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Ischemia-modified albumin levels in children having seizure
Brain & Development 35 (2013) 849–852 www.elsevier.com/locate/braindev
Original article
Ischemia-modified albumin levels in children having seizure Asli Inci a, Pinar Gencpinar c, Demet Orhan a, Gulbahar Uzun b, Sebahat Ozdem b, ¨ zgu¨r Duman c,⇑ Anıl Aktasß Samur d, Senay Haspolat c, O a Department of Pediatrics, Akdeniz University Hospital, Antalya, Turkey Department of Biochemistry, Akdeniz University Hospital, Antalya, Turkey c Department of Pediatric Neurology, Akdeniz University Hospital, Antalya, Turkey d Department of Biostatistics, Akdeniz University Hospital, Antalya, Turkey b
Received 10 August 2012; received in revised form 19 November 2012; accepted 21 November 2012
Abstract Convulsions are one of the frequently seen problems for a neurologist in the daily routine. It is difficult to distinguish the seizure from pseudo-seizure because of lack of conclusive tests. The aim of this study is to investigate the relationship between seizure types and seizure periods by studying IMA serum levels in children having seizure. Two groups were included (patients and control) in our study. The patient group consisted of the children admitted to Pediatric Emergency Care during January 2008–January 2010 with seizure and the control group consisted of healthy children. Serum Ischemia modified albumin (IMA) level in the group having seizures was 99.7 and 83.2 U/ml in the control group. In the comparison of the patient and control groups, significant differences were found between their IMA values (p = 0.000). There was a significant difference between IMA values of the group having generalized tonic–clonic seizures and those of the control group (p = 0.001). In comparison of the IMA values of the group having febrile convulsions and those of the control group, a significant difference was determined (p = 0.011). It has been shown that if the seizure was prolonged over 5 min, IMA level increased, and there was a significant difference between the groups experiencing over 5 min of seizures and the groups experiencing less than 5 min of seizures (p = 0.001). An increase in IMA levels in febrile convulsion supports the hypoxia development in the brain during the seizure. Serum IMA levels increased with the elongation of the seizure period and may be an indicator for status epilepticus. Ó 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved. Keywords: Epilepsy; Pseudoepilepsy; IMA
1. Introduction Seizures are caused by abnormal and excessive neuronal discharges. They may manifest themselves as involuntarily developed abnormal motor movements, behavioral abnormalities, sensory defects, or autonomic dysfunction [1,2]. Epilepsy is described as repetitive seizures. In order to define seizures as epilepsy, there must ⇑ Corresponding author. Address: Department of Child Neurology, Faculty of Medicine, Akdeniz University Hospital, 07070 Konyaaltı, Antalya, Turkey. Tel.: +90 242 249 65 56; fax: +90 242 227 43 43. ¨ zgu¨r Duman). E-mail address: [email protected] (O
be more than 2 unprovoked seizures and they must promote future attacks in the brain. Epilepsy is a neurological disorder diagnosed in the pediatric age group quite often and the incidence in general population was found between 0.5–0.8% [2–5]. To distinguish the epilepsy from pseudo-seizures is difficult because the diagnosis is specifically established based on episode, and there are no conclusive tests or EEG is misinterpreted and is not often made at the time of seizures [6]. Non-epileptic seizures are often confused with epileptic seizures due to the similarity of clinical properties. Therefore, differential diagnosis of epilepsy and non-epileptic cases is very important. Due to the
0387-7604/$ - see front matter Ó 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.braindev.2012.11.004
850
A. Inci et al. / Brain & Development 35 (2013) 849–852
lack of a diagnostic test to differentiate epilepsy and pseudo-epileptic seizures, new methods are needed for defining them. In ischemia cases, structural changes occur in the N-terminal part of albumin with the effect of O2 radicals. Molecular ischemia formed is called modified albumin. Cobalt, nickel, and copper cannot bind to N-terminal part of albumin. When albumin contained in the circulating blood reaches the ischemia area, it is converted into ischemia-modified albumin [7]. Its levels increase 10 min after the ischemic case and returns to normal levels within 6 h. IMA is converted into albumin with the removal of free oxygen radicals, and it returns to pre-ischemic stage. IMA improves in ischemia and hypoxic cases [8–11]. Hence, this study aimed at investigating the relationship between seizure types and seizure periods by studying IMA serum levels in children having seizure.
of cobalt chloride was adjusted to 0.58 mmol/L. It was reported that cobalt binding to albumin decreases substantially during ischemia [12]. In order to determine the amount of cobalt that does not bind to albumin, at the end of incubation period, 25 lL of dithiothreitol (final concentration 1.67 mmol/L) was added to measurement bath and mixed to let dithiothreiton form a colored complex with free (unbound) cobalt. Formed colored complex was measured at 500 nm spectrophotometrically. Absorbance values were measured in calibration curve formed with 5 points in 5–180 U/ml range.
2. Materials and methods
3. Results
2.1. Study group
Our patient group with seizures included 52 patients, 29 of whom were girls and 23 were boys. The mean age of the seizure group was 5.9 ± 5.3 years. Our control group included 42 healthy children, 22 of whom were girls and 20 were boys. The mean age of control group was 4.46 ± 3.46 years (Table 1). Control group consisted of healthy children who were admitted to hospital with routine control and had no complaints and no seizures before. Magnetic resonance imaging was performed in the 41 patients. Abnormalities were determined in 14 of the patients (26%) to explain the seizures, and MRIs of 27 patients (50.9%) were normal. Remaining 11 patients, whose seizures did not repeat, were evaluated with CT. The images were normal and no cranial MRI was performed. Epileptiform discharges were
Patients admitted to Pediatric Emergency Department of Medical School Hospital at Akdeniz University during January 2008–January 2010 with seizure were included. The control group included children, who had non-specific complaints and normal physical examination. Written approval forms were received from all participants while blood samples were taken from patient group for seizure reasons and from children in control group for routine tests. This study was approved by local Ethical Committee. The patients were examined physically and neurologically. Clinical data, electroencephalography (EEG), computerized tomography (CT) and/or magnetic resonance images (MRI) of the patients were evaluated and followed for 2 years. 2.1.1. Laboratories Serum samples were taken from the patients admitted with febrile and afebrile seizure to Pediatric Emergency Department within the first one hour following seizures. Routine laboratory studies (hemoglobin, white blood cells, platelets, blood sugar, liver function tests, blood urea, creatinine, electrolytes, c-reactive protein, serum albumin and antiepileptic pharmaceutical levels) were studied and IMA levels were determined in all cases. 2.1.2. Measurement of serum ischemia-modified albumin levels Level of serum IMA was measured with albumin cobalt binding test [12] in venous blood samples drew into biochemistry test tubes with gel. For the measurement of IMA levels, 95 lL of patients’ sera was mixed with 5 lL cobalt chloride and incubated for 5 min. During incubation, concentration
2.2. Statistical analysis The SPSS 11 version was used for evaluating the study results. Statistical evaluation was performed using the Chi-square and Mann–Whitney U. The value of p < 005 was considered to be significant.
Table 1 Demographic features and clinical findings of the patients. Number (n)
%
Gender (patient) Girls Boys
23 29
44 56
Gender (control) Girls Boys
22 20
52 48
Seizure type GTC Focal Febrile
30 8 14
Seizure period <5 min >5 min
27 25
IMA values 99.74
SD
p
18.26 0.000
83.20
25.52
57 15 27
106.4 91.3 102.77
13.827 7.176 12.914
0.011
51 49
90.56 105.93
11.279 19.628
0.001
0.001
Median values were used, SD means standard deviation, p < 0.05 significance.
A. Inci et al. / Brain & Development 35 (2013) 849–852
determined in 10 of the 52 patients (19.2%), and no epileptiform discharge was determined in EEGs in 27 of 51 patients (51.9%). No EEG was performed in the remaining 15 patients because they had their first febrile convulsion and they did not have any convulsions during the follow up. EEG was not performed in one patient because he could not be followed. Serum IMA level in the group having seizures was 99.7 U/ml and it was 83.2 U/ml in the control group (Table 2). Serum C-reactive protein and serum albumin levels were between the normal ranges according to age in the patient group. A significant difference was found between IMA levels when we compared the patient and control groups (p = 0.000). There was no significant difference between the types of seizure (generalized tonic–clonic (GTC), focal and febrile convulsion experiencing groups) (p > 0.05). There was a significant difference between the IMA values of the group having generalized tonic–clonic seizures and those of the control group (p = 0.001), and also there was a significant difference in the IMA values between the group having febrile convulsions and the control group (p = 0.011). In the evaluation of the seizure periods, there was a significant difference between the groups experiencing longer than 5 min of seizures and the groups experiencing less than 5 min of seizures (p = 0.001). The IMA levels were higher in the in the prolonged seizure groups than the control group. When we compared the seizure groups (GTC–Focal–Febrile) separately and the control group it has been shown that there was significantly difference between GTC-focal and GTC-febrile groups (p = 0.000, p = 0.011). There was no significantly difference between the focal type seizure and control groups (p = 0.057). Because of the small numbers of focal seizure group it couldn’t has been compared with the other seizure types. The comparison of GTC and febrile groups was not statistically significant (p = 0.64) (Table 3). 4. Discussion Ischemia-modified albumin (IMA) is a new biomarker in the identification of tissue hypoxia such as acute myocardial and mesenteric ischemia, obesity, polycystic ovary syndrome with or without insulin resistance, ovarian torsion and diabetes mellitus. It is well known that IMA increases within minutes from the onset of the ischemic event and remains elevated for several hours after the onset of tissue hypoxia. In spite of Table 2 Comparison of control group and patient.
Patient Control
Minimum
Maximum
Median
SD
67.33 45.07
176.46 153.90
99.74 83.20
18.26 25.52
SD means standard deviation.
851
Table 3 Evaluation of the IMA levels in the prolonged seizure according to seizure types. IMA values (mean)
SD
Prolonged seizure type 1. GTC 15 2. Focal 4 3. Febrile 6 4. Control 42
Number (n)
106.4 91.3 102.77 83.20
13.827 7.176 12.914 25.52
p Values Group 1–2 Group 1–3 Group 2–3
GTC-control Febrile-control Focal-control
– 0.64 –
0.000 0.011 0.057
the existence of a lot of studies about the relationship IMA and several conditions described previously, our study is the first study demonstrating the relationship between IMA levels and seizures. Seizure is the most common diagnosis in patients who are admitted to the hospital with loss of consciousness, and the diagnosis is made often clinically [6,13]. It is not easy to distinguish the epileptic seizures from pseudo-seizures most of the time, other than recognized clinical cases such as postictal phase and consciousness changes. Some characteristic defects were described in membrane potentials of the cortical neurons following seizures and in pyrexia types in the pathophysiology. It has been known that local brain blood flow increase in relation to the paroxysmal discharges during epileptic seizures. As ATP diminishes, substances such as AMP, ADP and lactic acid increase [14,15]. Croll et al. had shown that hypoxia develops during seizure, and that hypoxia improves vascular endothelial growth factor (VEGF) and attempts to protect the brain [16]. VEGF production increases following cerebral ischemia as well. On the other hand, Pinard et al., monitored oxygen and carbon dioxide pressures in rat brain during epileptic seizure in an experimental model and found that damages occurring in the brain depend on intracellular calcium, which increases along with hypoxia [17]. Magnetic resonance imaging (MRI) was used in order to evaluate biochemical state of the central nervous system in patients having seizure. There was a decline in Nacetyl-aspartate (NAA) peak indicating neuronal destruction, an increase in choline peak pointing to membrane breakdown, and an increase in lactate peak showing the hypoxia-ischemic state. Positron emission tomography (PET) illustrates cerebral metabolism distribution, and the epileptic zone looks much more hypo-metabolic than other areas [18]. Studies were also conducted on serum prolactin levels in the aftermath of seizures, and it was determined that prolactin serum values increase following seizures [19–21]. However, these methods such as MRI, PET or MR-Spectroscopy cannot be used for distinguishing a seizure from a pseudo-seizure, because these are not cost-effective, available, and useful.
852
A. Inci et al. / Brain & Development 35 (2013) 849–852
In this study, serum IMA levels of the groups having GTC seizure were determined to be significantly higher than IMA levels of the control group (p = 0.001). We obtained similar results in comparison of the IMA values of the group having febrile convulsion with those of the control group (p = 0.011). In contrast, there was no significant difference between the group having focal seizures and the control group (p > 0.05). It was observed that if the seizure period was prolonged, IMA levels increased. Serum IMA levels were significantly higher in prolonged seizure group (longer than 5 min.) than the group having a seizure period less than 5 min (p = 0.001). Because of the numbers of patients we could compare only GTC and febrile type and the comparison was not statistically significant. The comparison between the seizure types and control group separately there was statistically significant between GTC and febrile groups. When we compared focal and control group it has been shown that p value was over from 0.05. These results may be due to the differences and inadequate patients numbers. An increase in IMA levels in febrile convulsion supports the development of hypoxia in the brain as well during the seizure. Although IMA levels were higher in the non-febrile seizures than febrile ones, this difference was not statistically significant (p > 0.05). In comparison of the afebrile and febrile groups with the control group, serum IMA levels improved with an elongation of the period. When high serum IMA levels were established in epileptic patients, it is thought that it can be an indicator for a developmental risk of status epilepticus and duration of seizure. In conclusion, it is the first study showing the relationship of IMA and seizure in childhood. In addition to clinical findings, laboratory values, EEG and cranial imaging, it is considered that serum IMA levels may be helpful and useful in differential diagnosis of seizure as well and they can provide information about the risk of status epilepticus. Further studies are needed for both determination of cut-off values and evaluation of IMA levels in pseudo-seizure and status epilepticus with larger populations.
Acknowledgement This study was supported by Akdeniz University Scientific Committee. References [1] Monsen RE, Graham WM, Scell GF. Febrile seizures caring for patients and their parents. Postgrad Med 1991;90, 217–8, 221–6.
[2] Serdaroglu A, Ozkan S, Aydin K, Gu¨cu¨yener K, Tezcan S, Aycan S. Prevalance of epilepsy in Turkish children between the ages of 0–16 years. J Child Neurol 2004;19:271–4. [3] Hauser WA, Hersdorffer DH, editors. Epilepsy: frequency, causes and consequences. New York: Demos; 1990, p. 2–51. [4] Hauser WA, Annegers JF, Kurtland LT. Prevalance of epilepsy in Roncester, Minnesota: 1940–1980. Epilepsia 1991;32:429–45. [5] Annegers JF. Epidemiology of childhood onset seizures. In: Dodson WE, Pelock JM, editors. Pediatric epilepsy: diagnosis and therapy. New York: Demos; 1993. p. 57–61. [6] Ferrie CD. Preventing misdiagnosis of epilepsy. Arch Dis Child 2006;91:206–9. [7] Dusek J, St’a´sek J, Tichy´ M, Bis J, Gregor J, Voja´cek J, et al. Prognostic significance of ischemia-modified albumin after percutaneous coronary intervention. Clin Chim Acta 2006;367:77–80. [8] Abboud H, Labreuche J, Meseguer E, Lavallee PC, Simon O, Olivot JM, et al. Ischemia-modified albumin in acute stroke. Cerebrovasc Dis 2007;23:216–20. [9] Lippi G, Montagnana M, Guidi GC. Albumin cobalt binding and ischemia modified albumin generation: an endogenous response to ischemia? Int J Cardiol 2006;108:410–1. [10] Refaai MA, Wright RW, Parvin CA, Gronowski AM, Scott MG, Eby CS. Ischemia-modified albumin increases after skeletal muscle ischemia during arthroscopic knee surgery. Clin Chim Acta 2006;366:264–8. [11] Gu¨ndu¨z A, Tu¨redi S, Mentese A, Karahan SC, Hos G, Tatli O, et al. Ischemia-modified albumin in the diagnosis of acute mesenteric ischemia: a preliminary study. Am J Emerg Med 2008;26:202–5. [12] Bar-Or D, Lau E, Winkler JV. Novel assay for cobalt–albumin binding and its potential as a marker for myocardial ischemia – a preliminary report. J Emerg Med 2000;19:311–5. [13] Eiris-Punal J, Rodriguez-Nunez A, Fernandez-Martinez N, Fuster M, Castro-Gago M, Martinon JM. Usefulness of the headupright tilt test for distinguishing syncope and epilepsy in children. Epilepsia 2001;42:709–13. [14] Engel Jr J, Pedley TA. Epilepsy: a comprehensive textbook. Lippincott-Raven: Wolters Kluwer; 2008. [15] Selzer ME, Dichter MA. Cellular pathophysiology and pharmacology of epilepsy. In: Asbury AK, McKhann GM, McDonald WI, editors. Diseases of the nervous system – clinical neurobiology. Philadelphia: Saunders; 1992. p. 916–35. [16] Croll SD, Goodman JH, Scharfman HE. Vascular endothelial growth factor (VEGF) in seizures: a double-edged sword. Adv Exp Med Biol 2004;548:57–68. [17] Pinard E, Tremblay E, Ben-Ari Y, Seylaz J. Blood flow compensates oxygen demand in the vulnerable ca3 region of the hippocampus during kainate-induced seizures. Neuroscience 1984;13:1039–49. [18] Wycliffe ND, Thompson JR, Holshouser BA, Ashwal S. Pediatric neuroimaging. In: Swaiman KF, Ashwal S, Ferriero DM, editors. Pediatric Neurology Principles & Practice. Philadelphia: Mosby Elsevier; 2006. p. 167–202. [19] Yerby MS, van Belle G, Friel PN, Wilensky AJ. Serum prolactin in the diagnosis of epilepsy: sensitivity, specificity and predictive value. Neurology 1987;37:1224–6. [20] Dana-Haeri J, Trimble MR, Oxley J. Prolactin and gonadotropin changes following generalized and partial seizures. J Neurol Neurosurg Psychiatry 1983;46:331–5. [21] Wyllie E, Luders H, MacMillan JP, Gupta M. Serum prolactin levels after epileptic seizures. Neurology 1984;34:1601–4.
Original article
Ischemia-modified albumin levels in children having seizure Asli Inci a, Pinar Gencpinar c, Demet Orhan a, Gulbahar Uzun b, Sebahat Ozdem b, ¨ zgu¨r Duman c,⇑ Anıl Aktasß Samur d, Senay Haspolat c, O a Department of Pediatrics, Akdeniz University Hospital, Antalya, Turkey Department of Biochemistry, Akdeniz University Hospital, Antalya, Turkey c Department of Pediatric Neurology, Akdeniz University Hospital, Antalya, Turkey d Department of Biostatistics, Akdeniz University Hospital, Antalya, Turkey b
Received 10 August 2012; received in revised form 19 November 2012; accepted 21 November 2012
Abstract Convulsions are one of the frequently seen problems for a neurologist in the daily routine. It is difficult to distinguish the seizure from pseudo-seizure because of lack of conclusive tests. The aim of this study is to investigate the relationship between seizure types and seizure periods by studying IMA serum levels in children having seizure. Two groups were included (patients and control) in our study. The patient group consisted of the children admitted to Pediatric Emergency Care during January 2008–January 2010 with seizure and the control group consisted of healthy children. Serum Ischemia modified albumin (IMA) level in the group having seizures was 99.7 and 83.2 U/ml in the control group. In the comparison of the patient and control groups, significant differences were found between their IMA values (p = 0.000). There was a significant difference between IMA values of the group having generalized tonic–clonic seizures and those of the control group (p = 0.001). In comparison of the IMA values of the group having febrile convulsions and those of the control group, a significant difference was determined (p = 0.011). It has been shown that if the seizure was prolonged over 5 min, IMA level increased, and there was a significant difference between the groups experiencing over 5 min of seizures and the groups experiencing less than 5 min of seizures (p = 0.001). An increase in IMA levels in febrile convulsion supports the hypoxia development in the brain during the seizure. Serum IMA levels increased with the elongation of the seizure period and may be an indicator for status epilepticus. Ó 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved. Keywords: Epilepsy; Pseudoepilepsy; IMA
1. Introduction Seizures are caused by abnormal and excessive neuronal discharges. They may manifest themselves as involuntarily developed abnormal motor movements, behavioral abnormalities, sensory defects, or autonomic dysfunction [1,2]. Epilepsy is described as repetitive seizures. In order to define seizures as epilepsy, there must ⇑ Corresponding author. Address: Department of Child Neurology, Faculty of Medicine, Akdeniz University Hospital, 07070 Konyaaltı, Antalya, Turkey. Tel.: +90 242 249 65 56; fax: +90 242 227 43 43. ¨ zgu¨r Duman). E-mail address: [email protected] (O
be more than 2 unprovoked seizures and they must promote future attacks in the brain. Epilepsy is a neurological disorder diagnosed in the pediatric age group quite often and the incidence in general population was found between 0.5–0.8% [2–5]. To distinguish the epilepsy from pseudo-seizures is difficult because the diagnosis is specifically established based on episode, and there are no conclusive tests or EEG is misinterpreted and is not often made at the time of seizures [6]. Non-epileptic seizures are often confused with epileptic seizures due to the similarity of clinical properties. Therefore, differential diagnosis of epilepsy and non-epileptic cases is very important. Due to the
0387-7604/$ - see front matter Ó 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.braindev.2012.11.004
850
A. Inci et al. / Brain & Development 35 (2013) 849–852
lack of a diagnostic test to differentiate epilepsy and pseudo-epileptic seizures, new methods are needed for defining them. In ischemia cases, structural changes occur in the N-terminal part of albumin with the effect of O2 radicals. Molecular ischemia formed is called modified albumin. Cobalt, nickel, and copper cannot bind to N-terminal part of albumin. When albumin contained in the circulating blood reaches the ischemia area, it is converted into ischemia-modified albumin [7]. Its levels increase 10 min after the ischemic case and returns to normal levels within 6 h. IMA is converted into albumin with the removal of free oxygen radicals, and it returns to pre-ischemic stage. IMA improves in ischemia and hypoxic cases [8–11]. Hence, this study aimed at investigating the relationship between seizure types and seizure periods by studying IMA serum levels in children having seizure.
of cobalt chloride was adjusted to 0.58 mmol/L. It was reported that cobalt binding to albumin decreases substantially during ischemia [12]. In order to determine the amount of cobalt that does not bind to albumin, at the end of incubation period, 25 lL of dithiothreitol (final concentration 1.67 mmol/L) was added to measurement bath and mixed to let dithiothreiton form a colored complex with free (unbound) cobalt. Formed colored complex was measured at 500 nm spectrophotometrically. Absorbance values were measured in calibration curve formed with 5 points in 5–180 U/ml range.
2. Materials and methods
3. Results
2.1. Study group
Our patient group with seizures included 52 patients, 29 of whom were girls and 23 were boys. The mean age of the seizure group was 5.9 ± 5.3 years. Our control group included 42 healthy children, 22 of whom were girls and 20 were boys. The mean age of control group was 4.46 ± 3.46 years (Table 1). Control group consisted of healthy children who were admitted to hospital with routine control and had no complaints and no seizures before. Magnetic resonance imaging was performed in the 41 patients. Abnormalities were determined in 14 of the patients (26%) to explain the seizures, and MRIs of 27 patients (50.9%) were normal. Remaining 11 patients, whose seizures did not repeat, were evaluated with CT. The images were normal and no cranial MRI was performed. Epileptiform discharges were
Patients admitted to Pediatric Emergency Department of Medical School Hospital at Akdeniz University during January 2008–January 2010 with seizure were included. The control group included children, who had non-specific complaints and normal physical examination. Written approval forms were received from all participants while blood samples were taken from patient group for seizure reasons and from children in control group for routine tests. This study was approved by local Ethical Committee. The patients were examined physically and neurologically. Clinical data, electroencephalography (EEG), computerized tomography (CT) and/or magnetic resonance images (MRI) of the patients were evaluated and followed for 2 years. 2.1.1. Laboratories Serum samples were taken from the patients admitted with febrile and afebrile seizure to Pediatric Emergency Department within the first one hour following seizures. Routine laboratory studies (hemoglobin, white blood cells, platelets, blood sugar, liver function tests, blood urea, creatinine, electrolytes, c-reactive protein, serum albumin and antiepileptic pharmaceutical levels) were studied and IMA levels were determined in all cases. 2.1.2. Measurement of serum ischemia-modified albumin levels Level of serum IMA was measured with albumin cobalt binding test [12] in venous blood samples drew into biochemistry test tubes with gel. For the measurement of IMA levels, 95 lL of patients’ sera was mixed with 5 lL cobalt chloride and incubated for 5 min. During incubation, concentration
2.2. Statistical analysis The SPSS 11 version was used for evaluating the study results. Statistical evaluation was performed using the Chi-square and Mann–Whitney U. The value of p < 005 was considered to be significant.
Table 1 Demographic features and clinical findings of the patients. Number (n)
%
Gender (patient) Girls Boys
23 29
44 56
Gender (control) Girls Boys
22 20
52 48
Seizure type GTC Focal Febrile
30 8 14
Seizure period <5 min >5 min
27 25
IMA values 99.74
SD
p
18.26 0.000
83.20
25.52
57 15 27
106.4 91.3 102.77
13.827 7.176 12.914
0.011
51 49
90.56 105.93
11.279 19.628
0.001
0.001
Median values were used, SD means standard deviation, p < 0.05 significance.
A. Inci et al. / Brain & Development 35 (2013) 849–852
determined in 10 of the 52 patients (19.2%), and no epileptiform discharge was determined in EEGs in 27 of 51 patients (51.9%). No EEG was performed in the remaining 15 patients because they had their first febrile convulsion and they did not have any convulsions during the follow up. EEG was not performed in one patient because he could not be followed. Serum IMA level in the group having seizures was 99.7 U/ml and it was 83.2 U/ml in the control group (Table 2). Serum C-reactive protein and serum albumin levels were between the normal ranges according to age in the patient group. A significant difference was found between IMA levels when we compared the patient and control groups (p = 0.000). There was no significant difference between the types of seizure (generalized tonic–clonic (GTC), focal and febrile convulsion experiencing groups) (p > 0.05). There was a significant difference between the IMA values of the group having generalized tonic–clonic seizures and those of the control group (p = 0.001), and also there was a significant difference in the IMA values between the group having febrile convulsions and the control group (p = 0.011). In the evaluation of the seizure periods, there was a significant difference between the groups experiencing longer than 5 min of seizures and the groups experiencing less than 5 min of seizures (p = 0.001). The IMA levels were higher in the in the prolonged seizure groups than the control group. When we compared the seizure groups (GTC–Focal–Febrile) separately and the control group it has been shown that there was significantly difference between GTC-focal and GTC-febrile groups (p = 0.000, p = 0.011). There was no significantly difference between the focal type seizure and control groups (p = 0.057). Because of the small numbers of focal seizure group it couldn’t has been compared with the other seizure types. The comparison of GTC and febrile groups was not statistically significant (p = 0.64) (Table 3). 4. Discussion Ischemia-modified albumin (IMA) is a new biomarker in the identification of tissue hypoxia such as acute myocardial and mesenteric ischemia, obesity, polycystic ovary syndrome with or without insulin resistance, ovarian torsion and diabetes mellitus. It is well known that IMA increases within minutes from the onset of the ischemic event and remains elevated for several hours after the onset of tissue hypoxia. In spite of Table 2 Comparison of control group and patient.
Patient Control
Minimum
Maximum
Median
SD
67.33 45.07
176.46 153.90
99.74 83.20
18.26 25.52
SD means standard deviation.
851
Table 3 Evaluation of the IMA levels in the prolonged seizure according to seizure types. IMA values (mean)
SD
Prolonged seizure type 1. GTC 15 2. Focal 4 3. Febrile 6 4. Control 42
Number (n)
106.4 91.3 102.77 83.20
13.827 7.176 12.914 25.52
p Values Group 1–2 Group 1–3 Group 2–3
GTC-control Febrile-control Focal-control
– 0.64 –
0.000 0.011 0.057
the existence of a lot of studies about the relationship IMA and several conditions described previously, our study is the first study demonstrating the relationship between IMA levels and seizures. Seizure is the most common diagnosis in patients who are admitted to the hospital with loss of consciousness, and the diagnosis is made often clinically [6,13]. It is not easy to distinguish the epileptic seizures from pseudo-seizures most of the time, other than recognized clinical cases such as postictal phase and consciousness changes. Some characteristic defects were described in membrane potentials of the cortical neurons following seizures and in pyrexia types in the pathophysiology. It has been known that local brain blood flow increase in relation to the paroxysmal discharges during epileptic seizures. As ATP diminishes, substances such as AMP, ADP and lactic acid increase [14,15]. Croll et al. had shown that hypoxia develops during seizure, and that hypoxia improves vascular endothelial growth factor (VEGF) and attempts to protect the brain [16]. VEGF production increases following cerebral ischemia as well. On the other hand, Pinard et al., monitored oxygen and carbon dioxide pressures in rat brain during epileptic seizure in an experimental model and found that damages occurring in the brain depend on intracellular calcium, which increases along with hypoxia [17]. Magnetic resonance imaging (MRI) was used in order to evaluate biochemical state of the central nervous system in patients having seizure. There was a decline in Nacetyl-aspartate (NAA) peak indicating neuronal destruction, an increase in choline peak pointing to membrane breakdown, and an increase in lactate peak showing the hypoxia-ischemic state. Positron emission tomography (PET) illustrates cerebral metabolism distribution, and the epileptic zone looks much more hypo-metabolic than other areas [18]. Studies were also conducted on serum prolactin levels in the aftermath of seizures, and it was determined that prolactin serum values increase following seizures [19–21]. However, these methods such as MRI, PET or MR-Spectroscopy cannot be used for distinguishing a seizure from a pseudo-seizure, because these are not cost-effective, available, and useful.
852
A. Inci et al. / Brain & Development 35 (2013) 849–852
In this study, serum IMA levels of the groups having GTC seizure were determined to be significantly higher than IMA levels of the control group (p = 0.001). We obtained similar results in comparison of the IMA values of the group having febrile convulsion with those of the control group (p = 0.011). In contrast, there was no significant difference between the group having focal seizures and the control group (p > 0.05). It was observed that if the seizure period was prolonged, IMA levels increased. Serum IMA levels were significantly higher in prolonged seizure group (longer than 5 min.) than the group having a seizure period less than 5 min (p = 0.001). Because of the numbers of patients we could compare only GTC and febrile type and the comparison was not statistically significant. The comparison between the seizure types and control group separately there was statistically significant between GTC and febrile groups. When we compared focal and control group it has been shown that p value was over from 0.05. These results may be due to the differences and inadequate patients numbers. An increase in IMA levels in febrile convulsion supports the development of hypoxia in the brain as well during the seizure. Although IMA levels were higher in the non-febrile seizures than febrile ones, this difference was not statistically significant (p > 0.05). In comparison of the afebrile and febrile groups with the control group, serum IMA levels improved with an elongation of the period. When high serum IMA levels were established in epileptic patients, it is thought that it can be an indicator for a developmental risk of status epilepticus and duration of seizure. In conclusion, it is the first study showing the relationship of IMA and seizure in childhood. In addition to clinical findings, laboratory values, EEG and cranial imaging, it is considered that serum IMA levels may be helpful and useful in differential diagnosis of seizure as well and they can provide information about the risk of status epilepticus. Further studies are needed for both determination of cut-off values and evaluation of IMA levels in pseudo-seizure and status epilepticus with larger populations.
Acknowledgement This study was supported by Akdeniz University Scientific Committee. References [1] Monsen RE, Graham WM, Scell GF. Febrile seizures caring for patients and their parents. Postgrad Med 1991;90, 217–8, 221–6.
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