Fifty years of microneurography: learning the language of the peripheral sympathetic nervous system in humans.

As a primary component of homeostasis, the sympathetic nervous system enables rapid adjustments to stress through its ability to communicate messages among organs and cause targeted and graded end organ responses. Key in this communication model is the pattern of neural signals emanating from the central to peripheral components of the sympathetic nervous system. But what is the communication strategy employed in peripheral sympathetic nerve activity (SNA)? Can we develop and interpret the system of coding in SNA that improves our understanding of the neural control of the circulation? In 1968, Hagbarth and Vallbo (Hagbarth KE, Vallbo AB. Acta Physiol Scand 74: 96-108, 1968) reported the first use of microneurographic methods to record sympathetic discharges in peripheral nerves of conscious humans, allowing quantification of SNA at rest and sympathetic responsiveness to physiological stressors in health and disease. This technique also has enabled a growing investigation into the coding patterns within, and cardiovascular outcomes associated with, postganglionic SNA. This review outlines how results obtained by microneurographic means have improved our understanding of SNA outflow patterns at the action potential level, focusing on SNA directed toward skeletal muscle in conscious humans.

Review of the evolution of electrodiagnostic criteria for chronic inflammatory demyelinating polyradicoloneuropathy.

Chronic inflammatory demyelinating polyradicoloneuropathy (CIDP) is a treatable form of neuropathy. Efforts to devise sets of electrodiagnostic (nerve conduction) criteria to distinguish primary demyelination from primary axonal neuropathies have been elusive, and at least 16 criteria have been proposed. Modifications to criteria frequently represent minor changes based on applying a set to a small number of patients with the clinical diagnosis of CIDP, whereas others are based on physiological changes related to demyelination and other pathophysiological features. The various modifications continue to result in limited sensitivity, likely related to the wide range of nerve conduction abnormalities among CIDP patients. Although some sets are appropriate for formal clinical drug trials, their complexity makes them difficult to apply in the clinic or electromyography laboratory. This study considers the evolution of the criteria, discusses their limitations, and ends with a simplified set of guidelines that can be applied in the clinic or laboratory.

The threshold of the new epileptology: Dr Lennox at the London Congress, 1935.

By the time that Dr William Lennox presented his discovery of the diagnostic electrical signature of brain electrical activity in epileptic seizures at the 2nd International Neurology Congress, held in London in 1935, research in epileptology had become mired in conceptual confusion. Not only had the vain quest for extracerebral seizure triggers resulted in decades of negative research, but outré theories such as autointoxication and psychoanalysis had severely damaged and confused the conceptual approach to this condition. Lennox and the Harvard team, in applying the novel technology of electroencephalography helped to clear up this confusion radically. His landmark contribution and the confusion into which epilepsy research had been diverted at that time, is worthy of examination--for this was indeed the threshold of new era of epileptology.

Wilhelm Heinrich Erb, M.D. (1840 to 1921): a historical perspective on Erb's palsy.

Erb's palsy is well known to physicians across medical specialties, and its clinical manifestations present a formidable challenge to reconstructive surgeons. Although the condition is well established, knowledge pertaining to its namesake, Wilhelm Heinrich Erb, is rather obscure in the existing scientific literature. Erb was influential not only through his description of classic brachial plexus palsy involving the superior (or upper) roots, but also by his indelible contributions to our understanding of peripheral nerve physiology, deep tendon reflexes, and the muscular dystrophies. Erb's contributions to medicine transcend specialty boundaries. In this article, the authors seek to convey his scientific achievements and the character of the man through translation of his German manuscripts. These texts, complemented by the existing English literature, provide a unique perspective on Wilhelm Heinrich Erb's contribution to medicine. The authors will also emphasize his role in describing and clarifying the nature of Erb's palsy.

Electroneurodiagnostics--for the joy of it!

During the middle of the last century, discoveries about the brain and the nervous system gave birth to a new technology. Thanks to the pioneers in those efforts, the early EEG technicians, and our efforts through the years, the technology has grown, expanded, and become amazingly sophisticated. This is about loving what we do, and finding joy and satisfaction in our accomplishments. We make health care better. We improve the quality of people's lives. We prompt physicians to sit up and take notice because we complement their efforts at diagnosing, monitoring, and treating people's neurologic illnesses. We're old enough to have a history, and a story...about Kathy Mears and hundreds of dedicated technologists, many of whom sprouted from those first small groups trained by the Fathers of EEG to give them important scientific data. And here we are, fifty-some years later, several thousand strong, influenced by things those first technicians never dreamed about! We're still producing data, but things have changed. Let's examine the challenges electroneurodiagnostic (END) technologists encounter in the current healthcare arena, and focus on what we need to find joy and fulfillment in our important work. Come celebrate our profession. Come share the joy!

The electroolfactogram: a review of its history and uses.

The electroolfactogram (EOG) is a negative electrical potential recorded at the surface of the olfactory epithelium of vertebrates. It represents primarily, if not exclusively, the summated generator potential in the olfactory receptor neurons (ORNs). While a number of studies suggest that secretory or inhibitory events may also contribute to the EOG, these are not well established. This review outlines (1) the cellular and physiological nature of the EOG response; (2) methodological considerations regarding odor selection and delivery, surgical preparation, response descriptions, and analysis; and (3) application of the EOG in human, fish, and insect olfaction and pheromonal responsivity. A number of technical issues associated with EOG recording are also discussed.

[The fiftieth anniversary of Miodonski's electro-rhino-spirometry]. / Piecdziesieciolecie elektrorynospirometrii Miodonskiego.

On the 50th anniversary of the introduction of the electro-rhino-spirometry by Miodonski the author recalls its theoretical foundations and diagnostic possibilities. Moreover, it has been stressed that Miodonski's method was the first one which does not disturb the nasal function, and the development of electronics supported and widened its diagnostic possibilities leaving the theoretical basis for examination unchanged.

Scientific support for electrodiagnosis

The use of acupuncture, homoeopathy and electrodermal instruments is increasing among physicians. Federal and state regulatory agencies have recently stepped up their investigations into the use of electrodiagnostic devices. A review of the history of medicine, the advent of electrodiagnosis and how it relates to acupuncture and homoeopathy, past and present research, scientific support and future possibilities is presented. Scientific concepts of holism and nonlinear physics provide a new medical paradigm, quantum morphodynamics

History of magnetic stimulation of the nervous system.

The use of a time-varying magnetic field to induce a sufficiently strong current to stimulate living tissue was first reported by d'Arsonval in 1896. Since then, there have been many studies in what is now called magnetic stimulation. This paper traces the history of this field from d'Arsonval to its present use in neurophysiology.

Duchenne de Boulogne: electrodiagnosis of poliomyelitis.

Duchenne de Boulogne was among the first to investigate neuromuscular diseases. He stimulated muscle and nerve with moistened surface electrodes, thereby avoiding tissue necrosis. Technique and self-designed equipment are discussed in his first major work de l'électrisation localisée. During his 30 years of practice, he examined several hundred patients with poliomyelitis. With electrodiagnostic evaluation, he focused on "electrocontractility," the intensity of muscle contraction elicited by electrical stimulation. Based on his electrophysiologic findings, Duchenne suggested that the responsible lesion resided within the spinal cord. He used electrical stimulation for treatment and recognized prognostic features.