Comparison of Noninvasive Measurements of Intracranial with Tap Test Results in Patients with Idiopathic Normal Pressure Hydrocephalus

Figures & data

Figure 1 Headband used on patients' heads for the Brain4care non-invasive ICP measuring device.

Figure 2 Band connected to Brain4care's non-invasive ICP measuring device.

Table 1 Clinical Background of Patients

		Positive (n=18)	Negative (n=07)	Inconclusive (n=03)
Age (Mean±SD)		73,2 ± 6,8	75,7 ± 6,7	70,7± 1,2
Gender female		4	3	1
Gender Male		14	4	2
Duration of symptoms (Months)		18,3±3,1	22,1±4,2	19,3±3,3
FIM (mean score)		85,7±29,5	54,1±37,4	63±34,4
iNPH Grading Scales, Mean / SD scores
TUG (sec)	Pre-tt	34,8±38,3	50±69,2	91,3±129,9
	Post-tt	29,2±28	45±33,2	140±242,5
DGI	Pre-tt	7,7±7,5	2,2±5,2	0±0
	Post-tt	8,2±7,9	2,5±7,6	0±0
BBT	Pre-tt	30±17,7	16,1±15,9	3,7±0
	Post-tt	34±17,8	19,2±19,5	0±0
JNS	Pre-tt	6,2±3,7	6,2±4,5	8,7±2,3
	Post-tt	4,7±3,8	4,7±4,9	5,7±5,5

Abbreviations: FIM, Functional Independence measure; TUG, Timed up and Go; DGI, Dynamic Gait Index; BBT, Berg Balance Test; JNS, Japanese NPH Scale; tt, tap test.

Table 2 P-value of the Variable P2/P1 in the Inconclusive Tap Test in Each Position

Group	P-value for the Wilcoxon Test
Dorsal decubitus	0.124
Standing	< 0.001
Sitting	< 0.001

Table 3 Statistics of the Variable P2/P1 in the Inconclusive Tap Test for Each Moment According to Position

Inconclusive Tap Test	Position
	Dorsal Decubitus		Standing		Sitting
Moment	Pre	Post	Pre	Post	Pre	Post
Average	1.131 [1.087; 1.175]	1.116 [1.018; 1.228]	0.965 [0.922; 1.002]	1.587 [1.527; 1.650]	1.145 [1.120; 1.171]	1.608 [1.586; 1.633]
Median	1.069 [1.043; 1.108]	0.943 [0.910; 1.148]	0.933 [0.899; 1.011]	1.560 [1.536; 1.619]	1.127 [1.105; 1.159]	1.606 [1.572; 1.635]
Standard Deviation	0.230 [0.191; 0.265]	0.313 [0.221; 0.386]	0.179 [0.130; 0.237]	0.140 [0.068; 0.200]	0.143 [0.114; 0.169]	0.065 [0.050; 0.077]
n	100	33	73	21	125	30

Figure 3 Comparison of the P2/P1 variable in relation to the inconclusive tap test before and after the puncture.

Table 4 P-value of the TTP Variable in the Inconclusive Tap Test in Each Position

Group	P-value for the Wilcoxon Test
Dorsal decubitus	< 0.001
Standing	< 0.001
Sitting	0.014

Table 5 Statistics of the TTP Variable in the Inconclusive Tap Test for Each Moment According to Position

Inconclusive Tap Test	Position
	Dorsal Decubitus		Standing		Sitting
Moment	Pre	Post	Pre	Post	Pre	Post
Average	0.224 [0.209; 0.240]	0.166 [0.140; 0.197]	0.206 [0.183; 0.233]	0.261 [0.250; 0.280]	0.242 [0.228; 0.258]	0.251 [0.247; 0.256]
Median	0.217 [0.170; 0.243]	0.117 [0.087; 0.264]	0.151 [0.141; 0.204]	0.251 [0.247; 0.254]	0.231 [0.221; 0.240]	0.250 [0.247; 0.253]
Standard Deviation	0.083 [0.074; 0.092]	0.088 [0.078; 0.093]	0.112 [0.068; 0.157]	0.039 [0.006; 0.069]	0.084 [0.061; 0.106]	0.012 [0.006; 0.017]
n	100	33	73	21	125	30

Figure 4 Comparison of the TTP variable in relation to the inconclusive tap test before and after the puncture.

Table 6 P-value of the Variable P2/P1 in the Negative Tap Test in Each Position

Group	P-value for the Wilcoxon Test
Dorsal decubitus	< 0.001
Standing	< 0.001
Sitting	< 0.001

Table 7 Statistics of the P2/P1 Variable in the Negative Tap Test for Each Moment According to Position

Negative Tap Test	Position
	Dorsal Decubitus		Standing		Sitting
Moment	Pre	Post	Pre	Post	Pre	Post
Average	0.963 [0.933; 0.998]	1.079 [1.048; 1.113]	0.911 [0.872; 0.952]	0.988 [0.957; 1.021]	1.178 [1.145; 1.213]	1.079 [1.038; 1.118]
Median	0.932 [0.904; 0.954]	1.063 [1.045; 1.091]	0.912 [0.876; 0.942]	0.985 [0.955; 1.032]	1.226 [1.160; 1.281]	1.072 [1.006; 1.127]
Standard Deviation	0.237 [0.212; 0.260]	0.232 [0.195; 0.265]	0.197 [0.152; 0.238]	0.207 [0.172; 0.239]	0.268 [0.242; 0.295]	0.274 [0.251; 0.296]
n	204	177	89	165	232	186

Figure 5 Comparison of the P2/P1 variable in relation to the negative tap test before and after the puncture.

Table 8 P-value of the TTP Variable in the Negative Tap Test in Each Position

Group	P-value for the Wilcoxon Test
Dorsal decubitus	< 0.001
Standing	< 0.001
Sitting	< 0.001

Table 9 Statistics of the TTP Variable in the Negative Tap Test for Each Moment According to Position

Negative Tap Test	Position
	Dorsal Decubitus		Standing		Sitting
Moment	Pre	Post	Pre	Post	Pre	Post
Average	0.189 [0.177; 0.201]	0.255 [0.241; 0.268]	0.182 [0.158; 0.206]	0.226 [0.210; 0.244]	0.251 [0.239; 0.261]	0.223 [0.210; 0.237]
Median	0.174 [0.166; 0.181]	0.235 [0.225; 0.264]	0.152 [0.133; 0.164]	0.213 [0.198; 0.220]	0.249 [0.234; 0.266]	0.228 [0.207; 0.246]
Standard Deviation	0.091 [0.074; 0.106]	0.090 [0.080; 0.099]	0.124 [0.084; 0.160]	0.110 [0.092; 0.126]	0.088 [0.080; 0.096]	0.097 [0.080; 0.113]
n	203	177	89	162	231	185

Figure 6 Comparison of the TTP variable in relation to the negative tap test before and after the puncture.

Table 10 P-value of the Variable P2/P1 in the Tap Test Positive in Each Position

Group	P-value for the Wilcoxon Test
Dorsal decubitus	< 0.001
Standing	< 0.001
Sitting	0.008

Table 11 Statistics of the P2/P1 Variable in the Positive Tap Test for Each Moment According to Position

Positive Tap Test	Position
	Dorsal decubitus		Standing		Sitting
Moment	Pre	Post	Pre	Post	Pre	Post
Average	1.181 [1.159; 1.202]	1.125 [1.106; 1.143]	1.166 [1.142; 1.190]	1.070 [1.052; 1.088]	1.137 [1.119; 1.156]	1.189 [1.169; 1.207]
Median	1.191 [1.178; 1.213]	1.156 [1.122; 1.184]	1.161 [1.133; 1.188]	1.038 [1.022; 1.057]	1.188 [1.167; 1.209]	1.204 [1.182; 1.231]
Standard Deviation	0.271 [0.247; 0.293]	0.243 [0.228; 0.259]	0.249 [0.232; 0.266]	0.215 [0.200; 0.231]	0.231 [0.216; 0.244]	0.231 [0.216; 0.246]
n	617	577	457	555	602	596

Figure 7 Comparison of the P2/P1 variable in relation to the positive tap test before and after the puncture.

Table 12 P-value of the Variable P2/P1 in the PositiveTap Test in Each Position

Group	P-value for the Wilcoxon Test
Dorsal decubitus	< 0.001
Standing	< 0.001
Sitting	0.968

Table 13 Statistics of the TTP Variable in the Positive Tap Test for Each Moment According to Position

Positive Tap Test	Position
	Dorsal decubitus		Standing		Sitting
Moment	Pre	Post	Pre	Post	Pre	Post
Average	0.259 [0.251; 0.267]	0.234 [0.227; 0.242]	0.236 [0.228; 0.245]	0.221 [0.212; 0. 230]	0.239 [0.232; 0.247]	0.239 [0.232; 0.246]
Median	0.243 [0.238; 0.250]	0.228 [0.223; 0.232]	0.224 [0.217; 0.229]	0.202 [0.193; 0.210]	0.228 [0.223; 0.235]	0.227 [0.222; 0.235]
Standard Deviation	0.102 [0.092; 0.112]	0.088 [0.082; 0.094]	0.093 [0.077; 0.110]	0.114 [0.093; 0.134]	0.089 [0.079; 0.100]	0.089 [0.077; 0.102]
n	613	577	457	549	599	594

Figure 8 Comparison of the TTP variable in relation to the positive tap test before and after the puncture.