Table 2.
Mean volume (mL) and ratio (%) of brain parenchyma and CSF.
| Idiopathic NPH (85) | Adult-onset congenital NPH (7) | Secondary NPH (17) | |
|---|---|---|---|
| Intracranial volume | 1,516 ± 150 | 1,621 ± 128 | 1,474 ± 140* |
| Brain parenchyma | 1,093 (72.1%)* | 1,092 (67.3%) | 1,176 (80.0%)* |
| Total CSF | 423* (27.9%)* | 529 (32.7%) | 297* (20.1%)* |
| Total ventricles | 162* (10.7%)* | 275 (17.0%) | 121* (8.2%)* |
| Bilateral ventricles | 150* (9.8%)* | 259 (16.0%) | 112* (7.6%)* |
| Third ventricle | 5.1* (0.3%)* | 10.1 (0.6%) | 5.2* (0.3%)* |
| Fourth ventricle | 3.7 (0.2%) | 5.5 (0.3%) | 4.4 (0.3%) |
| Total subarachnoid spaces | 262 (17.2%) | 254 (15.7%) | 176* (11.9%) |
| Convexity subarachnoid space | 75.8* (5.0%)* | 128 (7.9%) | 75.7* (5.1%)* |
| Basal cistern and Sylvian fissure | 122* (8.0%)* | 62.0 (3.8%) | 54.8 (3.7%) |
| Posterior fossa | 64.4 (4.2%) | 63.7 (3.9%) | 45.5* (3.1%)* |
*Statistically significant difference from the adult-onset congenital NPH value (P < 0.05).