Ictal Single-Photon Emission Computed Tomography Imaging in Extra Temporal Lobe Epilepsy Using Statistical Parametric Mapping

PURPOSE: To examine the application of statistical parametric mapping (SPM) to analyze ictal single-photon emission computed tomography (SPECT) scans in surgical candidates with extratemporal lobe epilepsy. METHODS: The authors selected patients who underwent successful ictal SPECT acquisition in the process of surgical treatment of intractable partial epilepsy. Thirteen patients were identified who met inclusion criteria for confident seizure localization from either intracranial electroencephalogram recordings or epilepsy surgery outcome. In these cases, ictal scans were registered to an in-house-developed normal SPECT atlas composed of 14 spatially normalized brains of normal subjects. SPM96 was used to test on a voxel-by-voxel basis for statistically significant increases in blood flow associated with each patient's ictal scan. The results were then mapped back onto the patient's magnetic resonance image (MRI) for final interpretation. Statistical parametric mapping (SPM) analysis of ictal SPECT scans was compared to both conventional visual interpretation and the analysis of subtraction ictal SPECT co-registered to MRI (SISCOM). RESULTS: Ten of 13 patient scans showed localizing focal ictal increases in regional cerebral blood flow, all of which were concordant with ultimate epilepsy localization. Of the 3 cases not localized with SPM, 1 was localized by conventional visual interpretation and another, not localized by visual interpretation, was correctly localized with SISCOM. Two cases not localized by SISCOM were localized by both visual and SPM analysis. CONCLUSIONS: This work provides supportive evidence for proof of principle that SPM can be used to provide objective, accurate analysis of ictal SPECT scans in patients with extratemporal lobe epilepsy.     

3H]-flunitrazepam binding after morphine treatment and under abstinence syndrome.

Chronic morphine treatment produced increases in [3H]-flunitrazepam binding in some hippocampal areas of the rat brain. The differences in binding were statistically significant in some cases. Both morphine-dependent and morphine-deprived (abstinence syndrome) animals showed an identical response in binding, which confirms a real, although small, increase in benzodiazepine binding sites in the hippocampus after morphine treatment, that is not affected by a naloxone-induced abstinence syndrome under the conditions studied. These findings support the hypothesis of a morphine-induced up-regulation of benzodiazepine binding sites in the hippocampus. A possible different response in benzodiazepine binding sites 1 and 2 could explain the different findings reported in the literature. Our data suggest that the detected increase in benzodiazepine binding would be mainly due to type 2 binding sites, since the hippocampus has a higher density of this type of benzodiazepine binding sites.     

Brainstem anaesthesia after peribulbar anaesthesia

Purpose  To present a case of brainstem anaesthesia as a complication of peribulbar anaesthesia. Clinical features  A 75-yr-old woman received peribulbar anaesthesia for cataract surgery. A few seconds after the block was performed, she had a respiratory arrest, became unconscious, and developed hypertension and tachycardia followed by hypotension and bradycardia. Ventilatory and haemodynamic support were performed before the patient regained adequate spontaneous breathing and normal heart rate and blood pressure. Conclusion  Peribulbar anaesthesia generally cames a low risk of serious complications. However, respiratory arrest and brainstem anaesthesia may occur as complications of peribulbar blocks.

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Résumé Objectif  Présenter un cas d’anesthésie du tronc cérébral compliquant une anesthésie péribulbaire. éléments cliniques  Un bloc péribulbaire était réalisé chez une femine de 75 ans pour l’extraction d’une cataracte. Quelques secondes après l’injection, la patiente cessait de respirer et perdait conscience. Elle devenait hypertendue et tachycarde puts hypotendue et bradycarde. La ventilation et la circulation devaient être supportées jusqu’au retour spontané à la normale. Conclusion  En général, l’anesthésie péribulbare comporte un faible risque de complications sérieuses. Un arrêt respiratoire par anesthésie du tronc cérébral est toujours possible.

     

A Drosophila melanogaster hobo-white+ vector mediates low frequency gene transfer in D. virilis with full interspecific white+ complementation

Transformation of a Drosophila virilis white mutant host strain was attempted using a hobo vector containing the D. melanogaster mini-white⁺ cassette (H[w⁺, hawN]) and an unmodified or heat shock regulated hobo transposase helper. Two transformant lines were recovered with the unmodified helper (HFL1), one containing only the white⁺ marked vector, and a sibling line containing the vector as well as an HFL1 helper integration. An approximate total transformation frequency of 1% is deduced. A high frequency of wing and eye morphology mutants were also observed, suggesting that hobo may have mobilized a related element in D. virilis. The data reaffirms a relatively low transformation vector activity for the hobo transposon in D. virilis; however, nearly full interspecific expression of the white⁺ marker supports its possible function in other species as well.     

Acute epidural hematoma: an analysis of factors influencing the outcome of patients undergoing surgery in coma

Mortality due to epidural hematoma is virtually restricted to patients who undergo surgery for that condition while in coma. The authors have analyzed the factors influencing the outcome of 64 patients who underwent epidural hematoma evacuation while in coma. These patients represented 41% of the 156 patients operated on for epidural hematoma at their centers after the introduction of computerized tomography (CT). Eighteen patients (28.1%) died, two (3.1%) became severely disabled, and 44 (68.8%) made a functional recovery. The mortality rate for the entire series was 12%, significantly lower than the 30% rate observed when only angiographic studies were available. A significant correlation was found between the final result and the mechanism of injury, the interval between trauma and surgery, the motor score at operation, the hematoma CT density (homogeneous vs. heterogeneous), and the hematoma volume. The patient's age, the course of consciousness before operation (whether there was a lucid interval), and the clot location did not correlate with the final outcome. The mortality rate was significantly higher in patients operated on within 6 hours or between 6 and 12 hours after injury than in those undergoing surgery 12 to 48 hours after injury. Compared with the patients operated on later, the patients undergoing surgery in the early period were, on the average, older and had more rapidly developing symptoms, more pupillary changes, lower motor scores at surgery, larger hematomas, a higher incidence of mixed CT density clots, more severe associated intracranial lesions, and higher postoperative intracranial pressure (ICP). The mechanism of trauma seems to influence the course of consciousness before and after surgery. Passengers injured in traffic accidents had a lower incidence of a lucid interval and longer postoperative coma than patients with low-speed trauma, suggesting more frequent association of diffuse white matter-shearing injury. The duration of postoperative coma correlated with the morbidity rate in survivors. Forty-eight patients (75%) had one or more associated intracranial lesions, and 70% of these required treatment for elevation of ICP after hematoma evacuation. An ICP of over 35 mm Hg strongly correlated with poor outcome; administration of high-dose barbiturates was the only effective means for lowering ICP in nine of 15 patients who developed severe intracranial hypertension after surgery. This study attempts to identify patients at greater risk for presenting postoperative complications and to define a strategy for control CT scanning and ICP monitoring.     

Inward rectification in response to FMRFamide in Aplysia neuron L2: summation with transient K current

The response of Aplysia abdominal ganglion neuron L2 to the molluscan neuroactive peptide Phe-Met-Arg-Phe-NH2 (FMRFamide) was studied in voltage-clamp experiments. In all of the experiments, focal application of the peptide to the soma activated an inward rectifier current and reduced the apparent amplitude of the transient K current, IA. In a few cells, Na and K currents were activated in addition to these effects. Voltage-jump experiments were performed to study the ionic dependence, kinetics, and voltage dependence of the inward rectifier. Inward rectification increased exponentially during hyperpolarizing pulses and recovered exponentially on return to the resting potential. The reversal potential was variable, but was near -40 mV at the beginning of experiments. Inward rectification was insensitive to changes in external Na, Ca, or K concentration, but lowering the external Cl concentration had complicated effects on current amplitude. When KCl microelectrodes were used, perfusion with low-Cl external saline increased the amplitude of the peptide-dependent inward rectifier and shifted its reversal potential to a more positive voltage. With KAc microelectrodes, perfusion with low-Cl saline reduced the amplitude of the current. Inward rectification increased when a KAc microelectrode was withdrawn and replaced with a low-resistance KCl electrode, even when there was no measurable change in reversal potential. These results suggest that the FMRFamide-dependent inward rectifier is a Cl current that, like the current described by Chesnoy-Marchais (1982, 1983), is modulated by intracellular Cl. FMRFamide reduced the apparent amplitude of IA without affecting the voltage dependence of IA activation or inactivation.(ABSTRACT TRUNCATED AT 250 WORDS)