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L F Quesney

Publications and source records attributed to L F Quesney.

67 records · Page 4Linked to original sources
PubMed1977

Pathophysiology of generalized penicillin epilepsy in the cat: the role of cortical and subcortical structures. I. Systemic application of penicillin.

The mechanism of precipitation of generalized epileptiform discharges in feline generalized penicillin epilepsy, a model of human generalized corticoreticular ('centrencephalic') epilepsy, was studied in acute and chronic experiments in cats with implanted skull and intracerebral electrodes. Single shock and low frequency repetitive stimulation of subcortical sites from which prior to penicillin administration spindle activity and recruiting responses could be elicited, readily triggered epileptiform discharges in the same animals after penicillin. These structures comprised the intralaminar and midline thalamic nuclei, the neostriatum, and some posterior thalamic association nuclei (Pulvinar and nucleus lateralis posterior). Subcortical and cortical structures which prior to penicillin elicited neither spindle activity nor recruiting responses were significantly less effective in triggering generalized epileptic bursts after penicillin injection. The probability with which such bursts were elicited from these structures was still, however, in many instances above chance level. It is concluded that the generalized epileptiform discharges in feline generalized penicillin epilepsy can be triggered from a large number of brain sites, but most reliably so from subcortical nuclei involved in spindle generation and recruiting responses. The experimental evidence presented still does not allow one to determine whether epileptic alteration of neuronal function in this form of epilepsy primarily resides in cortical or subcortical nerve cells or in both.

Animals↗
PubMed1975

Effect of PGF2 alpha and 15(S)-15-methyl PGE2 methyl ester on feline generalized penicillin epilepsy.

The effect of PGF2alpha and 15(S)-15-methyl PGE2 methyl ester on transient generalized epilepsy in the cat induced by penicillin was examined. Epileptic activity before and after administration of the prostaglandins by several routes was determined from continuous EEG recordings and expressed in epileptic bursts per min. The PGE2 analogue given in single non-toxic doses (1.6-3 mug/kg) by intramuscular or intravenous routes at the peak of epileptic activity significantly reduced epileptic activity for up to four hours. Subcutaneous administration was less effective. PG2alpha given by the intramuscular route (0.3 mg/kg) also markedly reduced the number of epileptic bursts. Increasing the dosage 4-fold almost completely suppressed epileptic activity. Intracarotid infusion of PGF2alpha for one hour (10 mug/min) almost abolished all epileptic activity. Neither prostaglandin given in non-toxic doses induced EEG abnormalities in non-epileptic cats. Toxic doses of the E2 analogue (greater than 16 mug/kg) caused bilaterally synchronous high voltage slow wave activity. It is concluded that these prostaglandins reduce penicillin epilepsy in the cat. The findings are consistent with either a direct excitatory action on neurones of the medial reticular formation or anatagonism of the depressant action of norepinephrine on Purkinje cells.

Animals↗
PubMedDate not supplied

Excitatory amino acids modulate phosphoinositide signal transduction in human epileptic neocortex.

Stimulation of phosphoinositide (PI) hydrolysis by norepinephrine (NE), carbachol (Carb), and excitatory amino acids (EAAs) was measured in slices prepared from neocortex excised during epilepsy surgery. NE and Carb markedly enhanced PI turnover (EC50: NE, 12 microM; Carb, 661 microM) as reflected by [3H]inositol monophosphate (IP1) accumulation in tissue slices prelabeled with [3H]myoinositol. These effects were dose-dependent, saturable, and five to six times higher than basal IP1 accumulation. A weaker stimulation (twofold) was observed with quisqualate (QUIS; EC50, 1.1 microM) and glutamate (GLU; EC50, greater than 1 mM), while minimal or no stimulation was seen with kainate (KA) and N-methyl-D-aspartate (NMDA). Agonist-stimulated PI turnover was significantly reduced in samples from actively spiking epileptic neocortex versus nonspiking areas as defined by electrocorticography (NE, -23%, p less than 0.05; Carb, -44%, p less than 0.01). Preincubation of slices with various EEAs inhibited Carb-induced IP1 formation. The maximal extent of inhibition (1 mM) was both amino acid-dependent (IC50: NMDA, 5 microM; KA, 3.3 microM; QUIS, 47 microM; GLU, greater than 1 mM). These data suggest that epileptic activity modulates PI metabolism and alters receptor-effector coupling. As important mediators of epileptogenesis, EAAs may interfere++ with the efficiency of this second messenger system.

Carbachol↗
PubMedDate not supplied

Temporal lobe epilepsy after prolonged febrile convulsions: excellent outcome after surgical treatment.

We studied 47 consecutive patients who underwent temporal resection for seizure control. Nineteen (40%) had febrile convulsions preceding onset of their habitual seizures. In 17 of 18 patients whose disease duration was known, the febrile convulsions were prolonged (mean 4 h). As compared with patients without preceding febrile convulsions, patients with antecedent febrile convulsions had a significantly higher prevalence of positive family history of febrile convulsions, an increased incidence of retrospectively identified gestational or perinatal complications, and no foreign tissue lesions. Pathologic studies showed gliosis and cell loss in mesiotemporal structures, usually moderate, in addition to usually mild gliosis in lateral temporal cortex. These patients had an excellent outcome after temporal resection: 84% were seizure-free, had residual auras only, or occasional convulsions with medication discontinuation. One patient (5%) had > 90% improvement. Two patients (11%) in whom the hippocampus was totally spared continued to have complex partial seizures: in both, seizures stopped after reoperation and hippocampal resection. Thus, 95% of these patients had an excellent result. Only 16% required invasive preoperative studies to confirm lateralization. These results were significantly better than those of the group without preceding febrile convulsions (p = 0.0013).

Adolescent↗
PubMedDate not supplied

Occipitotemporal epilepsies: evaluation of selected patients requiring depth electrodes studies and rationale for surgical approaches.

In 8 patients in whom it was uncertain whether they had occipital or temporal lobe (TL) epilepsy, clinical, scalp EEG, and radiologic features were correlated with the sites of seizure onset as determined by depth EEG. The 8 patients were selected from > 40 with occipital epilepsy because they had (a) an aura considered to be of occipital lobe (OL) origin, (b) an occipital interictal epileptic focus, (c) an OL lesion, or (d) a combination of all of these. Scalp EEG and clinical patterns suggested temporal involvement in all, however. Extracranial EEG recordings were often misleading, showing multilobar interictal epileptic abnormalities, and seizure onset was of poor localizing value and did not clarify the problem sufficiently. Intracranial EEG recordings showed that seizure onset could be ordered along an occipitotemporal gradient. Consistent OL seizure onset was observed in patients who had only elementary visual auras. Those who had inconsistent aura or no aura, suggesting OL origin, had onset of most attacks in the TL. All patients had a seizure spread pattern suggesting early TL involvement. To prevent visual field defect, surgical approaches included temporal resection when temporal seizure origin or spread was demonstrated; although occasionally this produced excellent results, it was of limited benefit in most patients, even when some seizures were proven to originate in TL structures. In patients with malignant epilepsy and in those with an occipital lesion, occipital resection should be considered.

Adolescent↗
PubMedDate not supplied

Surgical treatment of children with medically intractable frontal or temporal lobe epilepsy: results and highlights of 40 years' experience.

Etiologic, pathologic, and clinical features of possible prognostic significance were studied in 118 children who underwent frontal or temporal lobe epilepsy surgery at the Montreal Neurological Institute (MNI) between 1940 and 1980 (excluding tumor cases). Mean age of seizure onset was 5.1 years (range 0-12 years), mean age at operation was 11.7 years (range 0.6-15 years), and median duration of follow-up was 15 years (range 2-31 years). Thirteen of 45 frontal surgery patients and 43 of 73 temporal surgery patients had an excellent outcome. In the frontal surgery group, this was restricted almost entirely to patients with an established etiology, particularly if this included a circumscribed resectable structural abnormality. In the temporal surgery group, a history of early, prolonged febrile seizures was usually associated with good outcome, unless there was additional evidence of extratemporal epilepsy. In the entire series, the presence of a nonresectable structural lesion or secondarily generalized seizures was associated with a poor outcome.

Child↗
PubMedDate not supplied

Seizures with onset in the sensorimotor face area: clinical patterns and results of surgical treatment in 20 patients.

It is not generally appreciated that intractable seizures involving the face area are amenable to surgical treatment. Twenty patients with onset of sensorimotor seizures in the face area of the pre- and postcentral gyri have been studied and surgically treated since 1948. Seizures started in the face, tongue, or throat, followed by diverse patterns depending on spread of seizure activity. Two patients had epilepsia partialis continua; 6 had either tonic or atonic drop attacks. All patients had pre- and postcentral face area resections, 12 in the dominant hemisphere. In addition, 3 had more extensive postcentral removal, 7 had temporal lobe, and 4 had small separate or contiguous frontal or parietal resection. Because the seizures were not sufficiently reduced by the first operation, 6 required reoperation; 4 of these patients had residual epileptiform activity on electrocorticogram (ECoG) after the first resection. Three patients had new neurologic signs that did not return to the preoperative level, but in 2 of them the deficit related mainly to higher resection in the central area. All but 2 of these 20 patients had at least moderate seizure reduction. Corticectomy can be performed for treatment of seizures arising in the lower central area and usually does not lead to significant permanent neurologic deficit.

Adolescent↗
PubMedDate not supplied

Reevaluation of surgical failures and the role of reoperation in 39 patients with frontal lobe epilepsy.

Between 1929 and 1980, 284 patients with refractory nontumoral frontal lobe epilepsy (FLE) underwent operation at the Montreal Neurological Institute (MNI). We studied 39 patients (14%) who required reoperation. Mean age at the time of first operation was 18 years and at reoperation was 22 years. Clinical manifestations were similar to those of patients with "a pure culture of frontal lobe epilepsy" as reported by Rasmussen in 1983. At the time of first operation, large epileptogenic zones were noted in most patients. Resection was confined to the frontal lobe. Continuing seizure activity was due to residual areas of epileptogenesis, and reoperation with more extensive resection of cortex increased the number of seizure-free patients. Twenty-six patients underwent further frontal resection, and in 13 surgical removal was extended to the temporal lobe. Residual electrocorticographic (ECoG) spiking was documented in 15 of 23 (65%) of the reoperated patients. Thirty-five patients were followed for periods ranging from 4 to 46 years. One fifth became seizure-free, and 31% had significant seizure reduction. Thus, half of these patients had a good result. Patients with residual postexcision ECoG spiking had poor outcomes and evidence of large epileptogenic zones. None of the patients who underwent frontotemporal resections became seizure-free. Reoperation should be considered if initial resection does not lead to a satisfactory result and may convert an initial failure into a good surgical result.

Adolescent↗
PubMedDate not supplied

Acute postictal psychosis: a stereo EEG study.

An acute psychosis characterized by auditory hallucinations and paranoid delusions developed in a 19-year-old man with temporal lobe epilepsy after he had a cluster of seizures when antiepileptic drugs (AEDs) had been gradually discontinued. Continuous sterotactic depth and epidural EEG recordings confirmed that this was a postictal rather than an ictal event. Acute postictal psychosis is a self-limited condition phenomenologically distinct from ictal or postictal confusion.

Adult↗