Glucose and oxygen in the early intrauterine environment and their role in developmental abnormalities

The early life environment can have profound impacts on the developing conceptus in terms of both growth and morphogenesis. These impacts can manifest in a variety of ways, including congenital fetal anomalies, placental dysfunction with subsequent effects on fetal growth, and adverse perinatal outcomes, or via effects on long-term health outcomes that may not be detected until later childhood or adulthood. Two key examples of environmental influences on early development are explored: maternal hyperglycaemia and gestational hypoxia. These are increasingly common pregnancy exposures worldwide, with potentially profound impacts on population health. We explore what is known regarding the mechanisms by which these environmental exposures can impact early intrauterine development and thus result in adverse outcomes in the immediate, short, and long term.

Sex differences in the intergenerational inheritance of metabolic traits

Strong evidence suggests that early-life exposures to suboptimal environmental factors, including those in utero, influence our long-term metabolic health. This has been termed developmental programming. Mounting evidence suggests that the growth and metabolism of male and female fetuses differ. Therefore, sexual dimorphism in response to pre-conception or early-life exposures could contribute to known sex differences in susceptibility to poor metabolic health in adulthood. However, until recently, many studies, especially those in animal models, focused on a single sex, or, often in the case of studies performed during intrauterine development, did not report the sex of the animal at all. In this review, we (a) summarize the evidence that male and females respond differently to a suboptimal pre-conceptional or in utero environment, (b) explore the potential biological mechanisms that underlie these differences and (c) review the consequences of these differences for long-term metabolic health, including that of subsequent generations.

Programming of cardiometabolic health: the role of maternal and fetal hyperinsulinaemia

Obesity and gestational diabetes during pregnancy have multiple short- and long-term consequences for both mother and child. One common feature of pregnancies complicated by maternal obesity and gestational diabetes is maternal hyperinsulinaemia, which has effects on the mother and her adaptation to pregnancy. Even though insulin does not cross the placenta insulin can act on the placenta as well affecting placental growth, angiogenesis and lipid metabolism. Obese and gestational diabetic pregnancies are often characterised by maternal hyperglycaemia resulting in exposure of the fetus to high levels of glucose, which freely crosses the placenta. This leads to stimulation of fetal ß-cells and insulin secretion in the fetus. Fetal hyperglycaemia/hyperinsulinaemia has been shown to cause multiple complications in fetal development, such as altered growth trajectories, impaired neuronal and cardiac development and early exhaustion of the pancreas. These changes could increase the susceptibility of the offspring to develop cardiometabolic diseases later in life. In this review, we aim to summarize and review the mechanisms by which maternal and fetal hyperinsulinaemia impact on (i) maternal health during pregnancy; (ii) placental and fetal development; (iii) offspring energy homeostasis and long-term cardiometabolic health; (iv) how interventions can alleviate these effects.

Maternal but not fetoplacental health can be improved by metformin in a murine diet-induced model of maternal obesity and glucose intolerance

Maternal obesity is a global problem that increases the risk of short- and long-term adverse outcomes for mother and child, many of which are linked to gestational diabetes mellitus. Effective treatments are essential to prevent the transmission of poor metabolic health from mother to child. Metformin is an effective glucose lowering drug commonly used to treat gestational diabetes mellitus; however, its wider effects on maternal and fetal health are poorly explored. In this study we used a mouse (C57Bl6/J) model of diet-induced (high sugar/high fat) maternal obesity to explore the impact of metformin on maternal and feto-placental health. Metformin (300 mg kg-1  day-1 ) was given to obese females via the diet and was shown to achieve clinically relevant concentrations in maternal serum (1669 ± 568 nM in late pregnancy). Obese dams developed glucose intolerance during pregnancy and had reduced uterine artery compliance. Metformin treatment of obese dams improved maternal glucose tolerance, reduced maternal fat mass and restored uterine artery function. Placental efficiency was reduced in obese dams, with increased calcification and reduced labyrinthine area. Consequently, fetuses from obese dams weighed less (P < 0.001) at the end of gestation. Despite normalisation of maternal parameters, metformin did not correct placental structure or fetal growth restriction. Metformin levels were substantial in the placenta and fetal circulation (109.7 ± 125.4 nmol g-1 in the placenta and 2063 ± 2327 nM in fetal plasma). These findings reveal the distinct effects of metformin administration during pregnancy on mother and fetus and highlight the complex balance of risk vs. benefits that are weighed in obstetric medical treatments. KEY POINTS: Maternal obesity and gestational diabetes mellitus have detrimental short- and long-term effects for mother and child. Metformin is commonly used to treat gestational diabetes mellitus in many populations worldwide but the effects on fetus and placenta are unknown. In a mouse model of diet-induced obesity and glucose intolerance in pregnancy we show reduced uterine artery compliance, placental structural changes and reduced fetal growth. Metformin treatment improved maternal metabolic health and uterine artery compliance but did not rescue obesity-induced changes in the fetus or placenta. Metformin crossed the placenta into the fetal circulation and entered fetal tissue. Metformin has beneficial effects on maternal health beyond glycaemic control. However, despite improvements in maternal physiology, metformin did not prevent fetal growth restriction or placental ageing. The high uptake of metformin into the placental and fetal circulation highlights the potential for direct immediate effects of metformin on the fetus with possible long-term consequences postnatally.

Maternal diet-induced obesity during pregnancy alters lipid supply to mouse E18.5 fetuses and changes the cardiac tissue lipidome in a sex-dependent manner

Maternal obesity during pregnancy has immediate and long-term detrimental effects on the offspring heart. In this study, we characterized the cardiac and circulatory lipid profiles in late gestation E18.5 fetuses of diet-induced obese pregnant mice and established the changes in lipid abundance and fetal cardiac transcriptomics. We used untargeted and targeted lipidomics and transcriptomics to define changes in the serum and cardiac lipid composition and fatty acid metabolism in male and female fetuses. From these analyses we observed: (1) maternal obesity affects the maternal and fetal serum lipidome distinctly; (2) female fetal heart lipidomes are more sensitive to maternal obesity than males; (3) changes in lipid supply might contribute to early expression of lipolytic genes in mouse hearts exposed to maternal obesity. These results highlight the existence of sexually dimorphic responses of the fetal heart to the same in utero obesogenic environment and identify lipids species that might mediate programming of cardiovascular health.

The imprinted Igf2-Igf2r axis is critical for matching placental microvasculature expansion to fetal growth

In all eutherian mammals, growth of the fetus is dependent upon a functional placenta, but whether and how the latter adapts to putative fetal signals is currently unknown. Here, we demonstrate, through fetal, endothelial, hematopoietic, and trophoblast-specific genetic manipulations in the mouse, that endothelial and fetus-derived IGF2 is required for the continuous expansion of the feto-placental microvasculature in late pregnancy. The angiocrine effects of IGF2 on placental microvasculature expansion are mediated, in part, through IGF2R and angiopoietin-Tie2/TEK signaling. Additionally, IGF2 exerts IGF2R-ERK1/2-dependent pro-proliferative and angiogenic effects on primary feto-placental endothelial cells ex vivo. Endothelial and fetus-derived IGF2 also plays an important role in trophoblast morphogenesis, acting through Gcm1 and Synb. Thus, our study reveals a direct role for the imprinted Igf2-Igf2r axis on matching placental development to fetal growth and establishes the principle that hormone-like signals from the fetus play important roles in controlling placental microvasculature and trophoblast morphogenesis.

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Fetus-derived IGF2 controls placental microvasculature expansion in late gestation

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The angiocrine effects of IGF2 are mediated via angiopoietins/Tek and IGF2R-ERK1/2

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Fetus-derived IGF2 also regulates trophoblast morphogenesis via Gcm1 and Synb

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The imprinted Igf2-Igf2r axis matches placental development to fetal demand

Enhanced Electric Dipole Strength for the Weakly Bound States in ^{27}Ne

An enhanced low-energy electric dipole (E1) strength is identified for the weakly bound excited states of the neutron-rich isotope ^{27}Ne. The Doppler-shift lifetime measurements employing a combination of the γ-ray tracking array GRETINA, the plunger device, and the S800 spectrograph determine the lower limit of 0.030  e^{2} fm^{2} or 0.052 W.u. for the 1/2^{+}→3/2^{-}  E1 transition in ^{27}Ne, representing one of the strongest E1 strengths observed among the bound discrete states in this mass region. This value is at least 30 times larger than that measured for the 3/2^{-} decay to the 3/2_{gs}^{+} ground state. A comparison of the present results to large-scale shell-model calculations points to an important role of core excitations and deformation in the observed E1 enhancement, suggesting a novel example of the electric dipole modes manifested in weakly bound deformed systems.

Quasifree (p, 2p) Reactions on Oxygen Isotopes: Observation of Isospin Independence of the Reduced Single-Particle Strength

Quasifree one-proton knockout reactions have been employed in inverse kinematics for a systematic study of the structure of stable and exotic oxygen isotopes at the R^{3}B/LAND setup with incident beam energies in the range of 300-450  MeV/u. The oxygen isotopic chain offers a large variation of separation energies that allows for a quantitative understanding of single-particle strength with changing isospin asymmetry. Quasifree knockout reactions provide a complementary approach to intermediate-energy one-nucleon removal reactions. Inclusive cross sections for quasifree knockout reactions of the type ^{A}O(p,2p)^{A-1}N have been determined and compared to calculations based on the eikonal reaction theory. The reduction factors for the single-particle strength with respect to the independent-particle model were obtained and compared to state-of-the-art ab initio predictions. The results do not show any significant dependence on proton-neutron asymmetry.

The interaction network of the YidC insertase with the SecYEG translocon, SRP and the SRP receptor FtsY

YidC/Oxa1/Alb3 are essential proteins that operate independently or cooperatively with the Sec machinery during membrane protein insertion in bacteria, archaea and eukaryotic organelles. Although the interaction between the bacterial SecYEG translocon and YidC has been observed in multiple studies, it is still unknown which domains of YidC are in contact with the SecYEG translocon. By in vivo and in vitro site-directed and para-formaldehyde cross-linking we identified the auxiliary transmembrane domain 1 of E. coli YidC as a major contact site for SecY and SecG. Additional SecY contacts were observed for the tightly packed globular domain and the C1 loop of YidC, which reveals that the hydrophilic cavity of YidC faces the lateral gate of SecY. Surprisingly, YidC-SecYEG contacts were only observed when YidC and SecYEG were present at about stoichiometric concentrations, suggesting that the YidC-SecYEG contact in vivo is either very transient or only observed for a very small SecYEG sub-population. This is different for the YidC-SRP and YidC-FtsY interaction, which involves the C1 loop of YidC and is efficiently observed even at sub-stoichiometric concentrations of SRP/FtsY. In summary, our data provide a first detailed view on how YidC interacts with the SecYEG translocon and the SRP-targeting machinery.

Cystathionase mediates senescence evasion in melanocytes and melanoma cells

The development of malignant melanoma is a highly complex process, which is still poorly understood. A majority of human melanomas are found to express a few oncogenic proteins, such as mutant RAS and BRAF variants. However, these oncogenes are also found in nevi, and it is now a well-accepted fact that their expression alone leads to senescence. This renders the understanding of senescence escape mechanisms an important point to understand tumor development. Here, we approached the question of senescence evasion by expressing the transcription factor v-myc myelocytomatosis viral oncogene homolog (c-MYC), which is known to act synergistically with many oncogenes, in melanocytes. We observed that MYC drives the evasion of reactive-oxygen stress-induced melanocyte senescence, caused by activated receptor tyrosine kinase signaling. Conversely, MIZ1, the growth suppressing interaction partner of MYC, is involved in mediating melanocyte senescence. Both, MYC overexpression and Miz1 knockdown led to a strong reduction of endogenous reactive-oxygen species (ROS), DNA damage and senescence. We identified the cystathionase (CTH) gene product as mediator of the ROS-related MYC and MIZ1 effects. Blocking CTH enzymatic activity in MYC-overexpressing and Miz1 knockdown cells increased intracellular stress and senescence. Importantly, pharmacological inhibition of CTH in human melanoma cells also reconstituted senescence in the majority of cell lines, and CTH knockdown reduced tumorigenic effects such as proliferation, H2O2 resistance and soft agar growth. Thus, we identified CTH as new MYC target gene with an important function in senescence evasion.

Oncogene activation in melanocytes links reactive oxygen to multinucleated phenotype and senescence

Contrary to malignant melanoma, nevi are a benign form of melanocytic hyperproliferation. They are frequently observed as precursor lesions of melanoma, but they also feature biochemical markers of senescence. In particular, evidence for oncogene-induced melanocyte senescence as natural means to prevent tumorigenesis has been obtained in nevi with mutated B-Raf(V600E). Here, we demonstrate that strong oncogenic growth factor receptor signalling drives melanocytes into senescence, whereas weaker signals keep them in the proliferative state. Activation of oncogene-induced senescence also produces multinucleated giant cells, a long known histological feature of nevus cells. The protein levels of the senescence mediators, p53 and pRB, and their upstream activators do not correlate with senescence. However, strong oncogene signalling leads to pronounced reactive oxygen stress, and scavenging of reactive oxygen species (ROS) efficiently prevents the formation of multinucleated cells and senescence. Similarly, expression of oncogenic N-RAS results in ROS generation, DNA damage and the same multinuclear senescent phenotype. Hence, we identified oncogenic signalling-dependent ROS production as critical mediator of the melanocytic multinuclear phenotype and senescence, both of them being hallmarks of human nevus cells.

The Wada test in Austrian, Dutch, German, and Swiss epilepsy centers from 2000 to 2005: a review of 1421 procedures

Twenty-six Austrian, Dutch, German, and Swiss epilepsy centers were asked to report on use of the Wada test (intracarotid amobarbital procedure, IAP) from 2000 to 2005 and to give their opinion regarding its role in the presurgical diagnosis of epilepsy. Sixteen of the 23 centers providing information had performed 1421 Wada tests, predominantly the classic bilateral procedure (73%). A slight nonsignificant decrease over time in Wada test frequency, despite slightly increasing numbers of resective procedures, could be observed. Complication rates were relatively low (1.09%; 0.36% with permanent deficit). Test protocols were similar even though no universal standard protocol exists. Clinicians rated the Wada test as having good reliability and validity for language determination, whereas they questioned its reliability and validity for memory lateralization. Several noninvasive functional imaging techniques are already in use. However, clinicians currently do not want to rely solely on noninvasive functional imaging in all patients.

Early diffusion-weighted MRI predicts regional neuronal damage in generalized status epilepticus in rats treated with diazepam

We applied diffusion-weighted MRI (DWI) in the pilocarpine-induced status epilepticus (SE) model to investigate the evolution of acute phase changes in brain diffusion with and without early anticonvulsive therapy correlated to long-term SE-induced neuronal cell loss. Hereby, DWI was performed before (baseline) and serially between 3 and 120 min after onset of SE in untreated and treated animals (n=15 in each group). Anticonvulsive-treated animals received 20 mg/kg diazepam at 15 min after onset of SE. Apparent diffusion coefficients (ADC) were calculated for the parietal, temporal and piriform cortex, thalamus, hippocampus and amygdala and compared to baseline. Neuronal cell loss was quantified at 2 weeks after onset of SE utilizing cresyle-violet-staining. The results of ADC-mapping demonstrated a significant transient increase in ADC (to 116+/-4% of baseline) in the very acute phase starting 3 min after SE onset, lasting for 10 min in both groups. In untreated animals, there was a significant gradual decline in ADC to 75+/-12% of baseline while this decline in diazepam-treated animals was significantly less pronounced (P<0.05) and ADC recovered to 93+/-6% of baseline. There was good correlation between neuronal cell loss in specific brain regions at 2 weeks after SE and maximal decrease in ADC (r>0.79). In conclusion, serial DWI is a sensitive noninvasive technique for early detection, monitoring and prediction of SE-induced neuronal alterations. Using ADC-mapping, verification of early anticonvulsive therapy in SE seems to be possible as there is good correlation between the maximal decrease in ACD in the acute phase of SE and late neuronal cell loss.

Monitoring of acute generalized status epilepticus using multilocal diffusion MR imaging: early prediction of regional neuronal damage

BACKGROUND AND PURPOSE

Diffusion-weighted MR imaging (DWI) has emerged as tool for noninvasive and early detection of neuronal alterations. The aim of this study was to investigate the evolution of acute phase changes in different brain regions during experimental status epilepticus (SE) using DWI correlated with SE-induced neuronal cell loss.

METHODS

DWI was performed in 20 rats before (baseline) and 3, 5, 10, 15, 20, 30, 45, 60, 90, and 120 minutes after onset of pilocarpine-induced SE. Apparent diffusion coefficients (ADCs) were calculated for the parietal cortex, temporal cortex, pyriform cortex, hippocampus, amygdala, and thalamus and compared with baseline. Neuronal cell loss was quantified at different time points after SE using cresyl-violet-staining.

RESULTS

ADC-mapping demonstrated a significant transient increase in ADC (to 116 +/- 4% of baseline) in the very acute phase, starting 3 minutes after SE onset, lasting for 10 minutes, followed by a significant gradual decline in ADC in all animals. Compared with surviving animals (76 +/- 7%), decline in ADC was significantly lower for the animals who died within 2 hours for all regions of interest (63 +/- 6.5%, 0.45 +/- 0.03 x 10(-3) mm(2)/s) except the thalamus (P < .01, analysis of variance). There was good correlation between neuronal cell loss in specific brain regions 2 weeks after SE and maximal decrease in ADC (r > 0.76).

CONCLUSION

Serial ultrafast DWI is a sensitive noninvasive technique for early detection and monitoring of seizure-induced neuronal alterations. Using ADC-mapping differentiation of regional severity of neuronal damage may be possible because there is good correlation between the maximal decrease in ADC in the acute phase of SE and late neuronal cell loss.

Alteration of the in vivo nicotinic receptor density in ADNFLE patients: a PET study

Nicotinic acetylcholine receptors (nAChRs) are involved in a familial form of frontal lobe epilepsy, autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). In several ADNFLE families, mutations were identified in the nAChR alpha4 or beta2 subunit, which together compose the main cerebral nAChR. Electrophysiological assessment using in vitro expression systems indicated a gain of function of the mutant receptors. However the precise mechanisms by which they contribute to the pathogenesis of a focal epilepsy remain obscure, especially since alpha4beta2 nAChRs are known to be widely distributed within the entire brain. PET study using [18F]-F-A-85380, a high affinity agonist at the alpha4beta2 nAChRs, allows the determination of the regional distribution and density of the nAChRs in healthy volunteers and in ADNFLE patients, thus offering a unique opportunity to investigate some in vivo consequences of the molecular defect. We have assessed nAChR distribution in eight non-smoking ADNFLE patients (from five families) bearing an identified mutation in nAChRs and in seven age-matched non-smoking healthy volunteers using PET and [(18)F]-F-A-85380. Parametric images of volume of distribution (Vd) were generated as the ratio of tissue to plasma radioactivities. The images showed a clear difference in the pattern of the nAChR density in the brains of the patients compared to the healthy volunteers. Vd values revealed a significant increase (between 12 and 21%, P < 0.05) in the ADNFLE patients in the mesencephalon, the pons and the cerebellum when compared to control subjects. Statistical parametric mapping (SPM) was then used to better analyse subtle regional differences. This analysis confirmed clear regional differences between patients and controls: patients had increased nAChR density in the epithalamus, ventral mesencephalon and cerebellum, but decreased nAChR density in the right dorsolateral prefrontal region. In five patients who underwent an additional [(18)F]-fluorodeoxyglucose (FDG) PET experiment, hypometabolism was observed in the neighbouring area of the right orbitofrontal cortex. The demonstration of a regional nAChR density decrease in the prefrontal cortex, despite the known distribution of these receptors throughout the cerebral cortex, is consistent with a focal epilepsy involving the frontal lobe. We also propose that the nAChR density increase in mesencephalon is involved in the pathophysiology of ADNFLE through the role of brainstem ascending cholinergic systems in arousal.

MRI changes associated with partial status epilepticus

Neurological disorders of different etiology may cause identical clinical symptoms requiring additional diagnostic procedures for a precise differential diagnosis. Focal epileptic seizures have been shown to cause increased signal intensities in T2 and diffusion-weighted magnetic resonance images (MRI), mimicking other neurological disorders or diseases such as viral encephalitis. In some cases even the combination of neuroimaging and cerebrospinal fluid (CSF) analysis is not sufficient to obtain the final diagnosis, since epileptic seizures may cause pleocytosis as well. Some epilepsy centers presented cases of focal status epilepticus with severe but reversible MRI changes. These cases indicate that MRI-changes following focal seizures are reversible over a different time window compared to MRI changes associated with other etiologies, such as viral infection. This data further suggest that in cases where focal seizures can not be ruled out, a follow-up MRI scan within a few days following the onset of symptoms significantly improves the precision of the differential diagnosis. Recently new scientific data were reported in this review.

Cerebral perfusion alterations during the acute phase of experimental generalized status epilepticus: prediction of survival by using perfusion-weighted MR imaging and histopathology

BACKGROUND AND PURPOSE

Persistent generalized status epilepticus (SE) is associated with alterations of cerebral perfusion (CP). Because perfusion-weighted MR imaging (PWI) allows noninvasive CP-determination, the aim of this study was to investigate CP alterations during acute experimental SE correlated with SE-induced neuronal cell loss.

METHODS

The rat pilocarpine model was used to induce SE. Multilocal PWI was performed before (baseline) and 3, 15, 30, 60, and 120 minutes after onset of SE. Bolus-peak ratio (BPR) was calculated for the retrosplenial and piriform cortex, hippocampus, amygdala, and thalamus and compared with baseline. Neuronal cell loss was quantified at different time points after induction of SE by cresyle violet staining.

RESULTS

Immediately after SE onset (3 minutes), BPR temporarily increased to 102%-130% in all regions, with a maximum in the amygdala (129 +/- 16%) and hippocampus (130 +/- 21%). At 15, 30, and 60 minutes, BPR decreased continuously to 57%-76%. BPR values <55% in the parietal and/or temporal cortex resulted in death. In surviving animals, BPR recovered to 66%-79% and there was a good correlation between neuronal cell loss in specific brain regions at 2 weeks after SE onset and maximal decrease in BPR (r > 0.73).

CONCLUSION

PWI demonstrated a transient cerebral hyperperfusion immediately after SE onset, followed by a significant continuous decline to different perfusion levels. In our experimental setting, a decline of cortical BPR below 55% of baseline seems to be a prognostic threshold value associated with subsequent death. In surviving animals, there is good correlation between the maximal decrease in BPR in the acute phase of SE and late neuronal cell loss.

Erh�hte zerebrale Erregbarkeit und "spreading depression"

Increased co-occurrence and common clinical aspects of epilepsy and migraine lead to the question of a common pathophysiological model of the diseases. Shared genetic risk factors as an explanation for comorbidity could not be proven. Clinical studies underline the unspecific association of migraine and epilepsy. Comorbidity is based on spreading depression as an expression of altered brain state with neuronal hyperexcitability. In comorbid conditions, therapy with valproate, gabapentin, or topiramate may be effective.

Cortical activation in patients with functional hemispherectomy

Functional hemispherectomy, a safe and effective therapeutical procedure in medically intractable epilepsy, offers the chance to investigate a strictly unilateral cortical activation in ipsilateral limb movement. We assessed the pattern of cortical activation in a group of patients following functional hemispherectomy. We measured regional cerebral blood flow (rCBF) in 6 patients postoperatively and 6 normal subjects with positron emission tomography using 15[O]H2O as a tracer. Brain activation was achieved by passive elbow movements of the affected arm. Analysis of group results and between-group comparisons were performed with statistical parametric mapping, (SPM96). In normal subjects brain activation was found contralaterally in the cranial sensorimotor cortex and the supplementary motor area and ipsilaterally in the inferior parietal cortex. In patients significant rCBF increases were found in the inferior parietal cortex, caudal sensorimotor cortex and the supplementary motor area ipsilaterally. The activation was weaker than in normal subjects. Compared with normal subjects patients showed additional activation in the premotor cortex, caudal sensorimotor cortex and the inferior parietal cortex of the remaining hemisphere. Less activation compared with normal subjects was found in the cranial sensorimotor cortex and the supplementary motor area. A functional network connecting the inferior parietal cortex, premotor cortex and the supplementary motor area as well as the existence of ipsilateral projections originating from these regions may explain why these areas are predominantly involved in reorganization confined to a single hemisphere.

Seizure-associated headache in epilepsy

PURPOSE

Headache is often ignored as a symptom of epileptic seizures. The purpose of this prospective study was to analyze frequency, classification, and characteristics of seizure-associated headache (SH) according to the criteria of the International Headache Society.

METHODS

Over a period of 15 months, 341 patients with epilepsy, consecutively evaluated at our outpatient clinic for SH, completed a standardized questionnaire.

RESULTS

Of the 341 epilepsy patients, 115 (34%) experienced SH with a pain intensity of 6.1 +/- 1.6 (SD) on the visual analogue scale and a duration of 12.8 +/- 15.7 (SD) h. Seizures were always accompanied by headache in 69 (60%) of these 115 patients. SH occurred in four (3%) of 115 patients only preictally, in 31 (27%) of 115 patients periictally, and in 80 (70%) of 115 patients only postictally. In the majority of the 115 patients (55.7%), SH could be classified as migraine headache, whereas in 36.5%, as tension-type headache. The type of SH was not correlated with sex, an epilepsy syndrome, or a seizure type. Migraine-like SH was significantly associated with a history of migraine (p < 0.001). In 20 (77%) of the 26 patients experiencing migraine-like SH with a history of migraine, the phenomenology of migraine-like SH and migraine attacks was identical.

CONCLUSIONS

SH is a frequent, long-lasting, and severe symptom of epileptic seizures, causing major impairment of daily living. A history of migraine significantly increases the risk for developing migraine-like SH.

Cortical reorganization following multiple subpial transection in human brain - a study with positron emission tomography

We investigated the cortical activation pattern in a 30-year-old woman 4 years after multiple subpial transection (MST) of the right fronto-parietal cortex and six healthy controls using positron emission tomography. Sequential finger-to-thumb opposition at the frequency of 1.5 Hertz contralateral to the operated hemisphere was used as the activation paradigm. We found preserved cortical activation in the transected fronto-parietal cortex and additional activation of the prefrontal cortex bilaterally and the inferior parietal cortex contralaterally when compared with the control group. This activation pattern indicates that MST induces a rather selective lesion leaving the cortical structures functionally intact. However, it necessitates the recruitment of additional motor areas.

Incidence and prevalence of neurological disorders associated with HIV since the introduction of highly active antiretroviral therapy (HAART)

OBJECTIVE

To determine the change of incidence and prevalence of neurological disorders caused by the human immunodeficiency virus (HIV) and opportunistic infections in HIV positive patients under treatment since the introduction of highly active antiretroviral therapy (HAART).

METHODS

The data of all HIV infected patients were retrospectively analysed, who were examined in the HIV outpatients clinic of the neurological department of the University Clinic Essen between 1995 and 1998 (n=563, total number of visits=735). Data from identified patients were divided into two groups according to the time of examination from 1995 to 1996 (334 visits) and from 1997 to 1998 (401 visits). The incidence and prevalence of neurological disorders were statistically compared between both time intervals.

RESULTS

Significantly more patients received HAART in 1997-8 (p<0. 001) and mean CD4+ cell count was significantly higher in 1997-8 (p<0.001). The prevalence of HIV associated dementia and HIV associated polyneuropathy were significantly lower in 1997-8 (both: p=0.02) and the incidence of toxoplasma encephalitis decreased from 5.7% in 1995-6 to 2.2% in 1997-8 (p=0.015). Based on the small number of patients significant changes in HIV associated myopathy, progressive multifocal leukoencephalopathy, cryptoccocal meningitis, and cytomegalovirus-encephalitis could not be detected.

CONCLUSION

The prevalence of the most frequent HIV associated neurological disorders and incidence of toxoplasma encephalitis decreased since the introduction of HAART. This may be due to the improvement of immunostatus by HAART as demonstrated by the higher CD4+ cell count in the later time interval. Direct antiretroviral effects within the nervous system may be considered causative as well. The prevalence and incidence of HIV associated neurological disorders and opportunistic CNS infections decreased after introduction of HAART.

Cortical motor reorganization following early brain damage and hemispherectomy demonstrated by transcranial magnetic stimulation

BACKGROUND

Transcranial magnetic stimulation (TMS) was utilized to study 7 patients who had undergone hemispherectomy for control of longstanding intractable epilepsy to assess cortical motor reorganization and MEP (motor evoked potentials) ipsilateral to the remaining hemisphere. Five patients were seizure-free post-operatively. All patients displayed a spastic hemiparesis, were able to walk, raise and bend the paretic arm and use the paretic hand to different degrees.

METHODS

We examined MEP threshold, site of maximal response to TMS, and latency to the biceps brachii, abductor pollicis brevis and the anterior tibial muscles using a 7 and 12 cm diameter round coil.

RESULTS

The following results were obtained: (1) No MEP could be induced to either side by use of the small coil. (2) When using the large coil MEP-threshold was elevated also when stimulating the non-affected hemisphere in comparison to normal controls. (3) Ipsilateral MEP were found to: be non-inducible in two patients, demonstrate largely increased latencies in 3 and be identical to contralateral MEP in two patients. (4) Ipsilateral MEP could be evoked more often in distal than proximal muscles. (5) The site of maximal ipsilateral MEP response was found approximately 2 cm anteriorly to that of the contralateral MEP to the non-affected side of the body (6) No correlation was found between the degree of hemiparesis and inducability of MEP.

CONCLUSIONS

The pattern of reorganization of ipsilateral motor control following early brain damage and hemispherectomy appears to be extremely diverse and does not correlate with the degree of neurological impairment.

Different effects of GABAergic anticonvulsants on 4-aminopyridine-induced spontaneous GABAergic hyperpolarizations of hippocampal pyramidal cells--implication for their potency in migraine therapy

Clinical studies indicate anti-migrane efficacy of the probably GABAergic anticonvulsants valproate and gabapentin. For the GABAergic anticonvulsants vigabatrin and tiagabine, studies about antimigrane efficacy are missing. The aim of this study was to test the GABAergic potency of these drugs in vitro before further clinical studies. Intracellular recordings were obtained from hippocampal pyramidal cells. Spontaneous GABAergic hyperpolarizations (SGH) elicited by 75 microM 4-aminopyridine were used to test the effect of these drugs on GABA-dependent potentials. Tiagabine (0.1 mM) prolonged the duration of SGH. Furthermore, monophasic SGH turned over into triphasic typical GABAergic membrane potential fluctuations within 20 min. In contrast, valproate, gabapentin, and vigabatrin failed to affect SGH up to 60 min of application. The reason for the fast action of tiagabine on SGH may be caused by a faster increase of synaptic GABA levels compared with other drugs. As migraine therapy benefits from an augmentation of GABA activity, we recommend clinical studies of tiagabine as a fast-acting agent in migraine attacks.

Clinical relevance of quantified intracranial interictal spike activity in presurgical evaluation of epilepsy

PURPOSE

Electrocorticograms of 32 patients with medically intractable seizures, recorded through intracranial electrodes, were retrospectively analyzed. The objective was to assess whether quantitative analysis of interictal spikes may be used for delineation of the epileptogenic zone.

METHODS

We used a newly developed computer program for automatic detection of interictal spikes and averaging procedures. This allowed determination of the earliest spike of each spike cluster, the maximal averaged spike amplitude, the highest spike frequency, and the shortest averaged spike duration at each recording site.

RESULTS

The following results were obtained: (a) Within a zone </=2 cm from the site of seizure origin, we localized the averaged earliest spike of a spike cluster in 27 (84%) of 32 patients, the highest averaged spike amplitude in 24 (75%) of 32, the shortest averaged spike duration in 22 (69%) of 32, and the maximal spike frequency in 17 (53%) of 32; (b) No correlation was found between spike occurrence and histopathology; (c) No evidence was found for decreased postoperative seizure control in patients with several multilobar or bihemispheric occurrence of spike clusters.

CONCLUSIONS

The zones of the earliest spike and seizure origin demonstrate a high correlation that favors a common epileptic generator. Removal of all brain areas demonstrating spike clusters is unnecessary to achieve seizure control. Quantification of interictal spike activity is a valuable tool for localization of the seizure generator.

Stroke following chiropractic manipulation of the cervical spine

We analyzed the clinical course and neuroradiological findings of ten patients aged 27-46 years, with ischemic stroke secondary to vertebral artery dissection (VAD; n = 8) or internal carotid artery dissection (CAD; n = 2), all following chiropractic manipulation of the cervical spine. The following observations were made: (a) All patients had uneventful medical histories, no or only mild vascular risk factors, and no predisposing vascular lesions. (b) VAD was unilateral in five patients and bilateral in three. VAD was located close to the atlantoaxial joint in all eight patients and showed additional involvement of lower sections in six, as well as temporary occlusion of one vertebral artery in three. (c) Nine of ten patients had brain infarction documented by magnetic resonance imaging or computed tomography. (d) Onset of symptoms was immediately after the manipulation (n = 5) or within 2 days (n = 5). (e) Progression of neurological deficits occurred within the following hours to a maximum of 3 weeks. (f) Maximum neurological deficits were severe in nine of ten patients. (g) Outcome after 4 weeks-3 years included no or mild neurological deficits in five patients, marked deficits in three, persistent locked-in syndrome in one, and persistent vegetative state in one. (h) Informed consent was obtained in only one of ten patients. Thus, patients at risk for stroke after chiropractic manipulation may not be identified a priori. Neurological deficits may be severely disabling and are potentially life threatening.

Properties of advanced headmodelling and source reconstruction for the localization of epileptiform activity

During the last decade multiple work has been done to determine the sources of epileptiform activity by means of dipole source localization based on recordings of the magnetoencephalogram (MEG) or the electroencephalogram (EEG). The actual available advanced volume conductor models and the multiple source reconstruction by regularization may give new impulse to EEG based source analyses in epilepsy patients. This study demonstrates the principal properties of these techniques. We applied two different EEG source reconstruction techniques within different volume conductor models to localize induced spike activity in a selected patient suffering from medically intractable temporal lobe epilepsy: 1) single moving dipole solution in a 3-shell spherical model versus individual head models (boundary-element-model, BEM, and finite-element-model, FEM); 2) a regularization technique for current density reconstructions using both BEM and FEM. When compared to findings of invasive recordings no adequate source locations were derived from the moving dipole solution in both the 3-shell head model and BEM. In contrast, a high congruence of source reconstruction and invasive determination of the focus was obtained using the regularization techniques in both BEM and FEM, indicating the high spatial accuracy of this technique in individual head models.

Effect of partial volume correction on muscarinic cholinergic receptor imaging with single-photon emission tomography in patients with temporal lobe epilepsy

Animal experiments and preliminary results in humans have indicated alterations of hippocampal muscarinic acetylcholine receptors (mAChR) in temporal lobe epilepsy. Patients with temporal lobe epilepsy often present with a reduction in hippocampal volume. The aim of this study was to investigate the influence of hippocampal atrophy on the quantification of mAChR with single photon emission tomography (SPET) in patients with temporal lobe epilepsy. Cerebral uptake of the muscarinic cholinergic antagonist [123I]4-iododexetimide (IDex) was investigated by SPET in patients suffering from temporal lobe epilepsy of unilateral (n=6) or predominantly unilateral (n=1) onset. Regions of interest were drawn on co-registered magnetic resonance images. Hippocampal volume was determined in these regions and was used to correct the SPET results for partial volume effects. A ratio of hippocampal IDex binding on the affected side to that on the unaffected side was used to detect changes in muscarinic cholinergic receptor density. Before partial volume correction a decrease in hippocampal IDex binding on the focus side was found in each patient. After partial volume no convincing differences remained. Our results indicate that the reduction in hippocampal IDex binding in patients with epilepsy is due to a decrease in hippocampal volume rather than to a decrease in receptor concentration.

Safety of intrahippocampal depth electrodes for presurgical evaluation of patients with intractable epilepsy

PURPOSE

Intracerebral depth electrodes are used in preoperative evaluation of selected patients with intractable epilepsies. In spite of their usefulness, safety of depth electrodes is disputed, and the number of insertions is decreasing. This study examined retrospectively possible deleterious effects such as perioperative complications, induction of epileptogenesis, and neuropsychologic deficits.

METHODS

Clinical course and neuroradiologic findings of 115 patients with bilaterally inserted longitudinal intrahippocampal depth electrodes (IDEs) were analyzed. Hippocampal resection specimens were examined histopathologically. To detect newly developed epileptogenic areas, EEG recordings, seizure control, and semiology after standardized resection procedures were compared between patients who received IDEs and those who did not. To demonstrate functional deficits caused by IDE insertion into an unaffected hippocampus of the speech-dominant hemisphere, changes of verbal learning and memory performances before and after right amygdalohippocampectomy were compared between patients evaluated with and without IDEs.

RESULTS

Five significant complications without any permanent neurologic deficit were noted, and only one was specifically linked to IDE insertion. The tissue damage associated with the insertion was minimal and sharply circumscribed. No differences of seizure outcome after standardized resections were identified between patients with and without IDEs. In postoperative EEG recordings, there was no evidence of new epileptogenic areas. No verbal memory deficit caused by IDE implantation into the hippocampus of the speech-dominant hemisphere was detectable.

CONCLUSIONS

Results indicate that it is safe to implant these IDEs in selected patients.

Surgical treatment of neoplasms associated with medically intractable epilepsy

OBJECTIVE

Surgical treatment in patients with brain tumors and medically intractable epilepsy is aimed at the removal of the neoplasm and complete seizure control. However, an adequate surgical approach is still controversial. This study was designed to analyze the factors for the optimum surgical treatment of these patients.

METHODS

The clinical, electrophysiological, operative, and histopathological data of 146 consecutive patients who underwent surgery between November 1987 and May 1995 for intrinsic brain tumors and pharmacoresistant epilepsy were evaluated.

RESULTS

The majority of the tumors were located in the temporal lobe (n = 116) and involved the cortical gray matter. The most frequent tumors were gangliogliomas (n = 65), pilocytic astrocytomas (n = 21), and dysembryoplastic neuroepithelial tumors (n = 19). All but three tumors (98%) were of low histopathological grade (World Health Organization Grades I or II). The biological behavior of the tumors was strikingly indolent, as indicated by a long preoperative history of chronic seizures (mean, 14 yr). In all cases, complete resection of the tumor, including the epileptogenic area (as determined by noninvasive and/or invasive recordings of the zone of seizure onset and persistent interictal activity), was intended. Complications were encountered in 11 cases (8%). However, no patient died and there was no permanent morbidity. Of the 124 patients who had postoperative follow-up examinations more than 6 months after resection, 71% were seizure-free, 11% had no more than two seizures per year, 13% showed a reduction of seizure frequency of at least 75%, and 5% had no appreciable reduction in seizure frequency.

CONCLUSION

The data indicate that neoplasms associated with medically intractable epilepsy constitute a distinct clinicopathological group of tumors that arise in young hosts, involve the cortex, and exhibit indolent biological behavior for many years. Complete surgical removal of these tumors, including the epileptogenic area, can achieve excellent seizure control.

[The Churg-Strauss syndrome with cerebral seizures and terminal kidney failure]

HISTORY AND CLINICAL FINDINGS

A 67-year-old man with known bronchial asthma was admitted to hospital because of deteriorating general state of health, fever, progressive renal failure and confusional states.

INVESTIGATIONS

Erythrocyte sedimentation rate was 70/95 mm and the concentration of C-reactive protein raised to 30 mg/dl. WBC count was 19,000/microliter with 39% eosinophilia. Anticytoplasmatic antibodies (cANCA) had a high titre (1:160). On admission the creatinine level was 5.6 mg/dl. Renal biopsy indicated marked glomerular and tubulo-interstitial scarring. Chest radiograms showed transient pulmonary infiltrates. Churg-Strauss syndrome (CSS) was diagnosed on the basis of the clinical and biochemical findings.

TREATMENT AND COURSE

Haemodialysis was instituted to counteract the renal failure with water retention. Inflammatory parameters and clinical symptoms rapidly responded to administration of corticosteroids (prednisolone, initially 250 mg/d for 3 days, then 150 mg/d for 5 days followed by slowly decreasing doses). Two weeks after starting prednisolone he had secondary generalised seizures. Magnetic resonance imaging (MRI) of the skull demonstrated marked hyperintense focal changes which in their pattern were characteristic of cerebral vasculitis. As a steroid-refractory condition had to be assumed, cyclophosphamide was also given (100 mg/d). Within 6 weeks the clinical symptoms gradually regressed and the MRI changes became practically normal.

CONCLUSION

Early combined immunotherapy should be given if CSS runs a complicated course, rather than the usually recommended corticosteroid monotherapy.