Table 1. Frequency of neurological disease subgroups in the studies contributing IPD.
| Neurological disease | Studies (N = 83) n (%) | Patients (N = 1979) n (%) |
|---|---|---|
| Encephalopathy | 61 (73.5) | 978 (49.4) |
| Encephalitis | 37 (44.6) | 92 (4.6) |
| Delirium | 32 (38.6) | 161 (8.1) |
| Coma | 13 (15.7) | 37 (1.9) |
| Encephalopathy–other | 40 (48.2) | 688 (34.8) |
| Insufficient information to define subtype | 0 (0) | 0 (0) |
| Cerebrovascular event | 55 (66.3) | 506 (25.6) |
| Ischaemic | 45 (54.2) | 308 (15.6) |
| Haemorrhagic | 29 (34.9) | 90 (4.5) |
| Vasculitis | 2 (2.4) | 2 (0.1) |
| Cerebrovascular event—other | 27 (32.5) | 106 (5.4) |
| Insufficient information to define subtype | 0 (0) | 0 (0) |
| Meningitis | 9 (10.8) | 15 (0.8) |
| Acute Disseminated Encephalomyelitis (ADEM) | 12 (14.5) | 14 (0.7) |
| Myelitis | 12 (14.5) | 13 (0.7) |
| Guillain-Barré syndrome | 30 (36.1) | 51 (2.6) |
| Radiculitis | 2 (2.4) | 4 (0.2) |
| Peripheral neuropathy | 24 (28.9) | 115 (5.8) |
| Myositis | 2 (2.4) | 2 (0.1) |
| Other neurological presentation | 31 (37.3) | 382 (19.3) |
| Smell or taste disturbance | 13 (15.7) | 247 (12.5) |
| Neuropsychiatric disorder | 2 (2.4) | 49 (2.5) |
| Myopathy | 5 (6) | 38 (1.9) |
| Autonomic dysfunction | 4 (4.8) | 27 (1.4) |
IPD = individual patient data
1. Individual counts of studies and patients exceed the total numbers in the database, as patients with more than one diagnosis may have been counted more than once within different neurological disease categories.
2. Encephalitis and encephalopathy (including delirium and coma) are pooled together.
3. If patients have more than one neurological disease diagnosis (e.g., encephalitis and myelitis), they are described here. For some diagnoses, these patients may not be captured within the disease categories above.
4. For inclusion, neurological disease had to be acute, i.e. that reached a clinical zenith or plateau less than 28 days from the onset of first neurological symptoms, We included all clinician-defined ‘other’ neurological presentations, including smell or taste disturbance, but we excluded common systemic core complaints of COVID-19 without further qualification, e.g. fatigue, asthenia, myalgia without clinical suspicion of myopathy/myositis, or headache without clinical suspicion of meningitis/cerebrovascular event.