Periictal speech as function of the age of cerebral damage.
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Biomedical subjects
Publications and source records attributed to H Stefan.
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The new occurrence of epileptic disorders increases continuously above the age of 60 years. The most frequent etiology of epilepsy in the elderly is vascular (32-54%). Tumors are the cause of epilepsy in the elderly in 11 to 33 per cent of cases, with a peak around the age of 60. The etiology of about one third of the cases of epilepsy newly diagnosed in old age cannot be clarified. The risks of inducing epileptic disorders are: after cerebral ischemia 4-9%, intracerebral hemorrhage 3%, and subarachnoidal hemorrhage 4-12%. It is important to recognize confusional states, for they may be symptoms of a psychomotor status or a prolonged postical phase. Occasional seizures occur more often in the elderly. Due to altered pharmacokinetics and problems of compliance in old age, the titration period of antiepileptic drugs should be planned with particular care and patients given simple drug regimens.
In primary pseudotumor cerebri (PTC) intracranial pressure is elevated by so far unknown mechanisms. There is a wide range of clinical courses. Therapy is controversial. We present a case of PTC with acute visual loss. After optic nerve sheath decompression a relapse occurred. A 30-year old female patient experienced visual loss within 48 h accompanied by headache and slight neck stiffness. Visual acuity was 1/50 in the right eye; in the left eye just hand movements and light were perceived. Fundoscopy revealed a 9 dptr. prominent optic disc bilaterally. After optic nerve sheath decompression (ONSD) she improved, but underwent a relapse after 3 months. Twenty-four-hour measurement of intracranial pressure revealed elevated values. As a consequence ventriculo-peritoneal shunting was performed, leading to prominent improvement. Primary PTC can cause acute visual loss. If conservative treatment fails, different surgical procedures should be considered.
We report 3 cases of an ictal sinus arrest. All patients suffered from temporal lobe epilepsy (TLE). Seizures were monitored with simultaneous video-eeg during preoperative epilepsy diagnosis. One patient with cortical dysplasia, who frequently suffered from long lasting syncopes, had a nearly completely missing cardiac sympathetic innervation in MIBG-SPECT (=Meta-Iodide-Benzyle-Guanidine-single-photon-emission tomography). Cardiac investigation including long-term ECG and echocardiography had shown normal findings. After epilepsy surgery the syncopal events in all patients disappeared. A dominant parasympathetic ictal stimulus following excitation of the reticular formation might cause the ictal bradycardia and sinus arrest. A missing sympathetic innervation, possibly occurring as fehlbildung together with cortical dysplasia, which makes autoregulation impossible, might then be the explanation for sudden cardiac ictal death.
Valproate is a frequently used antiepileptic drug. It is associated with rare but serious adverse effects like liver failure. The first symptom is impairment of the patient's well being. Isolated changes of standard laboratory liver parameters are not reliable early indicators. Thus, according to the knowledge of today, prophylactic blood screening cannot predict complications. On the contrary, clinical symptoms are the most relevant indicators of impending complications, eventually supported by laboratory findings. An abrupt withdrawal of valproate and administering carnitin in parallel can interrupt the otherwise fatal course of the complication and induce a subsequent recovery. At a Consensus Conference the current knowledge about early detection and therapy of the valproate-induced serious hepatotoxicity was discussed. The results regarding recommended laboratory screening, as well as diagnostic and therapeutic strategies are reported.
PURPOSE: During presurgical evaluation, 14 patients with medically intractable focal epilepsies underwent magnetoencephalographic (MEG) recordings for focus localization. To increase the number of epileptic discharges required for MEG analysis, we administered methohexital (MHT), a short-acting barbiturate known to provoke epileptic activity. We also investigated the spike-provoking properties of clonidine in comparison with MHT. METHODS: Patients were briefly anesthetized with intravenously administered MHT after being premedicated orally with clonidine. Numbers and locations of epileptic MEG discharges were assessed after clonidine premedication as well as during MHT anesthesia. Results were compared with baseline MEG recordings. RESULTS: MHT increased the frequency of focal epileptic discharges in 8 of 13 patients ( of the 14 patients did not receive MHT after premedication with clonidine). Premedication with clonidine also increased focal epileptic discharges in 9 of 14 patients. The numbers of epileptic signals and numbers of spikes contributing to MEG source localizations were significantly increased in MEG recordings under both treatment conditions (clonidine premedication and MHT anesthesia) as compared with baseline MEG recordings. CONCLUSIONS: Our results confirmed the selective proconvulsive effects of MHT on the epileptic focus, as previously suggested by EEG and electrocorticographic (ECoG) investigations. However, our present data establish for the first time that clonidine increases epileptic activity in patients with seizure disorders and indicate that clonidine is suitable as an activating agent for localization of epileptogenic foci by MEG. This effect of clonidine on specific epileptic activity also indicates that specific care must be taken when clonidine is used as an antihypertensive drug in patients with seizure disorders.
PURPOSE: During presurgical evaluation, 14 patients with medically intractable focal epilepsies underwent magnetoencephalographic (MEG) recordings to localize the epileptogenic focus. To increase the number of epileptiform discharges required for MEG analysis, methohexital a short-acting barbiturate that is known to activate epileptiform activity, was used. Additionally, we investigated the spike-provoking properties of clonidine in comparison to methohexital. METHODS: After oral premedication with clonidine, short-lasting anesthesia was provided by intravenously administered methohexital. The number and location of epileptiform MEG discharges were assessed after clonidine premedication and during methohexital anesthesia. Results were compared with baseline MEG recordings. RESULTS: Methohexital increased the frequency of focal epileptiform discharges in eight of 13 patients (one of the 14 patients did not receive methohexital after premedication with clonidine). Additionally, premedication with clonidine was found to increase focal epileptiform discharges in nine of 14 patients. When compared with baseline MEG recordings, recordings after treatment with both clonidine premedication and methohexital anesthesia showed a significant increase in the total number of epileptiform signals and the number of spikes contributing to MEG source localizations. CONCLUSIONS: This study confirms the selective proconvulsant effects of methohexital on the epileptogenic focus as suggested previously by EEG and electrocorticogram (ECoG) investigations. Additionally, our data establish for the first time that clonidine increases epileptiform activity in patients with seizure disorders. These results indicate that clonidine is suited as an activating agent for the localization of epileptogenic foci by means of MEG. This effect of clonidine on specific epileptic activity also indicates that clonidine should be used with caution as an antihypertensive drug in patients with seizure disorders.
OBJECTIVE: Assessment of usefulness of magnetoencephalography (MEG) as a novel non-invasive technique in the diagnostic evaluation of patients with recurrent seizures after unsuccessful epilepsy surgery. MATERIAL AND METHODS: Seventeen patients in whom epilepsy surgery had failed underwent reevaluation by means of MEG in addition to standard presurgical investigations (EEG, MRI, SPECT, and neuropsychologic testing). RESULTS: Source analysis of interictal epileptic MEG discharges revealed dipole localizations immediately adjacent to the borders of previous resection in 10 of 17 patients. Standard non-invasive presurgical evaluation suggested epileptogenicity over the general area of previous resection in all patients, but did not provide any detailed spatial localizing data. Invasive EEG recordings confirmed the MEG focus localization in all of 5 patients who were selected for reoperation. Second operation at the site of previous resection achieved complete seizure control in 3 and cessation of tonic-clonic seizures in 1 of these patients. CONCLUSION: MEG may provide useful information in the diagnostic reevaluation of postoperative epileptic patients in whom skull and dura defects produce a "breach effect" which alters non-invasive and invasive EEG.
An incidence of bilateral gonadoblastoma in a 23-month old, mentally retarded boy with congenital sporadic aniridia, undescended dysgenetic testes, deletion of a chromosome (11) (p1302p14.2) and a later occurring unilateral Wilms' tumor is reported. The patient was treated by bilateral gonadectomy, nephrectomy, and chemotherapy, and is alive and well five years later. Another three aniridia/gonablastoma observations from the literature are discussed, two of them without and one in combination with Wilms' tumor. Diagnosis of gonadoblastoma remained unsuspected in two cases until autopsy and in another two cases it was done at surgery. A comparison of four cases reveals common finding--aniridia, dysgenetic gonads, genital abnormalities, mental retardation, deletion of 11p13, early occurrence and bilaterality of gonadoblastoma.
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To date, cortical regions activated by olfactory stimulation have not been identified precisely in humans. In this study we used magnetic source imaging to localize neuronal activity following olfactory stimulation with two odorants, hydrogen sulphide and vanillin. Peak latencies of the olfactory event-related magnetic fields corresponded to the ascending and descending slopes of the major deflections of the olfactory event-related potentials (OERP). At these latencies we obtained consistent activation of the anterior-central parts of the insula (agranular-periallocortical and dysgranular regions) the parainsular cortex and the superior temporal sulcus. No reproducible equivalent current dipoles were found in other brain areas, including the orbitofrontal cortex. For the first time, brain areas were identified that generate most components of olfactory bioresponses (OERPs) in humans.
Standard antiepileptic drugs (AEDs) are associated with a wide variety of acute and chronic adverse events and with many interactions with each other and with non-AEDs that complicate patient management. The safety and interaction profiles of the newer AEDs have also been intensively studied. Safety data are available for six of the newer AEDs, lamotrigine (LTG), vigabatrin (VGB), gabapentin (GBP), tiagabine (TGB), felbamate (FBM), and topiramate (TPM). The potential for the most recently developed AEDs for producing rare idiosyncratic reactions cannot be ascertained until additional patient exposures have been reported from careful postmarketing surveillance.
In female epispadias complete repair of the wide and short urethra and bladder neck abnormalities facilitate achievement of bladder regrowth with adequate bladder capacity and urinary continence. Attention must be given to correct the appearance of malformed anatomy of the external genitalia which is of importance for later sexual function. Eight cases are described of congenital female epispadias and incontinence treated during the years 1964-1995. Of these patients, 2 had had failed previous procedures. Eight patients underwent bladder neck plasty and creation of an adequate urethral channel using a combined perineal and transvesical approach. Ureters were reimplanted in five cases if they had VUR reflux or facilitate bladder neck plasty. Simultaneous genitourinary reconstruction of the external genital defect, monsplasty, creation of urethral channel and bladder neck plasty were performed in 6 patients and in two as a secondary procedure. Five patients are completely continent day and night, two patients are dry, but during the day they are a little stress incontinent. One patient underwent urinary diversion after she failed one bladder neck procedure.
The authors describe the radical treatment of two locally advanced tumours of the penis without detectable generalization. Both cases were resolved by radical surgery, emasculinization. With regard to the size of the tumour which infiltrated the area of the perineum and hypogastrium the covering of the defect after removal of the tumourous mass called for skin transplantations and tubular plastic operations. The authors describe also the complications which developed during the postoperative period and their solution.
The origin of inter-ictal epileptic activity can be localized from the magnetoencephalogram (MEG) using the Equivalent Current Dipole (ECD) as a source model. One problem with such localizations is that in many patients, the localization of an epileptic spike source becomes inaccurate because the epileptic spikes are superimposed by pathologic brain rhythmic activities. This paper proposes to use the spatial coherence of the measured magnetic field caused by the measured magnetic field to suppress its influence in the ECD localization. In the method proposed here, the covariance matrix, which expresses the spatial coherence of the rhythmic magnetic field, is first calculated using a data portion where no spikes exist and rhythmic slow waves are evident. Then, ECD localization is performed by minimizing the least-squares cost function modified by the covariance matrix. Experiments using a computer generated ECD field and rhythmic slow waves measured from a patient suffering from complex partial epilepsy prove the basic effectiveness of the method proposed. Localizations of actual spike sources in the same clinical data are performed, and results indicating the effectiveness of the proposed method are obtained.