Nayef R.F. Al-Rodhan

Transitional cavernous aneurysms of the internal carotid artery.

Twenty-three cases of transitional cavernous aneurysms are presented. Aneurysms of this subgroup (of a total of 118 cases of cavernous sinus aneurysms) arise entirely from within the cavernous sinus but project into the extracavernous intradural subarachnoid space, thus resembling other intracranial aneurysms in their increased risk of rupture. Six aneurysms were small (less than 15 mm), 6 were large (15 to 25 mm), and 11 were giant (more than 25 mm). Thirteen patients (57%) had a subarachnoid hemorrhage, nine patients (39%) had compressive symptoms, and one patient (4%) was asymptomatic. A direct surgical approach was performed successfully in 18 cases (78%), and indirect bypass methods were performed in 5 cases. The overall surgical outcome was excellent in 87% of the patients, with three complications (13%) including one fatality. It is suggested that this subgroup is a different entity from other cavernous or extracavernous aneurysms and should be managed aggressively with direct clipping whenever possible because of the increased risk of subarachnoid hemorrhage. A simplified numerical classification system of clinoidal-region aneurysms of the internal carotid artery (including transitional aneurysms) is also proposed.

Structure-antinociceptive activity of neurotensin and some novel analogues in the periaqueductal gray region of the brainstem

Neurotensin, an endogenous tridecapeptide, produces a potent, naloxone-insensitive antinociceptive response when it is microinjected into the periaqueductal gray region of the rat brainstem. In the present study, the ED50 for neurotensin in inducing antinociception was 1.5 nmol, two times more potent than morphine. We sought to find whether neurotensins antinociceptive effects were mediated by the same receptor that mediates its other functions. We found that the structure-activity relationship of neurotensin-induced antinociception was different from that required for the stimulation of intracellular cyclic GMP production in neuroblastoma clone N1E-115 and the binding to N1E-115 cells, human brain tissue, or rat periaqueductal gray. These data suggest there exists a subtype of neurotensin receptors in neural tissue that mediates its antinociceptive actions.

The antinociceptive effects of SCH-32615, a neutral endopeptidase (enkephalinase) inhibitor, microinjected into the periaqueductal, ventral medulla and amygdala

The local effects of SCH-32615, an inhibitor of enkephalinase (EC 3.4.24.11) on the hot-plate (HP) and tail-flick (TF) responses were examined following unilateral intracerebral microinjection into the periaqueductal brain (PAG), the medial ventral medulla (VM) and bilateral microinjection into the amygdala (AM) of the rat. In the PAG and VM, SCH-32615 resulted in a dose-dependent increase in HP and TF response latencies over a dose range of 1-30 micrograms with the ED50 values (micrograms) being PAG-TF = 17; PAG-HP = 11; VM-TF = 7; VM-HP = 6. In the AM, dose-dependent increases were only observed on the HP. (ED50 (micrograms) HP = 17). Peak effects were observed within 10 min and response latencies remained elevated for 45-60 min. Injections of SCH-32615 at sites outside of the PAG or VM were considerably less effective. All antinociceptive effects were antagonized by naloxone (1 mg/kg, i.p.). Twenty-four hours following the microinjection of beta-funaltrexamine (an irreversible opioid antagonist) into the PAG or the VM, the effects of SCH-32615 in the PAG were virtually abolished while in the VM, its effects were only moderately reduced. These data suggest that in the presence of a strong thermal stimulus, the behavioral response is subject to a tonically active or stimulus-evoked modulation by the local release in the PAG, VM and AM of an agent, presumably an enkephalin peptide, the degradation of which is altered by enkephalinase inhibition.

Meningioma: a historical study of the tumor and its surgical management.

The history of meningioma is reviewed, highlighting the personalities and events that shaped our understanding and management of this tumor. Early descriptions, nomenclature, and the history of surgical removal of meningioma are discussed and the important role of this tumor in the development of neurosurgery as a whole is stressed.

Factors Affecting Survival of Children with Malignant Gliomas

Fourty-four patients (23 male and 21 female, aged 2 to 20 years (mean, 9.6], harboring pathologically proven malignant glioma (Grades III and IV) were treated between 1976 and 1985. Tumor sites included the cerebral hemisphere (26 patients), thalamus (6 cases), brain stem (7 cases), and the cerebellum (5 cases). All patients underwent operation and initial treatment with steroids. Irradiation was given in 35 patients; 3 had adjuvant chemotherapy. At the time of study, 22 were deceased. The longest period of follow-up was 65 months. Survival curves were calculated from the date of the first visit to the date of the last evaluation or death. The mean survival times were 30 months for all patients, 14 months for cerebellar cases, 17 months for brain stem cases, 26 months for thalamic cases, and 33 months for cerebral hemisphere cases. However, the differences between mean survival times were not statistically significant. The patients age was the single most significant factor, with those 5 to 10 years old having the worst survival curve (P = 0.0036). Irradiation was associated with an improved mean survival time (34 vs. 19 months); however, this was not statistically significant (P = 0.15). Girls had shorter mean survival times than boys (16.5 vs. 37 months, P = 0.0511). Otherwise, there was no clinical or radiological factor that indicated a better prognosis. This was also confirmed by chi 2 analyses comparing 72 factors between patients with more than 24 months of survival and those with less than 24 months of survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Pioneers of Stereotactic Neurosurgery

The beginnings of stereotactic and functional neurosurgery can be traced as far back as 1873 when Dittmar reported the use of a guiding device for the placement of probes into the medulla oblongata in animals. Further pioneering work was done by Zernov and Altukhov in Russia (1889), Clarke and Horsley in England (1908), and Spiegel and Wycis in the United States (1947), as well as others. After a promising initiation, interest in stereotactic neurosurgery waned after the introduction of L-dopa in the 1960s. Later, the introduction and incorporation of new imaging technology into stereotactic techniques signaled the rebirth of stereotactic and functional neurosurgery as a versatile and exciting subspecialty not only in the resection of previously unresectable lesions but also in the functional restoration of central nervous system function. This brief paper will focus on the personalities that have pioneered stereotactic neurosurgery over the past century.

Al-Zahrawi and Arabian neurosurgery, 936–1013 ad

The authors highlight the neurosurgical contributions of an Arabic surgeon by the name of Abul-Qasim Al-Zahrawi, known in Western literature as Abulcasis. This man lived during the Middle Ages from 936 to 1013 AD and wrote a 30-volume treatise on medicine. A significant part of his work on surgery consists of early descriptions of neurosurgical diagnosis and treatment, including the surgical treatment of head injuries and skull fractures, spinal injuries and dislocations, hydrocephalus and subdural effusions, headache, and many other medical afflictions. He described neurosurgical instruments such as cranial drills that avoided puncture of the dura mater. Abulcasis is known for his concepts of pain as a symptom and his emphasis on anatomy of the skull and brain in relation to the neurosurgical operations of that period. Because his works were translated from Arabic to Latin, Hebrew, and Turkish with only recent or limited translation into the modern occidental languages, the historic role played by this man has been largely unknown by neurosurgeons who are not fluent in these languages.

The Low Incidence of Cerebral Aneurysms in the Middle East: Is It a Myth?

It is common belief that there is a relatively low incidence of cerebral aneurysm in the Middle East; however, there are neither routine autopsy studies nor reliable public health data to confirm this impression. We analyzed the clinical data of all patients admitted with a diagnosis of nontraumatic subarachnoid hemorrhage to the King Faisal Specialist Hospital, a modern tertiary medical center in Riyadh, Saudi Arabia. These data were compared with reports from other countries. Although environmental or inherited factors may predispose to a lower incidence of intracranial aneurysm in the Middle East, the true incidence is higher and is not apparent because of the previous referral system for medical care. Medical facilities and expertise are rapidly improving, and future studies undoubtedly will show a higher incidence of intracranial aneurysm.

Histiocytosis-X of the spinal cord: a case report

A rare case of histiocytosis-X of the spinal cord with evidence of intramedullary infiltration and epidural spinal cord compression is reported. The clinical, radiological, and histopathological features are discussed, and the pertinent literature is reviewed.

100 years of neurological surgery at the Mayo Clinic.

The practice of neurological surgery at the Mayo Clinic began as early efforts were undertaken by Drs. Charles Mayo and Emil Beckman, and surgical procedures were performed for trauma, infection, tumor, epilepsy, and hemorrhage. In 1919, the Section of Neurologic Surgery was established, with Alfred W. Adson as its first chair. Subsequently, Drs. Winchell McK. Craig, J. Grafton Love, Collin S. MacCarty, Ross H. Miller, and Thoralf M. Sundt, Jr., followed as eminent chairmen. Beginning with a modest number of cases per year, the neurosurgical service at the Mayo Clinic has grown to become one of the largest in North America. Under the current leadership of Dr. David G. Piepgras, approximately 3200 surgical procedures spanning the spectrum of subspecialties are performed each year by a staff of 10 neurosurgeons. This article traces neurosurgery at the Mayo Clinic, including several persons who contributed to its achievements over the past century.