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Biomedical subjects

I Fried

Publications and source records attributed to I Fried.

At least 73 records · Page 4Linked to original sources
PubMed1993

Anatomic temporal lobe resections for temporal lobe epilepsy.

Temporal lobe epilepsy is not a single clinicopathologic entity but a group of syndromes requiring different surgical solutions. Anatomic resections planned for the treatment of these syndromes are aimed at pathologic substrates minimizing ablation of normal tissue. Most of these procedures involve mesial and lateral temporal resections. The syndrome of mesial temporal sclerosis should be treated with resection aimed at hippocampus and the PHG, including entorhinal cortex, and at part of the amygdala. Improvement in diagnostic methods and refinement of anatomic surgical procedures that maximize resection of hippocampus resulted in excellent outcome in the treatment of patients with this syndrome. Mass lesions in patients with intractable seizures should be resected with some surrounding margins, but additional clinical studies will be required to determine the role of anatomic resections, including hippocampectomy, in the treatment of these patients. Extrahippocampal temporal lobe epilepsy is the most difficult to evaluate and treat. Tailored individualized resections based on acute or chronic EEG recordings may be required until and if discrete anatomically based syndromes can be identified in this patient population.

Epilepsy, Temporal Lobe↗
PubMed1992

Hippocampal pathology in patients with intractable seizures and temporal lobe masses.

The authors examined hippocampal tissue removed during surgical procedures in 17 patients with intractable epilepsy who were found by preoperative magnetic resonance imaging or computerized tomography to have intra-axial masses in the temporal lobe. Neuronal densities in the cornu ammonis (CA) fields of the hippocampus and in the dentate granule cell layer were measured in hematoxylin and eosin-stained sections and were found to be lower compared to a group of 18 autopsy controls. The neuronal densities in all hippocampal fields except CA2 were related to the patient's age at seizure onset. Patients with an earlier onset of seizures had lower neuronal densities. With the exception of CA4, neuronal densities were not significantly related to the duration of the seizure disorder. Cell counts in all fields except CA2 were also related to the location of the lesion in the temporal lobe. Patients with mesial temporal lesions had lower neuronal counts. These results suggest increased vulnerability of hippocampal cytoarchitecture to proximal lesions with early ictal manifestation.

Adolescent↗
PubMed1992

Encephalo-omental synangiosis in the management of moyamoya disease.

Moyamoya disease is a chronic occlusive cerebrovascular disorder characterized by stenosis of the intracranial internal carotid artery often accompanied by stenosis of the anterior and/or middle cerebral arteries. This results in cerebral ischemia, which manifests clinically as transient, repetitive episodes of hemiplegia, dysarthria, and involuntary movements. This case report documents a patient in whom an initial extracranial-intracranial bypass (superficial temporal-middle cerebral artery) failed to alleviate the ischemic symptoms. In a subsequent procedure, a pedicle graft of omentum was created and through a subcutaneous tunnel was placed on the right cerebral cortex. Over a 2 1/2-year period, this has resulted in a dramatic resolution of the patient's symptomatology. The report delineates the condition and reviews other therapeutic options.

Adult↗
PubMed1991

Functional organization of human supplementary motor cortex studied by electrical stimulation.

The presence of somatotopic organization in the human supplementary motor area (SMA) remains a controversial issue. In this study, subdural electrode grids were placed on the medial surface of the cerebral hemispheres in 13 patients with intractable epilepsy undergoing evaluation for surgical treatment. Electrical stimulation mapping with currents below the threshold of afterdischarges showed somatotopic organization of supplementary motor cortex with the lower extremities represented posteriorly, head and face most anteriorly, and the upper extremities between these two regions. Electrical stimulation often elicited synergistic and complex movements involving more than one joint. In transitional areas between neighboring somatotopic representations, stimulation evoked combined movements involving the body parts represented in these adjacent regions. Anterior to the supplementary motor representation of the face, vocalization and speech arrest or slowing of speech were evoked. Various sensations were elicited by electrical stimulation of SMA. In some cases a preliminary sensation of "urge" to perform a movement or anticipation that a movement was about to occur were evoked. Most responses were contralateral to the stimulated hemisphere. Ipsilateral and bilateral responses were elicited almost exclusively from the right (nondominant) hemisphere. These data suggest the presence of combined somatotopic organization and left-right specialization in human supplementary motor cortex.

Adolescent↗
PubMed1989

Electrocorticographic (ECoG) correlates of language. I. Desynchronization in temporal language cortex during object naming.

The electrocorticogram (ECoG) was recorded during a language task, silent naming, from sites identified as essential for naming by electrical stimulation mapping and from surrounding cortex of left dominant temporal cortex at craniotomies under local anesthesia. The ECoG was analyzed quantitatively for a reduction in spectral density in 7-12 Hz frequencies indicating 'desynchronization.' These measurements were made on the averaged ECoG in 3 subjects and on individual ECoG segments in 4. Statistically significant increases in desynchronization were identified during silent naming at most sites essential for language, most often in the epoch from 700 to 1200 msec after presentation of the item to be named. During silent naming, there was a greater degree of desynchronization at those sites than in surrounding cortex. At several sites essential for language in several subjects, significantly less desynchronization was evident during a spatial task using physically identical stimuli. Thus, localized desynchronization in temporal cortex is an ECoG change with temporal, anatomic, and sometimes behavioral specificity to a language task. This finding provides insights into cortical physiologic mechanisms active during human language.

Adult↗
PubMed1985

Dendritic organization of the anterior speech area.

Golgi studies revealed significant differences in dendritic patterns between neurons of the left and right opercular regions of the frontal lobe (Broca's speech area on the dominant side) and between cells of the left and right precentral areas (the orofacial motor zones) just behind. Although total dendritic length of the basilar dendritic array seemed characteristic of an area independent of side, a larger proportion of the length on the left (dominant) side was made up of higher order (4, 5, 6) dendrite branches, and lower order (1, 2, 3) segments predominated on the right. The pattern was partially reversed in non-right-handed patients. These findings can be interpreted as indicating an early preponderance of dendrite growth in the non-speech-gifted hemisphere followed by enhanced dendrite growth in the dominant hemisphere coincident with the beginning of conceptualization and speech function.

Aged↗
PubMed1984

Scanning electron microscopy of the central nervous system. II. The hippocampus.

This study has presented cells, fibers and non-neuronal elements as seen in 3 dimensions using the SEM. Our discussion on possible artifacts which can occur with this method is offered in the hope that others will develop better techniques of dissection and specimen preparation. With the picture of normal tissue in mind, the investigator can undertake studies to determine the effects of various interventions on the structures of interest. Such treatments could include deafferentation or the use of macromolecular probes bound to cell surfaces. We anticipate that improvements in tissue preparation techniques by ourselves and others will open the way to intensive investigation of the nervous system using this powerful tool.

Animals↗
PubMed1981

Structural correlates of seizure behavior in the mongolian gerbil.

Hippocampi of seizure-sensitive and seizure-resistant Mongolian gerbils were examined in search of structural correlates of seizure behavior. In animals with well-established seizure histories, differences were found in both presynaptic and postsynaptic structures. Seizing animals had less dense dendritic spines, a greater proportion of mossy tuft area devoted to presynaptic vesicles, and a smaller proportion devoted to spines. The possible relationship of these findings to epilepsy is discussed.

Animals↗
PubMed1981

Language-related potentials specific to human language cortex.

Event-related potentials following silently named object pictures were recorded directly from the exposed left hemisphere of the human cortex at sites whose relation to naming was subsequently established by electrical stimulation mapping. Two simultaneous potential changes are specific to sites where stimulation disrupts naming: slow potentials as premotor sites and focal desynchronization at posterior sites surrounding the Sylvian fissure. These anatomically specific changes are also specific to the task--present with silent naming and absent in a spatial task with the same visual input. Overt speech is also preceded by slow potentials with earliest onset at premotor sites.

Adult↗
PubMed1981

Scanning electron microscopy of the central nervous system. I. The cerebellum.

The fine structure of the cerebellar cortex has been studied by means of scanning electron microscopy (SEM). The neuropil is revealed by careful tearing of aldehyde-fixed tissue specimens which are prepared by means of dehydration, critical point freeze-drying, and sputter-coating with gold-palladium. Specimens are subsequently viewed at magnifications of up to X 16,000 with capabilities for extension up to about X 40,000. The technique provides remarkable three-dimensional views of neuropil including cell bodies and dendrites, details of presynaptic and postsynaptic morphology, axonal structure, neuroglia, and the microvasculature. It seems particularly powerful in demonstrating relationships between neuropil elements such as the terminal synaptic array on neuron somata and the arrangements of structures on membrane surfaces.

Animals↗
PubMed1980

Cartilagenous tumors of the larynx: a review of literature and two case experiences.

Cartilagenous tumors of the larynx are uncommon. A review of the experience from four major hospitals affiliated with McGill University, Montreal, from 1960-1977 revealed only two cases. The treatment and follow-up of these cases is discussed. A thorough review of English literature from 1816 revealed 177 reported cases. Management of benign and malignant cartilagenous tumors of the larynx is discussed and literature is compared.

Aged↗
PubMedDate not supplied

Syndrome E.

The transformation of groups of previously nonviolent individuals into repetitive killers of defenceless members of society has been a recurring phenomenon throughout history. This transformation is characterised by a set of symptoms and signs suggesting a common syndrome--Syndrome E. Affected individuals show obsessive ideation, compulsive repetition, rapid desensitisation to violence, diminished affective reactivity, hyperarousal, environmental dependency, group contagion, and failure to adapt to changing stimulus-reinforcement associations. Yet memory, language, planning, and problem-solving skills remain intact. The main risk factors are male sex and age between 15 and 50. A pathophysiological model--"cognitive fracture"--is hypothesised, where hyperaroused orbitofrontal and medial prefrontal cortices tonically inhibit the amygdala and are no longer regulated by visceral and somatic homoeostatic controls ordinarily supplied by subcortical systems. It is proposed that the syndrome is a product of neocortical development rather than the manifestation of a disinhibited primitive brain. Early recognition of symptoms and signs could lead to prevention through education and isolation of affected individuals.

Adolescent↗
PubMedDate not supplied

Intracranial, intraaxial, space-occupying lesions in patients with intractable partial seizures: an anatomoclinical, neuropsychological, and surgical correlation.

Fifty of approximately 250 patients evaluated for intractable partial seizures were shown to have a space-occupying lesion detected with radiographs and/or neuroimaging. Twenty-eight males and 22 females had a mean age at seizure onset of 13 years and a mean duration of seizures of 11 years. All patients had closed-circuit television with EEG monitoring and complete neurologic and neuropsychological assessment. Findings were correlated with lesion location and surgical data. Twenty-seven lesions (54%) were located in the temporal lobe. Thirty-five lesions (70%) were neoplastic. All patients with temporal lobe lesions had complex partial seizures, as did 74% of patients with extratemporal lesions. A good correlation between clinical seizure characteristics and lesion localization was found with the temporal, occipital, and frontal lesions but not with the parietal lesions. Sixty-six percent of patients had focal interictal EEG findings. Lateralization corresponded to the side of the lesion in 64% and was localized to the region of the lesion in 30%. Lateralized ictal EEGs occurred in 58% of patients, corresponding with the side of the lesion in all but one patient. Abnormal findings on neuropsychological testing were congruent with lesion lateralization in 56% of patients and were localized to the region in 26%. Thirty-nine of 47 patients who underwent a subtotal lobectomy to include the lesion are seizure-free after greater than or equal to 1 year of follow-up, and five others are markedly improved.

Brain↗