Diagnostic modelling in neurology based on the temporal course of symptom onset
| Time course | Onset time | Probable aetiology |
|---|---|---|
| Hyperacute | Seconds | • Vascular eg stroke
• Epileptic seizure |
| Acute | Minutes | • Vascular
• Toxic-metabolic • Compressive lesions • Vasovagal syncope |
| Subacute | Over 72 hours | • Toxic-metabolic eg B12 deficiency
• Inflammation (Infective or immune-mediated) • Closed space pathology eg subdural haemorrhage • Infiltrative or neoplastic process • Myasthenia gravis • Medical decompensation of previous neurological insult (can occur with or without delirium) |
| Remitting –Relapsing | Back to baseline within a day | • transient ischemic attack (usually recovered in <1 hour)
• Periodic disorders (migraine with aura, epilepsy, ocular myasthenia) |
| Remitting –Relapsing | Returning to baseline but taking days–weeks | • Multiple sclerosis
• Toxic-metabolic eg drug toxicity |
| Stuttering | Usually acute or subacute in onset but patient developing new deficits rather than progression of existing ones | • Stroke-like syndromes due to vasculitis/endocarditis
• Autoimmune encephalitis • Myasthenia and atypical forms of Guillain-Barré syndrome |
| Chronic, progressive | Weeks | • Guillain-Barré syndrome
• Malignancy |
| Chronic, progressive | Months | • Degenerative diseases eg Alzheimer's disease, motor neurone disease
• Malignancy |
Common diseases may present in an atypical manner