ICD-10-CM > G00-G99 > G89-G99 > G99 > G99.8 G99.8 Other specified disorders of nervous system in diseases classified elsewhere Billable/Specific Copy Code Copy Description Code First underlying disorder, such as:amyloidosis (E85.-)avitaminosis (E56.-) Type 1 Excludes nervous system involvement in:cysticercosis (B69.0)rubella (B06.0-)syphilis (A52.1-)