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Biomedical subjects

J Siegfried

Publications and source records attributed to J Siegfried.

At least 73 records · Page 4Linked to original sources
PubMed1983

[Parameters of high-frequency thermocoagulation of the Gasserian ganglion in the treatment of trigeminal neuralgia in order to obtain analgesia without anesthesia].

Voltage and current within Gasserian ganglion have been measured during a therapeutical high frequency coagulation of the Gasserian ganglion in 25 consecutive cases. From these values, the impedance (Ohm), the work (Watt) and the total energy (Joule) necessary to obtain an analgesia without anesthesia have been calculated. The study has shown that the temperature and the time of coagulation in correlation with the length of the non isolated tip of the electrode are actually the only constancy in the control of the therapeutical lesions.

Electrocoagulation↗
PubMed1981

[Neurosurgical treatment of pain].

Chronic pain may be considered a disease and its treatment a necessity. Neurosurgical treatment of chronic pain is justified in cases where conservative treatment is no longer effective or causes excessive side effects. The new percutaneous methods involve no stress, minimal risk and short hospitalization. Destructive neurosurgical procedures are mainly used for cancer pain, with the exception of trigeminal neuralgia. Non-destructive neurostimulating methods to control pain are well on the way to achieving their optimum clinical potential and preserve the integrity of the nervous system.

Electric Stimulation↗
PubMed1981

Electrical spinal cord stimulation for spastic movement disorders.

Clinical results of electrical stimulation of the spinal cord at three different clinics are reported for 53 patients suffering from different spastic movement disorders out of a series of 164 cases tested transitorily. Two-thirds of the cases were multiple sclerosis patients. The difficulty of objective assessment is emphasized. Motor function was principally evaluated and surprisingly showed a marked improvement 1-5 years after the implantation of an electrical device. Other criteria are analyzed and compared with literature. Dorsal cord stimulation seems to be a valuable method for improving the quality of life in a limited percentage of cases of neurological motor disorders.

Adult↗
PubMed1980

Is the neurosurgical treatment of Parkinson's disease still indicated?

Long-term results of the medical treatment of Parkinson's disease are somewhat disappointing despite an increased longevity and a more prolonged functional ability. The appearance of iatrogenic side-effects lead some authors to withhold levodopa until severity of symptoms really warrants its use. In this context the place of neurosurgery is re-evaluated. With specific indications a correctly performed stereotactic operation is still the best therapy available capable of suppressing tremor, iatrogenic hyperkinesias and rigidity and must be considered when these symptoms incapacitate the functional and social life of the patient.

Antiparkinson Agents↗
PubMed1980

Clinical and chronotopographic psychomotor seizure patterns (SEEG study with reference to postoperative results).

In 29 selected patients who underwent stereo-electroencephalographic exploration because of uncontrolled psychomotor epilepsy, 213 seizures were recorded. These seizures were analyzed in 10-second-intervals with respect to the sequence of clinical signs and the electrical chronotopographic patterns. By the aid of a computerized cluster analysis four comparatively distinct localization-patterns were found: a) opercular, b) frontobasal-cingular, c) temporobasal-limbic and d) posterior temporal neocortical. The lowest trend for propagation to the opposite hemisphere is found in a) followed by d). Fairly strong tendency for contralateral propagation is seen in c). Strategically important structures for contralateral propagation are: 1. amygdala and hippocampus, and to a lesser degree 2. the frontal cortex. Seizures propagating to the parietal cortex very often involve the frontal area of the same side before affecting the opposite hemisphere. For each of these "epileptic clusters" the characteristic clinical signs are pointed out. Special emphasis was put on the primictal symptom-sequence. By this and a similar study with Bancaud et al. we show that significantly better postoperative results are found, when strategy for surgery was based on the evidence of several SEEG recorded spontaneous seizures. In some patients belonging to the "temporobasal-limbic" cluster stereotactic procedures proved successful.

Amygdala↗
PubMed1980

Indications and ethical considerations of deep brain stimulation.

Electrical impulses through chronically implanted electrodes in the human brain are used today in the relief of chronic crippling pain, motor movement disorders and behavior disturbances. A great number of reports from animal studies and several descriptions of the results produced by human stimulation seem to suggest that pain can often be adequately controlled. However, the perspectives of such methods raise many ethical problems and ask for caution. Nervous tissue damage after long-term stimulation, biochemical modifications, electrode migration and long-term follow-up of its clinical value are still under study and are the factors which might limit for the time being the indications. A restrictive role for this procedure is advocated for: 1. cases of chronic facial pain, 2. cases of chronic pain in other locations where other neurosurgical operations have failed and where the patient is not too young and is not suffering from pain of benign origin.

Brain↗
PubMed1980

Treatment of spasticity by dorsal cord stimulation.

Two types of operations can be proposed today in the neurosurgical treatment of spasticity; the destruction of a brain target, a medullary pathway or a nerve root, and electrical stimulation of nervous structures. Striking improvements in voluntary motor control and sensory appreciation were first reported by Cook and Weinstein (1) in 1973, after implantation of a dorsal cord stimulator for intractable back pain in a case of muiltiple scleroris. The favourable effect on spasticity was confirmed later by other groups. Our own experience, with 26 cases tested for a few days with floating electrodes and 11 cases operated on and followed up for more than 3 years, shows that the best results are obtained in cases of medullary spasticity, without complete section of the cord, occurring mainly in multiple sclerosis. Cerebral spasticity did not respond as well. The objective data, measurement of stretch and H-reflexes, support the clinical results. The physiological mechanisms of dorsal cord stimulation on spasticity have not yet been elucidated.

Electric Stimulation Therapy↗
PubMed1979

Inhibition by transcutaneous electrical stimulation of noxious heat elicited in human Gasserian ganglion.

During percutaneous thermocoagulation of the Gasserian ganglion for trigeminal pain, the pain perception threshold was established in a series of 25 awake patients by measuring the temperature at the electrode tip within the ganglion during slow increase of the radiofrequency current. Between 42 and 48 degress C pain perception was regularly reported by the patients. A cutaneous-stimulating system was then applied to the trigeminal area which was reported to be painful during the heating. The external stimulation attempted to preferentially stimulate the A afferent nerve fibres. When external stimulation was applied during the heating of the Gasserian ganglion, the pain perception threshold was enhanced in about half of the cases. A transcutaneous electrical stimulation of part of the body not related with the investigated pain sensation did not produce the same inhibitory action in 3 out of 5 cases.

Adult↗
PubMed1979

[Macro-electrode recording in man's brain-stem 1. Electrical activity during wakefulness and nightsleep (author's transl)].

In the context of a functional treatment for pain five patients had electrodes chronically implanted in the periaqueductal gray matter (PGM) and at the same time in thalamic nuclei. The spontaneous activity of these structures was analyzed in comparison with the simultaneously recorded scalp-EEG. The structure-specific differences between the activity of the PGM and the thalamic nuclei were pointed out. In waking state a close functional relation between the alpha-activity of the PGM and the scalp-EEG was found. Physiological sleep patterns were recorded in the mesencephalon earleir than at the surface. REM-phases were initiated by 4/sec rhythms in the PGM. During rapid eye movements sharp waves in the PGM appeared which are evidently related to the eye movements themselves. The findings are discussed in reference to the literature. Special emphasis is placed on the anatomical connexions between the explored mesencephalic and thalamic structures and the temporo-occipital cortex and on the role of ponto-mesencephalic structures in slow-wave-sleep and REM-sleep.

Adult↗