[Lower urinary tract dysfunction in normal pressure hydrocephalus: Review of the literature]. / Troubles vésico-sphinctériens dans l'hydrocéphalie à pression normale : revue de la littérature.

INTRODUCTION: Lower urinary tract dysfunction in normal pressure hydrocephalus has received little attention from the scientific community. The aim of this review article was to discuss diagnostic and therapeutic options for these patients. SOURCES: A literature review of MedLine publications on urinary incontinence in normal pressure hydrocephalus was conducted. The following keywords were used: "hydrocephalus, normal pressure" and "bladder dysfunction" or "urinary incontinence" or "overactive bladder" or "urinary bladder, neurogenic". Prospective and retrospective studies as well as previous reviews were analyzed. RESULTS: Urinary symptoms in normal pressure hydrocephalus are mainly represented by overactive bladder, which is a significant burden for the concerned patients. Isolated overactive bladder is more frequent (64%) than urinary incontinence (57%). Detrusor overactivity is seen in 95.2% of the cases. Neuro-surgery is efficient on urinary symptoms for 61.5% of the patients. Bladder recovery after surgery relates with increased mid-cingulate perfusion, probably linked with a functional restoration of the mid-cingulate that normally inhibits the micturition reflex. Medical options, added or not to surgery, include anticholinergic drugs unable to pass through the blood-brain barrier, Transcutaneous Electrical Nerve Stimulation and sacral neuromodulation. CONCLUSION: There is actually an insufficient concern about urinary symptoms in normal pressure hydrocephalus. This article highlights the importance of a harmonization of neuro-urological practices in the pre-therapeutic evaluation of patients suffering from normal pressure hydrocephalus.

Communicating chronic hydrocephalus: A review.

Formerly called normal pressure hydrocephalus, communicating chronic hydrocephalus (CCH) is a condition affecting 0.1 to 0.5% of patients over 60years of age. The pathophysiology of this disease is poorly understood, but a defect in cerebrospinal fluid (CSF) resorption appears to be commonly defined as the cause of the neurological disorders. The last important discovery is the description of the glymphatic system and its implication in CCH and CSF resorption. Comorbidities (Alzheimer's disease, microangiopathy, parkinsonism) are very frequent, and involve a diagnostic challenge. The clinical presentation is based on the Hakim and Adams triad, comprising gait disorders, mainly impairing walking, cognitive disorders, affecting executive functions, episodic memory, visuospatial cognition, and sphincter disorders as urinary incontinence (detrusor hyperactivity). The diagnosis is suspected through a set of arguments, combining the clinical presentation, the radiological data of the magnetic resonance imaging (MRI) showing a ventriculomegaly associated with signs of transependymomous resorption of the CSF and disappearance of the cortical sulci, and the clinical response to the depletion of CSF. In the presence of all these elements, or a strong clinical suspicion, the standard treatment will be of a permanent CSF shunt, using a ventriculoatrial or ventriculoperitoneal shunt. The effectiveness of this treatment defines the diagnosis. The clinical improvement is better when treatment occurs early after the onset of the disorders, reaching 75 to 90% of motor improvement.

[Normal pressure hydrocephalus: A review and practical aspects]. / Hydrocéphalie à pression normale: mise au point et aspects pratiques.

Idiopathic normal pressure hydrocephalus is a chronic disorder affecting the elderly. It is defined by Adams and Hakim's triad in addition to ventricular dilation visible by brain imaging and normal cerebrospinal fluid pressure during lumbar puncture. The objective of this review was to propose a standard of care for idiopathic normal pressure hydrocephalus based on an extensive literature review conducted on 459 articles published over the last 10 years. Those articles were obtained by searching for the keywords "normal pressure hydrocephalus" in the PubMed database and selecting all the articles published in English or in French. The diagnosis of idiopathic normal pressure hydrocephalus is difficult because of commonly associated diseases, such as Alzheimer's disease and microangiopathy. Brain MRI is one of the key procedures to assist in the diagnosis of idiopathic normal pressure hydrocephalus. Indeed, the presence of certain MRI features is highly predictive of a positive tap test and shunt responsiveness. Nevertheless, tap test remains the standard of care for diagnosis. Continuous cerebrospinal fluid drainage test is an alternative because it improves the sensitivity of diagnosis (but is a more complicated test to perform). Alzheimer's biomarkers dosing in the cerebrospinal fluid seems interesting when diagnosis remains uncertain: the presence of Alzheimer's profile of the biological markers is predictive of a lower response to the tap test.

Deformation of the corona radiata and internal capsule in normal pressure hydrocephalus.

BACKGROUND AND PURPOSE: The pathophysiology of the clinical manifestations in normal pressure hydrocephalus (NPH) remains obscure. Ventricular dilatation could generate forces on the paracentral fibers of the corona radiata (CR), hence interfering with their function and producing the classical clinical triad. The analysis of the regional displacement and deformation of the white matter bundles, forming the corona radiata and internal capsule, may clarify the relationship between ventricular dilatation and clinical manifestations in NPH. METHOD: An experimental finite element (FE) analysis was used to simulate ventricular dilatation in 3 dimensions (3D) and to calculate the strain and deformation on the surrounding parenchyma. Magnetic resonance diffusion tensor imaging-based white matter tractography was then applied to retrieve the displacement and deformation exerted along various fiber bundles of the corona radiata and internal capsule. Anterior and posterior limb displacements and elongations were compared using a paired samples t-test. RESULTS: The internal capsule, hence the corona radiata, of each cerebral hemisphere was segmented into anterior and posterior limbs. Mean displacements and elongations were calculated for each limb. Mean displacement was significantly larger in the anterior limb whereas mean deformation was larger in the posterior limb (P<0.01). CONCLUSION: The present simulation demonstrates that ventricular dilatation does not have a homogeneous effect on the periventricular fibre tracts, with a particular load on the corticospinal tract. The affection of this tract remains thereby a potential factor in the generation of the NPH gait disorders.