Table 2.
Characteristics of unique studies (n = 19; one study had two co-principal investigators).
| Principal investigator training background | |
| Neurologist | 4 |
| Neurosurgeon | 10 |
| Other clinician | 2 |
| Non-clinician PhD | 4 |
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.