Shunt-Responsive Idiopathic Normal Pressure Hydrocephalus Patient with Delayed Improvement after Tap Test

Abstract

The cerebrospinal fluid tap test (CSFTT) is recommended as a key step in the diagnosis of idiopathic normal pressure hydrocephalus (iNPH). While there is no generally accepted evaluation period for ascertaining a CSFTT responder, a substantial number of patients are evaluated only once within 24 hours of the test for improvement in gait. We report an iNPH patient with a favorable response to shunt surgery, who was first judged a non-responder by this standard, though subsequently was judged a responder in virtue of repetitively testing gait over 7 days. A 68-year-old man presented with progressive impairment of gait, balance, and memory. He was diagnosed as iNPH with an Evans' ratio of 0.35. At first hospitalization, change in gait was evaluated 24 hours after the CSFTT. He didn't show any significant improvement and was judged as a non-responder. However, at the second CSFTT, we repetitively tested his change in gait over seven days. Forty-eight hours after the tap, he showed significant improvement in his gait. He was then confirmed as a responder. After the operation, the gait difficulties were almost fully resolved. Further studies developing the standard procedure of the CSFTT should be considered.

Asymmetric and Upper Body Parkinsonism in Patients with Idiopathic Normal-Pressure Hydrocephalus

“… 11 12 During the follow-up period, results with the greatest improvement were used for comparisons between baseline and follow-up measurements. 11 12 Changes in cognition and urination were evaluated at one week. 13 Response to the CSFTT was defined using these three major scales.…”

Assessment of response to cerebrospinal fluid tap test for normal pressure hydrocephalus: how we do it

“…Owing to its potentially treatable nature, the selection of patients who may benefit from CSF shunt surgery is important 1. The most widely used prognostic test to assess candidacy for shunt placement is the CSF TT 2.…”

Hydrocéphalie à pression normale : mise au point et aspects pratiques

“…En effet, une des difficultés actuelles repose sur l'absence de consensus pour évaluer l'efficacité du drainage ou de la PL. Kang et al [34] ont souligné l'absence de données sur le délai auquel il faut réaliser l'évaluation de l'efficacité de la PL ou du drainage. D'après leur étude, on peut observer une efficacité différée de la PL soustractive.…”

“…D'après leur étude, on peut observer une efficacité différée de la PL soustractive. L'absence d'évaluation du patient au-delà de 24 heures après le test peut alors conduire à un faux-négatif [34,35]. En pratique clinique, la marche peut être évaluée par différents outils.…”