The predictive value of cerebrospinal fluid tap-test in normal pressure hydrocephalus

Abstract

-Eighteen patients (mean age of 66.5 years) with normal pressure hydrocephalus (NPH) underwent a ventriculo-peritoneal shunt surgery. Prior to operation a cerebrospinal fluid tap-test (CSF-TT) was performed with measurements of gait pattern and psychometric functions (memory, visuo-motor speed and visuo-constructive skills) before and after the removal of 50 ml CSFby lumbar puncture (LP). Fifteen patients improved and 3 were unchanged after surgery. Short duration of disease, gait disturbance preceding mental deterioration, wide temporal horns and small sulci on CT-scan were associated with good outcome after shunting. There was a good correlation between the results of CSF-TT and shunt surgery (X 2 = 4,11 ,phi = 0.48, p < 0.05), with gait test showing highest correlation (r = 0.99, p = 0.01). In conclusion, this version of CSF-TT proved to be an effective test to predict improvement after shunting in patients with NPH.KEY WORDS: normal pressure hydrocephalus, lumbar puncture, shunt surgery. Valor preditivo da punção liquórica ("tap test") na hidrocefalia de pressão normalRESUMO -Este estudo visa melhorar o valor diagnóstico e preditivo da punção liquórica ("tap test", TT) na hidrocefalia de pressão normal (HPN), particularmente nos casos em que os dados clinicos e de neuroimagem são inconclusivos e não permitem uma decisão cirúrgica segura. Dezoito pacientes (média de idade = 66.5 anos) com HPN foram submetidos a derivação ("shunt") ventriculo-peritoneal. O TT era realizado antes da cirurgia, consistindo na análise quantitativa da marcha e funções cognitivas (memória, rapidez perceptivo-motora e habilidade vísuo-construtiva) antes e depois da retirada de 50 ml de liquor via punção lombar. Quinze pacientes melhoraram e 3 permaneceram inalterados após a cirurgia. Curta duração da doença, distúrbio da marcha precedendo a deterioração mental, dilatação dos cornos temporais e apagamento (ou redução) dos sulcos corticais na tomografia computadorizada cerebral estavam associados a bons resultados pós-operatórios. Houve boa correlação entre os resultados do TT e os do "shunt" (X 2 = 4.11, phi = 0.48, p < 0.05), principalmente no teste da marcha (r = 0.99, p = 0.01). Esta versão do TT liquórico mostrou-se efetiva na prediçâo da melhora pós-operatória em pacientes com HPN. PALAVRAS-CHAVE: hidrocefalia de pressão normal, punção lombar, cirurgia de "shunt".Normal pressure hydrocephalus (NPH) is characterized by gait disturbance, progressive mental deterioration and urinary incontinence associated with enlargement of the ventricular system and normal cerebrospinal fluid (CSF) pressure. In typical cases, gait disturbance is the first and most salient sign, followed by forgetfullness or mild dementia, psychomotor retardation, apathy (with parkinsonian or depressive appearance) and, later on, urinary urgency or incontinence. These cases present minor diagnostic difficulties and they are the most likely to improve after shunting"" 11 .Differential diagnostic problems may, however, arise in some patients with atypical o...

Gait in normal pressure hydrocephalus: characteristics and effects of the CSF tap test

“…The patient's gait speed was considered reduced when the time spent to traverse 10 m was greater than 11 seconds (s). 21 Stolze et al 19 adopted a result greater than 20% as indicative of an improvement in gait velocity, while Damasceno et al 8 considered an improvement as any result greater than 5%. In our study, an intermediate value was adopted.…”

“…According to Japanese guidelines, the CSF-TT should be the first invasive test indicated 3 when NPH is suspected; it has a positive predictive value of between 72% and 100% and a low rate of complications 7 . Gait disturbance is considered the first and main symptom in NPH 8,9 . Close observance of any changes in gait is fundamental for early diagnosis of the disease, as this ensures a more favorable outcome for ventriculoperitoneal shunting 3 .…”

Guidelines for Management of Idiopathic Normal Pressure Hydrocephalus Guidelines From the Guidelines Committee of Idiopathic Normal Pressure Hydrocephalus, the Japanese Society of Normal Pressure Hydrocephalus

“…The improvement is sometimes noted immediately and usually within a few days. 22) Among various components of the gait, walking speed and stride are improved. 110B) Many studies show that the CSF tap test is useful for the prediction of shunt efficacy, 41,100,129) although a contradictory report is known.…”

Demência na população de pacientes do Hospital das Clínicas da Unicamp

“…Um tap-teste negativo não afastava HPN e seu objetivo era a obtenção de um índice mais seguro de prognóstico pós-operatório 16,17 .…”