Seizure vs. syncope: measuring serum creatine kinase in the emergency department

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.

The diagnostic utility of hypophosphatemia for differentiating generalized tonic-clonic seizures from syncope in dogs: A case control study

Transient hypophosphatemia is often detected in humans following generalized tonic-clonic seizures (GTCS), and serum phosphorus concentration (sPi) serves as a marker to differentiate GTCS from syncope. The objective of this retrospective study was to assess the usefulness of hypophosphatemia as a diagnostic marker for GTCS in dogs. Eighty-seven and 26 client-owned dogs with GTCS or syncope, respectively, were enrolled. Dogs were included if the episode occurred ≤ 3 h from presentation, and if sPi and serum creatinine (sCr) were measured. Dogs were excluded if aged < 1 year or if sCr exceeded 176.8 μmol/L. There were no group differences in sCr. Hypophosphatemia (sPi ≤ 0.97 mmol/L) occurred in 28 dogs (32%) in the seizure group, and in no dogs in the syncope group. Median sPi was significantly (P < 0.001) lower in the seizure group (1 mmol/L, [range, 0.31-2.87 mmol/L]) compared to the syncope group (1.35 mmol/L [range, 0.97-2.71 mmol/L]). Furthermore, in dogs presented while seizing (n = 24/87; 28%) median sPi was significantly lower compared to those that were not (0.9 mmol/L [range, 0.3-1.74 mmol/L] vs. 1 mmol/L [range, 0.33-2.18 mmol/L], P = 0.050). ROC analysis of sPi as a marker of GTCS yielded an AUC of 0.757 (95% confidence interval 0.667-0.847), with an optimum cutoff point of 0.97 mmol/L, corresponding to specificity and sensitivity levels of 100% and 44%, respectively. In conclusion, sPi may, in certain cases, serve as an additional diagnostic tool to differentiate GTCS from syncope in dogs. Hypophosphatemia, especially with sPi < 0.97 mmol/L, may be useful in clinical practice to rule in GTCS.

Transient chemotherapy-induced alopecia after successful reversal of 5-fluorouracil myelosuppression and neurotoxicosis in a 9-month-old dog

BACKGROUND

5-Fluorouracil (5-FU) cream is a common human topical chemotherapy agent with potentially fatal neurotoxic effects on dogs if accidentally ingested. There are seldom reports in veterinary literature describing the successful outcome of intervention after accidental ingestion of 5-FU cream.

CASE SUMMARY

A 9-month-old spayed female labradoodle presented 14 h after ingesting an unknown amount of 40 g tube of Efudex cream (5% 5-FU). The dog presented in status epilepticus, which was managed with benzodiazepines and levetiracetam in conjunction with induced coma and mechanical ventilation. No further seizure activity occurred throughout the ensuing 5 days of hospitalisation; however, myelosuppression was featured. The dog was discharged home after 5 days of hospitalisation. Three days post discharge, the dog was noted to develop focal alopecia around the eyes and temporal region. 14 days after discharge, the alopecia progressed to a majority of the head and body.

CONCLUSION

To the authors' knowledge, this is the first report that documents the enduring adverse effects of 5-FU cream after survival of the initial episode, including an earlier onset of myelosuppression and diffuse alopecia. Successful treatment of accidental 5-FU ingestion is possible several hours after the initial event with minimal long-term consequences.

Psychogenic non-epileptic seizures (PNES) in the context of concurrent epilepsy – making the right diagnosis

Epilepsy is a risk factor for the development of psychogenic non-epileptic seizures (PNES) and comorbid epilepsy is recognized as a comorbidity in about 10–30% of patients with PNES. The combination of epileptic and nonepileptic seizures poses a particular diagnostic challenge. In patients with epilepsy, additional PNES may be suspected on the basis of their typical semiology. The possibility of additional PNES should also be considered if seizures fail to respond to antiepileptic drug treatment, in patients with frequent emergency admissions with seizures and in those who develop new types of seizures. The description of semiological details by patients and witnesses can suggest additional PNES. Home video recordings can support an initial diagnosis, however, especially in patients with mixed seizure disorders it is advisable to seek further diagnostic confirmation by capturing all habitual seizure types with video-EEG. The clinical features of PNES associated with epilepsy are similar to those in isolated PNES disorders and include longer duration, fluctuating course, asynchronous movements, pelvic thrusting, side-to-side head or body movement, persistently closed eyes and mouth, ictal crying, recall of ictal experiences and absence of postictal confusion. PNES can also present as syncope-like episodes with unresponsiveness and reduced muscle tone. There is no unique epileptological or brain pathology profile putting patients with epilepsy at risk of additional PNES. However, patients with epilepsy and PNES typically have lower educational achievements and higher levels of psychiatric comorbidities than patients with epilepsy alone. Psychological trauma, including sexual abuse, appears to be a less relevant aetiological factor in patients with mixed seizure disorders than those with isolated PNES, and the gender imbalance (i.e. the greater prevalence in women) is less marked in patients with PNES and additional epilepsy than those with PNES alone. PNES sometimes develop after epilepsy surgery. A diagnosis of ‘known epilepsy’ should never be accepted without (at least brief) critical review. This narrative review summarises clinical, electrophysiological and historical features that can help identify patients with epilepsy and additional PNES.

Role of Biomarkers in Differentiating New-onset Seizures from Psychogenic Nonepileptic Seizures

Introduction:

Review of literature revealed very limited studies considering a combination of serum prolactin (PRL) and serum creatine kinase (CK) as markers for differentiating epileptic and psychogenic nonepileptic seizures (PNES). Therefore, in the present study, we analyzed the role of serum PRL and serum CK, individually and in combination.

Methodology:

This prospective study was conducted in a tertiary care medical teaching hospital over a period of 18 months. Patients aged over 15 years suspected to have new-onset seizures presenting within 5 h of ictus were included in this study. CK, serum PRL was measured at 0–1, 1–3, and 3–5 h after seizures.

Results:

Hundred subjects were studied for the role of serum PRL and serum CK in differentiating epileptic and PNES. The mean age was 42.24 years with a male:female ratio of 1.27:1. All patients of generalized tonic–clonic seizures (GTCS), who presented within 1 h, had elevated PRL, whereas 75% of patients with partial seizures had elevated PRL within 1 h of presentation. Nearly 91.66% of patients with GTCS who presented within 1 h had elevated CPK, whereas 70% of patients with partial seizures had elevated CPK. None of the patients diagnosed with PNES showed rise in either of the markers.

Conclusion:

In the present study, none of the patients with PNES showed raise in either serum PRL or CK. However, there was no correlation between the types of seizure and PRL or serum CK levels.

[Laboratory diagnostics in transient loss of consciousness : Serum lactate compared to serum creatine kinase as diagnostic indicator for generalized tonic-clonic seizures]

BACKGROUND

Laboratory parameters can help in the differential diagnostics of acute episodes of transient loss of consciousness. Especially serum lactate and serum creatine kinase (CK) levels may provide valuable hints to distinguish generalized tonic-clonic seizures (GTCS) from syncope.

MATERIAL AND METHODS

Serum lactate levels at admission and CK levels 10-48 h after the episodes that led to admission were compared between patients with GTCS (n = 30) and those with syncope (n = 15). In addition, sensitivity and specificity of lactate and CK as diagnostic markers for syncope and GTCS were determined.

RESULTS

The serum lactate and serum CK levels were significantly increased in patients with GTCS as compared to syncope patients (serum lactate: p < 0.001; CK: p < 0.005). The area under the curve (AUC) for serum lactate as an indicator for GTCS was 0.94 (95% confidence interval [CI] 0.88-1.0). For CK the receiver operating characteristics (ROC) analysis produced an AUC of only 0.77 (95% CI: 0.63-0.9).

CONCLUSION

The determination of the lactate value as point-of-care diagnostics appears to be highly relevant in the rapid clarification of unclear episodes with transient loss of consciousness. The CK level at follow-up is also suitable for distinguishing GTCS from syncope but is inferior to the serum lactate value.

Postictal syndrome: The forgotten continent. An overview of the clinical, biochemical and imaging features

Postictal syndrome (PIS) encompasses the clinical, biological, electroencephalographic (EEG) and magnetic resonance imaging (MRI) signs that follow the termination of a seizure. These signs occur as soon as the epileptic discharge ends, but might remain for a substantially long period of time, making them amenable to clinical observation. As a direct consequence, neurologists and intensivists are more frequently attending patients with PIS than during their seizure. Moreover, careful PIS documentation may help physicians to diagnose epileptic seizure from other non-epileptic disorders. Careful analysis of PIS could also be helpful to better characterize the seizure (seizure subtypes, and to some extent, the localization and/or lateralization of the seizure). This article aims to review the main clinical, biological, EEG and MRI components of PIS, discuss differential diagnoses and propose a general clinical attitude, based on the acronym "WAITTT": W for "Watch", to monitor and investigate PIS in order to provide relevant information on seizure, AIT for "Avoid Inappropriate Treatment", to underscore the risk carrying out unnecessary drug injections and intensive care procedures in the setting of a self-limited symptomatology, and TT for "Take Time", to keep in mind that time remains the clinician's best ally for treating patients with PIS.

Early postictal serum lactate concentrations are superior to serum creatine kinase concentrations in distinguishing generalized tonic-clonic seizures from syncopes

Concentrations of serum creatine kinase (CK) and serum lactate are frequently measured to help differentiate between generalized tonic-clonic seizures (GTCS) and syncope. The aim of this prospective cohort study was to systematically compare these two markers. The primary outcome is the measurement of serum lactate and CK in blood samples drawn within 2 h of the event in patients admitted with either a GTCS (n = 49) or a syncope (n = 36). Furthermore, the specificity and sensitivity of serum lactate and CK are determined as diagnostic markers in distinguishing between GTCS and syncope. GTCS patients have significantly higher serum lactate levels compared to syncope patients (p < 0.001). In contrast, CK does not differ between groups at admission. Regarding the first hour after the seizure, we identify a cut-off for serum lactate of 2.45 mmol/l for diagnosing GTCS as the cause of an impairment of consciousness with a sensitivity of 0.94 and a specificity of 0.93 (AUC: 0.97; 95% CI 0.94-1.0). In the second hour after the event, the ROC analysis yields similar results (AUC: 0.94; 95% CI 0.85-1.0). Serum lactate is a sensitive and specific diagnostic marker to discriminate GTCS from syncope and is superior to CK early after admission to the emergency department.

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.

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.

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.

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.

Transient hyperammonemia in seizures: a prospective study

PURPOSE

To investigate the incidence and duration of transient hyperammonemia in seizures and to verify the significant confounders related to transient hyperammonemia in seizures.

METHODS

One hundred twenty-one noncirrhotic adult patients with seizures admitted to the emergency department were enrolled in the study. Laboratory examination was performed, including plasma ammonia level assessment. In addition, the basic parameters, underlying systemic diseases, and seizure-related conditions were assessed. The patients were classified into a group with hyperammonemia on arrival and a group without, in order to compare seizure-related adverse events that occurred during a 9-month period.

KEY FINDINGS

The incidence of hyperammonemia in patients with seizures was 67.77%. Plasma ammonia levels in patients with generalized tonic-clonic (GTC) seizures were significantly higher than those in patients in the non-GTC seizure group (median 174.5 vs. 47 μg/dl; proportion 76.5% vs. 21.1%; p < 0.001). Median plasma ammonia levels decreased spontaneously from 250 to 54 μg/dl (p < 0.00001) in an average interval of 466.79 min. GTC seizures (p < 0.0001), male gender (p < 0.0001), bicarbonate (p < 0.0001), diabetes (p = 0.0139), and alcohol-related seizures (p = 0.0002) were significant factors associated with hyperammonemia on arrival. No significant differences related to admission rates or mortalities were found between the two groups.

SIGNIFICANCE

The presence of transient hyperammonemia in patients with seizures is significantly related to GTC seizures, male gender, bicarbonate, diabetes, and alcohol-related seizures. The appropriate period to study ammonia levels following a seizure event is within 8 h. Because these phenomena are self-limited, ammonia-lowering management are not necessary. Hyperammonemia on arrival is not necessarily related to adverse outcomes.

Serum creatine phosphokinase is helpful in distinguishing generalized tonic-clonic seizures from psychogenic nonepileptic seizures and vasovagal syncope

OBJECTIVE

Distinguishing epileptic generalized tonic-clonic seizures (GTCS) from either psychogenic nonepileptic seizures (PNES) or vasovagal syncope (VVS) is important. In this study, we investigated the use of postictal serum creatine phosphokinase (CPK) concentrations in distinguishing between these events.

METHODS

Patients admitted to the Neurology Ward at Namazi Hospital in Shiraz, Iran, with an attack of transient loss of consciousness and abnormal movements witnessed by a neurologist were studied. We categorized the patients into three groups: 20 patients with GTCS, 22 with VVS, and 20 with PNES. A group of 20 normal healthy individuals were included in the study as the control group. Serum CPK concentration was measured 12-15 h after the attack in all patients and at one time in the control group. A P value less than 5% was considered significant.

RESULTS

There were no significant differences between the four groups with respect to age and sex. Mean CPK concentrations statistically significantly differed between the four groups, with higher levels in patients with GTCS (P=0.0001). Serum CPK concentration had a sensitivity of 75% and specificity of 86% for the diagnosis of GTCS. CPK concentration was above 160 mg/dl in 75% of patients with GTCS, 15% of patients with PNES, 13.6% of patients with VVS, and 15% of the control group (P=0.0001). The PNES, VVS, and control groups did not statistically significantly differ with respect to CPK concentrations.

CONCLUSION

In patients with a recent loss of consciousness and abnormal movements, serum CPK concentration is a useful, practical, and relatively accurate parameter to assist in the differentiation of epileptic seizures from either VVS or PNES.

[Differential diagnosis of status epilepticus]

The diagnosis of status epilepticus can be retained, wrongly, in several circumstances. Nonepileptic pseudoseizures from a psychiatric origin and some movement disorders can mimic convulsive status epilepticus. Encephalopathy of various causes (post-anoxic, metabolic, toxic, Creutzfeldt-Jakob disease) can be wrongly taken for non-convulsive status epilepticus, mainly due to inadequate interpretation of the electroencephalogram (EEG). In these encephalopathies, the existence of (non-epileptic) myoclonus and the abolition of the EEG abnormalities with the use of a benzodiazepine (without correction of the clinical symptoms) are additional confounding factors, leading to false diagnosis. Nevertheless, in general, the diagnosis of status epilepticus can be confirmed or rejected base on a combined analysis of the clinical data and the EEG.

[Management of refractory status epilepticus from a neurologic and neuropediatric perspective]

Status epilepticus is a frequent neurologic emergency that is refractory to benzodiazepines and phenytoin in 60% to 70% of cases. Patients commonly require management in an intensive care unit incorporating aggressive treatment with intravenous anaesthetics. Treatment guidelines commonly comment on initial pharmacologic management in detail, as they can refer to data from randomised controlled trials. In contrast, recommendations for the management of refractory status epilepticus often are sparse, as they rely on data from retrospective or uncontrolled prospective studies only. Since status epilepticus is refractory in every third patient, a critical analysis of the available data and a review focussing on the further management of this condition are urgently needed. The Koenigstein Team, a panel of expert epileptologists and neuropediatricians, discussed at its 31(st) meeting in March 2006 the clinical and experimental aspects and implicit prognostic variables of refractory status epilepticus. Here we present the results of that discussion and state recommendations from a neurologic and neuropediatric perspective for current und future management of refractory status epilepticus.

Hyperammonemia is associated with generalized convulsion

PURPOSE

The possibility that hyperammonemia may be associated with generalized convulsion (GC) was retrospectively investigated.

METHODS

Subjects comprised 17 patients with GC who were transported to our department and underwent analysis of serum biochemistry, including ammonia, since October 2004.

RESULTS

Causes of convulsion included intracranial lesions (n=8), endocrine diseases (n=2), epilepsy (n=2) and others (n=5). Ammonia levels in all cases exceeded the upper limit of normal range. Ammonia levels in 8 subjects were re-checked on hospital day 2, and all were lower than levels on hospital day 1 without any treatment for hyperammonemia.

CONCLUSION

GC itself appears to be associated with hyperammonemia. Although hyperammonemia is also known to induce convulsion, biochemical analysis immediately after GC is not useful for diagnosing hyperammonemia-induced convulsion.

Serum neuron-specific enolase, prolactin, and creatine kinase after epileptic and psychogenic non-epileptic seizures

PURPOSE

To evaluate the discriminative power of serial, simultaneous determinations of serum neuron-specific enolase (NSE), prolactin (PRL) and creatine kinase (CK) in differentiating psychogenic non-epileptic seizures (PNES) from epileptic seizures (ES).

METHODS

Prospective measurement of the three markers after 44 single seizures (32 ES and 12 PNES) during continuous video-EEG monitoring at seven different sampling points.

RESULTS

Patients with ES had a significantly greater increase in PRL at 10, 20, 30 min, 1 and 6 h. The sensitivity for elevated NSE and CK was low. PRL showed a higher sensitivity. However, the corresponding positive predictive value was lower than in CK and NSE. Additionally, PRL had the lowest specificity of all parameters.

CONCLUSIONS

The limited discriminative power of PRL, CK, and NSE calls into question if these markers are helpful in differentiating PNES and ES.

Serum creatine kinase elevation in a medical department

Serum creatine kinase (CK) levels are diagnostic markers for acute myocardial infarction. Many other causes however, including neuromuscular disorders, may induce serum CK elevation as well. Aim of the study was to investigate the prevalence of potential causes for serum CK elevation in a medical department. In particular we were interested in the recognition of patients in whom serum CK elevation was due to a neuromuscular disorder. Included in this prospective study were 100 consecutive patients in whom the CK level, determined at admission, was increased (> 70 IU/l in female, > 80 IU/l in male patients). After admission we looked for the presence of causes known to induce CK elevation. Patients with no potential cause for CK elevation were invited for follow-up investigations three months later. If no potential cause could be found and if CK was elevated again on this occasion, the patient was referred for a comprehensive neurological investigation. The prevalence of patients with CK elevation was 11.2%. The 100 patients (44 female, 56 male) were aged from 23 to 94 (mean 67) years. In 95% CK elevation was only up to 500 IU/l. The most frequent cause for serum CK elevation was acute myocardial infarction in 32%. Further frequent causes were drug intake (32%), fall (24%), haematoma (17%), intramuscular injection (16%) and malignancy (11%). In 61% of the cases at least two potential causes for serum CK elevation could be detected. Neuromuscular disorders were found in only 2%. This study shows that serum CK elevation occurs in 11% of patients admitted to a medical department and can be explained by acute myocardial infarction in only 32%. In almost two thirds of the patients, more than one potential cause for serum CK elevation can be found thus making CK elevation a rather unspecific finding. Neuromuscular disorders are rarely found as a cause of serum CK elevation in a medical department.

Evaluation of syncope in the emergency department

Although most cases of syncope are benign, an adequate evaluation, which begins in the emergency department, is required to exclude life-threatening disorders. In addition, life-threatening disorders such as QT prolongation as well as confounding alternative diagnoses (e.g., seizure disorder) are also discussed.

Syncope: current diagnosis and treatment

The patient with syncope often poses a formidable diagnostic challenge. A large number of underlying causes must be considered, ranging in severity from benign to life-threatening. A careful, systematic clinical evaluation beginning with a history, physical examination, and ECG will establish the diagnosis in most patients, and the judicious use of specialized testing will confirm or uncover the cause in many of the remaining cases. Further basic and clinical research into the pathogenesis and treatment of neurocardiogenic syncope, the role of HUT testing in neurally mediated syncope, and the optimal use of EPS in patients with cardiac disease will markedly improve our management of these patients in the future.

Sequential serum creatine kinase determination differentiates vaso-vagal syncope from generalized tonic-clonic seizures

MATERIALS AND METHODS

In a prospective study we evaluated patients with first generalized tonic-clonic seizure (GTCS) (n = 16, age: 31 +/- 11 years, 8 women) and patients with vaso-vagal syncope (VVS) (n = 17, age: 32 +/- 13 years, 8 women), diagnosed on the basis of past history and clinical presentation who had serum creatine kinase (CK) levels assessed at admission to the emergency room and 24-26 h later. Patients with physical injuries were excluded.

RESULTS

On admission, CK levels were > 130 mU/ml (2.16 microkat/l) in 25% (4/16) GTCS vs 6% (1/17) VVS patients; 24 h later, the figures were 56% (9/16) vs 12% (2/17) respectively. For GTCSD patients CK level > 200 mU/ml (3.33 microkat/l) had a sensitivity and specificity of 0.12 and 0.94 on the first day, and 0.25 and 1.0 respectively on the second day. The change in the CK level from the first to the second day was 155 +/- 266 mU/ml (2.58 +/- 4.43 microkat/l) for GTCS group and -2 +/- 37 mU/ml (-0.03 +/- 0.61 microkat/l) in VVS. An increase of more than 15 mU/ml (0.25 microkat/l) was observed in 11/16 GTCS patients and only in 1/17 VVS patients. Taking an increase of > 15 mU/ml (0.25 microkat/l) as a cut-off value, the sensitivity of this figure is 0.69 and specificity 0.94. An increase of > 15 mU/ml (0.25 microkat/l) in CK level among the patients with normal CK on both days was seen in 50% of GTCS but in none with VVS. Using the criteria of CK levels > 200 mU/ml (3.33 microkat/l) (on either day) and/or elevation from the first to the second day of > 15 mU/ml (0.25 microkat/l), there were only 12% false negatives and 12% false positives.

CONCLUSIONS

We conclude that a higher increase in CK levels from the first to the second day occurs in GTCS as compared to VVS, and even when both sequential tests are within the normal range, an increase of at least 15 mU/ml (0.25 microkat/l) is highly indicative of an epileptic event. CK levels above 200 mU/ml (3.33 microkat/l) are unlikely to be the result of VVS.

Syncope: categories and considerations for practice

Cardiogenic and orthostatic syncope can be diagnosed in the majority of cases in the ED setting. Neurogenic causes of syncope may require more extensive testing and a longer in-hospital stay to determine the underlying cause. However, with the advent of more definitive laboratory tests such as CK determination, neurologic syncope may be more easily diagnosed in the emergency department. It is hoped that the morbidity and mortality rate related to syncope (falls, motor vehicle accidents) will decline with patient education, early diagnosis, and treatment. Cognizance of the various types and categories of syncope can assist the emergency nurse in triage, as well as enhance the differential diagnosis and treatment of the patient with syncope.