This code system https://kip.rkkp.dk/fhir/CodeSystem/NIHSS9Language defines the following codes:
Code
Definition
0
No aphasia; normal.
1
Mild-to-moderate aphasia; some obvious loss of fluency or facility of comprehension, without significant limitation on ideas expressed or form of expression. Reduction of speech and/or comprehension, however, makes conversation about provided materials difficult or impossible. For example, in conversation about provided materials, examiner can identify picture or naming card content from patient's response.
2
Severe aphasia; all communication is through fragmentary expression; great need for inference, questioning, and guessing by the listener. Range of information that can be exchanged is limited; listener carries burden of communication. Examiner cannot identify materials provided from patient response.
3
Mute, global aphasia; no usable speech or auditory comprehension.