subjects in their 70s;and 82.0(IQR80.0–83.0)years(n=5)for subjects in their 80s. Comparisons of these groups revealed no significant differences in preoperative mRS scores between the 60s and 70s groups, but a significant difference of p=0.032 was seen between the 60s and 80s groups. Preoperative MMSE scores showed no statistically significant differences among the different age groups. Although mRS scores had improved in all age groups 2 years after LPS,a significant difference (p=0.031) was seen in the 60s and 80s groups (Fig. 6). An evaluation 2 years later revealed that the group of patients who had under gone shunt treatment in their 80s showed only slight improvements in cognitive function (Table 4).
4.Discussion
We previously reported that measurement of sAPPα in the CSF is useful for differential diagnosis of iNPH[19]. CSF amyloid precursor protein (sAPP, sAPPαand sAPPβ) levels in iNPH patients are significantly
lower than in normal control subjects of all age groups. In this study, the levels of these APP CSF biomarkers did not change within 2 years after the shunt. An analysis of iNPH shunt treatment and cognitive function showed that the group whose MMSE scores did not improve 2 years after surgery tended to have had low MMSE scores before surgery. CSF biomarkers p-tau, Aβ1–38/Aβ1–42 ratio, and Aβ1–42/p-tau ratio [10,13] were prognostic predictors of cognitive function (Table 3). Moreover, analysis of the Aβ1–38/Aβ1–42 ratio revealed that, while the “Improved Cognitive group” showed a tendency to shift from Aβ1–42 to Aβ1–38 2 years after surgery, the “Poor Cognitive group” showed similar results before and 2 years after the same. Concentrations of Aβ1–38 and Aβ1–42 increased after shunt treatment, perhaps due to a change in γ-secretase activity [12]. In age-specific analyses of the 60s,70s,and 80s groups,following the iNPH diagnostic guidelines and performing shunting treatment, all age groups attained improved mRS scores; however, younger age at the