Chronic Daily Headache (CDH)
There is no consensus on the classification of daily and near daily headaches, often known as chronic daily headaches (CDH).
Chronic daily headache is an umbrella term that includes chronic migraine (CM), transformed migraine (TM), chronic tension – type headache (CTTH), or any headache that occurs on a daily or near daily basis. Most use CDH to refer to people with more than 15 headache days per month, not related to a structural or systemic illness. Others use daily headaches associated with medication overuse as chronic daily headaches or rebound headaches.
CHRONIC MIGRAINE OR TRANSFORMED MIGRAINE
Patients often have a history of episodic migraine. Most patients are women, 90% of whom have a history of migraine that begins in their teens or 20’s. Often the patients complain of a process of transformation characterized by headaches that have grown more frequent over months to years with the associated symptoms of photophobia, phonophobia, and nausea becoming less frequent over the years.
These patients often develop a pattern of daily or near daily headaches that resemble chronic tension-type headaches. That is, the pain is of mild to moderate intensity and not associated with photophobia, phonophobia or gastrointestinal features. Patients with chronic migraine or transformed migraine frequently have a family history of headaches, depression, anxiety, panic disorders, bipolar disorders, fibromyalgia, and/or alcohol abuse. Eighty percent of people with transformed migraine have depression. Medication overuse occurs in more than 80% of the patients with chronic daily headaches.
Although migraine transformation may develop as a result of medication overuse, transformation may occur without overuse.
CHRONIC TENSION-TYPE HEADACHES (CTTH)
Daily headaches may also develop in patients with a history of episodic tension-type headaches (ETTH). These headaches are more often diffuse or bilateral, frequently involving the posterior aspect of the head and neck.
DRUG OVERUSE AND REBOUND HEADACHES
Patients with frequent headaches often overuse analgesics, opiates, and ergotamines. In headache prone patients, medication overuse may produce drug induced “rebound headaches” that is accompanied by dependence on medication. Most patients with drug induced headaches have a history of episodic migraine that has converted to transformed migraine as a result of medication overusage.
Treatment of Chronic Daily Headaches
Patient management of the patient should take into account the treatment of any comorbid psychiatric disorders that the patient may exhibit.
Non-pharmacologic treatments may be necessary. Behavioral psychotherapy with patient education and lifestyle changes have to be instigated. Included in the lifestyle changes should be exercise and sleep pattern changes.
In addition, preventative or prophylactic treatments of the headache may be needed, including antidepressants, beta blockers, anticonvulsants, calcium channel blockers, either alone or in combination.
In cases of medication overuse or rebound headaches, the first treatment should be to discontinue the offending medication causing the chronic daily headache, or rebound headache, with adequate preparation for adverse events related to the withdrawal. Sometimes the medication being withdrawn has to be withdrawn gradually over a period of weeks. While the medication is being tapered, anti-inflammatory agents such as steroids or NSAIDS may be needed.
Chronic daily headache is a difficult disorder to treat and may necessitate referral to a neurologist or headache specialist. Many of the patients will change doctors frequently to obtain their drug of choice or alternative analgesics, rather than face their primary problem which may be psychiatric. Hospitalization is sometimes needed in cases of refractory chronic migraine or chronic daily headache.