The Kuopio idiopathic normal pressure hydrocephalus protocol: initial outcome of 175 patients

Abstract

Background The Kuopio University Hospital (KUH) idiopathic normal pressure hydrocephalus (iNPH) cerebrospinal fluid (CSF) shunting protocol is described together with the initial outcomes of 175 patients with probable iNPH treated according to this protocol from a defined population. Our secondary aim was to display the variety of differential diagnoses referred to the KUH iNPH outpatient clinic from 2010 until 2017. Methods Patients were divided into four groups according to the prognostic tests: tap test (positive or negative) and infusion test (positive or negative). The short-term outcome was compared between groups. The 3-month outcome following shunt surgery was assessed by measuring gait speed improvement, using a 12-point iNPH grading scale (iNPHGS) and the 15D instrument. Results From 341 patients suspected of iNPH, 88 patients were excluded from further research mostly due to deviation from the protocol’s gait assessment guidelines. Hence 253 patients with suspected iNPH were included in the study, 177/253 (70%) of whom were treated with a CSF shunt. A favorable clinical outcome following surgery was observed in 79–93% of patients depending on the prognostic group. A moderate association (Cramer’s V = 0.32) was found between the gait speed improvement rate and the prognostic group (X 2 , p = 0.003). Patients with a positive tap test had the highest gait speed improvement rate (75%). In addition, an improvement in walking speed was observed in 4/11 patients who had both a negative tap test and a negative infusion test. Other outcome measures did not differ between the prognostic groups. Conditions other than iNPH were found in 25% of the patients referred to iNPH outpatient clinic, with the most prevalent being Alzheimer’s disease. Conclusions Our results emphasize the importance of a systematic diagnostic and prognostic workup especially in cases with an atypical presentation of iNPH. Additional diagnostic testing may be required, but should not delay adequate care. Active surgical treatment is recommended in patients with a high clinical probability of iNPH. Other neurological conditions contributed to most of the non iNPH diagnoses. Electronic supplementary material The online version of this article (10.1186/s12987-019-0142-9) contains supplementary material, which is available to authorized users.

Secondary deterioration in patients with normal pressure hydrocephalus after ventriculoperitoneal shunt placement: a proposed algorithm of treatment

“…But he also concluded in the study, that VP-shunting may remain a reasonable option for short-term management of patients with neurodegenerative disorders [38]. Junkkari et al [37] points out that additional tests should not delay treatment.…”

“…Thus, it is essential to rule out meticulously the disease before VPS placement. Junkkari et al [37] highlighted in the recently published study, that an accurate identification of NPH has a huge impact on the results of our treatment. Consequently, a systemic diagnostic workup becomes indispensable [37].…”

“…Junkkari et al [37] highlighted in the recently published study, that an accurate identification of NPH has a huge impact on the results of our treatment. Consequently, a systemic diagnostic workup becomes indispensable [37]. Espay et al [38] goes one step further and postulates that the NPH should be a diagnosis of exclusion that requires careful consideration of neurodegenerative disorders [38].…”

Diabetic phenotype in mouse and humans with β-amyloid pathology reduces the number of microglia around β-amyloid plaques

“…Patients characterized in Table 1, were diagnosed with probable iNPH [78] and selected for CSF shunt surgery according to the previously described protocol [37] in Department of Neurosurgery Kuopio University Hospital from 2012 until 2017. Diagnostic right frontal cortical brain biopsy was taken during shunt surgery and occurrence of β -amyloid and/or phospho-Tau was evaluated by neuropathologist as described previously [58].…”

Corticospinal excitability in idiopathic normal pressure hydrocephalus: a transcranial magnetic stimulation study

“…Depending on patient selection, less than 2/3 improve their functional status while some patients experience only a subjective benefit. This emphasizes the need to identify biomarkers for shunt surgery responders in iNPH [4,5].…”