The impact of HIV infection on primary headache. Unexpected findings from retrospective, cross-sectional, and prospective analyses

Primary headache disorders among people living with HIV in Lusaka, Zambia

OBJECTIVE

We completed a cross-sectional survey study to determine headache prevalence and its association with HIV characteristics among people living with HIV (PLHIV) in Lusaka, Zambia.

BACKGROUND

Headaches are common but their association with HIV status is unknown.

METHODS

The HARDSHIP survey, a headache epidemiology questionnaire previously validated in Zambia, was distributed during a 3-month period to 3666 consecutive adult PLHIV attending routine clinic appointments at the Adult Infectious Diseases Centre at the University Teaching Hospital in Lusaka, Zambia. HIV disease characteristics were abstracted from their charts.

RESULTS

1015 (27.7%) participants responded to the survey. Adjusted for age, 64% reported having a headache within the last year unrelated to another illness. Among participants, 201 met criteria for migraine (20%), 259 for tension-type headache (26%), 18 for probable medication-overuse headache (2%), and 121 for undetermined headache (12%). Prevalence for tension-type headache was significantly higher than that of migraine (P < 0.001). After adjusting for age and sex, higher CD4 counts were associated with migraine. No other associations were observed between overall headache or headache type with HIV disease characteristics including CD4 count, viral load, antiretroviral regimen, and time since HIV diagnosis.

CONCLUSIONS

Headaches are highly prevalent among this cohort of PLHIV in Zambia. Optimizing headache treatment and integrating it into routine HIV care may improve quality of life for a substantial proportion of PLHIV in Zambia.

Progress in Pathological and Therapeutic Research of HIV-Related Neuropathic Pain

HIV-related neuropathic pain (HRNP) is a neurodegeneration that gradually develops during the long-term course of acquired immune deficiency syndrome (AIDS) and manifests as abnormal sock/sleeve-like symmetrical pain and nociceptive hyperalgesia in the extremities, which seriously reduces patient quality of life. To date, the pathogenesis of HRNP is not completely clear. There is a lack of effective clinical treatment for HRNP and it is becoming a challenge and hot spot for medical research. In this study, we conducted a systematic review of the progress of HRNP research in recent years including (1) the etiology, classification and clinical symptoms of HRNP, (2) the establishment of HRNP pathological models, (3) the pathological mechanisms underlying HRNP from three aspects: molecules, signaling pathways and cells, (4) the therapeutic strategies for HRNP, and (5) the limitations of recent HRNP research and the future research directions and prospects of HRNP. This detailed review provides new and systematic insight into the pathological mechanism of HRNP, which establishes a theoretical basis for the future exploitation of novel target drugs. HIV infection, antiretroviral therapy and opioid abuse contribute to the etiology of HRNP with symmetrical pain in both hands and feet, allodynia and hyperalgesia. The pathogenesis involves changes in cytokine expression, activation of signaling pathways and neuronal cell states. The therapy for HRNP should be patient-centered, integrating pharmacologic and nonpharmacologic treatments into multimodal intervention.

Advocacy for patients with headache disorders

Primary headache disorders are worldwide highly prevalent and burdensome and should be therefore considered as a global public health priority. However, too many patients with primary headache disorders still do not receive satisfying care. The most likely identified reasons for such a scenario - lack of public awareness, stigma, lack of trained professionals with inadequate healthcare systems and policies - are remediable. Despite the progresses that were made in headache advocacy, these efforts have not yielded substantial improvements in research funding or access to specialty care and even standards of care. The situation is more complex in Low and Middle Income Countries (LMICs) where headache advocacy is urgently needed given the magnitude of the difficulties that patients with primary headache disorders face in accessing care. The growing emergence of coordinated, collaborative, patient-centered advocacy efforts with improved patient-clinician partnership is an opportunity to enhance progress in advocacy for a satisfying life and optimal and equitable care for people with primary headache disorders. LMICs can benefit greatly from coordinating these efforts on a global scale. The recent organization of a training program on headache diagnosis and management for healthcare professionals in Africa is a concrete example.

From Initiation to Maintenance: HIV-1 Gp120-induced Neuropathic Pain Exhibits Different Molecular Mechanisms in the Mouse Spinal Cord Via Bioinformatics Analysis Based on RNA Sequencing

Human immunodeficiency virus (HIV), which causes acquired immunodeficiency syndrome (AIDS), remains one of the most diverse crucial health and development challenges around the world. People infected with HIV constitute a large patient population, and a significant number of them experience neuropathic pain. To study the key mechanisms that mediate HIV-induced neuropathic pain (HNP), we established an HNP mouse model via intrathecal injection of the HIV-1 envelope glycoprotein gp120. The L3~L5 spinal cord was isolated on postoperative days 1/12 (POD1/12), 1 (POD1), and 14 (POD14) for RNA sequencing to investigate the gene expression profiles of the initiation, transition, and maintenance stages of HNP. A total of 1682, 430, and 413 differentially expressed genes were obtained in POD1/12, POD1, and POD14, respectively, and their similarity was low. Bioinformatics analysis confirmed that POD1/12, POD1, and POD14 exhibited different biological processes and signaling pathways. Inflammation, oxidative damage, apoptosis, and inflammation-related signaling pathways were enriched on POD1/12. Inflammation, chemokine activity, and downstream signaling regulated by proinflammatory cytokines, such as the MTOR signaling pathway, were enriched on POD1, while downregulation of ion channel activity, mitochondrial damage, endocytosis, MAPK and neurotrophic signaling pathways developed on POD14. Additionally, we screened key genes and candidate genes, which were verified at the transcriptional and translational levels. Our results suggest that the initiation and maintenance of HNP are regulated by different molecular mechanisms. Therefore, our research may yield a fresh and deeper understanding of the mechanisms underlying HNP, providing accurate molecular targets for HNP therapy.

The Interplay Between Neuroinfections, the Immune System and Neurological Disorders: A Focus on Africa

Neurological disorders related to neuroinfections are highly prevalent in Sub-Saharan Africa (SSA), constituting a major cause of disability and economic burden for patients and society. These include epilepsy, dementia, motor neuron diseases, headache disorders, sleep disorders, and peripheral neuropathy. The highest prevalence of human immunodeficiency virus (HIV) is in SSA. Consequently, there is a high prevalence of neurological disorders associated with HIV infection such as HIV-associated neurocognitive disorders, motor disorders, chronic headaches, and peripheral neuropathy in the region. The pathogenesis of these neurological disorders involves the direct role of the virus, some antiretroviral treatments, and the dysregulated immune system. Furthermore, the high prevalence of epilepsy in SSA (mainly due to perinatal causes) is exacerbated by infections such as toxoplasmosis, neurocysticercosis, onchocerciasis, malaria, bacterial meningitis, tuberculosis, and the immune reactions they elicit. Sleep disorders are another common problem in the region and have been associated with infectious diseases such as human African trypanosomiasis and HIV and involve the activation of the immune system. While most headache disorders are due to benign primary headaches, some secondary headaches are caused by infections (meningitis, encephalitis, brain abscess). HIV and neurosyphilis, both common in SSA, can trigger long-standing immune activation in the central nervous system (CNS) potentially resulting in dementia. Despite the progress achieved in preventing diseases from the poliovirus and retroviruses, these microbes may cause motor neuron diseases in SSA. The immune mechanisms involved in these neurological disorders include increased cytokine levels, immune cells infiltration into the CNS, and autoantibodies. This review focuses on the major neurological disorders relevant to Africa and neuroinfections highly prevalent in SSA, describes the interplay between neuroinfections, immune system, neuroinflammation, and neurological disorders, and how understanding this can be exploited for the development of novel diagnostics and therapeutics for improved patient care.

The Role of the Spinal Wnt Signaling Pathway in HIV-Related Neuropathic Pain

Human immunodeficiency virus (HIV)-related neuropathic pain includes HIV-induced neuropathic pain (HNP) and antiretroviral therapy-induced neuropathic pain (ART-NP). A significant amount of evidence from the past few years has shown that the development of HIV-related neuropathic pain is closely related to the activation of the Wnt signaling pathway in the spinal cord. This review summarizes the function of the spinal Wnt signaling pathway in HIV-induced neuropathic pain, focusing on the role of the spinal Wnt signaling pathway in HNP, and provides a theoretical basis for further studies and the exploration of new target drugs.

Reactive Oxygen Species (ROS) are Critical for Morphine Exacerbation of HIV-1 gp120-Induced Pain

Many HIV patients develop chronic pain and use opioid-derived medicine as primary analgesics. Emerging clinical evidence suggests that chronic use of opioid analgesics paradoxically heightens pain states in patients. This side effect of opioid analgesics has a significant negative impact on clinical practice, but the underlying pathogenic mechanism remains elusive. Using a mouse model of HIV-associated pain, we simulated the development of morphine exacerbation on pain and investigated potential underlying cellular and molecular pathways. We found that repeated morphine treatment promoted astrocyte activation in the spinal dorsal horn (SDH) and up-regulation of pro-inflammatory cytokines IL-1β and TNF-α. Furthermore, we observed that morphine administration potentiated mitochondrial reactive oxygen species (ROS) in the SDH of the HIV pain model, especially on astrocytes. Systemic application of the ROS scavenger phenyl-N-t-butyl nitrone (PBN) not only blocked the enhancement of gp120-induced hyperalgesia by morphine but also astrocytic activation and cytokine up-regulation. These findings suggest a critical role of ROS in mediating the exacerbation of gp120-induced pain by morphine. Graphical abstract.

Neuro-Ophthalmic Manifestations of HIV Infection

Purpose: To review the broad spectrum of clinical neuro-ophthalmic presentations associated with human immunodeficiency virus (HIV) infection. Methods: Critical review of the literature regarding neuro-ophthalmic consequences of HIV infection and its sequelae. Results: Neuro-ophthalmological diseases are common in both asymptomatic HIV-positive patients and those who profound immunosuppression with acquired immune deficiency syndrome (AIDS). Neuro-ophthalmic manifestations of HIV infection can involve the afferent or efferent visual pathway. Common clinical presentations include headache, papilledema, chorioretinitis, optic nerve involvement, meningitis, and cranial nerve palsies. Other neuro-ophthalmic manifestations include involvement of the visual pathway in the brain producing visual field defects such as occur in progressive multifocal encephalopathy. Pupil abnormalities have also been reported. Discussion: Neuro-ophthalmic consequences of HIV are important to recognize as it is critical to identify underlying neoplastic or infectious diseases which could be amenable to treatment.

Headache prevalence and its functional impact among HIV-infected adults in rural Rakai District, Uganda

Headache is common, but its prevalence and impact in sub-Saharan Africa and especially in HIV+ individuals is relatively unknown. We sought to determine the prevalence and functional impact of headache among HIV-infected (HIV+) adults in a cross-sectional observational cohort study in rural Rakai District, Uganda. Participants completed a sociodemographic survey, depression screen, functional status assessments, and answered the headache screening question, "Do you have headaches?" Participants responding affirmatively were assessed with the ID Migraine tool for diagnosis of migraine and Headache Impact Test-6 to determine functional impact of headache. Characteristics of participants with and without headaches and with and without functional impairment were compared using t tests for continuous variables, chi-square tests for categorical variables, and multivariate logistic regression. Of 333 participants, 51% were males, mean age was 37 (SD 9) years, 94% were on antiretroviral therapy (ART) and mean CD4 count was 403 (SD 198) cells/μL. Headache prevalence was 28%. Among those reporting headache, 19% met criteria for migraine, 55% reported functional impairment, and 37% reported substantial or severe impact of headache. In multivariate analyses, female sex (odds ratio (OR) 2.58) and depression (OR 2.49) were associated with increased odds and ART (OR 0.33) with decreased odds of headache. Participants with substantial/severe functional impact were more likely to meet criteria for depression (32% vs 9%). In conclusion, headache prevalence in HIV+ rural Ugandans was lower than global averages but still affected more than one quarter of participants and was associated with significant functional impairment.

HIV and Headache: A Cross-Sectional Study

INTRODUCTION

The head and neck are the second most common locations for pain among HIV-positive individuals. Most studies were conducted among HIV patients at an advanced stage of the disease.

METHODS

This was a cross-sectional study. Patients with HIV and CD4+ T lymphocyte counts >500 were included. Semi-structured interview, the Headache Impact Test (HIT-6), and the Hospital Anxiety and Depression Scale were used.

RESULTS

Of the 119 cases included, 63% were men. The mean age was 35.5 ± 10.4 years. Among the patients, 103 (87%) had headaches, 53 (45%) had migraines, 50 (42%) had tension-type headaches, and 53 (45%) had substantial and severe impact of headaches. Eleven patients had headaches that started after they had been diagnosed with HIV. These patients had more migraines (72% vs 43%; P < 0.05), greater intensity (8 ± 2 vs 6 ± 2; P < 0.01), and impact (HIT-6: 60 ± 11 vs 51 ± 12; P = 0.02) of headaches compared to others HIV patients. There were no correlations between CD4 counts and the intensity, frequency, or impact of headaches.

CONCLUSIONS

HIV-positive patients had a high frequency of headaches, which had a great impact on patients' lives. The pattern most often found was migraine. There was no correlation between CD4 counts and the severity of headaches.

EXPRESS: Oligodendrocytes in HIV-associated pain pathogenesis

Background

Although the contributions of microglia and astrocytes to chronic pain pathogenesis have been a focal point of investigation in recent years, the potential role of oligodendrocytes, another major type of glial cells in the CNS that generates myelin, remains largely unknown.

Results

We report here that cell markers of the oligodendrocyte lineage, including NG2, PDGFRα, and Olig2, are significantly increased in the spinal dorsal horn of HIV patients who developed chronic pain. The levels of myelin proteins myelin basic protein and proteolipid protein are also aberrant in the spinal dorsal horn of “pain-positive” HIV patients. Similarly, the oligodendrocyte and myelin markers are up-regulated in the spinal dorsal horn of a mouse model of HIV-1 gp120-induced pain. Surprisingly, the expression of gp120-induced mechanical allodynia appears intact up to 4 h after myelin basic protein is knocked down or knocked out.

Conclusion

These findings suggest that oligodendrocytes are reactive during the pathogenesis of HIV-associated pain. However, interfering with myelination does not alter the induction of gp120-induced pain.

Interactions of Opioids and HIV Infection in the Pathogenesis of Chronic Pain

Over 50% of HIV-1/AIDS patients suffer chronic pain. Currently, opioids are the cornerstone medications for treating severe pain in these patients. Ironically, emerging clinical data indicates that repeated use of opiate pain medicines might in fact heighten the chronic pain states in HIV patients. Both laboratory-based and clinical studies strongly suggest that opioids exacerbate the detrimental effects of HIV-1 infection on the nervous system, both on neurons and glia. The combination of opioids and HIV-1infection may promote the damage of neurons, including those in the pain sensory and transmission pathway, by activating both caspase-dependent and caspase-independent pro-apoptotic pathways. In addition, the opiate-HIV-1 interaction may also cause widespread disturbance of glial function and elicit glial-derived pro-inflammatory responses that dysregulate neuronal function. The deregulation of neuron-glia cross-talk that occurs with the combination of HIV-1 and opioids appears to play an important role in the development of the pathological pain state. In this article, we wish to provide an overview of the potential molecular and cellular mechanisms by which opioids may interact with HIV-1 to cause neurological problems, especially in the context of HIV-associated pathological pain. Elucidating the underlying mechanisms will help researchers and clinicians to understand how chronic use of opioids for analgesia enhances HIV-associated pain. It will also assist in optimizing therapeutic approaches to prevent or minimize this significant side effect of opiate analgesics in pain management for HIV patients.

Gp120 in the pathogenesis of human immunodeficiency virus-associated pain

OBJECTIVE

Chronic pain is a common neurological comorbidity of human immunodeficiency virus (HIV)-1 infection, but the etiological cause remains elusive. The objective of this study was to identify the HIV-1 causal factor that critically contributes to the pathogenesis of HIV-associated pain.

METHODS

We first compared the levels of HIV-1 proteins in postmortem tissues of the spinal cord dorsal horn (SDH) from HIV-1/acquired immunodeficiency syndrome patients who developed chronic pain (pain-positive HIV-1 patients) and HIV-1 patients who did not develop chronic pain (pain-negative HIV-1 patients). Then we used the HIV-1 protein that was specifically increased in the pain-positive patients to generate mouse models. Finally, we performed comparative analyses on the pathological changes in the models and the HIV-1 patients.

RESULTS

We found that HIV-1 gp120 was significantly higher in pain-positive HIV-1 patients (vs pain-negative HIV-1 patients). This finding suggested that gp120 was a potential causal factor of the HIV-associated pain. To test this hypothesis, we used a mouse model generated by intrathecal injection of gp120 and compared the pathologies of the model and the pain-positive human HIV-1 patients. The results showed that the mouse model and pain-positive human HIV-1 patients developed extensive similarities in their pathological phenotypes, including pain behaviors, peripheral neuropathy, glial reactivation, synapse degeneration, and aberrant activation of pain-related signaling pathways in the SDH.

INTERPRETATION

Our findings suggest that gp120 may critically contribute to the pathogenesis of HIV-associated pain.

Clinical aspects of headache in HIV

BACKGROUND

Headaches are commonly seen in those patients with human immunodeficiency virus (HIV) and are the most common form of pain reported among HIV patients. There have been relatively few studies attempting to determine the rates and phenotypes of the headaches that occur in patients with HIV.

DISCUSSION

Patients with HIV are susceptible to a much broader array of secondary headache causes, sometimes with atypical manifestations due to a dampened inflammatory response. The investigation of a headache in the HIV patient should be thorough and focused on making sure that secondary and HIV-specific causes are either ruled out or treated if present.

CONCLUSION

An effective treatment plan should incorporate the use of appropriate pharmacological agents along with the integration of non-pharmacological therapies, such as relaxation and lifestyle regulation. When treating for headaches in patients with HIV, it is important to keep in mind comorbidities and other medications, especially combination antiretroviral therapy. For those with complicated headache histories, referral to a specialized headache center may be appropriate.

Wnt signaling in the pathogenesis of human HIV-associated pain syndromes

Many synaptic plasticity-related signaling pathways have been identified as important regulators of the pathogenesis of chronic pain in animal models. However, their relevance to human pathological pain is rarely confirmed rigorously. Recent studies suggest that Wnt signaling plays critical roles in synaptic plasticity and is dysregulated in the spinal cord dorsal horn (SDH) of different mouse pain models. In this study, we compared the protein levels of Wnt ligands, Wnt receptors and their downstream effector proteins in the SDH from non-HIV patients, HIV patients who developed chronic pain ('pain-positive' HIV patients), and HIV patients who did not develop chronic pain ('pain-negative' HIV patients). Our results indicate that many Wnt ligands and downstream effector proteins were specifically up-regulated in the SDH of 'pain-positive' HIV patients but not in the 'pain-negative' HIV patients. These findings describe an HIV pain-associated activation of Wnt signaling in the SDH of human patients. Given the established role of Wnt signaling in the regulation of synaptic plasticity, these results suggest that the activated Wnt signaling might contribute to the expression of the synaptic plasticity in the SDH during the pathogenesis of HIV-associated chronic pain.

Chronic-pain-associated astrocytic reaction in the spinal cord dorsal horn of human immunodeficiency virus-infected patients

Studies with animal models have suggested that reaction of glia, including microglia and astrocytes, critically contributes to the development and maintenance of chronic pain. However, the involvement of glial reaction in human chronic pain is unclear. We performed analyses to compare the glial reaction profiles in the spinal dorsal horn (SDH) from three cohorts of sex- and age-matched human postmortem tissues: (1) HIV-negative patients, (2) HIV-positive patients without chronic pain, and (3) HIV patients with chronic pain. Our results indicate that the expression levels of CD11b and Iba1, commonly used for labeling microglial cells, did not differ in the three patient groups. However, GFAP and S100β, often used for labeling astrocytes, were specifically upregulated in the SDH of the "pain-positive" HIV patients but not in the "pain-negative" HIV patients. In addition, proinflammatory cytokines, TNFα and IL-1β, were specifically increased in the SDH of pain-positive HIV patients. Furthermore, proteins in the MAPK signaling pathway, including pERK, pCREB and c-Fos, were also upregulated in the SDH of pain-positive HIV patients. Our findings suggest that reaction of astrocytes in the SDH may play a role during the maintenance phase of HIV-associated chronic pain.

Tension-type headache and systemic medical disorders

Tension-type headache (TTH) is the most common form of headache in the general population. Diagnosis of TTH is based merely on clinical features and on careful exclusion of all possible causes of headache. Most of the headaches that present in the context of medical disorders (e.g., hypothyroidism, sleep disorders, and hypertensive crisis) have clinical features overlapping with those of TTH; medical history and specific features of the systemic disorder are usually the clues to establish a correct diagnosis. Some medical disorders may worsen a preexisting TTH, and is also possible the comorbidity of TTH with psychiatric disorders and fibromyalgia.

Neurologic disease burden in treated HIV/AIDS predicts survival: a population-based study

BACKGROUND

Combination antiretroviral therapy (cART) has improved the survival of patients with HIV/AIDS but its impact remains uncertain on the changing prevalence and incidence of neurologic disorders with ensuing effects on mortality.

METHODS

The prevalence and incidence of neurologic disorders were examined in patients receiving active care in a regional HIV care program from 1998 to 2008. The mortality hazard ratio (HR) was calculated by Cox proportional hazard models with adjustment for demographic and clinical variables.

RESULTS

Of 1,651 HIV-infected patients assessed, 404 (24.5%) were identified as having one or more neurologic disorders, while 41% of AIDS-affected persons exhibited neurologic disease. Symptomatic distal sensory polyneuropathy (DSP, 10.0%) and HIV-associated neurocognitive disorder (HAND, 6.2%) represented the most prevalent disorders among 53 recognized neurologic disorders. Patients with at least one neurologic disorder exhibited higher mortality rates (17.6% vs 8.0%, p < 0.0001), particularly AIDS-related deaths (9.7% vs 3.2%, p < 0.0001), compared with those without neurologic disorders. The highest mortality HR was associated with opportunistic infections of CNS (HR 5.3, 95% confidence interval [CI] 2.5-11.2), followed by HAND (HR 3.1, 95% CI 1.8-5.3) and the presence of any neurologic disorder (HR 2.0, 95% CI 1.2-3.2). The risk of AIDS-related death with a neurologic disorder was increased by 13.3% per 100 cells/mm(3) decrement in blood CD4+ T-cell levels or by 39% per 10-fold increment in plasma viral load.

CONCLUSIONS

The burden and type of HIV-related neurologic disease have evolved over the past decade and despite the availability of cART, neurologic disorders occur frequently and predict an increased risk of death.

Headache attributed to infections nosography and differential diagnosis

Headache is a very frequent symptom of infection. It has many possible underlying mechanisms, of which two or more can coexist in a single patient. It can be caused by direct stimulation of intracranial pain-producing structures, as in the case of brain abscesses, by irritation of the pachy- and leptomeninges, as in cases of bacterial or viral meningitis, or by a state of intracranial hypertension, as seen in obstructive hydrocephalus. There is no doubt that headache is often the first or the predominant symptom of serious, sometimes life-threatening, infectious diseases; certainly, it is a condition frequently encountered in all epidemiological studies. Indeed, it is estimated that over 60% of people have, at some point in their lives, experienced headache during an infection. This evidence leads to the need for a systematic approach to headache secondary to infection. This chapter provides some elements on pain mechanisms in systemic and intracranial infections and on the possible role of antimicrobial agents in the genesis of headache. The first section provides a detailed "etiology-based" description of the International Classification of Headache Disorders, 2nd edition (ICHD-II: Headache Classification Subcommittee of the International Headache Society, 2004), while the second section presents a "symptom-based" algorithm applicable in the first diagnostic assessment, according to the headache features and to the most frequently associated clinical manifestations during infections of the central nervous system (CNS).

[Highly active antiretroviral therapy of neuro-AIDS. Side effects on the nervous system and interactions]

Highly active antiretroviral therapy (HAART) has increased the mean survival time in the AIDS stage to sometimes more than 10 years. Five different groups of antiretroviral medications are known, of which integrase inhibitors and CCR5 antagonists represent the newest and most modern substances. The long AIDS survival time implies that side effects and interactions become relatively more important and must be differentiated from the symptoms of HIV itself. Side effects of HAART concern the central and peripheral nervous system and the muscles. The neurotoxicity of the components in HAART varies considerably and depends on the substance itself. Knowledge of side effects and interactions of HAART with antiepileptics, antidepressants, and analgetics are essential for the treatment of patients with neuro-AIDS.

The differential diagnosis of chronic daily headaches: an algorithm-based approach

Chronic daily headaches (CDHs) refers to primary headaches that happen on at least 15 days per month, for 4 or more hours per day, for at least three consecutive months. The differential diagnosis of CDHs is challenging and should proceed in an orderly fashion. The approach begins with a search for "red flags" that suggest the possibility of a secondary headache. If secondary headaches that mimic CDHs are excluded, either on clinical grounds or through investigation, the next step is to classify the headaches based on the duration of attacks. If the attacks last less than 4 hours per day, a trigeminal autonomic cephalalgia (TAC) is likely. TACs include episodic and chronic cluster headache, episodic and chronic paroxysmal hemicrania, SUNCT, and hypnic headache. If the duration is > or =4 h, a CDH is likely and the differential diagnosis encompasses chronic migraine, chronic tension-type headache, new daily persistent headache and hemicrania continua. The clinical approach to diagnosing CDH is the scope of this review.

HIV/AIDS-related Pain as a Chronic Pain Condition: Implications of a Biopsychosocial Model for Comprehensive Assessment and Effective Management

This paper reviews the current literature focusing on pain in HIV/AIDS, including prevalence, pathophysiology, substance abuse, treatment issues, and psychosocial contributions. In light of the high prevalence of pain among individuals with HIV/AIDS, attention is paid to the negative psychosocial impacts of pain in this population and to psychosocial barriers to optimal HIV/AIDS-related pain treatment. The paper conceptualizes HIV/AIDS pain as chronic pain. Subsequently, a biopsychosocial model of chronic pain assessment and treatment is applied. A multidimensional framework is presented for appropriate assessment and treatment of HIV/AIDS patients with pain, and specific recommendations and guidelines are offered for assessment and multimodal treatment of HIV/AIDS-related pain informed by the model.