This exclusion due to migrainous features could have adverse scientific, diagnostic, and treatment consequences.One proposal for reclassification of the criteria is from a study conducted on retrospective analysis of the records of 1348 patients regularly treated at the headache clinic of the Department of Neurology of Santa Casa de São Paulo, Brazil, and would be the following subdivision: NDPH with migraine features and without migraine features that would allow the inclusion of all individuals present who has a daily and persistent headache from the beginning.Another proposed reclassification of the criteria is from a study conducted as a retrospective chart review of patients seen at the Headache Center at Montefiore Medical Center in Bronx, New York, from September 2005 to April 2009. The revised criteria for NDPH definition does not exclude migraine features (NDPH-R), and three subdivisions were created and described based on prognosis: Persisting, remitting, and relapsing–remitting. Additionally, this revised criteria would not include parts C or D currently required by the ICHD diagnostic criteria for NDPH. Pathophysiology
The pathophysiology of NDPH is poorly understood. Research points to an immune-mediated, inflammatory process. Cervical joint hypermobility and defective internal jugular venous drainage have also been suggested as causes.In 1987, Vanast first suggested autoimmune disorder with a persistent viral trigger for CDH (now referred to as NDPH). Post-infectious origins have been approximated to make up anywhere between 30 and 80% of NDPH patients in different studies.
Often they are treated similar to migraines.A number of medications have been used including amitriptyline, gabapentin, pregabalin, propranolol, and topiramate. There are no prospective placebo controlled trials of preventive treatment. In those with migrainous features treatment may be similar to migraines.Opiates, or narcotics, tend to be avoided because of their side effects, including the development of medication overuse headaches and potential for dependency. NDPH is often associated with medication overuse. To avoid the development of medication overuse headaches, it is advised not to use pain relievers for more than nine days a month. NDPH, like other primary headaches, has been linked to comorbid psychiatric conditions, mainly mood and anxiety and panic disorders. The spectrum of anxiety disorders, particularly panic disorder, should be considered in NDPH patients presenting with psychiatric symptoms. Simultaneous treatment of both disorders may lead to good outcomes.Medications within the tetracycline family, mexiletine, corticosteroids and nerve blocks are being studied. Occipital nerve block have been reported to be helpful for some people. 23/71 people had undergone a nerve block for their severe headache. The NDPH-ICHD group responded to the nerve block much more often (88.9%) than the NDPH with migraine features (42.9% responded to nerve block). Prognosis
Most patients have persistent headaches, although about 15% will remit, and 8% will have a relapsing-remitting type. It is not infrequent for NDPH to be an intractable headache disorder that is unresponsive to standard headache therapies. References
External links

Evans, Randolph W.; Seifert, Tad D. (2011). "The Challenge of New Daily Persistent Headache".