Calpain-2 as a Treatment Target in Prenatal Stress-induced Epileptic Spasms in Infant Rats

Stress can induce a serious epileptic encephalopathy that occurs during early infancy. Recent studies have revealed that prenatal stress exposure is a risk factor for the development of infantile spasms. Our previous work demonstrates that prenatal stress with betamethasone-induced alterations to the expression of the K⁺/Cl⁻ co-transporter (KCC2) in gamma-aminobutyric acid (GABA) interneurons lowers the seizure threshold in exposed animals. Here, we further investigated the mechanisms involved in this KCC2 dysfunction and explored possible treatment options. We stressed Sprague-Dawley rats prenatally and further treated dams with betamethasone on gestational day 15, which increases seizure susceptibility and NMDA (N-Methyl-D-aspartate)-triggered spasms on postnatal day 15. In this animal model, first, we evaluated baseline calpain activity. Second, we examined the cleavage and dephosphorylation of KCC2. Finally, we checked the effect of a calpain inhibitor on seizure occurrence. The phosphorylated-N-methyl-D-aspartate Receptor 2B (NR2B):non-phosphorylated NR2B ratio was found to be higher in the cortex of the prenatally stressed beta-methasone model. We further found that the betamethasone model exhibited increased phosphorylation of calpain-2 and decreased phosphorylation of KCC2 and Glutamic acid decarboxylase 67 (GAD67). After using a calpain inhibitor in prenatal-stress rats, the seizure frequency decreased, while latency increased. GABAergic depolarization was further normalized in prenatal-stress rats treated with the calpain inhibitor. Our study suggests that calpain-dependent cleavage and dephosphorylation of KCC2 decreased the seizure threshold of rats under prenatal stress. Calpain-2 functions might, thus, be targeted in the future for the development of treatments for epileptic spasms.

Clinical manifestations of headache in children younger than 7 years / 소아과

PURPOSE: Headache is a common symptom during childhood. It is usually persistent and requires special care. This study aimed to identify the characteristics of headache in children < 7 years of age. METHODS: We reviewed 3 years of clinical files on children < 7 years of age with a chief complaint of headache. RESULTS: This study included 146 children (66 males, 80 females; mean age, 5.5±1.0 years). Mean symptom duration was 5.8±7.9 months. Attack durations were longer than 2 hours in 31 patients, shorter than 2 hours in 70 patients, and unchecked in 45 patients. Attack frequency was 15.1±10.6 times per month. Pain locations and characteristics were also variable. Mean pain severity score was 5.1±2.2 on the visual analog scale. Of 38 patients who underwent electroencephalography, 9 showed positive findings. Of 41 who underwent brain magnetic resonance imaging, 20 showed positive findings. The diagnoses were migraine (including probable migraine) in 34, tension-type headache in 5, and congenital malformations in 3. Medications were used in 29 patients: acetaminophen in 17, ibuprofen in 8, naproxen sodium in 1, and topiramate or amitriptyline in 3. CONCLUSION: In children aged < 7 years, headache has a relatively benign course, but detailed history taking is needed for more accurate diagnosis.

Outcome of ultrasonographic imaging in infants with sacral dimple / 소아과

PURPOSE: Sacral dimples are a common cutaneous anomaly in infants. Spine ultrasonography (USG) is an effective and safe screening tool for patients with a sacral dimple. The aim of this study was to determine the clinical manifestations in patients with an isolated sacral dimple and to review the management of spinal cord abnormalities identified with USG. METHODS: We reviewed clinical records and collected data on admissions for a sacral dimple from March 2014 through February 2017 that were evaluated with spine USG by a pediatric radiologist. During the same period, patients who were admitted for other complaints, but were found to have a sacral dimple were also included. RESULTS: This study included 230 infants under 6-months-old (130 males and 100 females; mean age 52.8±42.6 days). Thirty-one infants with a sacral dimple had an echogenic filum terminale, and 57 children had a filar cyst. Twenty-seven patients had a low-lying spinal cord, and only one patient was suspected of having a tethered cord. Follow-up spine USG was performed in 28 patients, which showed normalization or insignificant change. CONCLUSION: In this study, all but one infant with a sacral dimple had benign imaging findings. USG can be recommended in infants with a sacral dimple for its convenience and safety.

Long-term prenatal stress increases susceptibility of N-methyl-D-aspartic acid-induced spasms in infant rats / 소아과

PURPOSE: Infantile spasms, also known as West syndrome, is an age-specific epileptic seizure. Most patients with this condition also exhibit delayed development. This study aimed to determine the effect of long-term prenatal stress on susceptibility to infantile spasms. METHODS: We subjected pregnant rats to acute or chronic immobilization stress. Resulting offspring received N-methyl-D-aspartic acid (15 mg/kg, intraperitoneally) on postnatal day 15, and their behaviors were observed 75 minutes after injection. The expression of KCC2 and GAD67 was also determined using immunohistochemistry. RESULTS: Exposure to long-term prenatal stress increased the frequency of spasms and decreased the latency to onset of spasms compared with offspring exposed to short-term prenatal stress. Expression of KCC2 and GAD67 also decreased in the group exposed to long-term prenatal stress compared with the group exposed to short-term prenatal stress. CONCLUSION: Our study suggests that exposure to long-term prenatal stress results in increased susceptibility to seizures.

Iron Supplement in Paroxysmal Non-epileptic Events in Children / 대한소아신경학회지

PURPOSE: Paroxysmal non-epileptic event (PNE) is a common seizure-like symptom in children. With regard to therapy, a decrease in iron levels was reported in breath-holding spells, but not in other PNEs. The effects of iron supplementation were investigated on various PNEs. METHODS: Medical records of patients who visited our clinic with seizure-like symptoms were retrospectively reviewed at Chungnam National University Hospital, from March 2013 to March 2016. RESULTS: A total of 29 patients (65.9%) were boys and 15 (34.1%) were girls. The mean gestational age and birth weight were 39.3 weeks and 3,200 g, respectively. The mean age at the time of visit was 23.5 months. Of the 11 patients who underwent brain imaging, 10 (90.9%) had normal findings and 1 (9.1%) had subdural hemorrhage. An electroencephalogram was performed in 29 patients; 26 of them had normal findings (89.7%), 2 (6.9%) had slow background, and 1 (3.4%) had epileptiform discharges. A total of 31 patients (70.5%) had iron levels lower than 80 µg/dL. Iron supplementation was administered in 4 of the 13 patients with normal iron status and in 21 of the 31 patients with low iron status. A significant improvement in the frequency and severity of symptom was observed in 91.7% of patients who received iron supplementation (P<0.05). CONCLUSIONS: Symptoms improved in 80% of patients with PNE, and a higher rate of symptom improvement could be expected with iron supplementation.