthermore, fluid resuscitation, urine alkalization, and diuretic agents should be administrated when CK are significantly elevated after seizure onset. Serial assessment of CK levels after seizures should be performed, especially when the patient experiences electrolyte disorders. Fluid resuscitation, urine alkalization, and diuretic agents also should be administrated to patients when they exhibit a significantly elevated CK or myoglobin after seizures.

Classification Model for Epileptic Seizure Using Simple Postictal Laboratory Indices

Distinguishing syncope from epileptic seizures in patients with sudden loss of consciousness is important. Various blood tests have been used to indicate epileptic seizures in patients with impaired consciousness. This retrospective study aimed to predict the diagnosis of epilepsy in patients with transient loss of consciousness using the initial blood test results. A seizure classification model was constructed using logistic regression, and predictors were selected from a cohort of 260 patients using domain knowledge and statistical methods. The study defined the diagnosis of seizures and syncope based on the consistency of the diagnosis made by an emergency medicine specialist at the first visit to the emergency room and the diagnosis made by an epileptologist or cardiologist at the first outpatient visit using the International Classification of Diseases 10th revision (ICD-10) code. Univariate analysis showed higher levels of white blood cells, red blood cells, hemoglobin, hematocrit, delta neutrophil index, creatinine kinase, and ammonia levels in the seizure group. The ammonia level had the highest correlation with the diagnosis of epileptic seizures in the prediction model. Therefore, it is recommended to be included in the first examination at the emergency room.

YIPF5 (p.W218R) mutation induced primary microcephaly in rabbits

Primary microcephaly (PMCPH) is a rare autosomal recessive neurodevelopmental disorder with a global prevalence of PMCPH ranging from 0.0013% to 0.15%. Recently, a homozygous missense mutation in YIPF5 (p.W218R) was identified as a causative mutation of severe microcephaly. In this study, we constructed a rabbit PMCPH model harboring YIPF5 (p.W218R) mutation using SpRY-ABEmax mediated base substitution, which precisely recapitulated the typical symptoms of human PMCPH. Compared with wild-type controls, the mutant rabbits exhibited stunted growth, reduced head circumference, altered motor ability, and decreased survival rates. Further investigation based on model rabbit elucidated that altered YIPF5 function in cortical neurons could lead to endoplasmic reticulum stress and neurodevelopmental disorders, interference of the generation of apical progenitors (APs), the first generation of progenitors in the developing cortex. Furthermore, these YIPF5-mutant rabbits support a correlation between unfolded protein responses (UPR) induced by endoplasmic reticulum stress (ERS), and the development of PMCPH, thus providing a new perspective on the role of YIPF5 in human brain development and a theoretical basis for the differential diagnosis and clinical treatment of PMCPH. To our knowledge, this is the first gene-edited rabbit model of PMCPH. The model better mimics the clinical features of human microcephaly than the traditional mouse models. Hence, it provides great potential for understanding the pathogenesis and developing novel diagnostic and therapeutic approaches for PMCPH.

Elevated body temperature and leukocyte count are associated with elevated creatine kinase after seizures

Objective

To evaluate the independent risk factors for elevated creatine kinase (hyperCKemia) after seizures.

Methods

Data included in this retrospective study were obtained from two hospitals from July 1, 2017, to March 31, 2022. Clinical and laboratory data were acquired from the emergency department or within 24 h after patient admission. Variables that exhibited statistical differences (P < 0.05) were selected for further analysis. Associations between body temperature (BT), leukocyte count (LEU), percentage of neutrophils (NEU), and C-reactive protein (CRP) and creatine kinase (CK) levels were assessed using binary logistic regression analysis.

Results

One hundred twenty-three patients who exhibited seizures were included in the study, and 39 (31.7%) patients exhibited hyperCKemia based on a CK level that was >1.5 times the upper limit of the normal range for CK. No statistical differences were observed among the patient characteristics, seizure-related parameters, or electrolyte levels. However, BT, LEU, NEU, and CRP were elevated in patients with hyperCKemia compared to patients with normal CK levels. Specifically, a BT ≥ 37.5 °C (fever) and LEU >9.5×10⁹/L (elevated LEU) exhibited positive correlations with hyperCKemia, and presented an adjusted OR of 8.87 (95% CI: 2.11-37.24, P = 0.003) and 3.01 (95% CI: 1.12-8.05, P = 0.029), respectively.

Conclusion

In this study, hyperCKemia occurred in 31.7% of patients after seizures. Fever and elevated LEU were independent risk factors for seizure-related hyperCKemia. Earlier recognition of risks for seizure-related hyperCKemia would be beneficial in taking prophylactic measures.

Incidence and clinical spectrum of rhabdomyolysis in general neurology: a retrospective cohort study

The objective of this retrospective cohort study was to evaluate demographic, clinical and laboratory characteristics of patients with rhabdomyolysis as defined by a serum creatine kinase (sCK) activity > 950 U/L. A total of 248 patients were recruited from the Department of Neurology, Medical University of Vienna, between 01/2000 and 12/2017, with a median sCK activity of 2,160 U/l (IQR 1,342-4,786). Seizures (31.9%), illicit drugs/alcohol (9.7%) and exercise (8.5%) were the most common trigger factors. Rhabdomyolysis incidence rates in specific neurological diseases as estimated by the ratio between rhabdomyolysis cases and the total number of cases with the corresponding disease were highest in myopathies (49.8/1,000 person-years, 95% CI 32.3-67.4), followed by epilepsy (16.4/1,000 person-years, 95% CI 12.8-20.0) and stroke (11.9/1,000 person-years, 95% CI 8.4-15.4). The half-life of sCK activity was 1.5 days in the total cohort. In myopathies, sCK activity was significantly higher as compared to other disease entities 7 days after the peak measurement (p = 0.0023). Acute kidney injury (AKI) developed in 18 patients (7.3%) with no AKI-related deaths during the study period. In conclusion, rhabdomyolysis occurred in a broad range of neurological entities but was associated with a favorable prognosis in most cases rarely resulting in AKI and death.

[Psychogenic non-epileptic seizures]

The review provides epidemiological data and discuss the associated burden of non-epileptic seizures (PNES). Data on the prevalence, socio-demographic and clinical risk factors for the development of PNES are presented. The hypotheses of the PNES origin, including the contribution of psychological trauma, are considered. We also describe contemporary methods for differential diagnosis of epileptic seizures and PNES, including biomarkers and the use of diagnostic questionnaires. Special attention is given to the issues of the psychiatric comorbidity of PNES.

Epilepsy as a Comorbidity in Polymyositis and Dermatomyositis-A Cross-Sectional Study

Polymyositis (PM) and dermatomyositis (DM) are autoimmune-mediated multisystemic myopathies, characterized mainly by proximal muscle weakness. A connection between epilepsy and PM/DM has not been reported previously. Our study aim is to evaluate this association. A case–control study was conducted, enrolling a total of 12,278 patients with 2085 cases (17.0%) and 10,193 subjects in the control group (83.0%). Student’s t-test was used to evaluate continuous variables, while the chi-square test was applied for the distribution of categorical variables. Log-rank test, Kaplan–Meier curves and multivariate Cox proportional hazards method were performed for the analysis regarding survival. Of the studied 2085 cases, 1475 subjects (70.7%) were diagnosed with DM, and 610 patients (29.3%) with PM. Participants enrolled as cases had a significantly higher rate of epilepsy (n = 48 [2.3%]) as compared to controls (n = 141 [1.4%], p < 0.0005). Using multivariable logistic regression analysis, PM was found only to be significantly associated with epilepsy (OR 2.2 [95%CI 1.36 to 3.55], p = 0.0014), whereas a non-significant positive trend was noted in DM (OR 1.51 [95%CI 0.99 to 2.30], p = 0.0547). Our data suggest that PM is associated with a higher rate of epilepsy compared to controls. Physicians should be aware of this comorbidity in patients with immune-mediated myopathies.

Experimental Therapeutic Strategies in Epilepsies Using Anti-Seizure Medications

Epilepsies are among the most common neurological problems. The disease burden in patients with epilepsy is significantly high, and epilepsy has a huge negative impact on patients' quality of life with epilepsy and their families. Anti-seizure medications are the mainstay treatment in patients with epilepsy, and around 70% of patients will ultimately control with a combination of at least two appropriately selected anti-seizure medications. However, in one-third of patients, seizures are resistant to drugs, and other measures will be needed. The primary goal in using experimental therapeutic medication strategies in patients with epilepsy is to prevent recurrent seizures and reduce the rate of traumatic events that may occur during seizures. So far, various treatments using medications have been offered for patients with epilepsies, which have been classified according to the type of epilepsy, the effectiveness of the medications, and the adverse effects. Medications such as Levetiracetam, valproic acid, and lamotrigine are at the forefront of these patients' treatment. Epilepsy surgery, neuro-stimulation, and the ketogenic diet are the main measures in patients with medication-resistant epilepsies. In this paper, we will review the therapeutic approach using anti-seizure medications in patients with epilepsy. However, it should be noted that some of these patients still do not respond to existing treatments; therefore, the limited ability of current therapies has fueled research efforts for the development of novel treatment strategies. Thus, it seems that in addition to surgical measures, we should look for more specific agents that have less adverse events and have a greater effect in stopping seizures.

Prehospital lactate levels in blood as a seizure biomarker: A multi-center observational study

OBJECTIVE

The objective of this study was to assess the value of prehospital measurement of lactate level in blood for diagnosis of seizures in cases of transient loss of consciousness.

METHODS

Between March 2018 and September 2019, prehospital lactate was measured with a point-of-care device by the emergency medical services in an area serving a population of 900 000. A total of 383 cases of transient loss of consciousness were identified and categorized as tonic-clonic seizure (TCS), other seizure, syncope, or other cause, according to the final diagnosis in the electronic medical records system. Receiver operating characteristic curve analyses were used to identify the optimal lactate cut-off.

RESULTS

A total of 383 cases were included (135 TCS, 42 other seizure, 163 syncope, and 43 other causes). The median lactate level in TCS was 7.0 mmol/L, compared to a median of 2.0 mmol/L in all other cases (P < .001). The area under the curve (AUC) of TCS vs nonepileptic causes was 0.87 (95% confidence interval [CI] 0.83-0.91). The optimal cut-off (Youden index, 67.8%) was 4.75 mmol/L, with 79% sensitivity (95% CI 71-85) and 89% specificity (95% CI 85-93) for TCS.

SIGNIFICANCE

Prehospital lactate can be a valuable tool for identifying seizures in transient loss of consciousness. For acceptable specificity, a higher cut-off than that previously demonstrated for hospital-based measurements must be used when values obtained close to the time of the event are interpreted.

Suspected Levetiracetam-Induced Rhabdomyolysis: A Case Report and Literature Review

Patient: Male, 22-year-old

Final Diagnosis: Rhabdomyolysis

Symptoms: Creatine-kinase elevation

Medication: —

Clinical Procedure: —

Specialty: General and Internal Medicine

Quantitative EEG biomarkers for epilepsy and their relation to chemical biomarkers

The electroencephalogram (EEG) is the most important method to diagnose epilepsy. In clinical settings, it is evaluated by experts who identify patterns visually. Quantitative EEG is the application of digital signal processing to clinical recordings in order to automatize diagnostic procedures, and to make patterns visible that are hidden to the human eye. The EEG is related to chemical biomarkers, as electrical activity is based on chemical signals. The most well-known chemical biomarkers are blood laboratory tests to identify seizures after they have happened. However, research on chemical biomarkers is much less extensive than research on quantitative EEG, and combined studies are rarely published, but highly warranted. Quantitative EEG is as old as the EEG itself, but still, the methods are not yet standard in clinical practice. The most evident application is an automation of manual work, but also a quantitative description and localization of interictal epileptiform events as well as seizures can reveal important hints for diagnosis and contribute to presurgical evaluation. In addition, the assessment of network characteristics and entropy measures were found to reveal important insights into epileptic brain activity. Application scenarios of quantitative EEG in epilepsy include seizure prediction, pharmaco-EEG, treatment monitoring, evaluation of cognition, and neurofeedback. The main challenges to quantitative EEG are poor reliability and poor generalizability of measures, as well as the need for individualization of procedures. A main hindrance for quantitative EEG to enter clinical routine is also that training is not yet part of standard curricula for clinical neurophysiologists.

Acute metabolic effects of tonic-clonic seizures

OBJECTIVE

Tonic-clonic seizures (TCS) lead to metabolic stress and changes in related blood markers. Such markers may indicate harmful conditions but can also help to identify TCS as a cause of transient loss of consciousness. In this study, we hypothesized that the alterations of circulating markers of metabolic stress depend on the clinical features of TCS.

METHODS

Ninety-one adults undergoing video-EEG monitoring participated in this prospective study. Electrolytes, renal parameters, creatine kinase (CK), prolactin (PRL), lactate, ammonia, glucose, and other parameters were measured at inclusion and different time points after TCS.

RESULTS

A total of 39 TCS were recorded in 32 patients (six generalized onset tonic-clonic seizures in 6 and 33 focal to bilateral tonic-clonic seizures in 26 patients). Shortly after TCS, mean lactate, ammonia, and PRL levels were significantly increased 8.7-fold, 2.6-fold, and 5.1-fold, respectively, with levels of more than twofold above the upper limits of the normal (ULN) in 90%, 71%, and 70% of the TCS and returned to baseline levels within 2 hours. Only postictal lactate levels were significantly correlated with the total duration of the tonic-clonic phase. In contrast, CK elevations above the ULN were found in three TCS (~10%) only with a peak after 48 hours. Immediately after the TCS, hyperphosphatemia occurred in one third of the patients, whereas hypophosphatemia was observed in one third 2 hours later. TCS led to subtle but significant alterations of other electrolytes, creatinine, and uric acid, whereas glucose levels were moderately increased.

SIGNIFICANCE

Lactate is a robust metabolic marker of TCS with elevations found in ~90% of cases within 30 minutes after seizure termination, whereas ammonia rises in ~ 70%, similarly to PRL. Phosphate levels show an early increase and a decrease 2 hours after TCS in a third of patients. CK elevations are rare after video-EEG-documented TCS, challenging its value as a diagnostic marker.

Rhabdomyolysis: a rare adverse effect of levetiracetam

A 62-year-old previously healthy male was admitted with new onset generalised tonic-clonic seizures. Treatment was initiated with the antiepileptic levetiracetam and he had no further episodes of seizures. Creatine kinase (CPK) level was 1812 IU/L 12-hour postadmission. Despite good hydration, his CPK levels continued to rise dramatically and reached a level of 19 000 IU/L on day 5. This rise was unexplained as he did not have any further seizures and had a normal renal function. In the absence of other risk factors, the rare possibility of levetiracetam being responsible for the disproportionately high CPK was considered. Within 12 hours of withdrawal of levetiracetam, there was a downward trend in the CPK levels, with a 10-fold decrease in CPK levels over the next 4 days. This is only the ninth case reported in literature regarding this rare and potentially serious adverse effect of levetiracetam.

Can perfusion CT unmask postictal stroke mimics?

Objective

To study the diagnostic value of volume perfusion CT (VPCT) in patients with transient focal neurologic deficits following and during epileptic seizures, that mimic symptoms of stroke.

Methods

A retrospective case-control study was performed on 159 patients who presented with a seizure and received an emergency VPCT within the first 3.5 hours of admission, after being misjudged to have an acute stroke. The reference test was a clinical-based, EEG-supported diagnostic algorithm for seizure.

Results

We included 133 patients: 94 stroke-mimicking cases with postictal focal neurologic deficits (“Todd phenomenon,” n = 67) or ongoing seizure on hospital admission (“ictal patients,” n = 27), and 39 postictal controls without focal neurologic deficits. Patients with Todd phenomenon showed normal perfusion (64%), hypoperfusion (21%), and hyperperfusion (14%) on early VPCT. Ictal patients displayed more hyperperfusion compared to postictal patients (p = 0.015). Test sensitivity of hyperperfusion for ictal patients is 38% (95% confidence interval [CI] 20.7%–57.7%), specificity 86% (95% CI 77.3%–91.7%), positive predictive value is 42% (95% CI 27.5%–58.7%), and the negative predictive value 83% (95% CI 78.6%–86.9%). A cortical distribution was seen in all hyperperfusion scans, compared to a cortico-subcortical pattern in hypoperfusion (p < 0.001). A history of complex focal seizure and age were associated with hyperperfusion (p = 0.046 and 0.038, respectively).

Conclusion

VPCT can differentiate ictal stroke mimics with hyperperfusion from acute ischemic stroke, but not postictal patients who display perfusion patterns overlapping with ischemic stroke.

Classification of evidence

This study provides Class IV evidence that VPCT accurately differentiates ictal stroke mimics from acute ischemic stroke.

The diagnostic value of serum UCHL-1 and S100-B levels in differentiate epileptic seizures from psychogenic attacks

OBJECTIVE

To assess the value of postictal serum Ubiquitin C-terminal hydrolase (UCHL-1), a neuronal biomarker, and S100-B, a glial biomarker, levels, in differentiate epileptic seizures (ES) form psychogenic attacks.

METHODS

In this analytical cross-sectional study, serum UCHL-1 and S100-B levels were measured within six hours of occurring seizure, in 43 patients with ES, 20 patients with psychogenic non-epileptic seizures (PNES) and 19 healthy individuals by electrochemiluminescence immunoassay.

RESULTS

Both serum UCHL-1 and S100-B levels were significantly higher in patients with ES than PNES (P < 0.05) and controls (P < 0.01). PNES patients had significantly higher serum S100-B levels compared to controls (P < 0.01). There was a significant correlation between the serum UCHL-1 and S100-B levels in patients with ES (r = 0.46, P = 0.002).

CONCLUSIONS

Our study showed that serum UCHL-1 level could be potentially used in differentiate ES from PNES (sensitivity 72%, specificity 59%). Serum S100-B level had lower value compared to UCHL-1 (AUC 0.68 for UCHL-1 v/s 0.59 for S100B). Post-seizure serum UCHL-1 and S100-B levels could be used in future studies to better understand the underlying mechanism of seizures and may offer as an adjunctive diagnostic test in differentiate ES from PNES.

Diagnostic criteria to aid the differential diagnosis of patients presenting with transient loss of consciousness: A systematic review

BACKGROUND

Transient loss of consciousness (TLOC) is a common presentation in primary care. Over 90% of these are due to epileptic seizures (ES), syncope, or psychogenic non-epileptic seizures (PNES). Misdiagnosis rates are as high as 30%.

METHODS

Systematic review of inter-ictal clinical criteria to aid differential diagnosis of TLOC. We searched Medline, EMBASE, CINAHL and PsycInfo databases, as well as relevant grey literature depositories and citations of relevant reviews and guidelines for studies giving sensitivity and specificity of inter-ictal clinical characteristics used to differentiate between causes of TLOC. Two independent reviewers selected studies for inclusion and performed critical appraisal of included articles. We performed a narrative synthesis of included studies.

RESULTS

Of 1023 results, 16 papers were included. Two compared syncope, ES, and PNES; all others compared ES and PNES. All were at significant risk of bias in at least one domain. 6 studied patient symptoms, 6 medical and social history, 3 witness reports and 1 examination findings. No individual criterion differentiated between diagnoses with high sensitivity and specificity.

CONCLUSIONS

There is a lack of validated diagnostic criteria to help clinicians assessing patients in primary or emergency care settings to discriminate between common causes of TLOC. Performance may be improved by combining sets of criteria in a clinical decision rule, but no such rule has been validated prospectively against gold-standard diagnostic criteria.

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.

The discriminative value of blood gas analysis parameters in the differential diagnosis of transient disorders of consciousness

AIM

The differentiation between epileptic and non-epileptic episodes can be challenging. Our aim was to compare lactate, anion gap (AG), bicarbonate and the Denver Seizure Score (DSS) as point-of-care test (POCT) markers for episodes of transient alterations of consciousness.

METHODS

The blood serum parameters were drawn at arrival in the emergency department (ED) within 2 h of the episode. After calculating AG and DSS values, the four parameters were compared retrospectively between patients with generalized tonic-clonic seizures (GTCS) (n = 165) and patients with other disorders of consciousness [syncopes (n = 43), and psychogenic non-epileptic seizures (n = 15)]. Additionally, we compared all values among men and women.

RESULTS

In GTCS patients, all four parameters differed significantly compared to non-epileptic episode patients (p < 0.001). Serum lactate showed significant additional benefit over the remaining values, with an AUC of 0.947 (95% CI 0.92-0.975) and a high sensitivity and specificity for an optimal cut-off value of 2.45 mmol/l. For DSS, the AUC was 0.857 (95% CI 0.808-0.906; cut-off: 0.35), and for AG 0.836 (95% CI 0.783-0.889; cut-off: 12.45 mmol/l). In the case of serum bicarbonate, the AUC was 0.831 (95% CI 0.775-0.886; cut-off: 22.75 mmol/l). In the sex-dependent comparison, the results were similar. Men showed more significant differences in the compared values than women.

CONCLUSIONS

Serum lactate is best suited as POCT marker in the differential diagnosis of epileptic and non-epileptic episodes and is superior to AG, DSS and bicarbonate. The differences among sexes may pose a challenge in their implementation and interpretation.

Rhabdomyolysis: A Rare Adverse Effect of Levetiracetam

Levetiracetam is an anti-epileptic that works at the synapse and binds synapse vesicle protein 2A, thereby controlling the release of neurotransmitters. Its side effects mainly include somnolence, headache, fatigue, dizziness, vomiting, and behavioral alterations. Rhabdomyolysis is a rare adverse effect of levetiracetam. The underlying pathophysiology of this adverse effect is unknown. Our patient is a 42-year-old male who was brought to the hospital with a complaint of generalized tonic-clonic seizures and urinary incontinence. His symptoms were caused by hyponatremia. Levetiracetam was started for seizure prevention along with management for hyponatremia. His creatine phosphokinase levels increased on the third day of admission to 30,000 U/L. Four days after the discontinuation of levetiracetam and with the institution of supportive therapy, the patient's rhabdomyolysis resolved.

The first seizure as an indicator of epilepsy

PURPOSE OF REVIEW

Optimal treatment of a possible first seizure depends on the determination if the paroxysmal event was an epileptic seizure and was on an accurate assessment of the recurrence risk. This review summarizes evidence from the last 5 years addressing the following questions: Is it an epileptic seizure? Is it a first seizure? When does a first seizure indicate epilepsy?

RECENT FINDINGS

The acts of taking and interpreting the history from patients and witnesses continue to be the most important tools in the diagnosis of first seizures. Assessment tools based on factual questions and the observation of patients' conversational behaviour can contribute to the differentiation of patients with epileptic seizures from those who have experienced other types of transient loss of consciousness (TLOC). At present, only about 40% of patients are seen after their very first seizure. Tests have a limited role in the initial diagnosis of a seizure but help to determine the recurrence risk based on the cause. A remote symptomatic cause and detection of epileptiform discharges are associated with a recurrence risk of at least 60% and allow a diagnosis of epilepsy after a first seizure. The risk of recurrence after an acute symptomatic first seizure is well below 60%.

SUMMARY

Expert history-taking continues to be the most important tool in the diagnosis of a first seizure. Cause is the most important determinant of the recurrence risk. Unfortunately, there is currently no formula enabling a precise calculation of an individualized recurrence risk.

Clinical utility of serum lactate levels for differential diagnosis of generalized tonic-clonic seizures from psychogenic nonepileptic seizures and syncope

BACKGROUND

The differential diagnosis of generalized tonic-clonic seizures (GTCS), psychogenic nonepileptic seizures (PNES), and syncope constitutes a major challenge. Misdiagnosis rates up to 20 to 30% are reported in the literature.

PURPOSE

To assess the clinical utility of serum lactate levels for differentiation of GTCS, PNES, and syncope based on gender differences.

METHODS

Data from 270 patients were evaluated retrospectively. Only patients ≥18 years old with the final diagnosis of GTCS, PNES, or syncope in their chart were recruited. Serum lactate levels were measured in the first 2h of the index event.

RESULTS

Serum lactate levels in patients with GTCS (n=157) were significantly higher than in the patients with PNES (n=25) (p<0.001) and syncope (n=88) (p<0.001). When compared with the females, serum lactate levels in patients with GTCS were significantly higher in the male subgroup (p=0.004). In male patients the ROC analysis yielded a serum lactate value of 2.43mmol/l with a sensitivity of 0.85 and a specificity of 0.88 as the optimal cut-off value to distinguish GTCS from other events. The ROC analysis for the AUC yielded a high estimate of 0.94 (95% confidence interval: 0.91-0.98). When a cut-off value of 2.43mmol/l was chosen for the females, which was an optimal value for male patients, the specificity was 0.85, however, the sensitivity was 0.64.

CONCLUSION

We propose that serum lactate level when measured in the first 2h after the index event has a high clinical utility in the differential diagnosis of GTCS, PNES, and syncope. With concomitant clinical signs and physical examination findings besides neuroimaging and EEG, elevated levels of lactate should be taken into account when evaluating a patient with impaired consciousness. On the other hand, the suggested cut-off value 2.43mmol/l might not have a discriminative effect between GTCS, PNES, and syncope in female patients. This finding should be verified in a prospectively designed study with a larger patient population.

Laboratory markers of cardiac and metabolic complications after generalized tonic-clonic seizures

Background

Generalized tonic-clonic seizures (GTCS) frequently lead to emergency inpatient referrals. Laboratory blood values are routinely performed on admission to detect underlying causes and metabolic or cardiac complications. Our goal was to assess the nature and frequency of complications occurring in association with GTCS.

Methods

We retrospectively extracted data from emergency protocols and discharge letters of adult patients admitted to the Department of Epileptology between 01/2010 and 06/2015. Inclusion criteria were diagnosis of GTCS and admission via emergency services. Exclusion criteria were status epilepticus prior to admission to hospital and non-generalized seizures.

Results

A total of 223 patients (of 986 screened cases) were included. Overall, 1.8% required intubation while 1.3% had less severe respiratory problems. In 5.6% of patients, a transient hypoxemia was measured. Hypertensive urgencies affected 7.8% of the patients, sinus tachycardia occurred in 41.2%. Troponin I (cTNI) was determined in 75 patients and was increased in 12% of these cases. Occurrence of elevated cTNI levels was significantly correlated with patient’s age. Four patients were diagnosed with NSTEMI and one patient with STEMI. Creatine kinase (CK) was increased in 59.4% of the patients, with <5-fold increases in 47%, <10-fold in 5.8% and >10-fold increases in 4.3%. Rhabdomyolysis with an >50 fold increase in CK was detected in 1.9% of patients. Prolonged disturbances of consciousness affected 5% of cases while agitation, delirium, and psychotic episodes occurred in 6.3%. Minor traumatic injuries affected 45.7% of patients.

Conclusions

Troponin elevations in association with GTCS are one of the more common complications after emergency admissions especially in older patients. In our selected patient population, serious complications such as intracranial hemorrhage, myocardial infarction and acute renal failure occurred in <1% of GTCS only.

An Emergency Medicine-Focused Review of Seizure Mimics

BACKGROUND

Seizures result in a change in motor, sensory, and behavioral symptoms caused by abnormal neurologic electrical activity. The symptoms share similar presentations of several other conditions, leading to difficulties in diagnosis and frequent improper management.

OBJECTIVE

This review evaluates adult patients with suspected seizure, signs and symptoms of seizure, mimics of seizure, and an approach to management of seizure mimics.

DISCUSSION

A seizure is caused by abnormal neurologic electrical activity resulting in altered motor, sensory, and behavioral symptoms. Other conditions may present similarly, causing a challenge in diagnosis. These conditions include syncope, psychogenic nonepileptic seizures, stroke or transient ischemic attack, sleep disorders, movement disorders, and migraines. Diagnosis of seizures in the emergency department (ED) is often clinical. Differentiation between seizures and other conditions can be difficult. Laboratories and imaging provide little benefit in definitive diagnosis in the emergency setting. For patients that have an apparent seizure, resuscitation and management is precedent while identifying any provoking factors and treatment of those factors. For adults recovering from suspected seizure, the combination of a focused history, physical examination, and additional studies can provide assistance in diagnosis.

CONCLUSIONS

Patients with an apparent seizure should be resuscitated with identification of provoking factors. Many conditions can mimic seizures. A focused history, physical examination, and additional studies will assist in differentiating seizures from mimics.

Lactate as a diagnostic marker in transient loss of consciousness

PURPOSE

The diagnostic classification of disorders of consciousness is often challenging, particularly the distinction between epileptic and non-epileptic seizures. The aim of the study was to examine serum lactate as a diagnostic marker of transient loss of consciousness.

METHOD

Serum lactate levels in blood samples drawn within 2h of the event were compared retrospectively between patients with generalized tonic-clonic seizures (n=195) and patients with other seizures (syncopes [n=52], psychogenic non-epileptic seizures [n=17], and complex focal seizures [n=37]), respectively.

RESULTS

Serum lactate in patients with generalized tonic-clonic seizures was significantly (p<0.001, Mann-Whitney-U test) increased in comparison to other forms of seizure incidences. The area under the ROC-curve was 0.94 (95% CI 0.91-0.96). For a cut-off concentration of 2.45mmol/l, the sensitivity was 0.88 and the specificity 0.87.

CONCLUSIONS

Serum lactate levels in the acute diagnosis were an excellent biomarker for the discrimination of generalized seizures from psychogenic non-epileptic and syncopal events, corroborating its importance for the standard work-up of acute disturbances of consciousness.

Postictal ammonia as a biomarker for electrographic convulsive seizures: A prospective study

OBJECTIVE

Transient hyperammonemia (THA) was reported to follow generalized convulsions without sufficient evidence to confirm the epileptic nature of those events. We aimed to determine if postictal THA can differentiate between different types of events as confirmed electroencephalographically using video-electroencephalography (vEEG) monitoring.

METHODS

In our prospective cohort, we screened all consented adults (>18 years) admitted to the epilepsy monitoring unit. Ammonia was checked at baseline, within 60 min of the event (for all patients) and 24 h after event (whenever possible). Patients were grouped into generalized convulsive seizures (GCS), psychogenic nonepileptic seizures with convulsions (PNES-C), or focal seizures (FS) based on vEEG. Data were analyzed using descriptive statistics and parametric/nonparametric methods.

RESULTS

Of 78 patients enrolled, 13 had GCS, 8 had FS, and 9 had PNES-C. The groups were different with regard to gender (p = 0.04) and baseline ammonia (p = 0.02), but not age. The change in ammonia postictally from baseline was significantly different among the three groups (p = 0.004). The area under the receiver operator characteristic (ROC) curve for postictal ammonia to distinguish GCS from other groups was 0.88 (95% confidence interval [CI] 0.69-0.96) suggesting ammonia to be a good test differentiating epileptic GCS from other events. An ammonia level of ≥80 μmol/L correctly classified 80% of our patients (sensitivity 53.9%, specificity 100%).

SIGNIFICANCE

Our results provide objective evidence for the association between THA and GCS seizures utilizing vEEG monitoring, and a basis for future studies to determine the role of postictal ammonia as an inexpensive diagnostic test to diagnose GCS.

Recurrent rhabdomyolysis secondary to hyponatremia in a patient with primary psychogenic polydipsia

Rhabdomyolysis is characterized by the destruction of skeletal muscle tissue, and its main causes are trauma, toxic substances and electrolyte disturbances. Among the latter is hyponatremia-induced rhabdomyolysis, a rare condition that occurs mainly in patients with psychogenic polydipsia. Psycogenic polydipsia mostly affects patients with schizophrenia, coursing with hyponatremia in almost 25% of the cases. It is also in this context that rhabdomyolysis secondary to hyponatremia occurs most often. In this article, the case of a 49-year-old male with a history of schizophrenia, medicated with clozapine, and brought to the emergency room in a state of coma and seizures is described. Severe hypoosmolar hyponatremia with cerebral edema was found on a computed tomography examination, and a subsequent diagnosis of hyponatremia secondary to psychogenic polydipsia was made. Hyponatremia correction therapy was started, and the patient was admitted to the intensive care unit. After the hyponatremia correction, the patient presented with analytical worsening, showing marked rhabdomyolysis with a creatine phosphokinase level of 44.058UI/L on day 3 of hospitalization. The condition showed a subsequent progressive improvement with therapy, with no occurrence of kidney damage. This case stresses the need for monitoring rhabdomyolysis markers in severe hyponatremia, illustrating the condition of rhabdomyolysis secondary to hyponatremia induced by psychogenic polydipsia, which should be considered in patients undergoing treatment with neuroleptics.