Hydrocephalus — revision of its definition and classification with special reference to “intractable infantile hydrocephalus”

With the advent of computed tomography (CT) scan, much information has been obtained about the pathophysiology of hydrocephalus. It is now clear that hydrocephalus is not a disease entity but rather a syndrome or sign resulting from disturbances in the dynamics of cerebralspinal fluid (CSF) caused by various diseases. Consequently, it has become necessary to revise its definition and classification. In this paper, a contemporary definition and classification of hydrocephalus are presented. Also, a classification of "intractable hydrocephalus"--with its diagnostic criteria--which is a clinically unsolved problem, is attempted, bearing in mind its place in the clinical management and future investigation of the pathophysiology of hydrocephalus.     

Guideline for management and treatment of fetal and congenital hydrocephalus: Center Of Excellence��Fetal and Congenital Hydrocephalus Top 10 Japan Guideline 2011

INTRODUCTION: Hydrocephalus does not indicate a single clinical entity, but includes a variety of clinicopathological conditions caused by excessive cerebrospinal fluid (CSF) based on the disturbed circulation. Recent progress in prenatal neuroimagings such as MRI and ultrasound echoencephalography on fetus enables to understand clinicopathological conditions of CSF circulation disorder in conjunction with morphological changes in the central nervous system properly. It has been revealed that the CSF dynamics develop in the theory of evolution from the immature brain, as in the animals with the minor CSF pathway predominance, towards matured adult human brain together with the completion of the major CSF pathway: the "Evolution Theory in CSF Dynamics". Now, we can analyze CSF circulation dynamically and also analyze the flow velocity and direction of CSF movement. CENTER OF EXCELLENCE-FETAL HYDROCEPHALUS TOP 10 JAPAN: Along with this technical improvement, the standards of clinicopathological evaluation of hydrocephalus as well as the classification and concept of hydrocephalus shall undergo a major upgrade. Based on such remarkable improvement in the recent practical diagnostic evaluation of fetal hydrocephalus, it is now required to update the guideline for management and treatment of fetal and congenital hydrocephalus, and a nationwide study group; Center of Excellence-Fetal Hydrocephalus Top 10 Japan, was organized in 2008 in Japan. The retrospective analysis of 333 cases of congenital hydrocephalus indicated a fact that 43% of these cases were diagnosed prenatally, and the majority of cases were treated in these top 10 institutes in Japan. Now, congenital hydrocephalus diagnosed immediately after birth is regarded as to be based on embryonic stage; brain disorder in patients with congenital hydrocephalus should be considered in conjunction with neuronal mature process of embryonic stage. The fact is supported by the current trends in hydrocephalus research represented by "Perspective Classification of Congenital Hydrocephalus" and "Multi-categorical Hydrocephalus Classification". The ultimate goal of hydrocephalus treatment remains achieving arrested hydrocephalus by shunt surgeries. In the future, to achieve arrested hydrocephalus, minimum quantity of CSF to be drained should be elucidated. Consideration for accurate operative indication of ETV along with new neuroendoscopic device development and analysis of CSF circulation is expected in the future. The data in this prospective multicenter analysis in this guideline are credited in Oxford Evidence level 2b (Grade II).     

Semiologic classification of psychogenic non epileptic seizures (PNES) based on video EEG analysis: Do we need new classification systems?

PurposeDifferent studies have described useful signs to diagnose psychogenic non-epileptic seizure (PNES). A few authors have tried to describe the semiologic groups among PNES patients; each group consisting of combination of features. But there is no uniformity of nomenclature among these studies. Our aim was to find out whether the objective classification system proposed by Hubsch et al. was useful and adequate to classify PNES patient population from South India.MethodsWe retrospectively analyzed medical records and video EEG monitoring data of patients, recorded during 3 year period from June 2010 to July 2013. We observed the semiologic features of each PNES episode and tried to group them strictly adhering to Hubsch et al. classification. Minor modifications were made to include patients who were left unclassified.ResultsA total of 65 patients were diagnosed to have PNES during this period, out of which 11 patients were excluded due to inadequate data. We could classify 42(77.77%) patients without modifying the defining criteria of the Hubsch et al. groups. With minor modification we could classify 94.96% patients. The modified groups with patient distribution are as follows:

• Class 1 – dystonic attacks with primitive gestural activities [3(5.6%)].
• Class 2 – paucikinetic attacks with or without preserved responsiveness [5(9.3%)].
• Class 3 – pseudosyncope with or without hyperventilation [21(38.9%)].
• Class 4 – hyperkinetic prolonged attacks with hyperventilation, involvement of limbs and/or trunk [14(25.9%)].
• Class 5 – axial dystonic attacks [8(14.8%)].
• Class 6 – unclassified type [3(5.6%)].

ConclusionThis study demonstrates that the Hubsch's classification with minor modifications is useful and adequate to classify PNES patients from South India.     

Connatal (fetal) hydrocephalus: an acquired pathology?

We investigated the etiology of hydrocephalus present at birth, i.e. of fetal hydrocephalus. Both inherited and dysraphic major malformations are very rare. Intraventricular hemorrhages and viral infections during pregnancy are among the proposed etiologies; they are supported more by anatomical, physiopathological and experimental findings than by clinical evidence. Cases of fetal intraventricular hemorrhages cited in the literature are anecdotical, and the reports fail to identify maternal or fetal predisposing factors. The role of viruses in the etiology of connatal hydrocephalus has been postulated on the basis of epidemiological considerations in human pathology and of a considerable amount of experimental studies in animals. Investigations were generally focused on aqueduct ependyma, but research should also address other structures involved in the genesis of hydrocephalus (choroid plexus, extraventricular CSF pathways, including arachnoid villi). Furthermore, experimental evidence has emerged concerning a number of toxins and of drugs administered during pregnancy, which are thought to be involved in the genesis of hydrocephalus: once more, the conclusions reached in these experimental trials lend further credence to the human epidemiological data linking pregnancy disturbances with fetal hydrocephalus. Since most of these toxic agents are also thought to induce major malformations, we could assume the degree of their effect to depend on the embryonal stage affected: the earlier the action, the worse the malformation.Presented at the Consensus Conference: Hydrocephalus '92 Assisi, Italy, 26–30 April 1992     

The morphology and classification of α ganglion cells in the rat retinae: a fractal analysis study

Rat retinal ganglion cells have been proposed to consist of a varying number of subtypes. Dendritic morphology is an essential aspect of classification and a necessary step toward understanding structure-function relationships of retinal ganglion cells. This study aimed at using a heuristic classification procedure in combination with the box-counting analysis to classify the alpha ganglion cells in the rat retinae based on the dendritic branching pattern and to investigate morphological changes with retinal eccentricity. The cells could be divided into two groups: cells with simple dendritic pattern (box dimension lower than 1.390) and cells with complex dendritic pattern (box dimension higher than 1.390) according to their dendritic branching pattern complexity. Both were further divided into two subtypes due to the stratification within the inner plexiform layer. In the present study we have shown that the alpha rat RCGs can be classified further by their dendritic branching complexity and thus extend those of previous reports that fractal analysis can be successfully used in neuronal classification, particularly that the fractal dimension represents a robust and sensitive tool for the classification of retinal ganglion cells. A hypothesis of possible functional significance of our classification scheme is also discussed.     

Are numbers special? Comparing the generation of verbal materials from ordered categories (months) to numbers and other categories (animals) in an fMRI study

Months, days of the week, and numbers differ from other verbal concepts because they are ordered in a sequence, whereas no order is imposed on members of other categories, such as animals or tools. Recent studies suggest that numbers activate a representation of their quantity within the intraparietal sulcus (IPS) automatically, that is, in tasks that do not require the processing of quantity. It is unclear, however, whether ordered verbal materials in general and not only numbers activate the IPS in such tasks. In the present functional magnetic resonance imaging study word generation of months, numbers, and animals were compared. Word generation of numbers and nonnumerical materials from an ordered category (months) activated the IPS more strongly than generating items from a not-ordered category such as animals or the verbal control conditions. An ROI analysis of three subregions within the anterior IPS revealed that the most anterior and lateral of these regions, human intraparietal area hIP2, shows a greater sensitivity to ordered materials than the other two areas, hIP1 and hIP3. Interestingly, no difference in activation was observed within the IPS between numbers and months suggesting that the activation of the IPS might not be modulated by the additional quantity information carried by numbers.     

Chronic (“normal pressure”) hydrocephalus in childhood and adolescence

Normal pressure hydrocephalus (NPH) is generally considered to be a disorder of the adult and geriatric population. Only a few reports have described the possible occurrence of this condition in children. A series of 16 patients aged less than 20 years forms the basis of the present report. Among these 16 patients, 11 had a clearly identified etiologic factor and 7 had had a shunt previously implanted. The majority of patients exhibited at least two elements of the adult's triad of psychomotor retardation (14 cases) and/or psychotic-like symptoms (4 cases), gait anomalies (8 cases), and sphincter disturbances (3 cases). Six patients had their intracranial pressure (ICP) monitored. ICP values were estimated to be within the normal limits for age. All the 16 patients underwent shunting or shunt revision. Surgical results were as follows (mean follow-up 20±17.2 months): a good response to shunting was obtained in 12 cases (cured: 5, improved: 7), while the other 4 patients failed to improve. It seems likely that associated parenchymal disorders have played a major role in therapeutic failures. In children showing ventricular dilation on computed tomographic (CT) analysis and a clinical picture of subtle psychomotor deterioration, it may be difficult to distinguish an active disorder of the CSF dynamics from arrested hydrocephalus. Since intracranial manometry cannot be undertaken as a routine procedure, less invasive methods such as cerebrospinal fluid (CSF) tap test, psychometric or urodynamic tests deserve special attention as reliable predictors of outcome after shunting. Because most patients undergo shunting without prior assessment of their CSF pressure, the term chronic hydrocephalus is proposed as an alternative designation to NPH, since there is little argument for maintaining an instrumentally based definition of the syndrome.Presented at the XIV Congress of the European Society for Paediatric Neurosurgery, Lyon, France, 21–23 September 1994     

Mortality and risk of dementia in normal-pressure hydrocephalus: A population study

Introduction

We examined mortality, dementia, and progression of hydrocephalic symptoms among untreated individuals with idiopathic normal-pressure hydrocephalus (iNPH) in a population-based sample.

Decompressive craniectomy,interhemispheric hygroma and hydrocephalus: A timeline of events?

Background

Decompressive craniectomy (DC) is a known risk factor for the development of post-traumatic hydrocephalus. The occurrence of subdural hygroma (SH) was also reported in 23–56% of patients after DC and it seemed to precede hydrocephalus in more than 80% of cases. We analyzed the relationship among DC, SH and hydrocephalus.

Methods

From 2007 to 2011, 64 patients underwent DC after head trauma. Variables we analyzed were: intaventricular hemorrhage, age, GCS, distance of craniectomy from the midline, evacuation of a hemorrhagic contusion (HC) and infection. Logistic regression was used to assess the independent contribution of the predictive factors to the development of hydrocephalus.

Results

Nineteen patients (29.7%) developed hydrocephalus. Interhemispheric SH was present in 8/19 patients with hydrocephalus and temporally preceded the occurrence of ventricular enlargement. Moreover, most patients who developed a interhemispheric SH had been undergone DC whose superior margin was close to the midline. Logistic regression analysis showed that craniectomy closer than 25 mm to the midline was the only factor independently associated with the development of hydrocephalus.

Conclusion

Craniectomy close to the midline can predispose patients to the development of hydrocephalus. SH could be generated with the same mechanism, and these three events could be correlated on a timeline.     

William Watson Cheyne (1852–1932): a life in medicine and his innovative surgical treatment of congenital hydrocephalus

William Watson Cheyne lived and trained during a period of great advances in medical knowledge and surgical techniques. Despite his various contributions to the fields of bacteriology and surgery, little is known about his career or his life apart from his affiliations with Joseph Lister. This article aims to identify Cheyne as a pioneer in the treatment of congenital hydrocephalus and sheds light on the man who existed in Lister’s shadow for most of his life. Cheyne’s technique for surgical intervention of hydrocephalus was a great turning point and contributes to the current treatment strategy utilized today for hydrocephalus.     

Robert Liston (1794–1847): surgical anatomist and resurrectionist with an interest in hydrocephalus

Introduction

The Scottish surgeon Robert Liston was an accomplished anatomist of the nineteenth century. The study of anatomy during this day was often overshadowed by the so-called resurrectionists. Conclusions: The present historic paper reviews the life and contributions of Robert Liston and discusses his fascination with childhood hydrocephalus.     

Biochemical studies in Normal Pressure Hydrocephalus (NPH) patients: Change in CSF levels of amyloid precursor protein (APP), amyloid-beta (Aβ) peptide and phospho-tau

Normal Pressure Hydrocephalus (NPH) is one of the causes of dementia of the elderly characterized by impaired mental function, gait difficulties and urinary incontinence. Previously, it was proposed that some of the NPH patients may develop Alzheimer’s disease (AD) like pathology. Aim of this study was to compare levels of different CSF biomarkers, including total secreted β-amyloid precursor protein (sAPP), sAPP-alpha form (sAPPα), amyloid-beta (Aβ) peptide, total-tau protein and hyperphosphorylated-tau protein in subjects from NPH and Non-NPH Control (NNC). CSF was collected from 23 NPH patients and 13 Non-NPH controls by lumber puncture. Western blot analysis was performed to measure levels of sAPP-total. ELISA was used separately to determine levels of sAPPα, Aβ peptide, total-tau and phospho-tau proteins. We found a significant decrease in levels of total secreted APP, sAPPα and Aβ (1-42) in the CSF sample of NPH patients vs. NNC. We did not observe any change in levels of total-tau or phospho-tau in NPH vs. NNC subjects. Notably, phospho-tau level was significantly increased in the NPH patients, who were suffering from the disease for more than one year, vs. NNC. Among five biomarkers studied, decreased sAPP, sAPPα and Aβ (1-42) levels in CSF can be molecular markers to distinguish NPH cases from NNC. Disease severity can also be assessed by increased levels of CSF phospho-tau protein and the ratio of phospho-tau to Aβ (1-42), which might be a useful tool for predicting conversion of NPH individuals to other neurodegenerative disorders including Alzheimer’s disease (AD).     

Comparison between the 2007 and the 2016 WHO classification of tumours of the central nervous system(Ⅰ)

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Comparison between the 2007 and the 2016 WHO classification of tumours of the central nervous system(Ⅱ)

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