Worth Their Salt: One Hundred Years of Hyperosmolar Therapy.

In this article, we commemorate the centenary of the discovery and clinical implementation of hyperosmolar therapy for the treatment of increased intracranial pressure (ICP). Following the pioneering work of anatomists Weed and McKibben in 1919, the use of hypertonic solutions was soon adopted into clinical practice, even though the preferred hypertonic agent, route of administration, and ideas regarding the physiological mechanism by which it reduced ICP diverged. These divergent conceptions and practices have continued to surround the use of hyperosmolar therapy into present times.

The lucid interval associated with epidural bleeding: evolving understanding.

The aim of this paper was to elucidate the evolution of our understanding of the term "lucid interval." A number of texts were reviewed to assess their suitability for analysis. The primary requirement was that the text contain detailed descriptions of a series of patients. Details of the clinical course, the findings and timing of surgery, and, when relevant, the time of death and postmortem findings were required. Books written by Henri-François Le Dran, Percival Pott, and James Hill fulfilled these criteria. Surgical findings included the presence and type of fractures, changes in the bone, separation of periosteum, malodorous or purulent material, tense brain, and hematoma. Postmortem findings supplemented and/or complemented the surgical findings. The courses of the patients were then tabulated, and the correlation between different clinical and operative findings was thereby determined. Our understanding of a lucid interval began in the early 18th century with the work of Henri-François Le Dran and Percival Pott in London. They did not, however, demonstrate an interval without symptoms between trauma and deterioration in patients with epidural hematomas (EDHs). The interval they described was longer than usually expected with EDHs and occurred exclusively in patients who had a posttraumatic infection. In 1751, James Hill, from Dumfries, Scotland, described the first hematoma-related lucid interval in a patient with a subdural hematoma. The first case of a lucid interval associated with an EDH was described by John Abernethy. In the 19th century, Jonathan Hutchinson and Walter Jacobson described the interval as it is known today, in cases of EDH. The most recent work on the topic came from studies in Cincinnati and Oslo, where it was demonstrated that bleeding can separate dura mater and that hemorrhage into the epidural space can be shunted out via the veins. This shunting could delay the accumulation of a hematoma and thus the rise in intracranial pressure, which in turn would delay the development of symptoms. The lucid interval as previously conceived was not properly understood by the French school or by Percival Pott and Benjamin Bell, who all described a symptom-free period prior to the development of infection. The first to have a proper understanding of the interval in relation to an EDH was John Abernethy. The modern description and definition of the lucid interval was the work of Hutchinson and Jacobson in the latter half of the 19th century. Understanding of the pathophysiology of the lucid interval has been advanced by the work of Ford and McLaurin in Cincinnati and a group in Oslo, with the demonstration of what it takes to loosen dura and how an arteriovenous shunt slows down for a while the accumulation of an EDH.

Manucher Javid, urea, and the rise of osmotic therapy for intracranial pressure.

Therapy with hypertonic solutions is one of the mainstays of neurosurgical treatment for all types of neurological injury. Although the initial research with hypertonic agents in the early decades of the 20th century showed great promise for these agents to lower intracranial pressure, this research also showed a considerable rate of adverse effects and complications. By the 1940s and 1950s, hypertonic therapy had been discounted as unsafe and was rarely used in neurosurgery. In the late 1950s, Manucher J. Javid and Paul Settlage at the University of Wisconsin began experimenting with infusions of urea as an agent to control intracranial pressure. Their experiments were wildly successful, and urea became a drug of major importance to neurosurgeons worldwide in only a few years. This article chronicles the work of Javid and Settlage, including a discussion of the early research on hypertonic agents, the initial difficulty the Wisconsin researchers had in disseminating their results, the widespread acceptance that followed, and the impact that these discoveries had on the neurosurgical community. The prominent place that hypertonic agents now hold in the armamentarium of neurosurgeons is owed to the work of Dr Javid, as illustrated in this historical analysis.

Fronto-ethmoidal encephalocele in a historical skull with artificial deformation and no signs of chronic elevated intracranial pressure.

The intentional deformation of human skulls in the living being was one of the most curious rituals performed in historical and ancient times. It is thought that these practices cause chronic elevated intracranial pressure and subsequent symptoms of cognitive impairment. In this report, we examine such an artificially deformed skull dating from the sixteenth century that in addition shows a fronto-ethmoidal encephalocele. However, although the mild encephalocele was already manifest at birth and deformation practices were performed over years, the encephalocele did not progress into a more severe status. We conclude that the intentional deformation of skulls does not lead to chronic elevated intracranial pressure and mental retardation.

[Development of concepts of disease, diagnostics and neurosurgical treatment of brain tumours in The Netherlands (1890-1950)]. / Ontwikkeling van ziekteconcept, diagnostiek en neurochirurgische behandeling van hersentumoren in Nederland (1890-1950).

The history of the treatment ofbrain tumours in the Netherlands begins around 1890. From this time up to 1950, following other European countries and later the United States, the conceptualization, diagnostics, and surgical treatment of brain tumours changed dramatically. New morphological classifications were introduced, as well as technical innovations in the fields ofimaging diagnostics and surgical methods. At the same time, the common view ofclinical signs ofbrain tumours changed into the concept that symptoms were caused by increased intracranial pressure. As is the case today, the innovations in Dutch neurosurgery in the first half of the 20th century were based on the interaction between techniques, knowledge and clinical experiences.

Early evolution of neurological surgery: conquering increased intracranial pressure, infection, and blood loss.

At the end of the 19th century, the early evolution of the specialty of neurological surgery was restricted by complications related to infection, increased intracranial pressure, and excessive intraoperative blood loss. These complications often caused mortality rates of 30 to 50%. An improved understanding of pathophysiological factors involved in increased intracranial pressure, along with meticulous surgical techniques learned from William Halsted, allowed Harvey Cushing to increase the safety of neurosurgical procedures that were then in their infancy. Cushing's later development of the "silver clip" and incorporation of electrosurgical techniques facilitated safe resection of brain tumors previously assumed to be inoperable. These pivotal accomplishments paved the way for the establishment of our specialty.

The historical development of the pseudotumor concept.

The author outlines the history of the development of the pseudotumor concept, first specifically formulated by Nonne in 1904 but implicit in earlier descriptions. A scheme of periodization is applied, identifying otological, neurosurgical, neurological, and neuroophthalmological periods; he relates theoretical and practical developments in the understanding of the condition to the concerns of the dominant speciality involved in diagnosis and management. Key studies from each period are discussed in relation to the issues of mechanism, origin, nomenclature, diagnosis, and treatment. During the otological period, approaches to the condition were heavily influenced by its common association with middle ear infection, often with venous sinus involvement, and this led to the idea of disturbed cerebrospinal fluid dynamics as the cause. The advent of neuroradiological systems ushered in the neurosurgical period in which the significant but unfinished debate began: which intracranial compartment is primarily implicated in the intracranial hypertension? By the time of the neurological period cerebral edema was implicated as the cause, and this coincided with the availability of appropriate treatment methods and steroidal and diuretic agents. Toward the end of this period additional major advances in investigative methods again brought the issue of mechanism into contention, although a resolution was not to follow. The neuroophthalmological period is characterized by an increased awareness of the significance of visual loss and a return to one of the original methods of treatment. Finally, the possible significance of impaired cranial venous outflow, a thread running through all periods, is considered.