Beyond uncal herniation: An updated diagnostic reappraisal of ipsilateral hemiparesis and the Kernohan-Woltman notch phenomenon

PURPOSE

This works comprehensively analyses a modern cohort of patients with ipsilateral hemiparesis (IH) and discusses the pathophysiological theories elaborated to explain this paradoxical neurological sign according to the findings from contemporary neuroimaging and neurophysiological techniques.

METHODS

A descriptive analysis of the epidemiological, clinical, neuroradiological, neurophysiological, and outcome data in a series of 102 case reports of IH published on since the introduction of CT/MRI diagnostic methods (years 1977-2021) was performed.

RESULTS

IH mostly developed acutely (75.8%) after traumatic brain injury (50%), as a consequence of the encephalic distortions exerted by an intracranial haemorrhage eventually causing contralateral peduncle compression. Sixty-one patients developed a structural lesion involving the contralateral cerebral peduncle (SLCP) demonstrated by modern imaging tools. This SLCP showed certain variability in its morphology and topography, but it seems pathologically consistent with the lesion originally described in 1929 by Kernohan & Woltman. The study of motor evoked potentials was seldom employed for the diagnosis of IH. Most patients underwent surgical decompression, and a 69.1% experienced some improvement of the motor deficit.

CONCLUSIONS

Modern diagnostic methods support that most cases in the present series developed IH following the KWNP model. The SLCP is presumably the consequence of either compression or contusion of the cerebral peduncle against the tentorial border, although focal arterial ischemia may also play a contributing role. Some improvement of the motor deficit should be expected even in the presence of a SLCP, provided the axons of the CST were not completely severed.

[When to resume driving after primary total hip arthroplasty?]

INTRODUCTION

the current literature relates the return to driving with multiple variables. For various reasons, the current data on the time to return to driving after a total hip arthroplasty (THA) are diverse and even contradictory. We have proposed the objective of determining the time required to drive a manual gear vehicle again in a group of patients who underwent primary THA through a posterolateral approach with focus on manual gear cars.

MATERIAL AND METHODS

we have studied the functional results of 112 patients who underwent primary THA between January 2019 and January 2020 in a high level in Cadiz, Andalusia, Spain.

RESULTS

the median return to driving was three weeks (IQR 2-4). We have identified that 89.3% of the patients were able to drive again before the sixth week after surgery and in 92% of the cases they did so feeling even safer than before the THA.

CONCLUSION

we consider that after the sixth week of an THA it is safe to resume driving a vehicle.

Duct-like Recess in the Infundibular Portion of Third Ventricle Craniopharyngiomas: An MRI Sign Identifying the Papillary Type

BACKGROUND AND PURPOSE

Papillary craniopharyngiomas (PCPs) are particularly challenging lesions requiring accurate diagnosis to plan the best therapy. Our aim was to define a narrow duct-like recess identified on MR imaging at the base of papillary craniopharyngiomas with a strict third ventricle location.

MATERIALS AND METHODS

A duct-like recess at the infundibular portion of craniopharyngiomas was observed on conventional T1WI and T2WI in 3 strict third ventricle papillary craniopharyngiomas in our craniopharyngioma series (n = 125). We systematically investigated this finding on the MR imaging of 2582 craniopharyngiomas and 10 other categories of third ventricle tumors (n = 690) published in the modern era (1986-2020). The diagnostic value and significance of this finding are addressed.

RESULTS

The duct-like recess was recognized in 52 papillary craniopharyngiomas, including 3 of our own cases, as a narrow canal-shaped cavity invaginated at the tumor undersurface, just behind the optic chiasm. This structure largely involves papillary craniopharyngiomas with a strict third ventricle topography (96%), follows the same diagonal trajectory as the pituitary stalk, and finishes at a closed end. The duct-like recess sign identifies the papillary craniopharyngioma type with a specificity of 100% and a sensitivity of 38% in the overall craniopharyngioma population. This finding can also establish the strictly intra-third ventricle location of the lesion with a 90% specificity and 33% sensitivity. These recesses appear as hypointense circular spots on axial/coronal T1WI and T2WI. Their content apparently corresponds to CSF freely flowing within the suprasellar cistern.

CONCLUSIONS

The presence of a duct-like recess at the infundibular portion of a third ventricle tumor represents a distinctive hallmark of papillary craniopharyngiomas that can be used as a simple MR imaging sign to reliably diagnose these lesions.

Papillary Craniopharyngioma: A Type of Tumor Primarily Impairing the Hypothalamus - A Comprehensive Anatomo-Clinical Characterization of 350 Well-Described Cases

OBJECTIVE

Papillary craniopharyngiomas (PCPs) represent a rare histological type of craniopharyngiomas (CPs) usually involving the hypothalamus. This study systematically analyzes the clinical-anatomical correlation between tumor topography and symptoms related to hypothalamic dysfunction in the largest series of PCPs ever gathered.

METHODS

From 5,346 CP reports published from 1856 to 2021, we selected 350 well-described cases of the squamous-papillary type. Clinical presentation, tumor topography, severity of hypothalamic adhesion, patient outcome, and tumor recurrence were thoroughly analyzed.

RESULTS

PCPs predominantly occur in adult (96.3%), male (61.7%) patients presenting with headache (63.4%), visual alterations (56.2%), and psychiatric disturbances (50.4%). Most PCPs are solid (50%), round (72%) lesions that occupy the third ventricle (3V, 94.8%) and show low-risk severity adhesions to the hypothalamus (66.8%). Two major topographical categories can be found: strictly 3V (57.5%), growing above an intact 3V floor, and not-strictly or infundibulo-tuberal (32.9%), expanding at the infundibulum and/or tuber cinereum. The hypothalamic syndrome predominated among strictly 3V PCPs (p < 0.001). Psychiatric symptoms (p < 0.001) and high-risk hypothalamic attachments (p = 0.031) related to unfavorable postoperative outcomes among patients treated from 2006 onwards. The not-strictly 3V topography was identified as the major predictor of high-risk hypothalamic attachments (71.2% correctly predicted), which, along with incomplete tumor removal (p = 0.018), underlies the higher tumor recurrence of this topography (p = 0.001).

CONCLUSIONS

This systematic review evidences that PCP topography is a major determinant of hypothalamic-related symptoms, type of hypothalamic attachments, and tumor recurrence rate. Accurate preoperative definition of PCP-hypothalamus relationships is essential for the judicious, safe management of these complex lesions.

Strictly third ventricle craniopharyngiomas: pathological verification, anatomo-clinical characterization and surgical results from a comprehensive overview of 245 cases

The strictly third ventricle craniopharyngioma topography (strictly 3V CP) defines the subgroup of lesions developed above an anatomically intact third ventricle floor (3VF). The true existence of this exceedingly rare topographical category is highly controversial owing to the presumed embryological CP origin from Rathke's pouch, a structure developmentally situated outside the neural tube. This study thoroughly analyzes the largest series of strictly 3V CPs ever collected. From 5346 CP reports published between 1887 and 2021, we selected 245 cases with reliable pathological, surgical, and/or neuroradiological verification of an intact 3VF beneath the tumor. This specific topography occurs predominantly in adult (92.6%), male (64.4%) patients presenting with headache (69.2%), and psychiatric disturbances (59.2%). Neuroradiological features defining strictly 3V CPs are a tumor-free chiasmatic cistern (95.9%), an entirely visible pituitary stalk (86.4%), and the hypothalamus positioned around the tumor's lower pole (92.6%). Most are squamous papillary (82%), showing low-risk severity adhesions to the hypothalamus (74.2%). The adamantinomatous variant, however, associates a higher risk of severe hypothalamic adhesion (p < .001). High-risk attachments are also associated with psychiatric symptoms (p = .013), which represented the major predictor for unfavorable prognoses (83.3% correctly predicted) among cases operated from 2006 onwards. CP recurrence is associated with infundibulo-tuberal symptoms (p = .036) and incomplete surgical removal (p = .02). The exclusive demographic, clinico-pathological and neuroradiological characteristics of strictly 3V CPs make them a separate, unique topographical category. Accurately distinguishing strictly 3V CPs preoperatively from those tumors replacing the infundibulum and/or tuber cinereum (infundibulo-tuberal or not strictly 3V CPs) is critical for proper, judicious surgical planning.

Craniopharyngioma treatment: an updated summary of important clinicopathological concepts

INTRODUCTION

Craniopharyngiomas (CPs) are benign histological tumors that may develop at different positions along the hypothalamic-pituitary axis. Their close, heterogenous relationship to the hypothalamus makes surgical removal challenging even though this remains the primary treatment strategy.

AREAS COVERED

This article presents a critical overview of the pathological and clinical concepts regarding CPs that should be considered when planning treatment. Thus, we have performed a comprehensive review of detailed CP reports published between 1839 and 2020.

EXPERT OPINION

CP surgery should pursue maximal tumor resection while minimizing the risk of injuring the hypothalamus. Therefore, surgical strategies should be individualized for each patient. Accurate assessment of presenting symptoms and preoperative MRI has proven useful to predict the type of CP-hypothalamus relationship that will be found during surgery. CPs with dense and extensive adhesions to the hypothalamus should be highly suspected when MRI shows the hypothalamus positioned around the mid-third of the tumor and an amputated upper portion of the pituitary stalk. Symptoms related to functional impairment of the infundibulo-tuberal area of the third ventricle floor, such as obesity/hyperphagia, Fröhlich's syndrome, diabetes insipidus, and/or somnolence, also indicate risky CP-hypothalamic adhesions. In these cases, limited tumor removal is strongly advocated followed by radiation therapy.

Ipsilateral hemiparesis: the forgotten history of this paradoxical neurological sign

OBJECTIVE

Establishing the neurological localization doctrine for the contralateral hemispheric control of motor functions in the second half of the 19th century, researchers faced the challenge of recognizing false localizing signs, in particular paradoxical or ipsilateral hemiparesis (IH). Despite tremendous progress in current methods of neuroradiological and electrophysiological exploration, a complete understanding of this phenomenon has yet to be attained.

METHODS

The authors researched the well-described cases of hemiparesis/hemiplegia ipsilateral to an intracranial lesion published in the scientific literature in the pre-MRI era (before 1980). A comprehensive review of the physiopathological mechanisms proposed for paradoxical hemiparesis throughout this period, as well as the pathological evidence substantiating them, is provided.

RESULTS

A collection of 75 patients with hemiparesis/hemiplegia ipsilateral to the primary intracranial lesion reported between 1858 and 1979 were eligible for analysis. Most cases occurred in adults with supratentorial, slowly developing, extraparenchymatous mass lesions, such as neoplasms (38%) or chronic subdural hematomas (36%). Physiopathological theories proposed by the neurologists who investigated IH can be grouped into 4 major concepts: 1) lack of anatomical decussation of the corticospinal tract; 2) impaired functional activation of the contralateral hemisphere by the lesioned dominant hemisphere through the callosal connections; 3) Kernohan’s notch phenomenon, or mechanical injury of the contralateral cerebral peduncle against the free edge of the tentorium; and 4) cerebrovascular dysfunction involving the contralateral hemisphere owing to kinking and mechanical flattening of the carotid artery contralateral to the primary intracranial lesion.

CONCLUSIONS

IH represents a still underdiagnosed paradoxical neurological phenomenon. With the aid of modern neuroradiological and neurophysiological methods, Kernohan’s peduncle notch mechanism has been confirmed to cause IH in many of the cases reported in recent decades. Nevertheless, alternative functional and/or vascular mechanisms must be investigated further for unexplained IH cases, in particular for transitory IH without evidence of peduncle injury. The historical theories reviewed in this paper represent a conceptual framework that may be helpful for this purpose.

Percival S. Bailey: eminent scholar of neurosciences who revealed the workings of the hypothalamus through clinicopathological research on craniopharyngiomas

Percival S. Bailey (1892-1973) was a scholar, neuroscientist, neuropathologist, and neurosurgeon who made decisive contributions in the field of neuro-oncology. Far less known are his groundbreaking insights into understanding hypothalamic physiology through the study of craniopharyngiomas. As one of Harvey W. Cushing's most talented trainees, Bailey was instrumental in developing Cushing's project of a histologically based prognostic classification of brain tumors. He worked at Peter Bent Brigham Hospital on and off between 1919 and 1928, owing to frequent clashes with his mentor. A major cause of this long-term conflict was Bailey's 1921 experimental demonstration of the hypothalamic origin of diabetes insipidus and Fröhlich's syndrome. This finding challenged Cushing's view that both alterations were due to pituitary gland insufficiency. In a seminal monograph written with John F. Fulton in 1929, both authors provided the first comprehensive account of the specific hypothalamic disturbances caused by tumors that originated within the infundibulum and third ventricle. The methodical study of Cushing's craniopharyngioma specimens allowed Bailey to recognize the close contact between these lesions and hypothalamic nuclei, a key concept that Bailey originally advanced for proper surgical planning. This article aims to credit Bailey for his pioneering definition of craniopharyngiomas as tumors with a true intrahypothalamic position.

Legal and ethical implications of defining an optimum means of achieving unconsciousness in assisted dying

A decision by a society to sanction assisted dying in any form should logically go hand-in-hand with defining the acceptable method(s). Assisted dying is legal in several countries and we have reviewed the methods commonly used, contrasting these with an analysis of capital punishment in the USA. We expected that, since a common humane aim is to achieve unconsciousness at the point of death, which then occurs rapidly without pain or distress, there might be a single technique being used. However, the considerable heterogeneity in methods suggests that an optimum method of achieving unconsciousness remains undefined. In voluntary assisted dying (in some US states and European countries), the common method to induce unconsciousness appears to be self-administered barbiturate ingestion, with death resulting slowly from asphyxia due to cardiorespiratory depression. Physician-administered injections (a combination of general anaesthetic and neuromuscular blockade) are an option in Dutch guidelines. Hypoxic methods involving helium rebreathing have also been reported. The method of capital punishment (USA) resembles the Dutch injection technique, but specific drugs, doses and monitoring employed vary. However, for all these forms of assisted dying, there appears to be a relatively high incidence of vomiting (up to 10%), prolongation of death (up to 7 days), and re-awakening from coma (up to 4%), constituting failure of unconsciousness. This raises a concern that some deaths may be inhumane, and we have used lessons from the most recent studies of accidental awareness during anaesthesia to describe an optimal means that could better achieve unconsciousness. We found that the very act of defining an 'optimum' itself has important implications for ethics and the law.

Intrachiasmatic craniopharyngioma: Assessment of visual outcome with optical coherence tomography after complete surgical removal

Background:

Optic chiasm invasion by a craniopharyngioma (CP) is exceptional. Surgical treatment of intrachiasmatic CPs associates a high risk of chiasm injury, which should be properly addressed before surgery.

Case Description:

We present a 46-year-old woman admitted to the hospital with low visual acuity (0.1 in the right eye and 0.5 in the left) and a severe defect in her visual fields, in addition to headaches, diabetes insipidus, and a long-term depressive disorder. Her visual deficit progressed from a right homonymous temporal inferior quadrantanopia to an almost complete loss of vision in both eyes that only spared the upper nasal quadrants. Brain MRI showed a rounded third ventricle tumor with a potbelly expansion of the optic chiasm, suggesting chiasm invasion by the tumor. Optical coherence tomography (OCT) showed the thinning of the retinal nerve fiber layer (RNFL) in the superior and temporal wedges of the right eye and in the temporal wedge of the left one. The tumor was completely removed by employing a frontotemporal craniotomy and a translamina terminalis approach. Histological analysis showed a squamous-papillary CP. Postoperatively, a significant worsening of the visual defect was evidenced on the perimetry, which was related to a marked RNFL atrophy measured with OCT, as compared to the preoperative study. The poor long-term visual outcome in this patient correlated well with the results of postoperative OCT.

Conclusions:

Preoperative analysis of retinal atrophy with optic coherence tomography allows a reliable assessment of the patient's visual outcome in CPs involving the optic chiasm.

Cystic tumors of the pituitary infundibulum: seminal autopsy specimens (1899 to 1904) that allowed clinical-pathological craniopharyngioma characterization

A heterogeneous group of epithelial cystic tumors developed at the infundibulum and the third ventricle disconcerted pathologists at the dawn of the twentieth century. Very little was known at that time about the physiological role played by the pituitary gland, and there was almost complete ignorance regarding the function of the hypothalamus. Acromegaly, or enlargement of acral body parts, described in 1886 by Pierre Marie, was the only disease linked to primary hypertrophies of the pituitary gland, known as "pituitary strumas". A growing number of young patients manifesting an unexplained combination of physical and mental symptoms, including absent or delayed sexual maturation, progressive obesity, abnormal somnolence, and dementia-like changes in behavior were reported to present large solid-cystic tumors which characteristically expanded within the infundibulum and third ventricle, above an anatomically intact pituitary gland. Between 1899 and 1904, five seminal autopsy studies from different countries thoroughly described the anatomical relationships and histological features of this newly recognized type of infundibular tumors. These cases were instrumental in fostering the systematic investigation of similar lesions by the Austrian pathologist Jakob Erdheim (1874-1937), who in 1904 was able to classify these infundibulo-tuberal cysts under the common category of hypophyseal duct tumors. The pioneering American neurosurgeon Harvey Cushing (1869-1939) unsuccessfully attempted to surgically remove one of these cysts, for the first time in history, in 1902. The term "craniopharyngioma", chosen by Cushing in 1929 to designate these lesions, would eventually prevail over Erdheim's more accurate denomination, which linked their origin to squamous cell remnants derived from the embryological structures that give rise to the pituitary gland. This paper presents a comprehensive, renewed account of the five clinical-pathological reports which laid the groundwork for the proper clinical diagnosis, topographic conceptualization and pathological categorization of craniopharyngiomas.

Can tissue biomarkers reliably predict the biological behavior of craniopharyngiomas? A comprehensive overview

BACKGROUND

The growing interest in the molecular and genetic alterations of craniopharyngiomas (CPs) is embodied in recent studies revealing insights into the CP tumorigenesis and identifying novel molecular pathways amenable of targeted therapies. The actual impact of this new information, however, remains inconclusive.

METHODS

We present a comprehensive review of the accumulated knowledge on molecular biology of CPs and a critical analysis on the strengths and weaknesses of the studies focused on CP molecular/genetic alterations published to date.

RESULTS

A thorough analysis of the alterations of β-catenin/CTNNB1 and BRAF genes investigated in 1123 CP cases included in 27 studies, showed that, on average, CTNNB1 mutations were present in two-thirds of adamantinomatous CPs and BRAF mutations in 90% of papillary CPs. Their role as oncogenic drivers has not been well established. Although rare, coexistence of both mutations may occur. The involvement of pituitary stem cells in human CP tumorigenesis is still uncertain. Expression of stem markers in human CP samples predominantly occurred along the CP border in contact with brain tissue. Finally, none of the various molecular alterations which have been proposed as markers for CP recurrence can be used today as reliable predictors of the CP behavior.

CONCLUSIONS

The isolated evaluation of CPs' molecular or genetic profiles that do not take into consideration fundamental pathological and therapeutic factors, specifically the tumor topography and the degree of tumor removal, may actually generate confusion regarding the reliability of some biomarkers to predict the CP biological behavior.

Preoperative Assessment of Craniopharyngioma Adherence: Magnetic Resonance Imaging Findings Correlated with the Severity of Tumor Attachment to the Hypothalamus

BACKGROUND AND OBJECTIVE

Craniopharyngioma (CP) adherence represents a heterogeneous pathologic feature that critically influences the potentially safe and radical resection. The aim of this study was to define the magnetic resonance imaging (MRI) predictors of CP adherence severity.

METHODS

This study retrospectively investigated a cohort of 200 surgically treated CPs with their corresponding preoperative conventional MRI scans. MRI findings related to the distortions of anatomic structures along the sella turcica-third ventricle axis caused by CPs, in addition to the tumor's shape and calcifications, were analyzed and correlated with the definitive type of CP adherence observed during the surgical procedures.

RESULTS

CP adherence is defined by 3 components, as follows: 1) the specific structures attached to the tumor, 2) the adhesion's extent, and 3) its strength. Combination of these 3 components determines 5 hierarchical levels of adherence severity with gradually increasing surgical risk of hypothalamic injury. Multivariate analysis identified 4 radiologic variables that allowed a correct overall prediction of the levels of CP adherence severity in 81.5% of cases: 1) the position of the hypothalamus in relation to the tumor-the most discriminant factor; 2) the type of pituitary stalk distortion; 3) the tumor shape; and 4) the presence of calcifications. A binary logistic regression model including the first 3 radiologic variables correctly identified the CPs showing the highest level of adherence severity (severe/critical) in almost 90% of cases.

CONCLUSIONS

A position of the hypothalamus around the middle portion of the tumor, an amputated or infiltrated appearance of the pituitary stalk, and the elliptical shape of the tumor are reliable predictors of strong and extensive CP adhesions to the hypothalamus.

Topographic Diagnosis of Craniopharyngiomas: The Accuracy of MRI Findings Observed on Conventional T1 and T2 Images

BACKGROUND AND PURPOSE

The topography of craniopharyngiomas has proved fundamental in predicting the involvement of vital brain structures and the possibility of achieving a safe radical resection. Beyond the imprecise term "suprasellar," indiscriminately used for craniopharyngiomas, an accurate definition of craniopharyngioma topography should be assessed by preoperative MR imaging. The objective of this study was to investigate the MRI findings that help define craniopharyngioma topography.

MATERIALS AND METHODS

This study retrospectively investigated a cohort of 200 surgically treated craniopharyngiomas with their corresponding preoperative midsagittal and coronal conventional T1- and T2-weighted MR images, along with detailed descriptions of the surgical findings. Radiologic variables related to the occupation of the tumor of intracranial compartments and the distortions of anatomic structures along the sella turcica-third ventricle axis were analyzed and correlated with the definitive craniopharyngioma topography observed during the surgical procedures. A predictive model for craniopharyngioma topography was generated by multivariate analysis.

RESULTS

Five major craniopharyngioma topographies can be defined according to the degree of hypothalamic distortion caused by the tumor: sellar-suprasellar, pseudointraventricular, secondary intraventricular, not strictly intraventricular, and strictly intraventricular. Seven key radiologic variables identified on preoperative MRI allowed a correct overall prediction of craniopharyngioma topography in 86% of cases: 1) third ventricle occupation, 2) pituitary stalk distortion, 3) relative level of the hypothalamus in relation to the tumor, 4) chiasmatic cistern occupation, 5) mammillary body angle, 6) type of chiasm distortion, and 7) tumor shape.

CONCLUSIONS

Systematic assessment of these 7 variables on conventional preoperative T1 and T2 MRI is a useful and reliable method to ascertain individual craniopharyngioma topography.

Jean Camus and Gustave Roussy: pioneering French researchers on the endocrine functions of the hypothalamus

At the beginning of the twentieth century, the hypothalamus was known merely as an anatomical region of the brain lying beneath the thalamus. An increasing number of clinicopathological reports had shown the association of diabetes insipidus and adiposogenital dystrophy (Babinski-Fröhlich's syndrome), with pituitary tumors involving the infundibulum and tuber cinereum, two structures of the basal hypothalamus. The French physicians Jean Camus (1872-1924) and Gustave Roussy (1874-1948) were the first authors to undertake systematic, controlled observations of the effects of localized injuries to the basal hypothalamus in dogs and cats by pricking the infundibulo-tuberal region (ITR) with a heated needle. Their series of surgical procedures, performed between 1913 and 1922, allowed them to claim that both permanent polyuria and adiposogenital dystrophy were symptoms caused by damage to the ITR. Their results challenged the dominant doctrine of hypopituitarism as cause of diabetes insipidus and adiposogenital dystrophy that derived from the experiments performed by Paulescu and Cushing a decade earlier. With their pioneering research, Camus and Roussy influenced the experimental work on the hypothalamus performed by Percival Bailey and Frederic Bremer at Cushing's laboratory, confirming the hypothalamic origin of these symptoms in 1921. More importantly, they provided the foundations for the physiological paradigm of Neuroendocrinology, the hypothalamus' control over the endocrine secretions of the pituitary gland, as well as over water balance and fat metabolism. This article aims to credit Camus and Roussy for their groundbreaking, decisive contributions to postulate the hypothalamus being the brain region in control of endocrine homeostasis and energy metabolism.

Norman M. Dott, master of hypothalamic craniopharyngioma surgery: the decisive mentoring of Harvey Cushing and Percival Bailey at Peter Bent Brigham Hospital

Norman McOmish Dott (1897-1973) developed surgical neurology in Edinburgh, Scotland, and was a scholar of worldwide renown. One of Dott's most notable contributions to neurosurgery was his understanding of hypothalamic physiology, mostly acquired through the comprehensive study of patients with lesions involving this region of the diencephalon, particularly craniopharyngiomas (CPs). Recognition of symptoms caused by hypothalamic disturbances allowed him to predict the accurate anatomical relationships between CPs and the hypothalamus, despite the rudimentary radiological methods available during the 1930s. His sophisticated knowledge permitted Dott to perform radical removals of CPs originating within the third ventricle floor with acceptable success. Between 1934 and 1937, he operated on 4 CP cases originating in the hypothalamus, achieving a satisfactory postoperative outcome in 3 of the 4 patients. Aware of the strong attachment of hypothalamic CPs to the infundibulo-tuberal area, Dott used a double transbasal and transventricular approach to these lesions, a strategy providing an optimal view and control of the tumor boundaries. The decisive mentorship of several legendary figures of physiology and neurosurgery greatly influenced Dott's surgical evolution. The experimental pituitary gland work he performed with Sir Edward Sharpey-Schäfer at the beginning of his career stirred Dott's curiosity about the issue of hypothalamus-pituitary relationships. As a result, he decided to move to Peter Bent Brigham Hospital (Boston, Massachusetts) in 1923, to train in neurosurgery and neuropathology under the guidance of the leaders in these fields, Harvey Williams Cushing (1869-1939) and Percival Sylvester Bailey (1892-1973). They inspired the young Dott and shared with him their clinical and pathological expertise, in addition to their surgical strategies for best approaching and removing these challenging tumors. In time, Dott would come to surpass his mentors. This paper aims to credit Norman M. Dott for his decisive, modern contributions to hypothalamic CP surgery.

Infundibulo-tuberal syndrome: the origins of clinical neuroendocrinology in France

The birth of clinical neuroendocrinology can be dated to the year 1900, when the French neurologist Joseph Babinski (1857-1932) described a particular syndrome of adiposity and sexual infantilism in an adolescent with a craniopharyngioma expanding at the base of the brain. This condition of adipose-genital dystrophy, also known as Babinski-Fröhlich syndrome, represented the first clinical evidence that the brain controlled endocrine functions. Adipose-genital dystrophy forms part of infundibulo-tuberal syndrome, which groups the endocrine, metabolic and behavioral disturbances caused by lesions involving the upper neurohypophysis (median eminence) and the adjacent basal hypothalamus (tuber cinereum). This syndrome was originally described by the French neuropsychiatrists Henri Claude (1869-1946) and Jean Lhermitte (1877-1959) in 1917, also in a patient with a craniopharyngioma. This type of tumor involves specifically the infundibulo-tuberal region of the hypothalamus, providing a clinical model to conceptualize the separation of hypophyseal and hypothalamic functions. The French School of Neurology analyzed and reported the symptoms associated with dysfunction of the basal hypothalamus by craniopharyngiomas and other types of tumors, influencing significantly the development of clinical neuroendocrinology. Experimental lesions performed in the tuber cinereum by the French physiologists Jean Camus (1872-1924) and Gustave Roussy (1874-1948) demonstrated unmistakably the anatomical origin of infundibulo-tuberal syndrome in the basal hypothalamus. This article reviews the original findings on infundibulo-tuberal syndrome reported by the French School of Neurology in the first decades of the twentieth century and the great influence this school had on modern conceptions of hypothalamic control over endocrine functions and behavior.

The infundibulo-tuberal syndrome caused by craniopharyngiomas: clinicopathological evidence from an historical French cohort (1705-1973)

PURPOSE

Infundibulo-tuberal syndrome groups endocrine, metabolic and behavioral disturbances caused by lesions involving the upper neurohypophysis (median eminence) and adjacent basal hypothalamus (tuber cinereum). It was originally described by Henri Claude and Jean Lhermitte in 1917, in a patient with a craniopharyngioma. This study investigates the clinical, pathological and surgical evidence verifying the infundibulo-tuberal syndrome caused by craniopharyngiomas (CPs).

METHODS

A systematic retrospective review of craniopharyngiomas reported in French literature between 1705 and 1973 was conducted. A total of 128 well described reports providing a comprehensive clinical and pathological description of the tumors were selected. This series represents the historical French cohort of CPs reported in the pre-CT/MRI era.

RESULTS

Three major syndromes caused by CPs were categorized: pituitary syndrome (35%), infundibulo-tuberal syndrome (52%) and hypothalamic syndrome (49%). CP topography was significantly related to the type of syndrome described (p < 0.001). Infundibulo-tuberal syndrome occurred in CPs which replaced or invaded the third ventricle floor. In contrast, the majority of sellar/suprasellar CPs growing below the third ventricle showed a pituitary syndrome (82%). Cases with hypothalamic syndrome were characterized by anatomical integrity of the pituitary gland and stalk (p = 0.033) and occurred predominantly in adults older than 41 years old (p < 0.005). Among infundibulo-tuberal symptoms, abnormal somnolence was not related with the presence of hydrocephalus. All squamous-papillary CPs presented psychiatric disturbances (p < 0.001).

CONCLUSION

This historical CP cohort evidences a clinical-topographical correlation between the patient's type of syndrome and the anatomical structures involved by the tumor along the hypophysial-hypothalamic axis.

Sir Victor Horsley: pioneer craniopharyngioma surgeon

Sir Victor Horsley (1857–1916) is considered to be the pioneer of pituitary surgery. He is known to have performed the first surgical operation on the pituitary gland in 1889, and in 1906 he stated that he had operated on 10 patients with pituitary tumors. He did not publish the details of these procedures nor did he provide evidence of the pathology of the pituitary lesions operated on. Four of the patients underwent surgery at the National Hospital for Neurology and Neurosurgery (Queen Square, London), and the records of those cases were recently retrieved and analyzed by members of the hospital staff. The remaining cases corresponded to private operations whose records were presumably kept in Horsley's personal notebooks, most of which have been lost.

In this paper, the authors have investigated the only scientific monograph providing a complete account of the pituitary surgeries that Horsley performed in his private practice, La Patologia Chirurgica dell'Ipofisi (Surgical Pathology of the Hypophysis), written in 1911 by Giovanni Verga, Italian assistant professor of anatomy at the University of Pavia. They have traced the life and work of this little-known physician who contributed to the preservation of Horsley's legacy in pituitary surgery. Within Verga's pituitary treatise, a full transcription of Horsley's notes is provided for 10 pituitary cases, including the patients' clinical symptoms, surgical techniques employed, intraoperative findings, and the outcome of surgery. The descriptions of the topographical and macroscopic features of two of the lesions correspond unmistakably to the features of craniopharyngiomas, one of the squamous-papillary type and one of the adamantinomatous type. The former lesion was found on necropsy after the patient's sudden death following a temporal osteoplastic craniectomy. Surgical removal of the lesion in the latter case, with the assumed nature of an adamantinomatous craniopharyngioma, was successful. According to the evidence provided in Giovanni Verga's monograph, it can be claimed that Sir Victor Horsley was not only the pioneer of pituitary gland surgery but also the pioneer of craniopharyngioma surgery.

Acute epidural-like appearance of an encapsulated solid non-organized chronic subdural hematoma

We report the exceptional case of an encapsulated solid non-organized chronic subdural hematoma (SDH) in a 67-year-old woman that was admitted with acute hemiplegia followed by rapid deterioration in consciousness 5 months after a minor head trauma. Computed tomography (CT) showed an extracerebral biconvex shaped hyperdense mass that led to the misdiagnosis of an acute epidural hematoma. Urgent craniotomy revealed an encapsulated mass filled with solid fresh clot in the subdural space. Complete evacuation of this SDH, including both its inner and outer membranes, was achieved, and the patient recovered successfully. Histological analysis confirmed that the content of the hematoma corresponded to a newly formed clot that was enclosed between an inner membrane, composed of two collagen layers, and an outer membrane with a three layered structure. Chronic SDH may seldom present as an encapsulated solid non-organized lesion that consists of a fibrous capsule enclosing a fresh clot and lacking the thick fibrous septations that typically connect the inner and outer membranes of organized chronic SDH. This entity mimics the clinical course and radiological appearance of acute epidural hematomas and should be considered in the differential diagnosis of extracerebral hyperdense biconvex shaped lesions.

Predictive factors for craniopharyngioma recurrence: a systematic review and illustrative case report of a rapid recurrence

BACKGROUND

Recurrence of craniopharyngiomas (CPs) represents a frequent and unpredictable incident. Rapid tumor recurrence within a few months after surgery has been rarely reported. Nondefinitive predictive factors for rapid CP recurrence have been identified to date. We have systematically analyzed the tumor factors that presumably influence in CP recurrence.

METHODS

We present the histologic and immunohistochemical analysis of an infundibulo-tuberal CP that was operated twice within a 3-month interval due to rapid recurrence. We investigated the differential characteristics of the subgroup of CPs that recurred in large surgical series published in the literature, along with cases reporting rapid tumor recurrence after surgery.

RESULTS

Specimens of our patient showed an adamantinomatous CP with whorl-like arrays and thick peritumoral gliosis. Ki-67 labeling index in primary and recurrent samples was 20% and 15%, respectively. p53 labeling index was 18% and 15%, respectively. The thorough analysis of literature showed that presence of tumor remnants and missing radiotherapy treatment after subtotal removal are strong predictors of tumor recurrence. Third ventricle involvement, large tumor size, tight adherence to surrounding structures, and presence of whorl-like arrays might also foster recurrence. High Ki-67 levels, p53 expression, and an intense reactive gliosis might point to rapid tumor growth.

CONCLUSIONS

Reliable tumor markers that predict CP recurrence are still lacking. The CP features presumably related to a higher risk of its recurrence are thought to be a larger tumor size, a tight adherence to the hypothalamus, the presence of whorl-like arrays, and high Ki-67 and p53 levels.

Trigeminal neuralgia: Assessment of neurovascular decompression by 3D fast imaging employing steady-state acquisition and 3D time of flight multiple overlapping thin slab acquisition magnetic resonance imaging

Background:

Trigeminal neuralgia is most commonly caused by vascular compression at the trigeminal nerve (TN) root entry zone. Microvascular decompression (MVD) has been established as a useful treatment. Outcome depends on the correct identification of the compression site and its adequate decompression at surgery. Preoperative identification of neurovascular compression might predict which patients will benefit from MVD. Management of persistent or recurrent trigeminal neuralgia after an MVD is a baffling problem for neurosurgeons. An accurate neuroradiological evaluation of the TN padding following a failed MVD might help identify the underlying cause and plan further treatment.

Case description:

A 68-year-old female presented with a right-sided trigeminal neuralgia (V3) refractory to medical therapy. A high-resolution three-dimensional magnetic resonance imaging (3D MRI) study included fast imaging employing steady-state acquisition (FIESTA) and time of flight multiple overlapping thin slab acquisition (TOF MOTSA) sequences to evaluate the neurovascular anatomy in the cerebellopontine angle. An unambiguous compression of the right TN at the rostral-medial site by the superior cerebellar artery (SCA) was identified. The SCA loop compressing the TN was identical in location and configuration to that predicted in the preoperative study. After the MVD, the patient was relieved from her pain and a postoperative high-resolution 3D MRI study confirmed the appropriate placement of the Teflon implant between the TN and SCA.

Conclusion:

To our knowledge, this is the first report that characterizes the proper TN padding by high-resolution 3D MRI after trigeminal MVD. The present case also emphasizes the importance of performing a 3D MRI in patients with trigeminal neuralgia to anticipate the surgeon's view and predict the outcome after MVD.

Acute hemorrhage in a colloid cyst of the third ventricle: A rare cause of sudden deterioration

Background:

Acute neurological deterioration and death in a patient harboring a colloid cyst of the third ventricle remains a poorly understood phenomenon. Sudden neurological derangement caused by spontaneous bleeding within a colloid cyst is a rare and potentially fatal event, usually requiring immediate diagnosis and emergency surgical treatment.

Case Description:

A 47-year-old male presented with acute right-sided hemiparesis and speech impediment, followed by rapid deterioration of consciousness. Neuroimaging studies showed a rounded mass at the roof of the anterior third ventricle, causing biventricular hydrocephalus along with a left-sided basal ganglia hematoma. The lesion showed scattered foci of a recent hemorrhage which extended into the left lateral ventricle. Surgical treatment involved emergency external ventricular drainage followed by the prompt elective total resection of the lesion via a transcallosal route. Pathological findings confirmed the diagnosis of a colloid cyst with focal areas of vascular congestion and blood extravasation within its wall.

Conclusions:

Spontaneous bleeding into a colloid cyst of the third ventricle may cause acute obstructive hydrocephalus and intracranial hypertension due to rapid enlargement of the lesion. This event may account for the sudden neurological deterioration and/or death observed in a previously asymptomatic patient. The diagnosis of hemorrhagic phenomena within a colloid cyst represents a challenge due to the variable signal usually displayed by these lesions on computed tomography (CT) and magnetic resonance imaging (MRI). Emergency ventricular drainage followed by elective tumoral removal constitutes a valid and safe treatment strategy.

Infundibulo-tuberal or not strictly intraventricular craniopharyngioma: evidence for a major topographical category

PURPOSE

This study investigates retrospectively the clinical, neuroradiological, pathological and surgical evidence verifying the infundibulo-tuberal topography for craniopharyngiomas (CPs). Infundibulo-tuberal CPs represent a surgical challenge due to their close anatomical relationships with the hypothalamus. An accurate definition of this topographical category is essential in order to prevent any undue injury to vital diencephalic centres.

METHODS

A systematic review of all scientific reports involving pathological, neuroradiological or surgical descriptions of either well-described individual cases or large series of CPs published in official journals and text books from 1892 to 2011 was carried out. A total of 1,232 documents providing pathological, surgical and/or neuroradiological evidence for the infundibulo-tuberal or hypothalamic location of CPs were finally analysed in this study.

FINDINGS

For a total of 3,571 CPs included in 67 pathological, surgical or neuroradiological series, 1,494 CPs (42%) were classified as infundibulo-tuberal lesions. This topography was proved in the autopsy of 122 non-operated cases. The crucial morphological finding characterizing the tubero-infundibular topography was the replacement of the third ventricle floor by a lesion with a predominant intraventricular growth. This type of CP usually presents a circumferential band of tight adherence to the third ventricle floor remnants, formed by a functionless layer of rective gliosis of a variable thickness. After complete surgical removal of an infundibulo-tuberal CP, a wide defect or breach at the floor of the third ventricle is regularly observed both in the surgical field and on postoperative magnetic resonance imaging studies.

CONCLUSIONS

Infundibulo-tuberal CPs represent a major topographical category of lesions with a primary subpial development at the floor of the third ventricle. These lesions expand within the hypothalamus itself and subsequently occupy the third ventricle; consequently, they can be classified as not strictly intraventricular CPs. A tight attachment to the hypothalamus and remnants of the third ventricle floor is the pathological landmark of infundibulo-tuberal CPs.

Natural history of MELAS associated with mitochondrial DNA m.3243A>G genotype

OBJECTIVE

To describe the natural history of clinical and laboratory features associated with the m.3243A>G mitochondrial DNA point mutation. Natural history data are needed to obtain prognostic information and for clinical trial planning.

METHODS

We included 85 matrilineal relatives from 35 families with at least 2 visits in this prospective cohort study. Thirty-one were fully symptomatic with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), and 54 were carrier relatives. Evaluations included standardized questionnaires (medical history and daily living functioning), physical examination, neuropsychological testing, and a battery of imaging and laboratory tests. We evaluated changes in clinical and laboratory features over time and survival. Outcomes are reported over a follow-up period of up to 10.6 years (mean 3.8 ± 2.2 years for patients and 5.5 ± 3.0 for carrier relatives).

RESULTS

Neurologic examination, neuropsychological testing, and daily living scores significantly declined in all patients with MELAS, whereas no significant deterioration occurred in carrier relatives. Cerebral MRI scores declined significantly in patients with MELAS. Magnetic resonance spectroscopy estimates of lactate in the lateral ventricles increased over time, and high lactate was associated with increased mortality. Symptom onset in childhood often was associated with worse outcome. Patients with MELAS had a greater death rate than carrier relatives.

CONCLUSIONS

Patients with MELAS carrying the m.3243A>G mutation show a measurable decline in clinical and imaging outcomes. It is hoped that these data will be helpful in anticipating the disease course and in planning clinical trials for MELAS.