Sanjay Prakash

The prevalence of headache may be related with the latitude: a possible role of Vitamin D insufficiency?

According to recent observations, there is worldwide vitamin D insufficiency (VDI) in various populations. A number of observations suggest a link between low serum levels of vitamin D and higher incidence of chronic pain. A few case reports have shown a beneficial effect of vitamin D therapy in patients with headache disorders. Serum vitamin D level shows a strong correlation with the latitude. Here, we review the literature to delineate a relation of prevalence rate of headaches with the latitude. We noted a significant relation between the prevalence of both tension-type headache and migraine with the latitude. There was a tendency for headache prevalence to increase with increasing latitude. The relation was more obvious for the lifetime prevalence for both migraine and tension-type headache. One year prevalence for migraine was also higher at higher latitude. There were limited studies on the seasonal variation of headache disorders. However, available data indicate increased frequency of headache attacks in autumn–winter and least attacks in summer. This profile of headache matches with the seasonal variations of serum vitamin D levels. The presence of vitamin D receptor, 1α-hydroxylase and vitamin D-binding protein in the hypothalamus further suggest a role of vitamin D deficiency in the generation of head pain.

Chronic Tension‐Type Headache With Vitamin D Deficiency: Casual or Causal Association?

The prevalence of tension‐type headache and vitamin D deficiency are both very high in the general population. The inter‐relations between the two have not been explored in the literature. We report 8 patients with chronic tension‐type headache and vitamin D deficiency (osteomalacia). All the patients responded poorly to conventional therapy for tension headache. The headache and osteomalacia of each of the 8 patients responded to vitamin D and calcium supplementation. The improvement in the headache was much earlier than the improvements in the symptom complex of osteomalacia. We also speculate on the possible mechanisms for headache in the patients with vitamin D deficiency.

Secondary hemicrania continua: Case reports and a literature review.

Hemicrania continua (HC) is an indomethacin responsive primary headache disorder. Secondary or symptomatic HC is associated with another neurological or non-neurological disease. We report three patients with secondary HC. We also review the literature to identify the clinical predictors of an underlying disease entity. Intracranial structural lesion, head and neck vessel pathology, and carcinoma lung should be suspected in every patient. The factors that may suggest a secondary pathology are: elderly age, male sex, smoking habit, constitutional symptoms, symptoms related to respiratory system, frequent and short-lived exacerbation, nocturnal exacerbation, HC evolving from remitting form, recent neck and/or head trauma, miosis, elevated ESR, and fading effect of indomethacin. We recommend MRI brain in all the patients presenting with HC or HC like headache. Angiography and CT chest are two other investigations that may be supplemented in patients with high risk for head/neck vessel pathology and carcinoma lung.

A proposal for revision of hemicrania continua diagnostic criteria based on critical analysis of 62 patients

Background: Misdiagnosis of hemicrania continua (HC) is common. It is diagnosed according to the criteria of the International Headache Society (IHS), but in clinical practice, these criteria seem too restrictive and many hemicrania continua-like headaches remain unclassified. Subjects and methods: We retrospectively studied the patients fulfilling the IHS criteria for HC. In addition, we identified a group of patients who met all criteria minus cranial autonomic features (HC-A) or minus a complete response to indomethacin (HC-I). We compared epidemiological profiles, clinical features and therapeutic responses to drug(s) between the groups. In addition, we reviewed the literature and critically analysed the diagnostic criteria for HC. Results: Sixty-two patients with a putative diagnosis of HC were identified. Thirty patients (48%) fulfilled the IHS criteria for HC. Thirty-two (52%) patients failed to satisfy one of the features of HC. Thirteen patients (21%) did not show any evidence of cranial autonomic feature during the episodes of the exacerbations (HC-A). Another 19 patients (31%) did not show a complete response to indomethacin (HC-I). Epidemiological and clinical features of all three groups were compared. None of the differences were statistically significant. In review of the literature, we noted that cranial autonomic features, a sense of restlessness/agitation during exacerbations, and response to indomethacin (marked to complete) are the specific features of HC. However, these features may not all be present in all cases. Conclusion: Present diagnostic criteria are too restrictive. We suggest adding the site of pain in the criteria, as described for trigeminal autonomic cephalalgias. Cranial autonomic features, a sense of restlessness during exacerbations, and marked to complete response to indomethacin are three characteristics features of HC. We suggest that the presence of any two may be sufficient to diagnose HC.

Is there need to search for alternatives to indomethacin for hemicrania continua? Case reports and a review

Hemicrania continua (HC) is a daily continuous unilateral headache of moderate intensity with super imposed exacerbations of more severe pain accompanied by migrainous and cranial autonomic features. Response to indomethacin is an essential feature in the IHS diagnostic criteria. However, indomethacin is associated with a number of side effects. HC is a life long condition, and skipping of a single dose of indomethacin usually leads to reappearance of headache. Various drugs have been tried as alternatives to indomethacin in the patients intolerant to indomethacin. We report two cases of HC responsive to topiramate and review the available alternatives for the patients of HC. We also discuss the side effects of indomethacin in the various headache disorders and other painful conditions, and suggest the need for trial of other drugs for the patients of HC.

Phantom headache: pain-memory-emotion hypothesis for chronic daily headache?

The neurobiology of chronic pain, including chronic daily headache (CDH) is not completely understood. “Pain memory” hypothesis is one of the mechanisms for phantom limb pain. We reviewed the literature to delineate a relation of “pain memory” for the development of CDH. There is a direct relation of pain to memory. Patients with poor memory have less chance to develop “pain memory”, hence less possibility to develop chronic pain. Progressive memory impairment may lead to decline in headache prevalence. A similar relation of pain is also noted with emotional or psychiatric symptoms. Literature review suggests that there is marked overlap in the neural network of pain to that of memory and emotions. We speculate that pain, memory, and emotions are interrelated in triangular pattern, and each of these three is related to other two in bidirectional pattern, i.e., stimulation of one of these will stimulate other symptoms/networks and vice versa (triangular theory for chronic pain). Longstanding or recurrent noxious stimuli will strengthen this interrelation, and this may be responsible for chronicity of pain. Reduction of both chronic pain and psychological symptoms by cognitive behavioral therapy or psychological interventions further suggests a bidirectional interrelation between pain and emotion. Longitudinal studies are warranted on the prevalence of headache and other painful conditions in patients with progressive memory impairment to delineate the relation of pain to memory. Interrelation of headache to emotional symptoms should also be explored.

Hemicrania continua unresponsive or partially responsive to indomethacin: does it exist? A diagnostic and therapeutic dilemma

Hemicrania continua (HC) is a primary headache disorder characterized by a continuous, unilateral headache that varies in intensity, waxing and waning without disappearing completely. Ipsilateral cranial autonomic features and response to indomethacin are essential features for the diagnosis of HC. We hereby, describe three patients with the clinical phenotypes of HC in whom response to indomethacin was either incomplete or not sustained. We also review the literature especially for the presence of indomethacin response and ipsilateral cranial autonomic features.

Interrelationships between chronic tension-type headache, musculoskeletal pain, and vitamin D deficiency: Is osteomalacia responsible for both headache and musculoskeletal pain?

Background: Headache, musculoskeletal symptoms, and vitamin D deficiency are common in the general population. However, the interrelations between these three have not been delineated in the literature. Materials and Methods: We retrospectively studied a consecutive series of patients who were diagnosed as having chronic tension-type headache (CTTH) and were subjected to the estimation of serum vitamin D levels. The subjects were divided into two groups according to serum 25(OH) D levels as normal (>20 ng/ml) or vitamin D deficient (<20 ng/ml). Results: We identified 71 such patients. Fifty-two patients (73%) had low serum 25(OH) D (<20 ng/dl). Eighty-three percent patients reported musculoskeletal pain. Fifty-two percent patients fulfilled the American College of Rheumatology criteria for chronic widespread pain. About 50% patients fulfilled the criteria for biochemical osteomalacia. Low serum 25(OH) D level (<20 ng/dl) was significantly associated with headache, musculoskeletal pain, and osteomalacia. Discussion: These suggest that both chronic musculoskeletal pain and chronic headache may be related to vitamin D deficiency. Musculoskeletal pain associated with vitamin D deficiency is usually explained by osteomalacia of bones. Therefore, we speculate a possibility of osteomalacia of the skull for the generation of headache (osteomalacic cephalalgia?). It further suggests that both musculoskeletal pain and headaches may be the part of the same disease spectrum in a subset of patients with vitamin D deficiency (or osteomalacia), and vitamin D deficiency may be an important cause of secondary CTTH.

Coexistence of cluster headache and paroxysmal hemicrania: does it exist? A case report and literature review

The coexistence of different types of trigeminal autonomic cephalalgias is a rare phenomenon. The two different types of headache may occur either at two different periods or simultaneously at the same time. We report a 22-year-old male who had cluster headache (CH) and chronic paroxysmal hemicrania (CPH) since the onset of symptoms. Both types of headache responded to indomethacin. Review of the literature suggests that simultaneous occurrence of CH and CPH in a patient may be both over and under reported.

Hemicrania Continua Responsive to Intravenous Methyl Prednisolone

Hemicrania continua (HC) is a strictly unilateral, continuous primary headache disorder with periodic exacerbations, usually accompanied by cranial autonomic disturbances. Exquisite and persistent effect of indomethacin is a fundamental property of HC. We report 2 patients of HC in which attacks were successfully eliminated by repeated infusion of methyl prednisolone.