Oestrogenic, Androgenic and Gonadotrophic Substances in the Urine of Normal Women

Pedersen‐Bjergaard, K.; Tønnesen, M.

doi:10.1530/acta.0.0010038

Cited by 20 publications

(3 citation statements)

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“…Therefore, we do not expect a large age-dependent effect on the induced electric field from the growth in skull thickness in adults. The hypodermis thickness does not undergo significant change with aging in men, whereas hypodermis thickness in women correlates positively with estrogen level during the lifetime [16], [48]. In addition to structural changes that accompany hormonal fluctuations, estrogen is also known to increase the number of hippocampal excitatory neuron synapses and increase seizure susceptibility in female epileptic patients—factors that could also affect seizure threshold [49].…”

Section: Discussionmentioning

confidence: 99%

Effect of Anatomical Variability on Electric Field Characteristics of Electroconvulsive Therapy and Magnetic Seizure Therapy: A Parametric Modeling Study

Deng

Lisanby

Peterchev

2015

IEEE Trans. Neural Syst. Rehabil. Eng.

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Electroconvulsive therapy (ECT) and magnetic seizure therapy (MST) are conventionally applied with a fixed stimulus current amplitude, which may result in differences in the neural stimulation strength and focality across patients due to interindividual anatomical variability. The objective of this study is to quantify the effect of head anatomical variability associated with age, sex, and individual differences on the induced electric field characteristics in ECT and MST. Six stimulation modalities were modeled including bilateral and right unilateral ECT, focal electrically administered seizure therapy (FEAST), and MST with circular, cap, and double-cone coils. The electric field was computed using the finite element method in a parameterized spherical head model representing the variability in the general population. Head tissue layer thicknesses and conductivities were varied to examine the impact of interindividual anatomical differences on the stimulation strength, depth, and focality. Skull conductivity most strongly affects the ECT electric field, whereas the MST electric field is independent of tissue conductivity variation in this model but is markedly affected by differences in head diameter. Focal ECT electrode configurations such as FEAST is more sensitive to anatomical variability than that of less focal paradigms such as BL ECT. In MST, anatomical variability has stronger influence on the electric field of the cap and circular coils compared to the double-cone coil, possibly due to the more superficial field of the former. The variability of the ECT and MST electric field due to anatomical differences should be considered in the interpretation of existing studies and in efforts to improve dosing approaches for better control of stimulation strength and focality across patients, such as individualization of the current amplitude. The conventional approach to individualizing dosage by titrating the number of pulses cannot compensate for differences in the spatial extent of stimulation that result from anatomical variability.

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Section: Discussionmentioning

confidence: 99%

Effect of Anatomical Variability on Electric Field Characteristics of Electroconvulsive Therapy and Magnetic Seizure Therapy: A Parametric Modeling Study

Deng

Lisanby

Peterchev

2015

IEEE Trans. Neural Syst. Rehabil. Eng.

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“…The hypodermis thickness does not undergo significant change with aging in men, whereas changes in hypodermis thickness in women covaried with estrogen level during the lifetime [54]. In addition to structural changes that accompany hormonal fluctuations, estrogen is also known to increase the number of hippocampal excitatory neuron synapses and increase seizure susceptibility in female epileptic patients [55].…”

Section: Age-related Effectsmentioning

confidence: 96%

Effect of anatomical variability on neural stimulation strength and focality in electroconvulsive therapy (ECT) and magnetic seizure therapy (MST)

Deng

Lisanby

Peterchev

2009

2009 Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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We present a quantitative comparison of two metrics-neural stimulation strength and focality-in electrocon-vulsive therapy (ECT) and magnetic seizure therapy (MST) using finite-element method (FEM) simulation in a spherical head model. Five stimulation modalities were modeled, including bilateral ECT, unilateral ECT, focal electrically administered seizure therapy (FEAST), and MST with circular and double-cone coils, with stimulation parameters identical to those applied in clinical practice. We further examine the effect on the stimulation metrics of individual-, sex- and age-related variability in tissue layer thickness and conductivity. Neural stimulation by MST is shown to be more focal and superficial than ECT. This result suggests that it may be advantageous to reduce the current used in ECT. The stimulation strength in MST is also less sensitive to variations in head geometry and tissue conductivity than in ECT. Individualization of pulse amplitude in both ECT and MST could compensate for anatomical variability, which could lead to more consistent clinical outcomes.

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“…The steep decline in estrogen excretion with the onset of the menopause is shown by the observations of Pedersen‐Bjergaard and Tonnesen (5) on 360 women. That gonadal failure is dramatic was further verified in 1958 by Paulsen et al (6).…”

Section: The 24‐hour Urinary Excretion Of Estrogens In 253 Women*mentioning

confidence: 96%

The Fate of the Nontreated Postmenopausal Woman: A Plea for the Maintenance of Adequate Estrogen From Puberty to the Grave

Wilson

1963

J American Geriatrics Society

135

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Oestrogenic, Androgenic and Gonadotrophic Substances in the Urine of Normal Women

Cited by 20 publications

References 0 publications

Effect of Anatomical Variability on Electric Field Characteristics of Electroconvulsive Therapy and Magnetic Seizure Therapy: A Parametric Modeling Study

Effect of Anatomical Variability on Electric Field Characteristics of Electroconvulsive Therapy and Magnetic Seizure Therapy: A Parametric Modeling Study

Effect of anatomical variability on neural stimulation strength and focality in electroconvulsive therapy (ECT) and magnetic seizure therapy (MST)

The Fate of the Nontreated Postmenopausal Woman: A Plea for the Maintenance of Adequate Estrogen From Puberty to the Grave

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