G44 - Other headache syndromes
G44.1 - Vascular headache, not elsewhere classified
Excludes 2:
-cluster headache G44.0)
-complicated headache syndromes G44.5-)
-drug-induced headache G44.4-)
-migraine (G43.-)
-other specified headache syndromes G44.8-)
-post-traumatic headache G44.3-)
-tension-type headache G44.2-)