Significant research and investments are underway in neurological indications to get both early diagnosis and treatment. Significant irreversible brain damage can already be the case if the disease is detected when symptoms are advanced.
Early diagnosis is imperative in a broad range of infectious diseases to select the right treatment. This can be time-critical like antibiotic susceptibility testing to initiate a quick and effective decision for treatment. Pre-symptomatic earliness can be critical in less fast-developing diseases like tuberculosis.
With considerable success in oncology, companion diagnostics (CDx) are an integral part of precision medicine and are available since the 1980s. Genetic means are used to know if a medication works at all.