Lillian B. Boettcher

Seizure Freedom Rates and Prognostic Indicators After Resection of Gangliogliomas: A Review.

Gangliogliomas are rare tumors that comprise up to 40% of lesional epilepsy. Seizure control represents an important quality-of-life determinant in patients with these tumors. Here we present results of a literature review addressing rates of seizure freedom in in patients with gangliogliomas. Across studies, seizure freedom occurred in 63%-100% of patients. Many studies included follow-up times of greater than 5 years, suggesting that the responses are durable. We discuss potential prognostic factors associated with seizure freedom, including the duration of epilepsy, patient age, frequency and semiology of seizures, tumor location, extent of surgical resection, and operative strategy, including surgical approach and use of invasive monitoring. Although significant differences in study populations and treatments preclude meta-analysis, we discuss prognostic factors identified in individual studies. Increased extent of resection, lesser duration of epilepsy, and younger age at surgery have been associated with increased seizure freedom rates in at least 2 studies each. Although all studies were retrospective in nature and are consequently limited by the weaknesses inherent to such investigations, the literature suggests that surgery is able to relieve most ganglioglioma patients--regardless of patient demographics, tumor characteristics, and operative variables--of seizures.

Histology and molecular aspects of central neurocytoma.

Central neurocytoma (CN) is a well-differentiated tumor of neural cells occurring within the ventricles. It is composed of monomorphic cells with round, regular nuclei within clear cytoplasm and must be distinguished from other clear cell tumors. Immunohistochemical markers of CN that aid in diagnosis include synaptophysin and neuronal nuclear antigen. The molecular biology of these tumors is becoming increasingly elucidated, particularly with the use of microarray analyses. Several oncogenic pathways have been suggested by these studies. Although progress continues to be made, knowledge of CN has yet to dictate targeted therapies in treating patients with these tumors.

Operative results of keyhole supracerebellar-infratentorial approach to the pineal region

The supracerebellar-infratentorial approach to the pineal region is typically accomplished with a craniotomy that extends to at least the rim of the foramen magnum. Minimally invasive techniques that limit the inferior extent of the craniotomy have been described for this approach but, to our knowledge, no operative results have been published demonstrating the feasibility and safety of such techniques. We present a series of patients who underwent surgical resection of pineal region lesions using the minimally invasive method at our institution. Clinical, radiologic, and operative data were prospectively collected on patients treated for lesions of the pineal region by the senior author from January 2012 to July 2014. Seven patients were identified. The sitting position was employed in each patient. Keyhole craniotomies were limited to a maximum diameter of 2.5 cm. Adequate working corridors were attained, and in no patient was resection limited by the exposure. No neurological or systemic complications were seen in the perioperative and early follow-up periods. In this feasibility study, we demonstrate that it is not necessary to extend a craniotomy inferiorly to the rim of the foramen magnum in order to gain access to the pineal region via relaxation of the cerebellum. The same surgical goals can be safely accomplished with a smaller craniotomy.

White matter connections of the inferior parietal lobule: A study of surgical anatomy

Interest in the function of the inferior parietal lobule (IPL) has resulted in increased understanding of its involvement in visuospatial and cognitive functioning, and its role in semantic networks. A basic understanding of the nuanced white‐matter anatomy in this region may be useful in improving outcomes when operating in this region of the brain. We sought to derive the surgical relationship between the IPL and underlying major white‐matter bundles by characterizing macroscopic connectivity.

368 Anatomy and White Matter Connections of the Orbitofrontal Gyrus.

INTRODUCTION The orbitofrontal cortex is understood to have a role in outcome evaluation and risk assessment, and is commonly involved by infiltrative tumors. A detailed understanding of the exact location and nature of associated white tracts could go far to prevent postoperative morbidity related to declining capacity. Through diffusion tensor imaging (DTI)-based fiber tracking validated by gross anatomical dissection as ground truth, we have characterized these connections based on relationships to other well-known structures. METHODS Diffusion imaging from the Human Connectome Project for 10 healthy adult controls was used for tractography analysis. We evaluated the orbitofrontal cortex as a whole based on connectivity with other regions. All orbitofrontal cortex tracts were mapped in both hemispheres, and lateralization index was calculated with resultant tract volumes. Ten postmortem dissections were then performed using a modified Klingler technique to demonstrate the location of major tracts. RESULTS We identified 3 major connections of the orbitofrontal cortex: a bundle to the thalamus and anterior cingulate gyrus passing inferior to the caudate and medial to the vertical fibers of the thalamic projections; a bundle to the brainstem traveling lateral to the caudate and medial to the internal capsule; and radiations to the parietal and occipital lobes traveling with the inferior fronto-occipital fasciculus. There was no significant lateralization for any of the tracts described. CONCLUSION The orbitofrontal cortex is an important center for processing visual, spatial, and emotional information. Subtle differences in executive functioning following surgery for frontal lobe tumors may be better understood in the context of the fiber-bundle anatomy highlighted by this study.

Anatomy and white matter connections of the orbitofrontal gyrus

OBJECTIVE The orbitofrontal cortex (OFC) is understood to have a role in outcome evaluation and risk assessment and is commonly involved with infiltrative tumors. A detailed understanding of the exact location and nature of associated white matter tracts could significantly improve postoperative morbidity related to declining capacity. Through diffusion tensor imaging-based fiber tracking validated by gross anatomical dissection as ground truth, the authors have characterized these connections based on relationships to other well-known structures. METHODS Diffusion imaging from the Human Connectome Project for 10 healthy adult controls was used for tractography analysis. The OFC was evaluated as a whole based on connectivity with other regions. All OFC tracts were mapped in both hemispheres, and a lateralization index was calculated with resultant tract volumes. Ten postmortem dissections were then performed using a modified Klingler technique to demonstrate the location of major tracts. RESULTS The authors identified 3 major connections of the OFC: a bundle to the thalamus and anterior cingulate gyrus, passing inferior to the caudate and medial to the vertical fibers of the thalamic projections; a bundle to the brainstem, traveling lateral to the caudate and medial to the internal capsule; and radiations to the parietal and occipital lobes traveling with the inferior fronto-occipital fasciculus. CONCLUSIONS The OFC is an important center for processing visual, spatial, and emotional information. Subtle differences in executive functioning following surgery for frontal lobe tumors may be better understood in the context of the fiber-bundle anatomy highlighted by this study.

Rates of Seizure Freedom After Surgical Resection of Diffuse Low-Grade Gliomas

OBJECTIVE Patients with diffuse low-grade gliomas (DLGGs) typically present with seizures. We sought to review the neurosurgical literature for seizure outcome after resection of these tumors. METHODS Using PubMed, we identified surgical series reporting seizure freedom rates for grade II astrocytoma, oligoastrocytoma, and oligodendroglioma. Inclusion criteria included seizure outcomes reported specifically for DLGGs and at least 10 patients with follow-up data. RESULTS Twelve articles met the inclusion criteria. The median seizure-free rate after surgery in these patients was 71%, with an interquartile range of 64%-82%. In 10 studies, more than 60% of patients were seizure free. Studies used varying reporting times for seizure outcome determination. In the 6 studies that reported postoperative antiepileptic medication use, 5%-69% of seizure-free patients were weaned off these agents (median, 32%). The durability of seizure freedom has not been clearly studied to date. The most commonly reported prognostic factor for seizure freedom after resection was increasing extent of resection. CONCLUSIONS Among articles reporting seizure outcomes after resection of DLGG, the median seizure-free rate was 71% (interquartile range, 64%-82%). Seizure freedom is likely associated with extent of resection.

The early argument for prefrontal leucotomy: the collision of frontal lobe theory and psychosurgery at the 1935 International Neurological Congress in London

The pathophysiology of mental illness and its relationship to the frontal lobe were subjects of immense interest in the latter half of the 19th century. Numerous studies emerged during this time on cortical localization and frontal lobe theory, drawing upon various ideas from neurology and psychiatry. Reflecting the intense interest in this region of the brain, the 1935 International Neurological Congress in London hosted a special session on the frontal lobe. Among other presentations, Yale physiologists John Fulton and Carlyle Jacobsen presented a study on frontal lobectomy in primates, and neurologist Richard Brickner presented a case of frontal ablation for olfactory meningioma performed by the Johns Hopkins neurosurgeon Walter Dandy. Both occurrences are said to have influenced Portuguese neurologist Egas Moniz (1874-1955) to commence performing leucotomies on patients beginning in late 1935. Here the authors review the relevant events related to frontal lobe theory leading up to the 1935 Neurological Congress as well as the extent of this meetings role in the genesis of the modern era of psychosurgery.

Hitler's parkinsonism

Of the multitude of medical and psychiatric conditions ascribed to Hitler both in his lifetime and since his suicide in April 1945, few are more substantiated than parkinsonism. While the timeline of the development of this condition, as well as its etiology, are debated, there is clear evidence for classic manifestations of the disease, most prominently a resting tremor but also stooped posture, bradykinesia, micrographia, and masked facial expressions, with progression steadily seen over his final years. Though ultimately speculation, some have suggested that Hitler suffered from progressive cognitive and mood disturbances, possibly due to parkinsonism, that affected the course of events in the war. Here, the authors discuss Hitlers parkinsonism in the context of the Third Reich and its eventual destruction, maintaining that ultimately his disease had little effect on the end result.