Impact of Skull Thickness on Cerebral NIRS Oximetry in Neonates: An in silico Study.

Monitoring of cerebral tissue oxygen saturation (StO2) by near-infrared spectroscopy (NIRS oximetry) has great potential to reduce the incidence of hypoxic and hyperoxic events and thus prevent long-term disabilities in preterm neonates. Since the light has to penetrate superficial layers (bone, skin and cerebrospinal fluid) before it reaches the brain, the question arises whether these layers influence cerebral StO2 measurement. We assessed this influence on the accuracy of cerebral StO2 values. For that purpose, we simulated light propagation with 'N-layered medium' software. It was found that with a superficial layer thickness of ≤6 mm, typical for term and preterm neonates, StO2 accurately reflects cerebral tissue oxygenation.

Comparison of tissue oximeters on a liquid phantom with adjustable optical properties: an extension.

Cerebral near-infrared spectroscopy (NIRS) oximetry may help clinicians to improve patient treatment. However, the application of NIRS oximeters is increasingly causing confusion to the users due to the inconsistency of tissue oxygen haemoglobin saturation (StO2) readings provided by different oximeters. To establish a comparability of oximeters, in our study we performed simultaneous measurements on the liquid phantom mimicking properties of neonatal heads and compared the tested device to a reference NIRS oximeter (OxiplexTS). We evaluated the NIRS oximeters FORE-SIGHT, NIRO and SenSmart, and reproduced previous results with the INVOS and OxyPrem v1.3 oximeters. In general, linear relationships of the StO2 values with respect to the reference were obtained. Device specific hypoxic and hyperoxic thresholds (as used in the SafeBoosC study, www.safeboosc.eu) and a table allowing for conversion of StO2 values are provided.

Migraine and psychopathology. Results of the Zurich cohort study of young adults.

We present data regarding the association of psychiatric syndromes and migraine headache from a prospective epidemiologic cohort study of 27- and 28-year-olds in Zurich, Switzerland. The prevalence of migraine of 13.3% approximates estimates from previous epidemiologic studies in other regions of the world. Consistent with previous reports, there was a strong association between migraine and depression. However, this is the first study to demonstrate this association in an unselected epidemiologic sample with standardized assessment of psychiatric diagnoses by direct interview. The association between migraine and the anxiety disorders was even stronger than that for the affective disorders. The combination of anxiety disorder and major depression, but not pure anxiety disorders, nor pure depression, were significantly associated with migraine. Our data suggest that migraine with anxiety and depression may constitute a distinct syndrome comprising anxiety, often manifested in early childhood, followed by the occurrence of migraine headaches, and then by discrete episodes of depressive disorder in adulthood. Because of the prospective longitudinal design of this study, future assessments of this cohort will provide further information on the stability of these findings and the course of this cohort as subjects proceed through adulthood.

The effect of myelin basic protein (MBP) on the bioelectric activity of spinal cord and cerebellar neurones.

The effects of myelin basic protein (MBP) on the ventral root response in rat spinal cord in situ and on the spontaneous bioelectric activity of cultured rat Purkinje cells were investigated. Injection of 2 or 4 microl MBP (10(-4) M/l) into the motoneurone pool reduced the ventral root response to dorsal root stimulation. The depression was long-lasting (30-50 min) and partially reversible. At 5 x 10(-6) M/l MBP abolished the spontaneous activity of most cultured Purkinje cells, an effect which was not blocked by haloperidol, propranolol, phenoxybenzamine and bicuculline. The EC(50) for the depression was 4 + or - 1 x 10(-6) M/l.

The effects of human myelin basic protein (HMBP) on the bioelectrical activity of the frog spinal cord.

The effects of human myelin basic protein (HMBP) and its individual microheterogeneous components on the electrical activity of the frog spinal cord are compared with those of bovine MBP (BMBP) and glutamate (Glu). HMBP causes a dose-dependent depolarization of the ventral (VR) and dorsal (DR) roots with a reduction of the evoked root potentials. The amplitude of the depolarization induced by 0.01 mM HMBP corresponds to that observed with application of 1 mM Glu. A weaker depolarization persists during blockade of synaptic transmission by MgSO4 or tetrodotoxin, suggesting a direct depolarizing effect on motoneurones and primary afferents. HMBP causes a long-lasting tachyphylaxis. The individual microheterogeneous components of HMBP (peaks 1, 2 and 3), and a mixture of smaller myelin basic proteins elicit similar responses, whereas BMBP and its microheterogeneous components are slightly less active.

Topical treatment of standardized burns with a protein-free haemodialysate.

The utility of the protein-free haemodialysate Solcoseryl (HD) in the treatment of chronic skin ulcers and minor burns is well documented (Haigis et al., 1985). In this study the effects of HD ointment and HD gel on the healing of standardized deep partial thickness burns were investigated in rats. Treatment with HD-containing topical agents significantly reduced healing time (P less than or equal to 0.01) in comparison with non-treated controls; HD ointment and HD gel reduced relative healing rates by 20 per cent and 15 per cent respectively. Macroscopic and histological findings indicate that the effects of HD start in the early phase of the healing process (inflammatory/exudative), and that the entire healing process is improved.

Morphometric assessment of wound healing in rats treated with a protein-free haemodialysate.

Morphological changes during soft-tissue repair are prime indicators of the processes involved in wound healing. A method has been developed to quantify such changes and applied for assessing the healing of partial thickness dermatome wounds treated either with Solcoseryl jelly or the matching vehicle. After 4 days of treatment, the active-treated wounds had already reached the reparative phase, whereas the vehicle-treated wounds were still in the proliferative phase. Furthermore, wound re-epithelialization was significantly improved under active treatment (P less than 0.005).

[Romantic origins of electrophysiology]. / Romantische Ursprünge der Elektrophysiologie.

Research on static electricity and its effects on the human body date back to the invention of the electrizing or Wimshurst machine and the Leyden jar of 1743 and 1746. Such experiments often served as social pastimes, but they yielded many publications on medical aspects of static electricity. Attempts to explain the 'life force' of the vitalists and the old concept of the active principle of the nervous system, the 'spiritus animales', as electrical phenomena were unsuccessful because of the skeptic comments of leading experimental scientists such as Albrecht von Haller. When Mesmer reinvented 'animal magnetism' in 1776 as a fashionable term for treatment by suggestion, he appropriated theoretical, technical and social methods from the established ways of the experiments on static electricity. Therefore, the scientific character of Luigi Galvani's investigations was already compromised by his term 'animal electricity' when he published his famous 'Commentarius' in 1781. Volta in Pavia turned against Galvani, proving that galvanic currents are produced by metals alone, and rejecting 'animal electricity'. Volta's doctrine prevailed over Galvani's school after Volta's breakthrough with his pile, or battery, until Galvani's ideas were rehabilitated by Nobili, who in 1828 measured the 'frog current' with his galvanometer. This led to a flurry of bizarre experiments on rows of half-dismembered animals and severed parts of human cadavers. Johannes Müller in Berlin, who, with his students, established new principles of biology and neurology, asked Du Bois-Reymond to study these experiments. Du Bois-Reymond found that measurements of muscle currents in intact animals were more useful, and he compared them with his own observations on electric fishes.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cartesian misunderstanding as a cause of therapeutic failure]. / Das cartesianische Missverständnis als Ursache therapeutischen Versagens.

Headache patients disassociate themselves from their own automatic responses, relying on the traditional separation of body and mind. On the other hand, patients who obtain voluntary control of automatic functions by biofeedback training modify not only vegetative but also voluntary behaviour patterns, losing "neurotic" traits. The basic misconception of the separation of body and mind, Cartesian dualism, is now ingrained in our culture. In the 17th century Descartes asserted that concepts applied to the soul must be entirely different from those used for the body in order to improve comprehension of the immortality of the soul. This dualism also led to "enlightenment" and to many later social and philosophical developments. But his basic neurophysiology was obsolete when he wrote it down. Other models from mainstream natural philosophy were better compatible with observation and experiments. Gassendi assumed a "body soul" consisting of energy as the functional principle of the nervous system, and Willis accommodated a series of anticipations of 19th century discoveries within this model. No comparable progress resulted from Descartes' own medieval model. Cartesian dualism has become untenable in view of recent neuropsychology but it still obstructs our management of functional patients. Instead of reinforcing the delusion of separation of psyche and soma, we ought to encourage patients to understand that their malfunctioning organs are on-line with their emotions, and with their mind.

Headache patients in primary care and a tertiary care unit in Zürich, Switzerland.

The Headache and Pain Clinic (HPC) is a unit of the Zürich Neurology Department, established in 1966. In the present study demographic features, clinical characteristics and medical management of primary and tertiary care patients were compared in two groups of 181 patients each, seen by general practitioners (GPs) or the HPC, respectively, for primary headaches in 1998. There was a preponderance of women and the socially underprivileged in both samples. Chronic headache was overrepresented in the HPC (44.7%). Loss of work for >2 months was found exclusively in the HPC (9.9%). Of the GP patients, 40% were using triptans and 26.5% in the HPC. One-third of both groups had had complementary and alternative medical treatment. Differences in management strategies reflected differences in headache severity and chronicity. Results indicated that remaining shortcomings of diagnosis and treatment of headache in primary care could be minimized by involving GPs in similar non-commercial studies.

Episodic cluster headache from a textbook of 1745: van Swieten's classic description.

The first description of cluster headache is usually attributed to authors who published between 1867 and 1939, but lately several researchers have found accounts dating back to the 18th or even the 17th century which are incomplete or do not account for cluster headache in the strict sense. However, Gerhard van Swieten gave a full description of a case of episodic cluster headache meeting the IHS criteria in 1745, in his textbook of clinical medicine, the mainstream textbook of Continental medicine in those years, since van Swieten was the founder of the then leading medical centre, the Vienna School. That the case was found again only in 1992 is due to the circumstance that it was published in Latin. It is presented here in an English translation facing the original Latin text.