Chronic Daily Headache

Headache Prevalence at 4-11 Years After Deployment-Related Traumatic Brain Injury in Veterans of Iraq and Afghanistan Wars and Comparison to Controls: A Matched Case-Controlled Study

OBJECTIVE

Evaluate the extent and severity of headache following deployment-related TBI (D-TBI) in veterans of the Iraq (OIF) and Afghanistan (OEF) wars over a follow-up period of 4-11 years with comparison to age, sex, race, and time of deployment matched controls.

BACKGROUND

TBI has been recognized as the "signature Injury" of the OEF/OIF campaigns occurring in 14-20% of deployed soldiers. Currently, there are very few data on the longer term follow-up of soldiers with D-TBI. This study deals with prevalence and severity of headache and headache burden at 4-11 years following D-TBI for OEF/OIF veterans with comparison to controls without D-TBI.

METHODS

This is a matched case controlled-study. All subjects were recruited from Operation New Dawn (OND), a voluntary program for OEF/OIF Veterans at the Oklahoma VAMC designed to assist with re-integrating into civilian life. On entry into OND a medical questionnaire was administered that included a brief screen for D-TBI, and those with a possible D-TBI were referred to a TBI clinic, For this study, the first 500 TBI clinic patients who were found to have had a D-TBI (TBIS) were matched by age, sex, race, and time of deployment to control subjects (CS), drawn from the 4411 OND program members with no D-TBI, creating a pool of 500 TBIS/CS pairs. From this pool, 55 pairs (11%) were randomly selected for this study. Data were collected from both TBIS and CS by telephone interview with questionnaires regarding the DTBI, headache, depression, and PTSD. TBI severity was measured by duration of loss of consciousness (LOC) as: [a] Very Mild (VMTBI, dazed only, no LOC), [b] Mild (MTBI, LOC 1-30 minutes), and [c] Moderate-Severe (MSTBI, LOC > 30 minutes). Intensity for individual headaches was measured by disability produced by the headache as: [a] Disabling (must be in bed), [b] Severe (50-90% decrease in activity), or [c] Mild-Moderate (>50% of usual activity possible). Statistical analysis employed Fisher's exact test and odds ratio.

RESULTS

The 55 TBIS/CS pairs were segregated by severity of TBI for the TBIS. For the TBIS there were no significant differences among these three subgroups as to mechanism producing the TBI (blast injury or direct head trauma). Comparing TBIS vs CS for phenotypic classification of headaches, for TBIS - 89% had migraine, 2% probable migraine, 9% had tension, and 0% had no headaches, while for CS - 36% had migraine, 15% probable migraine, 27% tension, and 22% no headache (P < .0001). Migraine with aura occurred in 38% of TBIS and 6% of CS (P < .0001). As to headache frequency, for TBIS - chronic daily headache (CDH) occurred in 44%, frequent headache in 33%, and infrequent or no headache in 23%, while for CS - CDH occurred in 7%, frequent headache in 13%, and infrequent or no headache in 80% (P < .0001). For TBIS, 54% had severe or disabling headache ≥2 days/week as opposed to only 16% of CS (OR 6.13 [2.5-14.9]). As to onset of most severe and frequent headaches, this occurred shortly after TBI in 89% of TBIS while only 27% of CS reported most severe headaches starting during deployment. There was no correlation of severity of headache problem with severity of TBI. Comparing TBIS at 4-7 vs 8-11 years after injury, there was no difference in frequency or severity of headache between these groups.

CONCLUSIONS

At 4-11 years after D-TBI for TBIS, or after deployment for CS, the TBIS as compared to CS suffered much more frequent and severe headaches. For TBIS, there was no relation of headache intensity or phenotype to severity or cause of the TBI, and the Headache Burden has not improved over time up to 11 years after D-TBI. The process initiated by the D-TBI that relates to the headache has a prolonged effect up to and beyond 11 years.

Update on chronic daily headache

OPINION STATEMENT

Chronic daily headache (CDH), defined as a primary headache occurring at least 15 days per month, is a problem of worldwide scope, which is seen in 3% to 5% of the population. Though it has been recognized since ancient times, only recently have there been attempts to define and classify it. CDH usually consists of a mixture of migraine and tension-type headaches (TTH), with the more severe headaches having migraine features and the less severe headaches fitting the definition of TTH. Some patients have pure chronic TTH and no migrainous features, and others have only migraine, but most have a mixed migraine-TTH pattern. New daily persistent headache, a CDH pattern that comes on over a few days, constitutes 9% to 10% of this group and is otherwise indistinguishable from CDH. Hemicrania continua (1% of CDH) appears to be unique in being absolutely responsive to indomethacin. Accurate diagnosis of CDH is critical to management, as all organic etiologies of chronic headache must be ruled out. Problems often associated with CDH and complicating the diagnosis are head injury or medication overuse (rebound-withdrawal headache). These accompanying issues must be recognized and treated appropriately in the management plan. Finally, psychiatric problems (unipolar depression, bipolar disease, generalized anxiety disorder, and obsessive/compulsive disorder) often accompany CDH, as they are comorbid with migraine. These conditions must be recognized and treated along with the headache itself for treatment to succeed fully. Treatment of CDH is multimodal. The cornerstone of therapy is the use of prophylactic antimigraine medications to prevent or modulate the next headache. Amitriptyline, topiramate, valproic acid, and gabapentin have all had class I studies showing effectiveness in reducing headache occurrence. Recent studies with botulinum toxin have also shown effectiveness in reducing the headache burden. Recognition and treatment of medication overuse headache (MOH) must be carried out as part of the initial approach. Use of acute symptomatic treatments such as triptans or NSAIDs must be undertaken with care, as frequent use of these agents can lead to MOH. Educating the patient about the condition and reasonable expectations for therapy is essential to success. Recognition and appropriate treatment of psychiatric disorders is likewise essential. Adjunctive nondrug therapies and lifestyle changes round out the requirements for a management plan. The chances for long-term remission or significant improvement are up to 65%. The patient and physician must understand that CDH is a long-term process with relapses and remissions. A strong and trusting relationship between patient and physician is a major asset in managing this condition.

Rebound-withdrawal headache (medication overuse headache)

Rebound-withdrawal headache (medication overuse headache) is a problem that affects 1% of the population or perhaps more. Work from many countries has shown this to be a worldwide problem. It appears that the rebound-withdrawal headache often occurs on the background of pre-existing migraine or tension headache and may assume the phenotype of chronic migraine or chronic tension-type headache. The key feature of this entity is that the patient initially uses a symptomatic treatment for headache with good result. Use of this medication may increase over time, but as the use increases to more than 10 to 15 days per month, headache frequency may also increase, reaching a point where metabolic processing of the medication and removal from the system triggers another headache. The patient then finds that as use of the medication increases, the frequency and intensity of the headaches also increases, and the overall headache worsens. Once this pattern is established, therapy requires removal of the medication in order for the rebounding process to be terminated. Preventative antimigraine medications will not work in the presence of the rebound phenomenon. Once the rebound-withdrawal headache is established, it is difficult to treat. After withdrawal of the medication, there is often a high relapse rate of using the medication again with redevelopment of the rebound-withdrawal headache. Even in patients who do not relapse to drug use, headache usually remains a major problem. Recognition and treatment of rebound headache are key factors in management of these patients. Perhaps more important in regard to this entity is recognizing its existence and preventing patients from entering a pattern of rebound withdrawal, which can be achieved by early attention to their use of analgesic narcotic or migraine-abortive medications. Overall, it is likely that this will continue to be an increasing worldwide problem in managing patients with headache.

The long-term prognosis of tension-type headache

Tension-type headache (TTH) is a very common problem that usually causes only minimal to moderate discomfort and little disability. If episodic TTH evolves to chronic TTH, then the morbidity in terms of discomfort, disability, and use of medication escalates dramatically. There are no long-term studies, but inferences can be made from population surveys. These suggest that episodic TTH occurs in 15% to 75% of the population, but 30% to 40% is the most common estimate. There is a modest increase in prevalence between the ages of 30 and 50 years and a decrease to 25% to 35% prevalence after the age of 60 years. TTH appears to remain a problem for most sufferers throughout their lives.

The tension headache component of chronic daily headache

Chronic daily headache (CDH) is an overarching term that includes multiple types of frequent primary headaches that are not trigeminal-autonomic cephalgias. The components of typical CDH can be divided into a more severe or "big" headache and a less severe or "little" headache. The big headaches tend to have features of migraine while the little headaches have features of tension-type headache (TTH). Whether this represents a spectrum or continuum or whether it is the superimposition of two unique headache entities is open to debate. For subjects with big and little headache, the concept that the TTH component is part of a spectrum seems likely. Subjects with only TTH and no migrainous component seem to represent a different entity, pure chronic TTH. These patients have a daily moderate headache that is poorly responsive to current therapies and appears to be a different TTH than the migraine tension type of CDH. The TTH component of CDH may represent multiple subdivisions of TTH.