T. Glenn Pait

Medical complications of head injury

There are many common and significant medical complications of head injury. These include (1) cardiovascular problems such as hyperdynamic state, myocardial injury, and dysrhythmias; (2) respiratory changes such as neurogenic pulmonary edema, hypoxia, abnormal ventilatory patterns, pulmonary infections, and pulmonary emboli secondary to deep vein thrombosis; (3) consumption coagulopathy; (4) water and electrolyte derangements--hypo- and hypernatremia; (5) hypothalamic/pituitary dysfunction--syndrome of inappropriate secretion of antidiuretic hormone and diabetes insipidus; (6) increased general metabolism with loss of immunocompetence, respiratory compromise, and complications of decreased activity; (7) gastrointestinal difficulties, particularly stress gastritis; and (8) infectious problems including those related to contamination from open wounds and foreign bodies such as monitors.

Use of a motorized bicycle exercise trainer to normalize frequency-dependent habituation of the H-reflex in spinal cord injury.

Abstract Background/Objectives: Spasticity in patients with spinal cord injury (SCI) is difficult to manage. Exercise and stretching is advocated as a management tool, butthese activities are difficult to perform for mostpatients as a result of multiple barriers. This report shows the effect of passive range-of-motion exercise ina walking-like pattern on frequency-dependent habituation of the H-reflex in the lower extremities of anindividual with spastic tetraplegia due to SCI. Methods: The participant, a man with a chronic ASIA B C7 SCI due to a gunshot wound, used a motorized bicycle exercise trainer (MBET) developed at the Jackson T. Stephens Spine & Neurosciences Institute at theUniversity of Arkansas for Medical Sciencesthat could be operated from the individuals wheelchair. He usedthe MBET for 1 hour, 5 days a week, for 13 weeks. H-reflexhabituation was tested at the beginningof thestudy and then periodically over the course of 1 7 weeks,including 4 weeks after exercise had ceased. Results: Significant habituation of the H-reflex was evident beginning atthe 1Oth week of training. The habituation in the H-reflex reached a normal level at 5- and 10-Hz frequencies at 12 weeks. Subjective assessment of spasticity indicated that it was significantly reduced. The H-reflex amplitude was maintained at normal levels during the remaining week of the course of exercise and for 2 additional weeks after exerciseceased.The H-reflex habituation, however, returned to near baseline when reassessed at week 17,4 weeks after the exercise program had concluded. Subjective assessment indicated thatspasticity also had returned to pretraining levels. Conclusions: Habituation of the H-reflex, and perhaps spasticity, can be managed by aroutine passive range-of-motion exercise program using a MBET, but the exercise program may need to be continuous. The benefit of reduced medication for spasticity and possibly improved quality of lifecould be a motivating factor for an individual with SCI and spasticity to continue the program. Because of thelow complexity ofthe program, ease of use, and small size, this system could be inexpensive and could be used by an individual in the home. Ongoing studies will determine the minimum amount of MBET training required formaintaining long-term H-reflex habituation.

Postoperative Magnetic Resonance Imaging with Titanium Implants of the Thoracic and Lumbar Spine

Within recent years, the technologies of radiological imaging and spinal instrumentation have exponentially increased. New methods of preoperative imaging, that is, magnetic resonance imaging (MRI) and computed tomography, have allowed for a better understanding of surgical pathology. Such an understanding is likely to lead to a more successful surgical experience, which certainly is the case with spine surgery with instrumentation. However, after implantation of most instrumentation, imaging is greatly impaired. Metallurgic advancements in titanium were sought to reduce postoperative imaging problems. The purpose of this study is to assess the presence and extent of artifacts seen on postoperative MRI scans in patients with titanium spinal implants. Six patients, four with degenerative spine disease and two with neoplasms, had thoracic and/or lumbar spinal fixation performed with titanium instrumentation. All patients underwent postoperative conventional MRI with the use of T1-weighted, T2-weighted, and gradient-echo sequences. The scans and individual sequences were then analyzed for image quality. A progressive and significant increase in imaging artifact related to the titanium spinal instrumentation was observed on the T1-weighted, T2-weighted, and gradient-echo sequences. Titanium spinal instruments do not allow optimal postoperative imaging on conventional MRI scanners.

Thoracic, lumbar, and sacral spine anatomy for endoscopic surgery.

WE DISCUSS THE anatomy of the thoracic, lumbar, and sacral levels of the spinal cord. Given the nature of endoscopic surgery, it is recommended that the surgeon have thorough knowledge not only of the bony architecture but also of important visceral and other soft tissue structures. It is essential to understand the normal anatomy to recognize the abnormal and anatomic variations. We present the so-called normal anatomic configurations and illustrate how these structures vary at the different levels of the spinal column.

The legacy of Johann Friedrich Meckel the Elder (1724-1774): a 4-generation dynasty of anatomists.

FEW FAMILIES HAVE had an impact on medicine to equal that of the Meckel family. Johann Friedrich Meckel the Elder is of special interest to the neurosciences, given that his dissertation on the fifth cranial nerve included the first description of the arachnoid space investing the trigeminal nerve into the middle fossa. He was interested in neuroanatomy, along with botany and pathology of the inguinal hernia and the lymphatic system. His mentors included the eminent Albrecht von Haller (1708–1777) and August Buddaeus (1695–1753), and he extended his own influence on the work of Giovanni Morgagni and Alexander Monro II. He spent the latter part of his life in Berlin as professor of anatomy, botany, and obstetrics. His son, Philipp Friedrich Theodor Meckel (1755–1803), was one of the founders of the current collection of anatomic specimens at the University of Halle and provided important groundwork for the practice of obstetrics. Meckel the Elders grandson, Johann Friedrich Meckel the Younger (1781–1833), was a more prolific investigator and founder of the science of teratology. Many anatomic structures, such as Meckels diverticulum, bear his name, and he vastly expanded the universitys anatomic collection. August Albrecht Meckel (1789–1829), Meckel the Youngers brother, practiced legal medicine and investigated avian anatomy but died prematurely from tuberculosis. Augusts son, Johann Heinrich Meckel (1821–1856), took the instructors position in pathologic anatomy at the University of Berlin that his great-grandfather had held at the Charité. After his untimely death from pulmonary disease, his position was filled by Rudolf Virchow. The history of this family is discussed in detail.

The influence of war on the development of neurosurgery.

The treatment of craniospinal war wounds proved to be a significant driving force in the early growth of neurosurgery as a specialty. This publication explores the historical relationship between the evolution of combat methodology from antiquity through modern conflicts as it dovetails with and drives corresponding advancements in the field of neurosurgery. Whether its the basic management principles for intracranial projectile wounds derived from World War I experiences, the drastic improvement in the outcomes and management of spinal cord injuries observed in World War II, or the fact that both of these wars played a crucial role in the development of a training system that is the origin of modern residency programs, the influence of wartime experiences is pervasive.

Jacques Bénigne Winslow (1669-1760) and the Misnomer Cavernous Sinus

Sinus cavernosi, or the cavernous sinus, was coined by Jacques Bénigne Winslow in the 18th century. Among the neurosurgeons and the modern-day neuroanatomists, Winslow is mainly known for erroneously using the term cavernous sinus. As the anatomical understanding of the parasellar space advanced during the next 200 years, it was unclear as to why Winslow compared this space in the brain with that of a male reproductive organ (corpus cavernosum). Our primary objective was to study the historical treatise on anatomy written by Winslow in the 18th century and analyze his anatomical dissections and nomenclature for the parasellar compartment. In addition, his pertinent contributions to neuroscience are highlighted in this vignette.

John F. Kennedy’s back: chronic pain, failed surgeries, and the story of its effects on his life and death

The 35th president of the United States, John F. Kennedy (JFK), experienced chronic back pain beginning in his early 20s. He underwent a total of 4 back operations, including a discectomy, an instrumentation and fusion, and 2 relatively minor surgeries that failed to significantly improve his pain. The authors examined the nature and etiology of JFKs back pain and performed a detailed investigation into the former presidents numerous medical evaluations and treatment modalities. This information may lead to a better understanding of the profound effects that JFKs chronic back pain and its treatment had on his life and presidency, and even his death.

Placement of unilateral lag screw through the lateral mass of C-1: description of a novel technique.

Over the past several decades, many advancements and new techniques have emerged regarding the instrumentation and stabilization of the upper cervical spine. In this article, the authors describe a novel technique in which a unilateral lag screw was placed to reduce and stabilize a progressively widening fracture and nonunion of the right C-1 lateral mass approximately 8 weeks after the initial injury, which was sustained when a large tree branch fell onto the patients posterior head and neck.

Impact of 20th Century Wars on the Development of Neurosurgery

The treatment of neurosurgical casualties suffered during the wars of the 20th century had a significant impact on the formation and early growth of neurosurgery as a specialty. This chapter explores how the evolution of military tactics and weaponry along with the circumstances surrounding the wars themselves profoundly influenced the field. From the crystallization of intracranial projectile wound management and the formal recognition of the specialty itself arising from World War I experiences to the radical progress made in the outcomes of spinal-cord-injured soldiers in World War II or the fact that the neurosurgical training courses commissioned for these wars proved to be the precursors to modern neurosurgical training programs, the impact of the 20th century wars on the development of the field of neurosurgery is considerable.