Neuromuscular diseases associated with Human Immunodeficiency Virus infection

HIV-associated nemaline myopathy manifesting as bent spine syndrome

HIV-associated myopathies include HIV-associated polymyositis, inclusion body myositis, diffuse infiltrative lymphocytosis syndrome and sporadic late-onset nemaline myopathy (HIV-NM). HIV-NM typically manifests as a painless, progressive proximal and axial muscle weakness with characteristic histological findings of intracytoplasmic rods, or nemaline bodies, seen in atrophic muscle fibres. HIV-NM presents prior to or shortly after initiation of antiretroviral therapy (ART) and is treated with intravenous immunoglobulin, glucocorticoids or immunosuppression. We present a case of HIV-NM in a patient with well-controlled HIV on decades-long ART with progressive bent spine syndrome, or camptocormia. This case highlights the importance of considering HIV-associated myopathies such as HIV-NM in patients with HIV who present with musculoskeletal complaints.

Polymyositis: A Case Report

Inflammatory myopathies are a group of diseases whose common pathway is immune-mediated muscle damage, one of which is polymyositis. The definition of polymyositis is controversial, with proponents advocating a definition based on immunohistochemical and histopathological findings in muscle biopsies, while other proponents advocate a definition based on clinical manifestations and histopathological findings. Polymyositis is a quite rare disease that is clinically characterized by progressive proximal muscle weakness with a symmetric distribution. Within the diagnostic approach, laboratory studies show elevation of sarcoplasmic enzymes; nerve conduction tests are performed, which may aid in distinguishing myopathic causes of weakness from neuropathic disorders; and muscle biopsy is considered the gold standard to diagnose inflammatory myopathy and to distinguish the subclasses. We report the case of a 61-year-old male patient who presented generalized symmetrical weakness, predominantly in the upper extremities, and dysphagia, whose laboratory studies, autoantibodies, and muscle biopsy were confirmatory of this entity.

Neuromuscular Complications of SARS-CoV-2 and Other Viral Infections

In this article we review complications to the peripheral nervous system that occur as a consequence of viral infections, with a special focus on complications of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We discuss neuromuscular complications in three broad categories; the direct consequences of viral infection, autoimmune neuromuscular disorders provoked by viral infections, and chronic neurodegenerative conditions which have been associated with viral infections. We also include discussion of neuromuscular disorders that are treated by immunomodulatory therapies, and how this affects patient susceptibility in the current context of the coronavirus disease 2019 (COVID-19) pandemic. COVID-19 is associated with direct consequences to the peripheral nervous system via presumed direct viral injury (dysgeusia/anosmia, myalgias/rhabdomyolysis, and potentially mononeuritis multiplex) and autoimmunity (Guillain Barré syndrome and variants). It has important implications for people receiving immunomodulatory therapies who may be at greater risk of severe outcomes from COVID-19. Thus far, chronic post-COVID syndromes (a.k.a: long COVID) also include possible involvement of the neuromuscular system. Whether we may observe neuromuscular degenerative conditions in the longer term will be an important question to monitor in future studies.

HIV-associated painful neuropathy: where are we?

BACKGROUND

After the advent of combination antiretroviral therapy, infection with the human immunodeficiency virus (HIV) ceased to be a devastating disease, but sensory neuropathy resulting from the permanence of the virus and the side effects of treatment have worsened the morbidities of these patients.

OBJECTIVE

To investigate the quality of life of 64 HIV-positive patients: 24 with painful neuropathy (case group) and 40 without painful neuropathy (control group). The impact of other factors on quality of life was also assessed.

METHODS

To assess painful neuropathy, the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) scale, Douleur Neuropathique 4 (DN4) questions and Neuropathy Disability Score (NDS) were used. The Short Form Health Survey (SF-36) scale was used to assess quality of life. Factors related or unrelated to HIV were obtained through the medical history and analysis on medical records.

RESULTS

The quality of life of patients with neuropathic pain was worse in six of the eight domains of the SF-36 scale. The number of clinical manifestations related to HIV, length of time with detectable viral load since diagnosis, length of time since the diagnosis of HIV infection and length of time of HAART use had a negative impact on quality of life. Higher levels of CD4, education and family income had a positive impact.

CONCLUSIONS

Painful neuropathy related to HIV is a factor that worsens the quality of life of patients infected with this virus and should be included in the clinical evaluation.

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.

Strength exercise for balance and gait in HIV-associated distal symmetrical polyneuropathy: A randomised controlled trial

BACKGROUND

HIV-associated peripheral neuropathy (PN) is a common neurological complication associated with HIV infection. Distal symmetrical polyneuropathy (DSPN) is the most commonly occurring type, which is associated with symptoms such as numbness, unsteady gait and, in some cases, muscle atrophy and weakness when myelinated nerve fibres are affected. If unmyelinated nerve fibres are affected, a painful neuropathy and autonomic symptoms may occur.

OBJECTIVES

This research study assessed the effects of a strength exercise intervention on balance impairment and gait disturbance amongst individuals living with HIV-associated DSPN.

METHOD

The study was a single-blinded, randomised controlled trial (RCT) with participants sourced from four HIV centres in Kano metropolis, Nigeria. The intervention was supervised and included progressive resistance exercise (PRE) (three 40-min sessions per week for 12 weeks) using a quadriceps bench (n = 44). The control group (CG) included the non-exercise group (n = 47). The two groups continued to receive routine care. Data were summarised and analysed using inferential statistics (SPSS version 20 program) with the alpha level set at < 0.05.

RESULTS

At 12 weeks, the results revealed significant improvement with regard to balance performance (p = 0.001) and walking ability (p = 0.001) in the training group. In contrast, no significant differences in balance (P = 0.677) or gait (P = 0.578) were observed in the CG.

CONCLUSION

The findings suggest that PRE is beneficial for balance impairment and gait disturbance caused by neuropathy in persons living with HIV and receiving antiretroviral drugs.

HIV Neuropathy-Associated Foot Drop, a Presenting Sign of HIV Infection, Resolving After Initiation of Antiretroviral Therapy: A Clinical Vignette

ABSTRACT

Peripheral neuropathy is one of the most frequent complaints in patients with HIV. Many complex syndromes exist, with the etiology being secondary to the disease process itself, antiretroviral medication, or immune reconstitution. However, isolated mononeuropathy is rare. In this case, we present a previously healthy man who complained of several months of worsening right foot drop that did not improve with physical therapy or lifestyle interventions. He had begun to use an solid ankle-foot orthotic on this right lower limb to minimize tripping and prevent falls. He had no other neuromuscular involvement or constitutional complaints. Nerve conduction study of the right lower limb showed decreased peak amplitude, prolonged distal latency, and decreased conduction velocity of the deep peroneal nerve. Electromyography revealed abnormal insertional activity and absent motor unit action potentials in both the right tibialis anterior and right extensor digitorum brevis muscles. Magnetic resonance imaging of the right lower limb was suggestive of acute/subacute denervation of the right tibialis anterior muscle. An extensive laboratory workup revealed active HIV infection with a significant viral load. Once the diagnosis was made, the patient was started on antiretroviral treatment. Six months later, his foot drop had entirely resolved, in association with significant improvements in viral load and CD4 count. He has since been ambulating without assistive devices and his HIV/AIDS disease process remains well controlled. This clinical vignette is the first, to our knowledge, to illustrate that an acute focal mononeuropathy causing foot drop and gait dysfunction in an otherwise healthy-appearing individual can be a heralding sign of HIV/AIDS. Furthermore, it also suggests that this functional deficit can be reversed with timely initiation of antiretroviral treatment. Early recognition, diagnosis, and treatment in this patient have not only led to an uncomplicated AIDS disease course but also restored his ability to ambulate with complete independence and improved his quality of life.

Concurrent Myotonic Dystrophy and Inflammatory Myopathy in a Patient with HIV/AIDS

Neuromuscular complications are common in patients with HIV/AIDS at any stage of the disease process. Myopathies can be secondary to antiretroviral therapy, HIV myositis itself, or other etiologies. Here, we present the case of a middle-aged male with HIV who presented with myalgias and was diagnosed with myotonic dystrophy and HIV-associated polymyositis after extensive workup including clinical history and physical exam, laboratory markers, electromyogram, and muscle biopsy. This case illustrates the importance of a comprehensive workup for myopathy in HIV/AIDS and the possibility of multiple concurrent conditions.

HIV-1 gp120 Promotes Lysosomal Exocytosis in Human Schwann Cells

Human immunodeficiency virus type 1 (HIV-1) associated neuropathy is the most common neurological complication of HIV-1, with debilitating pain affecting the quality of life. HIV-1 gp120 plays an important role in the pathogenesis of HIV neuropathy via direct neurotoxic effects or indirect pro-inflammatory responses. Studies have shown that gp120-induced release of mediators from Schwann cells induce CCR5-dependent DRG neurotoxicity, however, CCR5 antagonists failed to improve pain in HIV- infected individuals. Thus, there is an urgent need for a better understanding of neuropathic pain pathogenesis and developing effective therapeutic strategies. Because lysosomal exocytosis in Schwann cells is an indispensable process for regulating myelination and demyelination, we determined the extent to which gp120 affected lysosomal exocytosis in human Schwann cells. We demonstrated that gp120 promoted the movement of lysosomes toward plasma membranes, induced lysosomal exocytosis, and increased the release of ATP into the extracellular media. Mechanistically, we demonstrated lysosome de-acidification, and activation of P2X4 and VNUT to underlie gp120-induced lysosome exocytosis. Functionally, we demonstrated that gp120-induced lysosome exocytosis and release of ATP from Schwann cells leads to increases in intracellular calcium and generation of cytosolic reactive oxygen species in DRG neurons. Our results suggest that gp120-induced lysosome exocytosis and release of ATP from Schwann cells and DRG neurons contribute to the pathogenesis of HIV-1 associated neuropathy.