Ketogenic diets in patients with inherited metabolic disorders.

Ketogenic diets (KDs) are diets that bring on a metabolic condition comparable to fasting, usually without catabolism. Since the mid-1990s such diets have been widely used in patients with seizures/epilepsies, mostly children. This review focuses on the use of KDs in patients with various inherited metabolic disorders (IMD). In glucose transporter type 1 deficiency syndrome (GLUT1-DS) and pyruvate dehydrogenase complex (PDHc) deficiency, KDs are deemed the therapy of choice and directly target the underlying metabolic disorder. Moreover, in other IMD, mainly of intermediary metabolism such as glycogen storage diseases and disorders of mitochondrial energy supply, KDs may ameliorate clinical symptoms and laboratory parameters. KDs have also been used successfully to treat symptoms such as seizures/epilepsy in IMD, e.g. in urea cycle disorders and non-ketotic hyperglycinemia. As a note of caution, catabolism may cause the condition of patients with IMD to deteriorate and should thus be avoided during KDs. For this reason, careful monitoring (clinical, laboratory and apparatus-supported) is warranted. In some IMDs specific macronutrient supply is critical. Therefore, in cases of PDHc deficiency the carbohydrate intake tolerated without lactate increase and in urea cycle disorders the protein tolerance should be determined. Considering this, it is particularly important in patients with IMD that the use of KDs be individualized and well documented.

Chromosomal microaberrations in patients with epilepsy, intellectual disability, and congenital anomalies.

Epilepsy is a common finding in patients with chromosomal macro- and micro-rearrangements but only few aberrations show a constant pattern of seizures. DNA array-based studies have reported causative copy number variations (CNVs) in 5-30% of patients with epilepsy with or without co-morbidities. The interpretation of many of the detected CNVs remains challenging. In order to identify CNVs carrying epilepsy-related genes we investigated 43 children with various patterns of epileptic seizures, intellectual disability (ID), and minor dysmorphism, using the Illumina® Infinium Human1M-DuoV1 array. In three patients we found likely causative de novo CNVs, i.e. deletions in 1q41q42.12 (3.4 Mb) and 19p13.2 (834 kb), and a mosaic two-segment duplication in 17p13.2 (218 kb) and 17p13.1 (422 kb). In six additional patients there were aberrations (a deletion in one and duplications in five patients) with uncertain clinical consequences. In total, the finding of causative chromosomal micro-rearrangements in 3 out of 43 patients (7%) and potentially causative CNVs in 6 additional patients (14%) with epilepsy and ID but without major malformations confirms the power of DNA arrays for the detection of new disease-related genetic regions.

Stroke-like episodes in propionic acidemia caused by central focal metabolic decompensation.

Propionic acidemia caused by propionyl-CoA carboxylase deficiency frequently leads to neurologic complications. Herein we report an eleven-year-old patient with propionic acidemia having three stroke-like episodes during a period of 13 months characterized by acute reversible hemiplegia and vegetative symptoms like bradycardia or drowsiness. No biochemical signs of severe metabolic decompensation were detectable in plasma. At all three episodes, EEG was not indicative for status epilepticus, but in the acute episode it showed slowing of background activity emphasized on one side. MRI revealed reversible hyperintensities in cortical grey matter and basal ganglia. During the third episode a lumbar puncture was done in parallel with venous puncture. Concentrations of glutamine (902 micromol/L), glycine (24 micromol/L) and alanine (78 micromol/L) were elevated in CSF. In plasma glycine (1 859 micromol/L) and alanine (608 micromol/L) concentrations were also elevated, whereas the glutamine (458 micromol/L) concentration was normal. CSF/plasma ratios were elevated for glutamine (1.97) and alanine (0.13) and normal for glycine (0.01). We assume that the stroke-like episodes in our patient may be caused by an acute focal cerebral metabolic decompensation, which is detectable by unspecific changes in MRI and by measuring amino acids and lactate in CSF versus plasma.

Epilepsy in patients with propionic acidemia.

Propionic acidemia (PA) is an autosomal recessively inherited defect of propionyl-CoA carboxylase with an incidence of approximately 1:50 000. There are few reports on the occurrence of EEG findings and development of epilepsy in patients with PA. Retrospectively, the data of 17 patients with PA from one Italian and four Austrian centers were evaluated concerning EEG findings and the development of epilepsy. Nine patients showed a disturbance of background activity, as well as epileptiform discharges. All nine patients with pathological EEG discharges developed seizures compatible with the definition of symptomatic epilepsy. Five of these nine patients showed fever induced seizures at the beginning. Two of them suffered from symptomatic absence epilepsy. Six of the nine patients with seizures were treated with antiepileptic drugs (AED), which were tolerated without side-effects. Four patients showed photosensitivity, which so far has never been reported in PA. We hypothesize that patients with PA are prone to cortical dysfunction caused by one or several pathological metabolites - leading to changes in background and epileptiform activity with a high manifestation rate of clinical seizures.

Electroclinical and imaging findings in ulegyria and epilepsy: a study on 25 patients.

PURPOSE: Ulegyria refers to cerebral cortex scarring, which results from a perinatal ischaemic brain injury. It presents with a characteristic gyral pattern: small circumvolutions with atrophy at sulci bottom and spared apex. Ulegyria is frequently associated with epilepsy, cerebral palsy and mental disability. We analysed electroclinical and MRI features in patients with ulegyria and epilepsy. PATIENTS AND METHODS: We reviewed 25 patients (14 males/11 females) with ulegyria and epilepsy from the database (about 5000 patients with epilepsy) of our unit. Patients were examined clinically, underwent high resolution MRI, EEG recordings, positron emission tomography, single photon emission computed tomography and neuropsychological testing. Two patients with refractory seizures underwent epilepsy surgery. RESULTS: Mean age of patients was 34 years (5-66) at the reassessment time. The majority (16/25, 64%) had a history of perinatal asphyxia. 15 patients had delayed developmental milestones; 20 had learning disabilities and five patients were severely disabled. Mean age at seizure onset was 4.2 years (1-18). 17 patients (68%) had medically intractable epilepsy. 11 patients (44%) had occipital lobe seizures. The majority (n = 24, 96%) had parieto-occipital lesions on MRI. In 13 patients (52%), ulegyria was bilateral. 12 patients (48%) had hippocampal sclerosis. Two patients underwent epilepsy surgery with an excellent postoperative outcome (Engel class IA and IC). CONCLUSION: Patients with ulegyria often have a history of perinatal asphyxia and present with pharmacoresistant seizures. Their presurgical assessment is complicated because of frequent dual pathology (hippocampal sclerosis) and bilateral lesions.

Amino acids in CSF and plasma in hyperammonaemic coma due to arginase1 deficiency.

UNLABELLED: We report the CSF and plasma amino acid concentrations and their ratios in a male patient with arginase1 deficiency with an unusual early presentation at 34 days of age. He developed hyperammonaemic coma (ammonia >400 µmol/L; normal <90 µmol/L) on postnatal day 35. CSF and plasma concentrations were assayed by ion-exchange chromatography on day 36. Arginine was increased both in plasma (971 µmol/L; controls (mean ± 2SD) 50 ± 42) and in CSF (157 µmol/L; controls 19 ± 8.6), resulting in a normal CSF/plasma ratio of 0.16 (controls 0.41 ± 0.26). Interestingly, glutamine was disproportionately high in CSF (3114 µmol/L; controls 470 ± 236) but normal in plasma (420 µmol/L; controls 627 ± 246); the ratio exceeded unity (7.4; controls 0.76 ± 0.31). The CSF/plasma ratios of most neutral amino acids were elevated but not those of the imino- and of the dibasic amino acids lysine and ornithine. The mechanism leading to the increase of most neutral amino acids in brain is not known. CONCLUSION: A normal glutamine in plasma does not exclude an increased concentration in CSF; it could be useful to ascertain by MRS that a high CSF glutamine concentration truly reflects a high concentration in brain tissue for better understanding its pathogenesis.

The relation of cerebrospinal fluid and plasma glycine levels in propionic acidaemia, a 'ketotic hyperglycinaemia'.

The characteristic elevation of plasma glycine concentrations observed in propionic acidaemia (PA) and other 'ketotic hyperglycinaemias' has been attributed to secondary inhibition of the hepatic glycine cleavage system (GCS) by accumulating CoA derivatives of branched-chain amino acid metabolites. In nonketotic hyperglycinaemia (NKH), cerebrospinal fluid (CSF) and plasma glycine levels and their ratio are increased due to primary deficiency of central nervous system (CNS) as well as hepatic GCS. Whether the GCS in the CNS is also inhibited in PA is unclear, as there are scant data available on CSF glycine levels in this disorder. We studied the relation of CSF and plasma glycine levels in 6 paired samples from 4 PA patients, including one PA patient with bacterial meningitis who underwent ventriculoperitoneal shunting and multiple CSF analyses (n = 26). In contrast to the CSF glycine levels which were generally elevated in all four PA patients, the CSF/plasma glycine concentration ratios in paired samples were normal (0.016-0.029), with the exception of a single sample (0.132) with extremely high CSF protein concentration (2010 mg/L) during the course of meningitis indicating a disturbed blood-brain barrier. This finding of normal CSF/plasma glycine ratio in PA suggests that the observed elevations of CSF glycine levels are a reflection of the concurrent hyperglycinaemia resulting from secondary inhibition of hepatic GCS, but that brain GCS is not affected, in contrast to the situation in NKH. The neurological sequelae in PA are therefore unlikely to be related to disturbed glycine metabolism.

Effect of valproic acid treatment on body composition, leptin and the soluble leptin receptor in epileptic children.

PURPOSE: The aim of the study was to determine the influence of valproic acid (VPA) treatment on leptin, the soluble leptin receptor (sOB-R), the sOB-R/leptin ratio, body composition and insulin resistance in epileptic children. METHODS: A cross-sectional cohort study was conducted at the Medical University Innsbruck, Austria. Children >6 years with idiopathic epilepsy and antiepileptic drug therapy since at least six months were eligible. Leptin concentration, the sOB-R, the sOB-R/leptin ratio, body composition and glucose homeostasis were determined. RESULTS: 87 children (median [range] age 12.8 years [6.0-18.6]) were on treatment with VPA, 55 (12.3 years [6.4-18.3]) on other AEDs, comprising the non-VPA group. VPA-treated children had higher leptin concentrations, body-mass-index standard-deviation score (SDS), body fat (each p<0.001), serum insulin concentrations (p=0.014) and homeostasis model assessment (HOMA) index (p=0.009), as well as a lower sOB-R/leptin ratio (p<0.001) when compared to the non-VPA group. Overweight VPA-treated children showed lower sOB-R concentrations and a lower sOB-R/leptin ratio (each p<0.001) as well as higher body fat and leptin levels (each p<0.001) compared to lean VPA-treated children. CONCLUSION: VPA monotherapy was associated with higher body weight, body fat and serum leptin concentrations as well as impaired glucose homeostasis. Low sOB-R concentrations and a low sOB-R/leptin ratio in overweight VPA-treated patients might contribute to disturbances in glucose homeostasis and to the development of the metabolic syndrome in these children later in life.

Epileptic phenotypes, electroclinical features and clinical characteristics in 17 children with anti-NMDAR encephalitis.

BACKGROUND: Anti-N-methyl d-aspartate receptor (NMDAR) encephalitis is a rare disorder characterized by seizures, neuropsychiatric symptoms, dyskinesia and autonomic instability. OBJECTIVE: Aim of the present study was to evaluate the seizure phenotypes and electroencephalogram (EEG) features in children with anti-NMDAR encephalitis. METHODS: Seizure types, electroclinical features and clinical characteristics of 17 children with anti-NMDAR encephalitis were analysed in a retrospective case series from nine centres in Europe. RESULTS: Nearly half (8/17) of the children presented with psychiatric symptoms, whereas in 4/17 patients seizures were the first symptom and in 5/17 both symptoms occurred at the same time. During the following course seizures were reported in 16/17 children. The first EEG detected generalized slowing in 11/17 patients, focal slowing in 3/17 and normal background activity in only 3/17 children. The extreme delta brush (EDB) pattern was detected in 9/17 (53%) patients. CONCLUSION: In addition to psychiatric symptoms, children with anti-NMDAR encephalitis often show generalized slowing in EEG with or without seizures at initial presentation. EDB is present in half of all children and is potentially a helpful tool for early detection of this immune-mediated disease.

ASPP2 deficiency causes features of 1q41q42 microdeletion syndrome.

Chromosomal abnormalities are implicated in a substantial number of human developmental syndromes, but for many such disorders little is known about the causative genes. The recently described 1q41q42 microdeletion syndrome is characterized by characteristic dysmorphic features, intellectual disability and brain morphological abnormalities, but the precise genetic basis for these abnormalities remains unknown. Here, our detailed analysis of the genetic abnormalities of 1q41q42 microdeletion cases identified TP53BP2, which encodes apoptosis-stimulating protein of p53 2 (ASPP2), as a candidate gene for brain abnormalities. Consistent with this, Trp53bp2-deficient mice show dilation of lateral ventricles resembling the phenotype of 1q41q42 microdeletion patients. Trp53bp2 deficiency causes 100% neonatal lethality in the C57BL/6 background associated with a high incidence of neural tube defects and a range of developmental abnormalities such as congenital heart defects, coloboma, microphthalmia, urogenital and craniofacial abnormalities. Interestingly, abnormalities show a high degree of overlap with 1q41q42 microdeletion-associated abnormalities. These findings identify TP53BP2 as a strong candidate causative gene for central nervous system (CNS) defects in 1q41q42 microdeletion syndrome, and open new avenues for investigation of the mechanisms underlying CNS abnormalities.

Childhood febrile convulsions--which factors determine the subsequent epilepsy syndrome? A retrospective study.

To analyze the spectrum of epilepsy syndromes which follow childhood febrile convulsions (FC) and to examine whether retrospective analysis of clinical features of the FC enables discrimination of patients who develop temporal lobe epilepsy (TLE) from those who develop generalized epilepsy (GE). One hundred and thirteen patients with epilepsy and antecedent FC were retrospectively analyzed. We inquired in detail about the clinical characteristics of FC (age, duration, number, focal symptoms) as well as family history, birth history, neurological status, and psychomotor development before onset of FC. Forty five (39.8%) patients had TLE, 41 (36.6%) GE, and 27 (23.9%) had extratemporal epilepsy (ETE). Patients with TLE had a significantly longer duration of FC (P< or =0.001), more often focal features (P< or =0.001), and febrile status epilepticus (P< or =0.001) than patients with GE. Age at FC, Number of FC, family history, birth history and neurological status at FC did not differ between groups. A stepwise discriminant model allowed correct assignment after cross validation in 84.2% to TLE and in 100% to GE. A broad spectrum of epilepsy syndromes follow FC. We found a strong association of prolonged and focal FC with later development of TLE. Short generalized FC were associated with GE.

[SIDS prevention program in Tyrol]. / Das SIDS-Vorsorgeprogramm Tirol.

In April 1994, an intervention campaign to reduce the incidence of sudden infant death syndrome (SIDS) was established in the Tyrol. The campaign was intended to increase knowledge concerning risk factors for SIDS in the general community and to improve individual care for infants at risk. In contrast to interventional programmes in other federal states of Austria (i.e. Vorarlberg, Styria), this programme did not utilise polysomnography for identifying infants at risk. A part of the intervention programme was the "Styrian risk questionnaire", a standardised questionnaire concerning risk factors for SIDS. Individual instructions for health care of children at risk (risk score > or = 7) were provided and, if necessary, subscription of home monitoring was performed at the out-patient department (SIDS out-patient service) of the Department of Paediatrics in Innsbruck and other paediatric departments throughout the Tyrol. The educational programme also included information concerning basic life support. Psychological support was offered to parents of SIDS infants. Risk factors for SIDS in the Tyrol before the campaign were assessed in a retrospective case-control study (time period 1984-1994; 99 SIDS infants, 136 controls). The risk of SIDS was markedly reduced when parents had detailed knowledge of the risk factors of SIDS (odds ratio (OR) 0.03; p < 0.001), which emphasises the importance of information and educational programmes. The incidence of SIDS declined after the beginning of the intervention campaign from 1.83/1000 live births (average incidence from 1984-1994) to 0.4/1000 live births and remained at this level thereafter. Post-neonatal mortality also declined from 3.9 to 1.3/1000 live births. The prevalence of the prone sleeping position declined immediately after the campaign (53.7% vs. 5.4%, p < 0.001), as did the frequency of maternal smoking during pregnancy (22.9% vs. 14.5%, p < 0.01). Breast feeding became more popular. In all, the low-cost intervention programme in the Tyrol proved to be highly efficient in reducing the risk of SIDS and in maintaining this effect for several years.

Limbic encephalitis in children and adolescents.

OBJECTIVE: Limbic encephalitis is rare in people <18 years of age and rarely given a formal diagnosis. DESIGN: Retrospective study on presentation and outcome of children and adolescents with the clinico-radiological syndrome of limbic encephalitis tested for specific neuronal autoantibodies (Abs) over 3.5 years. SETTING: Assessment, diagnosis, treatment and follow-up at 12 neuropaediatric and neurological departments in Europe, with Abs determined in Bonn, Germany and Oxford, UK. PATIENTS: Ten patients <18 years of age who presented with a disorder mainly affecting the limbic areas of <5 years' duration with MRI evidence of mediotemporal encephalitis (hyperintense T2/FLAIR signal, resolving over time). RESULTS: Median age at disease onset was 14 years (range 3-17). Eight patients had defined Abs: one each with Hu or Ma1/2 Abs, four with high titre glutamic acid decarboxylase (GAD) Abs, two of whom had low voltage-gated potassium channel (VGKC) Abs and two with only low titre VGKC Abs. A tumour was only found in the patient with Hu Abs (a neuroblastoma). After a median follow-up of 15 months with corticosteroid or intravenous immunoglobulin treatment, starting after a median of 4 months, two patients recovered, eight remained impaired and one died. CONCLUSIONS: Limbic encephalitis is a disease that can occur in childhood or adolescence with many of the hallmarks of the adult disorder, suggesting that both result from similar pathogenic processes. Since most of the cases were non-paraneoplastic, as now also recognised in adults, more systematic and aggressive immunotherapies should be evaluated in order to improve outcomes.

Hippocampal abnormalities in malformations of cortical development: MRI study.

OBJECTIVES: Hippocampal abnormalities may coexist with malformations of cortical development (MCD). This cross-sectional MRI study aimed at categorizing hippocampal abnormalities in a large group of MCD and comparing MCD patients with (group W) and without (group W/O) hippocampal abnormalities. METHODS: Hippocampal anatomy, rotation, size, internal structure, and MRI signal alterations were assessed visually by 3 independent raters in patients with MCD and epilepsy. Four types of hippocampal abnormalities were examined in 220 patients (116 women, mean age 31 +/- 16.6, range 2-76 years): partially infolded/hypoplastic hippocampus (HH), hippocampal sclerosis (HS), malrotated hippocampus (MH), and enlarged hippocampus (EH). The commonest MCD in the cohort were focal cortical dysplasia (27%), polymicrogyria (PMG) (21%), developmental tumors (15%), and periventricular nodular heterotopia (PNH) (14%). RESULTS: Hippocampal abnormalities were seen in 69/220 (31%) patients: HH in 34/69 (49%); HS in 18/69 (26%); MH in 15/69 (22%); and EH in 2/69 (3%). PNH (21/30 [70%]) and PMG (22/47 [47%]) were most commonly associated with hippocampal abnormalities. Compared to the W/O group, patients in the W group had a higher rate of learning disability (W 41/69 [59%] vs W/O 56/151 [37%]; p = 0.003) and delayed developmental milestones (W 36/69 [52%] vs W/O 53/151 [35%]; p = 0.025); groups did not differ otherwise with regard to clinical presentation. HH was associated with symptomatic generalized epilepsies (11/34 [32%]) and high rate of learning disability (27/34 [79%]), neurologic deficits (25/34 [73%]), and delayed developmental milestones (23/34 [68%]). CONCLUSIONS: About a third of patients with malformations of cortical development had hippocampal abnormalities. Patients with hypoplastic hippocampus had the most severe clinical phenotype.

Levetiractam in the treatment of two children with myoclonic status epilepticus.

Levetiracetam (LEV) is approved as second line treatment for partial onset seizures in adults and children older than four years of age. Recently, an intravenous formulation was developed as an alternative to standard oral medication. We report the successful treatment of two children suffering from myoclonic status epilepticus with intravenous LEV. Intravenous application of LEV was safe and not associated with significant side effects. In conclusion, intravenous application of LEV appears to be a further option in treatment of children with myoclonic status epilepticus.

Peripheral neuropathy as the sole initial finding in three children with infantile metachromatic leukodystrophy.

Metachromatic leukodystrophy (MLD) is a progressive white matter disease caused by arylsulfatase A deficiency. Demyelination in the nervous system is detected by cerebral magnetic resonance imaging (MRI) and neurophysiological studies. We present three children with infantile MLD, who had difficulties in standing and walking with absent reflexes. Protein levels in cerebral spinal fluid (CSF) were elevated and nerve conduction studies revealed slowing down of motor nerve conduction velocity. Initial cerebral MRIs showed no white matter changes. Consecutively, all three children developed clinical symptoms of neurodegenerative disease. Follow-up MRI and arylsulfatase A testing led to diagnosis of MLD. We conclude, that in young children who present with an acute/subacute demyelinating polyneuropathy, MLD is a differential diagnosis.

3-Heptanone as a potential new marker for valproic acid therapy.

Breath gas samples from 27 patients with epilepsy (17 male and 10 female patients; mean age: 9.7 years, median age: 8.2 years, SD: ±4.2 years) were screened via proton transfer reaction mass spectrometry. The patients were treated with valproic acid (VPA) therapy, and blood samples for determination of VPA concentrations were surveyed. All patients showed significantly elevated concentrations of 3-heptanone (C(7)H(14)O) in exhaled breath gas (mean: 14.7 ppb, median: 13.8 ppb SD: ±5.7 ppb). In human breath, several hundred different volatile organic compounds can be detected. In breath of patients with valproic acid monotherapy, an increased concentration of 3-heptanone was measured. The objective of this study was to investigate if serum VPA concentrations correlate with 3-heptanone concentrations in exhaled breath. In conclusion, 3-heptanone in breath gas is significantly elevated in patients treated with the valproic acid, but does not correlate significantly with the VPA concentrations in serum or the daily dose of this drug.