The lucid interval associated with epidural bleeding: evolving understanding

The enlightenment

The period begins with the work of Richard Wiseman who was associated with royalists in the English Civil War. A little later Dionis was the first to note a relationship between a disturbance of consciousness and extravasation of blood. This notion was continued and expanded by Le Dran, Pott, and Benjamin Bell, with Pott providing a pathophysiological explanation of the phenomenon. Daniel Turner commented on how confusing Galenic teaching was on the topic of consciousness. Heister further emphasized the relationship between clinical disturbance and the extravasation of blood. Le Dran stated that symptoms following cranial trauma related to cerebral injury, an opinion supported by Pott and never subsequently challenged. Latta noted the importance of meningeal arteries in the development of hematomas. Benjamin Bell considered trepanation only appropriate for a clinical deterioration consistent with hemorrhagic extravasation. The two Irish surgeons made it clear that the presence of periosteal separation was not in fact a reliable indicator of an extravasation. The most striking change of instruments was disappearance of simple straight trepans with non-perforating tips for making small holes safely. The use of scrapers gradually declined as did that of lenticulars. There was a great debate about the value of a conical rather than a cylindrical crown. The former was said to be safer. But this opinion faded and the cylindrical crown became preferred. Another improvement in technique involved the use of constant probing to check the depth of the drilled groove.

A Spherical Cap Model of Epidural Hematomas

Background Epidural hematomas (EDHs), which have a characteristic biconvex shape, are a type of post-traumatic intracranial mass. EDHs and other types of intracranial hematomas are often diagnosed with computed tomography (CT). The volumes of EDHs are important in treatment decisions and prognosis. Their volumes are usually estimated on CT using the "ABC" method, which is based on the ellipsoid shape rather than their biconvex shape. Objective To simulate the biconvex shape, we modeled the geometry of EDHs with two spherical caps. We aim to provide simpler estimation of EDH volumes in clinical settings, and eventually recommend a threshold for surgical evacuation. Methods Applying the relationship between the sphere radius, spherical cap height, and base circle radius, we derived formulas for the shape of an EDH, relating its largest diameter and location to the other two diameters. We also estimated EDH volumes using the spherical cap volume and conventional ABC formulas and then constructed a lookup table accordingly. Results Validation of the model was performed using 14 CT image sets from previously reported patients with EDHs. Our geometric model demonstrated accurate predictions. The model also allows reducing the number of parameters to be measured in the ABC method from three to one, the hematoma length, showcasing its potential as a reliable tool for clinical decision-making. Based on our model, an EDH longer than 7 cm would occupy more than 30 mL of the intracranial volume. Conclusion The proposed model offers a streamlined approach to estimating EDH volumes, reducing the complexity of parameters required for clinical assessments. We recommend a length of 7 cm as a threshold for surgical evacuation of EDHs. This acceleration in decision-making is crucial for managing critically injured patients with traumatic brain injuries. Further validation across diverse patient populations will enhance the generalizability and utility of this geometric modeling approach in clinical settings.

Analysis of eighteenth century neurosurgical series

BACKGROUND

The purpose of this paper is to introduce a new method of assessing historical clinical series with a view to obtaining more nuanced information from the relevant texts.

METHOD

Seven eighteenth century clinical series were analysed by determining different parameters which could then be tabulated, thus enabling the examination of correlations within and between series.

RESULTS

It could be seen that there were different patterns of practice related to different concepts of pathology and different patient characteristics. In particular, there were differences between urban and rural populations, particularly in relation to infection-related complications. On the other hand, the practice of acute surgery within the first 5 days after injury was similar across the series.

DISCUSSION

It would seem that the poor hygiene intrinsic to eighteenth century urban milieus outweighed all other factors which could affect the risk of post-traumatic infections. Traffic accidents were dangerous, not least because horses were not safe in the hands of inexpert equestrians.

CONCLUSIONS

The tabulation of clinical parameters in historical series could be a useful technique for more general application in clinical series in other fields of medicine.

Imaging of Intracranial Hemorrhage

Intracranial hemorrhage is common and is caused by diverse pathology, including trauma, hypertension, cerebral amyloid angiopathy, hemorrhagic conversion of ischemic infarction, cerebral aneurysms, cerebral arteriovenous malformations, dural arteriovenous fistula, vasculitis, and venous sinus thrombosis, among other causes. Neuroimaging is essential for the treating physician to identify the cause of hemorrhage and to understand the location and severity of hemorrhage, the risk of impending cerebral injury, and to guide often emergent patient treatment. We review CT and MRI evaluation of intracranial hemorrhage with the goal of providing a broad overview of the diverse causes and varied appearances of intracranial hemorrhage.

The life and work of the Dumfries surgeon James Hill (1703-1776): his contributions to the management of cancer and of head injury

James Hill was apprenticed to the formidable Edinburgh surgeon, physician and philosopher George Young from whom he learned the value of careful observation and scepticism in medicine. As a surgeon in Dumfries he was able to take advantage of newly established medical journals to publish case reports. His book Cases in Surgery summarised three aspects of his life's work as a surgeon. In it he provides a classical description of the features and transmission of sibbens (endemic syphilis) and suggests from careful clinical observation that sibbens and venereal syphilis were the same disease. His success with treatment of cancer led him to advocate curative rather than palliative excision, a view that ran counter to accepted contemporary practice. Hill's ability to diagnose cerebral compression caused by bleeding following head injury enabled him to treat this successfully by directed trephine and drainage. His results on the treatment of head injury were the best to be published in their day and an important addition to the increasing understanding of the basis of the management of head injury.

Trepanation and surgical infection in the 18th century

BACKGROUND

It is widely believed that trepanation prior to modern surgical hygiene was dangerous because of surgical infection, especially in the hospital. There has been a wide variability in the success and risks of different historical studies

PURPOSE

To obtain a more accurate assessment of the risks of post-operative infection following 18th-century cranial trauma and to note what factors were of prognostic significance.

MATERIAL AND METHODS

Seven 18th-century texts on head injury are reviewed and analyzed.

RESULTS

Infection was the commonest cause of death (in over 60% of patients) in five series but not in the other two. Hospital admission did not appear to be a major factor influencing mortality from infection. Delayed infection was the indication for patient referral and trepanation in more than two patients in two series. In one series, the patients were helped by the procedure, in the other they were not. The reasons for the difference are discussed. The most striking finding was that patients treated in rural areas had a much better prognosis.

CONCLUSIONS

The risks of suffering a surgical infection following head injury and trepanation are multifactorial. Admission to hospital seems to have been less risky than has been previously thought. It seems that the greatest risk factor for a lethal infection for these patients was living in an urban environment.