In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Extrapyramidal symptoms were evaluated using the Simpson - Angus Scale ( SAS ) , the Barnes Akathisia Rating Scale ( BARS ) , adverse event reports and anticholinergic drug usage .
### Output Text:
Extrapyramidal symptoms were evaluated using the Simpson - Angus Scale ( SAS ) , the Barnes Akathisia Rating Scale ( BARS ) , adverse event reports and anticholinergic drug usage . 