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Biomedical subjects

F Andermann

Publications and source records attributed to F Andermann.

At least 253 records · Page 14Linked to original sources
PubMed1991

Developmental anterobasal temporal encephalocele and temporal lobe epilepsy.

The authors describe the association between an antero-basal temporal lobe encephalocele and medically intractable temporal lobe epilepsy in three patients treated successfully by surgery. Two men and one woman, aged 26 to 37 years (mean 31 years), had onset of complex automatism and generalized seizures in their second and fourth decades (mean age 22.7 years). They had been epileptic for 6 to 14 years (mean 8.3 years) before surgery. Preoperative electroencephalograms localized ictal epileptic activity to the left mesial temporal lobe in all cases, and neuropsychological testing revealed dominant temporal lobe dysfunction. Magnetic resonance (MR) imaging demonstrated an anteromedial basal temporal encephalocele extending into the pterygopalatine fossa through a bone defect at the base of the greater sphenoid wing in the region of the foramen rotundum and pterygoid process, a discrete center of embryonal chondrification. At surgery, the encephaloceles were found in front of the uncus, and an area of gliosis extended from the encephalocele to the amygdalohippocampal region. All patients have been seizure-free following anterior temporal resection and amygdalohippocampectomy including the encephalocele. These three cases delineate a condition of disordered embryogenesis wherein a developmental anterobasal temporal encephalocele acts as the substrate for temporal lobe epilepsy. This lesion may be diagnosed preoperatively with MR imaging and should be considered in the differential diagnosis of late-onset temporal lobe epilepsy.

Adult↗
PubMed1991

Progressive myoclonus epilepsies: clinical and neurophysiological diagnosis.

Diagnosis and management of the progressive myoclonus epilepsies (PMEs) provides a challenge to the clinician and neurophysiologist. Over 15 specific disorders can cause the PME syndrome; all are rare, and individual physicians are unlikely to have experience in all of them. Accurate diagnosis is essential to provide a prognosis, optimal therapy, and genetic counseling. The major causes are PME of the Unverricht-Lundborg type, Lafora disease, neuronal ceroid lipofuscinoses (three forms), MERRF (myoclonus epilepsy and ragged red fibers), and sialidoses (two forms), in addition to a number of even rarer disorders. Here we review the clinical aspects and neurophysiology of these disorders, which can now be diagnosed in life by relatively simple methods in the vast majority of cases.

Electroencephalography↗
PubMed1991

Magnetic resonance imaging of hypothalamic hamartomas causing gelastic epilepsy.

Hypothalamic hamartomas may cause a peculiar epileptic syndrome characterized by seizures of laughter and precocious puberty. Four mentally handicapped patients suffering from gelastic epilepsy were referred to our institution for investigation; three of them also presented with precocious puberty. In all four cases magnetic resonance imaging (MRI) revealed a space-occupying lesion of the hypothalamus that was considered to be a hamartoma. Biopsies were not performed. Hamartomas appear isodense in plain computed tomography scans, and they do not enhance. Such lesions display an isointense signal in T1-weighted magnetic resonance images and a hyperintense signal in proton density and T2-weighted images. MRI is the procedure of choice for detecting such lesions at the base of the brain.

Adolescent↗
PubMed1991

Correlative multidisciplinary approach to the study of mitochondrial encephalomyopathies.

Mitochondrial encephalomyopathies can be caused by defects in the mitochondrial respiratory complexes. The clinical phenotypes are quite protean but in many instances a characteristic or suggestive clinical presentation permits a tentative bedside diagnosis. The diagnosis can be verified by laboratory investigations. The major laboratory hallmarks of mitochondrial encephalomyopathies include: ragged red fibers on muscle biopsy, a specific defect or deficiency in a mitochondrial respiratory enzyme complex, mtDNA abnormalities, reduced anaerobic threshold by bicycle ergometry, impaired cellular energy state by MRS and characteristic brain imaging abnormalities. Monitoring of some of these parameters along with the clinical phenotype will aid in the evaluation of therapeutic trials.

Brain Diseases↗
PubMed1990

Common dopaminergic mechanism for epileptic photosensitivity in progressive myoclonus epilepsies.

We studied the effect of apomorphine, a dopamine receptor agonist, on epileptic photosensitivity in 7 patients with progressive myoclonus epilepsy (PME). Specific diagnoses included Baltic PME (Unverricht-Lundborg disease), Lafora disease, Kufs' disease, juvenile neuroaxonal dystrophy, and action myoclonus-renal failure syndrome; 2 patients had PME of uncertain etiology. Apomorphine blocked the epileptic photosensitivity in all patients and also reduced intention myoclonus in a patient with Baltic PME. There is a common deficit of dopaminergic inhibitory neurotransmission at the level of the striate cortex in patients with PME, regardless of the nature of the specific underlying neuropathologic process.

Adolescent↗
PubMed1990

A proton magnetic resonance spectroscopy study of focal epilepsy in humans.

Localized in vivo proton magnetic resonance spectra obtained from diseased areas in 2 patients with chronic localized encephalitis (Rasmussen's syndrome) showed reduced resonance intensities from N-acetyl compounds, suggesting focally decreased N-acetylaspartate concentrations. One of the patients had epilepsia partialis continua secondary to the encephalitis. In this patient, the spectra demonstrated a high lactate resonance intensity (not seen in the normal, contralateral hemisphere) corresponding to an estimated local concentration of about 7.5 mM. We speculate that the observed decrease in the N-acetyl compound resonance may be a biochemical correlate of the neuronal loss characteristic of this disease. The results establish that excessive accumulation of lactate can occur in the human brain as a result of seizure activity even in the absence of ischemia. Thus, bioenergetic compromise may be 1 predisposing factor to the death of excitable cells in the epileptogenic area.

Aspartic Acid↗
PubMed1990

Reflex seizures induced by calculation, card or board games, and spatial tasks: a review of 25 patients and delineation of the epileptic syndrome.

Nine patients had reflex activation of seizures by calculation, card and board games, or spatial tasks. The common denominator for these and the 16 others reported in the literature appears to be activity related to function of the parietal lobe. The clinical and EEG findings in all 25 patients support the diagnosis of primary generalized epilepsy. Seizures usually start during adolescence and consist of myoclonus, absences, and generalized convulsions. Specific inquiry about reflex activation should be carried out in patients with generalized epilepsy since this is rarely provided spontaneously. Attacks could be controlled satisfactorily in 89% of our patients. The genetic features are those of a primary generalized epileptic disorder without evidence for a specific inheritance of reflex sensitivity. Neuropsychological analysis of the stimuli points to parietal cortical dysfunction. These stimuli lead to activation of a generalized epileptic process analogous to the occipital cortical participation in the activation of generalized epileptic abnormality occurring in patients with photosensitive epilepsy.

Adolescent↗
PubMed1989

Generalized cortical dysplasia manifested by diffusely thick cerebral cortex.

Unilateral or bilateral rolandic macrogyria has been described as a cause of epilepsy and, in some cases, retardation. Tissue from the periphery of these lesions shows the changes of focal cortical dysplasia. Evidence reported herein suggests that cortical dysplasia may also be generalized. Two patients with intractable epilepsy and mental retardation had diffusely abnormal, thick cortex, shallow gyri, and poor demarcation of gray and white matter. One patient had an anterior callosotomy that led to considerable improvement of the epilepsy. Cortical layers 5 and 6 could not be differentiated on biopsy material. The white matter was poorly myelinated and contained clusters of heterotopic neurons. This syndrome, a congenital disorder of neuronal migration, with prolonged survival, represents a mild form of lissencephaly. It can be diagnosed during life by computed tomography or magnetic resonance scanning.

Adolescent↗
PubMed1989

Depth electrode investigations in patients with bitemporal epileptiform abnormalities.

Fifty-seven patients showing bitemporal independent epileptiform abnormalities on extracranial electroencephalograms (EEGs) in whom the epileptogenic zone could not be localized or lateralized by extracranial EEG and other noninvasive tests were investigated with stereotactic depth electrode recordings. In a majority of 44 patients (77%), seizures originated exclusively or with a strong predominance in one temporal lobe only. Of the remaining 13 patients (23%), 8 had seizures originating independently in either temporal lobe without significant lateralized predominance, and 5 had multiple seizure patterns, which were often diffuse. The patterns of seizure onset as recorded by depth electrodes tended to vary even in the same patient. Electrical stimulation studies and the determination of afterdischarge thresholds were of limited utility for lateralization of seizure onset.

Adolescent↗
PubMed1989

Results of surgical treatment in patients with bitemporal epileptiform abnormalities.

Fifty-three of 57 patients who had evidence of bitemporal epileptiform abnormalities and who required investigation with stereotactic depth electroencephalography (SDEEG) recordings to determine the site of origin of seizures underwent surgical resection for the treatment of their epilepsy. A minimum of 2 years' follow-up was available in 48 patients who underwent a temporal lobe resection. In this group, 19 patients (40%) were greatly improved, and of these 14 (29%) became seizure free and 5 (10%) had no more than 3 seizures each year. Another 22 patients (46%) showed a worthwhile reduction in seizure frequency of at least 50%. Seven patients (15%) were not significantly improved. An etiological factor of early convulsions before age 3 (usually febrile) was associated with a better outcome. Both the lack of a strong predominance for SDEEG-recorded seizures to arise in the resected temporal lobe and the presence of residual epileptiform abnormalities in the postexcision electrocorticogram were correlated with poorer results.

Adult↗
PubMed1989

Bilateral central macrogyria: epilepsy, pseudobulbar palsy, and mental retardation--a recognizable neuronal migration disorder.

The neuronal migration disorders comprise several morphological entities that are recognizable during life using current imaging techniques. We studied 4 patients who had a characteristic bilateral central rolandic and sylvian macrogyria. The patients had pseudobulbar palsy with oromotor incoordination and developmental delay and were mildly retarded. Minor seizures developed between the ages of 8 and 9 years. Subsequently, atonic drop attacks became the predominant epileptic pattern. Epileptogenic electrographic abnormalities were secondary generalized or multifocal. The lesions were detected by computed tomography and magnetic resonance imaging in all patients. Bilateral symmetrical areas of thick cortex surrounding a large sulcus were seen. This syndrome consists of specific clinical, imaging, electroencephalographic, and epileptic features. It can be suspected clinically and confirmed by imaging studies. Callosotomy in two patients helped the intractable seizures.

Adolescent↗
PubMed1989

Myoclonus epilepsy and ragged-red fibres (MERRF). 1. A clinical, pathological, biochemical, magnetic resonance spectrographic and positron emission tomographic study.

Thirteen patients, including 6 from one family, with the syndrome of myoclonus epilepsy and ragged-red fibres (MERRF) were studied. There was considerable heterogeneity in the age of onset, severity and associated clinical features. Postmortem studies in 3 patients from the one family showed a particular system degeneration. In addition, the youngest and most severely affected family member showed the pathological changes of Leigh's syndrome. Cortical dysfunction is a prominent clinical feature in MERRF, but postmortem examination failed to reveal cortical abnormalities. Positron emission tomographic studies, however, showed decreased cortical metabolic rates for glucose and oxygen utilization, with normal cortical blood flow and cerebral pH. Analyses of kinetic rate constants for uptake and phosphorylation of the glucose analogue, fluorodeoxyglucose showed decreased hexokinase-mediated phosphorylation: normal K1 and k2 values but reduced k3. Phosphorus magnetic resonance spectroscopy studies suggested a normal cerebral intracellular pH. Biochemical studies on muscle homogenates in 6 patients showed partial deficiencies of the activities of certain mitochondrial enzymes in 4 cases, whereas in 2 patients no abnormality was found. Our data, combined with previous reports, show that MERRF is biochemically and genetically heterogeneous. Our experience, and analysis of the literature, suggests that many cases previously described as the Ramsay Hunt syndrome, as well as other hitherto unclassified system degenerations associated with myoclonus epilepsy, are examples of MERRF. These data permit the formulation of a hypothesis to explain the clinical, biochemical and genetic heterogeneity of MERRF, and its overlap with Leigh's syndrome. We suggest that different biochemical defects of the mitochondrial respiratory chain may cause similar cerebral metabolic effects, as measured by positron emission tomography, resulting in similar phenotypes. Reduced activity of one enzyme, however, may result in different phenotypes, depending on the severity of the defect and its tissue distribution. Moreover, the phenotypic expression of certain biochemical defects may be influenced by randomly occurring factors such as fever, which may increase metabolic demand and result in more deleterious cellular metabolic effects.

Adolescent↗
PubMed1989

Myoclonus epilepsy and ragged-red fibres (MERRF). 2. Electrophysiological studies and comparison with other progressive myoclonus epilepsies.

Electrophysiological studies (EEG, evoked potentials, nerve conduction and EMG) in 13 patients with myoclonus epilepsy with ragged red fibres (MERRF) are presented. The most notable findings are the presence of atypical irregular generalized spike and wave discharges arising from an abnormal EEG background (9 patients), focal epileptiform abnormalities (6 patients) most commonly over the occipital regions and giant cortical SEPs (4 of 6 patients tested). Similar findings of disturbed EEG background activity, generalized spike and wave discharges and giant cortical SEPs appear to be shared by the group of diseases characterized by progressive myoclonus epilepsy.

Adolescent↗
PubMed1989

Valproate prevents the recurrence of absence status.

We assessed the value of valproate in the prevention of recurrent attacks of absence status in 25 patients. Eighteen patients had primary generalized epilepsy with a mean frequency of attacks of absence status of 5.7 per year. After a mean follow-up period of 4.4 years, the attack frequency was reduced to 0.6 per year (p less than 0.0005); 14 patients had no recurrence, 3 had rare attacks with noncompliance, and 1 had an incomplete response probably due to gastrointestinal intolerance. Patients with evidence of generalized cerebral damage (n = 2) or with EEG evidence of focalization (n = 5) did not respond as favorably. Valproate is the drug of choice for the prevention of recurrence of absence status. Moreover, the response can be predicted on the basis of the electroclinical subtype of absence status.

Adolescent↗