Table 1.
Characteristics and Cerebrospinal Fluid (CSF) Findings in Patients Positive or Negative for Anti-S/S1 Immunoglobulin G in CSF. Neurological Symptoms and Respiratory Support at some stage in the disease course Before Lumbar Puncture
| Finding | Patients by CSF Anti-S/S1 IgG Results, No. (%)a | |
|---|---|---|
| Positive (n = 9) | Negative (n = 7) | |
| Time since symptom onset, median (IQR), d | 30 (21–74) | 43 (4–124) |
| Age, median (IQR), y | 64 (48–73) | 43 (36–54) |
| Male sex, no. (%) | 5 (56) | 3 (43) |
| Severity of COVID-19 | ||
| Mild | 0 (0) | 3 (43) |
| Moderate | 3 (33) | 1 (14) |
| Severe | 1 (11) | 2 (29) |
| Critical | 5 (56) | 1 (14) |
| ICU care | 7 (78) | 3 (33) |
| Duration of ICU stay, median (IQR), d | 10 (2–27) | 0 (0–2) |
| GCS ≤12 | 6 (67) | 1 (14) |
| High-flow oxygen | 2 (22) | 3 (43) |
| Invasive ventilation | 6 (67) | 1 (14) |
| Altered mental status | 8 (89) | 5 (71) |
| Cranial nerve symptoms | 2 (22) | 0 (0) |
| Anosmia or ageusia | 3 (33) | 3 (43) |
| Vertigo | 3 (33) | 4 (57) |
| Headache | 3 (33) | 7 (100) |
| Peripheral paralysis | 2 (22) | 1 (14) |
| Central paralysis | 3 (33) | 3 (43) |
| Sensory symptoms | 1 (11) | 3 (43) |
| Pleocytosis | 0 (0) | 2 (29) |
| CSF-serum albumin ratio,b median, (IQR), ×103 | 7.4 (6.5–12.5) | 4.5 (3.8–5.3) |
| IgG index,b median (IQR) | 0.44 (0.42–0.49) | 0.42 (0.38–0.44) |
| OCBs | 1 (11) | 1 (14)c |
| Elevated IgG in CSFd,e | 3 (33) | 0 (0) |
| Elevated T-taud | 5 (56) | 1 (14)f |
| Elevated NfLd | 7 (78) | 0 (0)g |
| Elevated GFApd | 2 (22) | 0 (0)g |
Abbreviations: COVID-19, coronavirus disease 2019; CSF, cerebrospinal fluid; GCS, Glasgow Coma Scale; GFAp, glial fibrillary acidic protein; ICU, intensive care unit; IgG, immunoglobulin G; IQR, interquartile range; NfL, neurofilament light chain; OCB, oligoclonal bands; T-tau, total tau protein.
aData represent no. (%) of patients unless otherwise specified.
bThe CSF-serum albumin ratio was calculated as CSF albumin/serum albumin, a measure of blood-brain barrier function (reference ranges: age 15–45 years, <6.8; age >45 years, <10.2), while the IgG index was calculated as (CSF IgG/serum IgG), as a measure of intrathecal IgG production (reference range: age >15 years, <0.63).
cUnique for CSF.
dIncreases in the T-tau, NfL, and GFAp biomarkers were determined in relation to age-related normal reference limits. The reference ranges for these assays were as follows: T-tau, <360 ng/L for age <50 and <479 ng/L for age >50 years; NfL, <560, <890, and <1850 ng/L for ages 30–40, 40–60, and >60 years, respectively; and GFAp, <750 and <1250 ng/L for ages 20–60 and >60 years, respectively.
eNonspecific increase in CSF IgG.
fData missing for 3 individuals.
gData missing for 1 individual.