Manejo da hidrocefalia de pressão normal: um update
Atualizações sobre conceito, diagnóstico e prognóstico por Romain Manet, Neurocirurgião da Universidade de Lyon
Management of Normal Pressure Hydrocephalus, an up-date.
Romain Manet, MD*
Evolution of the concept through five decades
Described as early as 1950 (1), chronic hydrocephalus without raised intracranial pressure (ICP) in adult patients was named “normal pressure hydrocephalus” (NPH) by Hakim and Adams in 1965 (2). During the next five decades, publications dedicated to NPH progressively grew until a strong raised during the recent years: number of publications referenced on Pubmed in 2016 was 2 fold higher than in 2010 and 10 fold higher than in 2000.
Pathophysiological mechanisms of NPH remain misunderstood but many have been proposed such as obstruction of CSF flow pathways, brain compliance impairment and hyper-pulsatility, alteration of CSF biomarkers turn-over. The recent description of the glymphatic system in animal (3) then in humans (4) is probably one of the most relevant breakthrough.
A difficult diagnosis
NPH is suspected in adult patients (generally > 65 years old) with the characteristic Hakim’s triad: gait and balance disturbance, sphincter incontinence and cognitive impairment, associated with ventriculomegaly on routine CT or MRI scans. However, these clinical and radiological findings are unspecific and can be interpreted as being part of other neurodegenerative conditions such Alzheimer disease. For this reason, NPH is probably widely under-diagnosed (5).
Development of clinical assessment tools and new radiological exams (phase contrast MRI, MR tractography, MR elastography, glymphatic MRI…) progressively improved the evaluation of NPH patients and the selection of the best candidates for shunt surgery, formalized by international guidelines (6).
In addition, supplemental tests can improve selection of patient and results of shunt surgery. Among them, 30-50mL tap test (TT) is the most used and has a good positive predictive value (75-92%) but low sensitivity (26–61%) ; thus a negative TT shouldn’t exclude patients for surgery (7). In opposite, prolonged external lumbar drainage (300 - 500 ml over 2-3 days) shows high positive predictive value (80–100%) and high sensitivity (50–100%) but is associated with significant morbidity: up to 3,3% infections and 0,2% mortality (8). Lumbar infusion tests represent a good alternative, with a similar morbidity and positive predictive value than TT but a higher sensitivity (57–100%) (7). Intracranial pressure monitoring can be valuable in the diagnosis of complex situations (9).
Treatment and prognosis
In addition to this improving selection, progress in surgical techniques (VP shunt, VA shunt, LP shunt, and endoscopic third ventriculostomy in specific situations) and devices (adjustable valves, MRI compatible valves) improved overall prognosis of NPH. Recent publications reported 82 % improvement following shunt surgery, a low overall complications and mortality rates, respectively 8.2 % and 0.2 % (10), and a subsequent improvement in quality of life (11).
NPH Seminar, Sao Paulo, November 2017
A NPH seminar held in Sao Paulo on 7th November 2017 with the support of Canada Trade ® and Sophysa®, chaired by Dr. Ronald de Lucena (president of the Brazilian Society of Neurosurgery) with a panel of four experts : Dr. Marco Prist (Professor da Disciplina de Neurocirurgia na Faculdade de Medicina do ABC), Dr. Dr.Valter Cescato (Chefe do de Neuroendocrinologia da Neurocirurgia Funcional do HCFMUSP e Chef do Setor de Neurocirurgia do Hospital IGESP), Dr. Wellingson Paiva (Professor Livre Docente na Faculdade de Medicina da USP) and Dr. Romain Manet (University Hospital of Lyon, FRANCE).
After an introductive state of the art presentation dedicated to NPH, report of clinical cases was the occasion of an interactive discussion dedicated to NPH management: difficulties and specific diagnosis modalities (clinical and radiological evaluation, tap test, infusion tests), treatment (non-adjustable and adjustable valves, VP/VA/LP shunts) and prognosis (assessment and follow-up modalities).
- Wertheimer P, Dechaume J. [Hydrocephalus in the adult]. Rev Neurol (Paris) 1950;82(5):335-76.
- Adams RD, Fisher CM, Hakim S, Ojemann RG, Sweet WH. Symptomatic occult hydrocephalus with « normal » cerebrospinal-fluid pressure.a treatable syndrome. N Engl J Med. 1965;273:117-26.
- Iliff JJ, Wang M, Liao Y, Plogg BA, Peng W, Gundersen GA, et al. A paravascular pathway facilitates CSF flow through the brain parenchyma and the clearance of interstitial solutes, including amyloid β. Sci Transl Med. 2012;4(147):147ra111
- Nedergaard M. Neuroscience. Garbage truck of the brain. Science. 2013;340(6140):1529-30.
- Martín-Láez R, Caballero-Arzapalo H, López-Menéndez LÁ, Arango-Lasprilla JC, Vázquez-Barquero A. Epidemiology of Idiopathic Normal Pressure Hydrocephalus: A Systematic Review of the Literature. World Neurosurg. 2015;84(6):2002-9.
- INPH Guidelines Study Group. Guidelines For the Diagnosis and Management of Idiopathic Normal-Pressure Hydrocephalus. Neurosurgery. 2005;57(Suppl 3).
- Marmarou A, Bergsneider M, Klinge P, Relkin N, Black PM. The value of supplemental prognostic tests for the preoperative assessment of idiopathic normal-pressure hydrocephalus. Neurosurgery. 2005;57(3 Suppl):S17‑28.
- Greenberg BM, Williams MA. Infectious complications of temporary spinal catheter insertion for diagnosis of adult hydrocephalus and idiopathic intracranial hypertension. Neurosurgery. 2008;62(2):431-435.
- Czosnyka Z, Czosnyka M. Long-term monitoring of intracranial pressure in normal pressure hydrocephalus and other CSF disorders. Acta Neurochir (Wien). 2017;159(10):1979‑80.
- Toma AK, Papadopoulos MC, Stapleton S, Kitchen ND, Watkins LD. Systematic review of the outcome of shunt surgery in idiopathic normal-pressure hydrocephalus. Acta Neurochir (Wien). 2013;155(10):1977‑80.
- Stein SC, Burnett MG, Sonnad SS. Shunts in normal-pressure hydrocephalus: do we place too many or too few? J Neurosurg. 2006;105(6):815‑22.
Hôpital Neurologique et Neurochirurgical Wertheimer
Centre Hospitalier Universitaire de Lyon
59 Bd Pinel, 69677, Lyon Cedex, France
Tel : +33472357495
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