Table 1.
Characteristics of patients with severe hyponatremia and neurological symptoms.
| Variables | All patients | Neuroimaging performed | No neuroimaging performed | P-Value |
|---|---|---|---|---|
| (n = 140) | (n = 95) | (n = 45) | ||
| Age, in years | 66 (55–79) | 73 (57–81) | 61 (51–76) | 0.013 |
| Gender (female in %) | 95 (67.9) | 70 (73.7) | 25 (55.5) | 0.032 |
| Vital Signs | ||||
| Systolic blood pressure, mmHg | 130 (116–146) | 140 (126–160) | 120 (109–133) | 0.007 |
| Diastolic blood pressure, mmHg | 80 (70–90) | 80 (70–90) | 75 (60–84) | 0.115 |
| Heart frequency/min | 80 (67–90) | 84 (72–91) | 80 (66–90) | 0.254 |
| Laboratory Parameters, mmol/l | ||||
| Plasma sodium | 120 (116–122) | 121 (117–122) | 119 (116–121) | 0.134 |
| Plasma osmolality | 246 (236–257) | 245 (236–256) | 248 (237–261) | 0.512 |
| Urine sodium | 47 (17–90) | 62 (20–95) | 37 (15–70) | 0.032 |
| Urine osmolality | 294 (200–381) | 321 (223–430) | 252 (170–344) | 0.017 |
| Etiology of Hyponatremia, in % | ||||
| Diuretics | 23.6 | 23.1 | 24.4 | 0.867 |
| SIAD | 31.4 | 29.4 | 33.3 | 0.956 |
| Cortisol deficiency | 5.7 | 4.2 | 8.9 | 0.120 |
| Hypovolemia | 20.0 | 17.9 | 26.7 | 0.232 |
| Hypervolemia | 6.4 | 2.1 | 15.5 | 0.002 |
| Primary Polydipsia | 7.9 | 8.4 | 6.7 | 0.880 |
| Others | 1.4 | 1.1 | 2.2 | 0.586 |
| Neurological symptoms resolved upon hyponatremia treatment | 124 (88.6) | 79/95 (83.2) | 45/45 (100.0) | 0.003 |
| pathological neuroimaging* | 1/17 (5.9) | |||
| non-pathological neuroimaging# | 78/78 (100) | |||
| Door-to-imaging-time, minutes | 123 (61–238) | |||
Median and interquartile range reported for continuous variables and frequency; percentage reported for categorical variables. Differences between patients with/without neuroimaging were calculated using the Mann-Whitney U test for continuous variables and the Chi-square test for categorical variables. Two-sided p values < 0.05 were considered statistically significant. SIAD, syndrome of inappropriate antidiuresis (SIAD). *Pathological neuroimaging: neuroimaging showed findings related to acute symptomatology, e.g., ischemic stroke. #Non-pathological neuroimaging: neuroimaging was unremarkable (no incidental/pathological finding) or showed incidental findings not related to acute symptomatology, e.g., general cerebral atrophy, old ischemic stroke.