Normal-pressure hydrocephalus: A critical review / Hidrocefalia de pressão normal: uma revisão crítica

ABSTRACT. Normal-pressure hydrocephalus (NPH) is a potentially reversible syndrome characterized by enlarged cerebral ventricles (ventriculomegaly), cognitive impairment, gait apraxia and urinary incontinence. A critical review of the concept, pathophysiology, diagnosis, and treatment of both idiopathic and secondary NPH was conducted. We searched Medline and PubMed databases from January 2012 to December 2018 using the keywords "normal-pressure hydrocephalus" / "idiopathic normal-pressure hydrocephalus" / "secondary normal-pressure hydrocephalus" / "NPH" / "ventriculoperitoneal shunt". The initial search produced 341 hits. After careful selection, a total of 54 articles were chosen and additional relevant studies were included during the process of writing this article. NPH is an important cause of potentially reversible dementia, frequent falls and recurrent urinary infections in the elderly. The clinical and imaging features of NPH may be incomplete or nonspecific, posing a diagnostic challenge for medical doctors and often requiring expert assessment to minimize unsuccessful surgical treatments. Recent advances resulting from the use of non-invasive MRI methods for quantifying cerebral blood flow, in particular arterial spin-labeling (ASL), and the frequent association of NPH and obstructive sleep apnea (OSA), offer new avenues to understand and treat NPH.

RESUMO. A hidrocefalia de pressão normal (HPN) é uma síndrome potencialmente reversível marcada por ventrículos cerebrais alargados (ventriculomegalia), declínio cognitivo, apraxia da marcha e incontinência urinária. Revisar criticamente o conceito, a fisiopatologia, o diagnóstico e o tratamento da HPN idiopática e secundária. Os autores acessaram as bases de dados Medline e Pubmed entre janeiro de 2012 e dezembro de 2018, utilizando as palavras-chave "normal-pressure hydrocephalus" / "idiopathic normal-pressure hydrocephalus" / "secondary normal-pressure hydrocephalus" / "NPH" / "ventriculoperitoneal shunt". A busca inicial resultou em 341 artigos. Após cuidadosa seleção, 54 estudos foram escolhidos e pesquisas adicionais foram incluídas durante o processo de elaboração do manuscrito. A HPN é uma importante causa de demência potencialmente reversível, quedas frequentes e infecção urinária recorrente em idosos. As características clínicas e de imagem da HPN podem ser incompletas ou inespecíficas, de modo que este se torna um diagnóstico difícil para médicos. Não raro uma avaliação por especialista é necessária, visando minimizar tratamentos cirúrgicos ineficazes. Avanços recentes advindos do uso não invasivo de ressonância magnética para quantificação do fluxo sanguíneo cerebral, em particular arterial spin-labeling (ASL), assim como a usual associação entre HPN e apneia obstrutiva do sono representam novos meios de entender e de tratar a HPN.

Different Outcomes in Two Cases of Idiopathic Normal Pressure Hydrocephalus in the Elderly Living Alone Diagnosed by Internists during Hospitalization / 日本プライマリ・ケア連合学会誌

Idiopathic normal pressure hydrocephalus (iNPH) is a disorder observed in elderly patients causing gait disturbance, urinary incontinence and cognitive impairment. Due to the rapidly aging society, the number of patients with iNPH continues to increase yearly. However, iNPH is often overlooked because of its insidious and variable presentation. In the primary care setting, iNPH can be coincidentally discovered by neuroimaging findings, including disproportionately enlarged subarachnoid space hydrocephalus (DESH). We report two cases of iNPH in the elderly living alone that had different outcomes depending upon the availability of neurosurgery specialists. It is essential for primary care physicians to consult neurosurgeons without delay because prompt diagnosis and treatment can improve the patient's quality of life and prolong their duration of living at home.

Neuroimaging in normal pressure hydrocephalus / Neuroimagem na hidrocefalia de pressão normal

ABSTRACT Normal pressure hydrocephalus (NPH) is a syndrome characterized by the triad of gait disturbance, mental deterioration and urinary incontinence, associated with ventriculomegaly and normal cerebrospinal fluid (CSF) pressure. The clinical presentation (triad) may be atypical or incomplete, or mimicked by other diseases, hence the need for supplementary tests, particularly to predict postsurgical outcome, such as CSF tap-tests and computed tomography (CT) or magnetic resonance imaging (MRI). The CSF tap-test, especially the 3 to 5 days continuous external lumbar drainage of at least 150 ml/day, is the only procedure that simulates the effect of definitive shunt surgery, with high sensitivity (50-100%) and high positive predictive value (80-100%). According to international guidelines, the following are CT or MRI signs decisive for NPH diagnosis and selection of shunt-responsive patients: ventricular enlargement disproportionate to cerebral atrophy (Evans index >0.3), and associated ballooning of frontal horns; periventricular hyperintensities; corpus callosum thinning and elevation, with callosal angle between 40º and 90º; widening of temporal horns not fully explained by hippocampal atrophy; and aqueductal or fourth ventricular flow void; enlarged Sylvian fissures and basal cistern, and narrowing of sulci and subarachnoid spaces over the high convexity and midline surface of the brain. On the other hand, other imaging methods such as radionuclide cisternography, SPECT, PET, and also DTI or resting-state functional MRI, although suitable for NPH diagnosis, do not yet provide improved accuracy for identifying shunt-responsive cases.

RESUMO. A hidrocefalia de pressão normal (HPN) é uma síndrome caracterizada por alteração da marcha, transtorno mental-cognitivo e incontinência urinária, associados a ventriculomegalia e pressão liquórica normal. A apresentação clínica (tríade) pode ser atípica ou incompleta, ou pode ser mimetizada por outras doenças, daí a necessidade de testes suplementares, principalmente para predição do resultado cirúrgico, tais como teste da punção lombar e tomografia computadorizada (TC) ou ressonância magnética (MR) de crânio. O teste da punção liquórica lombar, especialmente a drenagem externa contínua (≥150 ml/dia, por 3 a 5 dias), é o único método que simula o efeito da cirurgia, com alta sensibilidade (50-100%) e alto valor preditivo positivo (80-100%). Consensos internacionais consideram os seguintes achados da TC ou RM como decisivos para o diagnóstico de HPN e a seleção de pacientes bons respondedores à cirurgia: dilatação ventricular desproporcional em relação ao grau de atrofia cerebral (índice de Evans >0.3), associada a arredondamento dos cornos frontais; hipersinal difuso periventricular; adelgaçamento e elevação do corpo caloso, com ângulo do corpo caloso entre 40º e 90º; dilatação dos cornos temporais não explicada por atrofia hipocampal; sinal do fluxo vazio no aqueduto e quarto ventrículo; dilatação das fissuras Sylvianas e cisterna basal, e estreitamento ou apagamento dos sulcos e espaços subaracnoides nas superfícies cerebrais da convexidade alta e linha média. Por outro lado, a cisternografia isotópica, SPECT, PET, e mesmo técnicas mais modernas de RM funcional e tensor de difusão, embora compatíveis com o diagnóstico de HPN, não melhoram a acurácia na identificação de casos responsivos à cirurgia.

Assessment of fetal lung maturity by multiple testing with shake test, tap test and OD 650.

Assessment of fetal lung maturity is of great importance in obstetric practice to plan for the future care and proper time for termination of pregnancy. At present, there are many methods used for screening for fetal lung maturity. A good screening test should be simple, easy to perform, rapid, inexpensive and be sensitive and specific. This study was a comparative study of fetal lung maturity assessment by using multiple testing: shake test, tap test and OD 650. These three tests were performed simultaneously and interpreted within 10-15 minutes. The results were compared with lecithin and sphingomyelin ratio (L/S ratio) which was used as the gold standard. L/S ratio > 2 was interpreted as “mature” in this study. Aminotic fluid samples wee obtained from women with uncomplicated pregnancies who underwent amniocentesis for fetal lung maturity testing with consent. All samples were uncontaminated by blood or meconium. The results, analysed from 185 samples studied, showed that the shake test, tap test and OD 650 gave a sensitivity of 79.3%, 87.1%, 76.6% and a specificity of 60.0%, 45.0% and 54.2% respectively, which were not statistically different (P>0.05, Cochran’s test). Screening for maturity using two or more tests gave a sensitivity of 82.7% and a specificity of 55.8% which were also not statistically different when compared with each test. In conclusion, shake test, tap test or OD 650 can be easily used as a simple and sensitive screening method for fetal lung maturity. Multiple testing, performing all three tests simultaneously, did not increase the sensitivity or specificity of the test and is not recommended. The choice of test at a screening method is therefore up to individual preference of depends on facilities available.