Functional hemispherectomy: postoperative motor state and correlation to preoperative DTI.

INTRODUCTION: Functional hemispherectomy (FH) is an infrequent method to reduce seizure frequency in patients with intractable epilepsy. The risk that hemispherotomy injures brain structures involved in residual motor function is challenging to predict. Our purpose was to evaluate MR diffusion tensor imaging (DTI) to preoperatively assess residual ipsilateral motor function prior to FH. METHODS: We applied DTI in 34 patients scheduled for FH to perform fiber tracking in healthy and damaged hemispheres of the corticospinal tracts (CSTs) and of the corpus callosum. We assessed the CSTs and the commissural fibers for streamline count, for fractional anisotropy (FA), and for respective ratios (affected/unaffected side). We correlated these DTI values to post-to-prior changes of muscle strength and evaluated their diagnostic accuracy. RESULTS: FA of the affected CSTs and of commissural fibers was significantly higher in patients with postoperative loss of muscle strength compared to patients without (p = 0.014 and p = 0.008). In contrast, CST FA from healthy hemispheres was not different between both groups. Ratios of streamline counts and FA from CSTs were higher in patients with postoperative reduced muscle strength compared to those without (1.14 ± 0.22 vs. 0.58 ± 0.14, p = 0.040; 0.93 ± 0.05 vs. 0.74 ± 0.03, p = 0.003). CSTs' normalized FA ratio greater than -0.085 predicted loss of muscle strength with 80 % sensitivity and 69.6 % specificity. CONCLUSION: Preoperative tracking of the CST and of commissural fibers contributes to the prediction of postoperative motor outcome after functional hemispherectomy.

Pediatric functional hemispherectomy: outcome in 92 patients.

BACKGROUND: The revival of epilepsy surgery after the introduction of modern presurgical evaluation procedures has led to an increase in hemispherectomy or hemispherotomy procedures. Since a large part of our pediatric series was done using a newer hemispherotomy technique, we focus mainly on the outcomes after a recently developed hemispherotomy technique (transsylvian keyhole). METHODS: Ninety-six pediatric patients (aged 4 months to 18 years, mean 7.3) were operated on between 1990 and 2009; 92 were available with follow-up. RESULTS: The most frequent diagnosis was porencephaly in 46 % of all patients. Progressive etiologies were present in 20 % and developmental etiologies in 22 %. At last available outcome (LAO), 85 % of the patients were seizure free (ILAE class 1). Year-to-year outcome was rather stable; usually over 80 % were class 1 for up to 13 years (n = 24). Of 92 assessable patients, 71 were treated with the transsylvian keyhole technique, with 89 % being seizure free. The overall shunt rate was 5.3 % for the whole series and 3 % for the keyhole technique subgroup. Mortality was 1 of 96 patients. Excluding patients with hemimegalencephaly (HME), patients with the shortest duration of epilepsy and the lowest age at seizure onset had the highest rates of seizure freedom. The etiology does influence outcome, with HME patients having the poorest seizure outcome and patients with Sturge-Weber syndrome and porencephaly having excellent seizure control. CONCLUSION: Hemispherotomies/functional hemispherectomies are very effective and safe procedures for treating drug-resistant epilepsy with extensive unihemispheric pathology. Etiology and surgery type clearly influence seizure outcome.

Severe epilepsy as the major symptom of new mutations in the mitochondrial tRNA(Phe) gene.

OBJECTIVE: To present 2 families with maternally inherited severe epilepsy as the main symptom of mitochondrial disease due to point mutations at position 616 in the mitochondrial tRNA(Phe) (MT-TF) gene. METHODS: Histologic stainings were performed on skeletal muscle slices from the 2 index patients. Oxidative phosphorylation activity was measured by oxygraphic and spectrophotometric methods. The patients' complete mitochondrial DNA (mtDNA) and the relevant mtDNA region in maternal relatives were sequenced. RESULTS: Muscle histology showed only decreased overall COX staining, while a combined respiratory chain defect, most severely affecting complex IV, was noted in both patients' skeletal muscle. Sequencing of the mtDNA revealed in both patients a mutation at position 616 in the MT-TF gene (T>C or T>G). These mutations disrupt a base pair in the anticodon stem at a highly conserved position. They were apparently homoplasmic in both patients, and had different heteroplasmy levels in the investigated maternal relatives. CONCLUSIONS: Deleterious mutations in the mitochondrial tRNA(Phe) may solely manifest with epilepsy when segregating to homoplasmy. They may be overlooked in the absence of lactate accumulation and typical mosaic mitochondrial defects in muscle.

The validity of the Child Behavior Checklist for children with epilepsy.

The validity of the Child Behavior Checklist (CBCL) for patients with epilepsy has been questioned, because several items may reflect seizure semiology rather than habitual behavior. This study compared a standard version of the CBCL with an adjusted version that excluded those ambiguous items. Participants were 58 pediatric patients with epilepsy who were assessed preoperatively and 1 year after successful surgical treatment. Before surgery, the adjusted version indicated significantly lower values for the scales Attention Problems, Thought Problems, and Total Problems than the standard version. After surgery, the difference between the standard and adjusted versions and the scores for the ambiguous items were unchanged, although all patients were completely seizure free at that time. Elevated scores on the ambiguous items thus probably reflect real behavioral problems and are not due to confusion with seizure semiology. The results support the CBCL as a valid assessment tool in children with epilepsy.

Greater functional recovery after temporal lobe epilepsy surgery in children.

The purpose of our study is to evaluate whether children recover better than adults from memory deficits as a consequence of temporal lobe surgery. We compared 3 and 12 month outcomes obtained in children and adults with medically refractory epilepsy. Each candidate underwent temporal lobe resection for seizure control and children were matched with regard to pathology, onset of epilepsy, side of surgery and type of surgery with adults (N = 30 for each group, mean age at surgery 13 versus 30 years). Three months after surgery, both left-resected groups displayed a significant decline in verbal learning capacity. During the following 9 months, only the children recovered and were able to reach their preoperative level 1 year after surgery. The left-resected adults remained, for the most part, on their low level and one year after surgery, they were still significantly worse than at the time of their preoperative examination. The right-resected adults experienced a deterioration in visual memory 1 year after surgery relative to the results of the short-term follow-up; the children improved. The children also had a better outcome with regard to attentional functions and, as a trend, a better seizure outcome (Engel Outcome I--1 year after surgery: 63% adults, 80% paediatric patients). Our neuropsychological data provide evidence of greater plasticity and compensational capacity in childhood. The results can be taken as a strong argument for early surgical intervention.

MRI brain volumetry in Rasmussen encephalitis: the fate of affected and "unaffected" hemispheres.

Rasmussen encephalitis (RE) is regarded as a unihemispheric disease. Serial three-dimensional MRIs of 18 patients under immunotherapy were analyzed volumetrically and planimetrically. Median volume loss was significantly higher in the affected than in the unaffected hemispheres (29.9 cm3/y vs 6.8 cm3/y). Correlation of the planimetrically and volumetrically assessed hemispheric ratios (HRs) was significant. The results support the concept of RE as a basically unilateral disease. Planimetric HR assessment is valid and time efficient.

An open study of tacrolimus therapy in Rasmussen encephalitis.

Seven patients with Rasmussen encephalitis (RE) were treated with the immunosuppressant tacrolimus and followed for a median of 22.4 months. They were compared with 12 historical untreated RE patients (median follow-up 13.9 months). The tacrolimus-treated patients had a superior outcome regarding neurologic function and progression rate of cerebral hemiatrophy but no better seizure outcome. No treated patient, but 7 of 12 control patients, became eligible for hemispherectomy. Tacrolimus did not have any major side effects.

Clinical and neuropsychological characteristics of pediatric epilepsy patients with atypical language dominance.

Studies on intracarotid amobarbital procedures (IAP) in pediatric patients are rare and mainly focus on practicability aspects. Very few studies have reported characteristics of children with atypical language dominance. We compared children with left-sided focal epilepsy and atypical (i.e., right or bilateral) versus left-sided language representation (n=12 versus 17). Our results indicate a higher incidence of left handedness, extratemporal lesions, an earlier onset of epilepsy, and a neuropsychological "crowding effect" with distinct nonverbal memory deficits in the atypical group. We conclude that atypical language representation in children with left-sided epilepsy is associated with similar characteristics as in adults. It is recommended that the possibility of a language shift in the presurgical workup of pediatric patients be considered, particularly if a left-hemispheric epileptic focus is suspected.

Gelastic fits in a two years old boy with a complex cerebral malformation.

We report the case of a two years old boy showing gelastic fits as the leading clinical symptom of a rare complex cerebral malformation with closed-lip schizencephaly, an arachnoid cyst and a partial agenesis of the corpus callosum. After 5 uneventful interictal electroencephalograms the patient underwent 24 h EEG with telemetry while finally presenting two laughing fits with associated spike-wave discharges in the right-centroparietal region. Medical treatment with carbamacepine was initiated and the seizure frequency decreased significantly. This is the first cited case of gelastic fits occurring in schizencephaly. In contrast to previously cited cases with laughing fits we observed a good response to anticonvulsive treatment. Moreover our patient presented a surprisingly favourable psycho-mental and motor development during an 8 months observation period.

Pre- and postoperative verbal memory in pediatric patients with temporal lobe epilepsy.

Outcome studies concerning memory after pediatric temporal lobe surgery in the treatment of epilepsy are rare and have not yielded consistent results. In the present study, 55 children and adolescents with temporal lobe epilepsy (TLE; 26 left, 29 right, 6-17 years) performed a verbal memory test before and 3 as well as 12 months after different types of temporal lobe resections (anterior lobectomy, amygdalo-hippocampectomy (AH), lesionectomy (LX)). Groups did not significantly differ before surgery. Three months after surgery, the left resected group showed a decline in learning and delayed recall, and performed significantly lower than the right resected group. Recoveries were evident 1 year after surgery. The postoperative memory declines were associated with a left-sided resection and a higher preoperative performance. Comparisons on the different resection types suggest a special risk in patients undergoing a left-sided AH. In summary, our results indicate a functional association of verbal memory functions with the left temporal lobe similar to findings in adult patients. Declines after left-sided temporal resections seem to be reversible at least for part of the children, perhaps due to the greater plasticity of the immature brain.

Neuropsychological Outcome in Children after Frontal Lobe Epilepsy Surgery.

We investigated the neuropsychological performance of children with frontal lobe epilepsy (FLE, n = 12) before and 1 year after surgery. Children with temporal lobe epilepsy (TLE, n = 12) were included as control group. Preoperatively, children with FLE had a significantly higher IQ than children with TLE, but were significantly more often impaired in manual motor coordination. Postoperatively, both groups improved in attention, short-term and long-term memory, and manual coordination, although the latter was not significant. Neuropsychological outcome in FLE patients was not better in seizure-free patients than in patients with continuing seizures. To avoid deterioration in language functions of patients in whom surgery involved left area 44, correspondence of results in cortical stimulation and intracarotid amytal test may be essential. All in all, our data indicate a favorable cognitive outcome in children 1 year after frontal lobe surgery.

Bacteria and Archaea physically associated with Gulf of Mexico gas hydrates.

Although there is significant interest in the potential interactions of microbes with gas hydrate, no direct physical association between them has been demonstrated. We examined several intact samples of naturally occurring gas hydrate from the Gulf of Mexico for evidence of microbes. All samples were collected from anaerobic hemipelagic mud within the gas hydrate stability zone, at water depths in the ca. 540- to 2,000-m range. The delta(13)C of hydrate-bound methane varied from -45.1 per thousand Peedee belemnite (PDB) to -74.7 per thousand PDB, reflecting different gas origins. Stable isotope composition data indicated microbial consumption of methane or propane in some of the samples. Evidence of the presence of microbes was initially determined by 4,6-diamidino 2-phenylindole dihydrochloride (DAPI) total direct counts of hydrate-associated sediments (mean = 1.5 x 10(9) cells g(-1)) and gas hydrate (mean = 1.0 x 10(6) cells ml(-1)). Small-subunit rRNA phylogenetic characterization was performed to assess the composition of the microbial community in one gas hydrate sample (AT425) that had no detectable associated sediment and showed evidence of microbial methane consumption. Bacteria were moderately diverse within AT425 and were dominated by gene sequences related to several groups of Proteobacteria, as well as Actinobacteria and low-G + C Firmicutes. In contrast, there was low diversity of Archaea, nearly all of which were related to methanogenic Archaea, with the majority specifically related to Methanosaeta spp. The results of this study suggest that there is a direct association between microbes and gas hydrate, a finding that may have significance for hydrocarbon flux into the Gulf of Mexico and for life in extreme environments.

Methane ice worms: Hesiocaeca methanicola colonizing fossil fuel reserves.

During a research cruise in July 1997 in the Gulf of Mexico we discovered a gas hydrate approximately 1 m thick and over 2 m in diameter which had recently breached the sea floor at a depth of 540 m. The hydrate surface visible from the submarine was considerably greater than that of any other reported hydrate. Two distinct color bands of hydrate were present in the same mound, and the entire exposed surface of the hydrate was infested (2500 individuals/m2) with 2 to 4 cm-long worms, since described as a new species, Hesiocaeca methanicola, in the polychaete family Hesionidae (Desbruyères and Toulmond 1998). H. methanicola tissue stable isotope values are consistent with a chemo-autotrophic food source. No evidence of chemo-autotrophic symbionts was detected, but geochemical data support the presence of abundant free living bacteria on the hydrate. The activities of the polychaetes, grazing on the hydrate bacteria and supplying oxygen to their habitats, appears to contribute to the dissolution of hydrates in surface sediments.

Predictive value of a single CTG, ultrasound and Doppler examination to diagnose acute and chronic placental insufficiency in multiple pregnancies.

A non-stress test, an ultrasound biometry (biparietal and abdominal diameter) and a Doppler sonography blood flow measurement (fetal descending aorta, umbilical artery and fetal middle cerebral artery) were performed in the third trimester of 130 multiple pregnancies. These three methods were compared in terms of their prognostic value for fetal growth retardation (81 from 263 children; defined as weight at birth < 10 percentile) and a pathological "fetal outcome" (76 from 263 children, defined as 5-min-Apgar < 8, umbilical artery-pH < 7.20 and transfer to neonatal intensive care unit). Fetal growth retardation could best be predicted by means of the Doppler results for all three blood vessels ("total Doppler result") (sensitivity of 75.9%). Doppler results for all three blood vessels showed the best result in predicting a pathological "fetal outcome"; the sensitivity was 60.3%. The biometric examinations with ultrasound and the non-stress test produced worse results compared to Doppler sonography. Doppler velocimetry of only one blood vessel showed worse results compared to Doppler velocimetry of more than one blood vessel. Doppler sonography should be performed as a routine test for all multiple pregnancies. More intensive pregnancy surveillance is urgently recommended with pathological findings.

[Ischemic colitis after vascular surgery reconstruction of an abdominal aortic aneurysm]. / Ischämische Colitis nach gefässchirurgischer Rekonstruktion des Bauchaortenaneurysmas.

Between 1978 and 1994, a total of 678 patients were operated on for infrarenal (abdominal) aortic aneurysm at the Department of Surgery of Lübeck Medical University. Rupture had occurred in 165 patients, 351 were treated electively, and 162 presented with severe symptoms but no rupture. Only CT, angiography and intraoperative judgement were used for diagnosis. Reconstruction of the inferior mesenteric artery (IMA) was performed only in exceptional cases. Severe ischemic colitis occurred in 1.03% (in no case following elective surgery, in 0.66% of patients presenting with symptoms, and in 3.6% of patients in whom rupture had occurred prior to the operation). Three patients presented with mild ischemia, two with grade B ischemic colitis and three with transmural infarction. One patient had to be operated on for ischemic colitis despite open reconstruction of the IMA. We conclude from our data that there is no need to reconstruct the IMA as a routine procedure; this topic has been a controversial issue in the literature. We do reimplant a patent IMA when there is only oozing from the IMA and/or a borderline perfusion of the sigma following the operation, with at least one open internal iliac artery. When rupture had occurred, reconstruction should be performed if there is the slightest suspicion because of the increased risk, but only if the patient's cardiopulmonary condition allows this to be done. Analysis of our patients with ischemic colitis demonstrates the importance of maintaining stable circulatory conditions to prevent intestinal ischemia. Further diagnostic procedures (Doppler ultrasound, measuring of oxygen saturation or pH) may identify more patients at risk, but at the moment we do not consider these to be routine procedures.

Morphometry in the differential diagnosis of granulosa-cell tumors of the ovary.

Although the diagnosis of granulosa-cell tumors of the ovary is usually consistent and reproducible, in some cases the differentiation from poorly differentiated adenocarcinomas can be difficult. To investigate our subjective impression of the similarity of nuclei in both types of tumors, seven granulosa-cell tumors and eight poorly differentiated adenocarcinomas were studied with morphometry, with a variety of nuclear parameters measured in 100 nuclei per case. The findings showed that, in general, granulosa-cell tumors have a slightly higher mean nuclear contour index (NCI), which is a measure of the nuclear indentation or grooving, and a somewhat lower mean nuclear area than do adenocarcinomas. There is considerable overlap, however, with the nuclear patterns of the two types of tumors forming a morphologic continuum. Multivariate analysis gave a better discrimination but did not entirely eliminate the overlap. The maximum NCI was the best single discriminator. While only one of the granulosa-cell tumors had a maximum NCI less than 5.11, none of the adenocarcinomas exceeded this value. The only granulosa-cell tumor with a maximum NCI below the threshold was in a case with a much less favorable clinical course. The results of this study indicate that objective morphometric nuclear criteria are useful in the diagnosis of granulosa-cell tumors and possibly have some prognostic value.

Thermogenic gas hydrates in the gulf of Mexico.

Thermogenic gas hydrates were recovered from the upper few meters of bottom sediments in the northwestern Gulf of Mexico. The hydrates were associated with oil-stained cores at a water depth of 530 meters. The hydrates apparently occur sporadically in seismic "wipeout" zones of sediments in a region of the Gulf continental slope at least several hundred square kilometers in area.