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Related Subjects: |AIDS (HIV) Neurological Disease |AIDS (HIV) Respiratory disease |AIDS Dementia Complex (HIV) |AIDS HIV Infection |AIDS(HIV) Gastrointestinal Disease |Acute Retroviral Syndrome (HIV) |HIV and Post-Exposure Prophylaxis (PEP) |HIV and Pre-exposure prophylaxis |HIV associated nephropathy (HIVAN) |HIV disease Assessment

AIDS (HIV) Neurological Diseases

Individuals with AIDS (Acquired Immunodeficiency Syndrome) are at an increased risk of developing neurological diseases due to the immunosuppressive effects of HIV. These conditions can affect the central and peripheral nervous systems, leading to a range of neurological symptoms and complications. Below is an overview of common neurological diseases associated with AIDS.

HIV-Associated Neurocognitive Disorders (HAND)

• Asymptomatic Neurocognitive Impairment (ANI):
  • Mild neurocognitive impairment without significant impact on daily functioning.
  • Detected through neuropsychological testing.
• Mild Neurocognitive Disorder (MND):
  • Mild impairment in cognitive functions with noticeable impact on daily activities.
  • Symptoms: Difficulty with concentration, memory, and decision-making.
• HIV-Associated Dementia (HAD):
  • Severe cognitive impairment significantly affecting daily functioning.
  • Symptoms: Profound memory loss, motor dysfunction, and behavioral changes.

CNS Lymphoma and AIDS

• About
  • CNS lymphoma is a serious complication in individuals with AIDS
  • It is a type of Non-Hodgkin lymphoma in the brain, spinal cord, or meninges.
  • Associated with a significantly weakened immune system due to HIV infection.
• Causes and Risk Factors
  • Immunosuppression: Severe immunosuppression due to HIV infection is the primary risk factor. Typically occurs in individuals with a CD4 count of less than 50 cells/µL.
  • Epstein-Barr Virus (EBV): EBV infection is commonly associated with CNS lymphoma in AIDS patients. EBV DNA is often detected in the tumour cells.
• Symptoms
  • Headache, Seizures, Focal neurological deficits (e.g., weakness, numbness)
  • Cognitive and behavioral changes
  • Vision problems, Nausea and vomiting, Altered mental status
• Diagnosis
  • Imaging Studies:
    • Magnetic Resonance Imaging (MRI) is the preferred imaging modality.
    • Computed Tomography (CT) scan may also be used.
    • Characteristic findings include single or multiple lesions, often with ring enhancement.
  • Biopsy:
    • Stereotactic brain biopsy is used to obtain a definitive diagnosis.
    • Histopathological examination confirms the presence of lymphoma cells.
  • CSF Analysis:
    • Analysis of cerebrospinal fluid (CSF) for malignant cells and EBV DNA.
• Treatment
  • High-Dose Methotrexate:
    • Mainstay of treatment for CNS lymphoma.
    • Often combined with other chaemotherapeutic agents.
  • Antiretroviral Therapy (ART):
    • Essential for improving immune function and overall prognosis.
    • Helps to control HIV replication and increase CD4 counts.
  • Radiation Therapy:
    • Whole-brain radiation therapy may be used in combination with chaemotherapy.
  • Corticosteroids:
    • Used to reduce edema and alleviate symptoms.
    • Should be used with caution as they can affect biopsy results.
  • Intrathecal Chemotherapy:
    • Delivery of chaemotherapy directly into the CSF for better penetration into the CNS.
• Prognosis
  • Poor prognosis compared to non-HIV-associated CNS lymphoma. Survival rates have improved with the use of ART and more effective chaemotherapy regimens.
  • Early diagnosis and prompt treatment are crucial for better outcomes. Ongoing research and clinical trials are focused on improving treatment strategies and survival rates.

Opportunistic Infections

• Toxoplasmosis:
  • Caused by Toxoplasma gondii, leading to encephalitis in immunocompromised individuals.
  • Source: From uncooked meats, cat faeces.
  • Symptoms: Headache, confusion, fever, seizures, and focal neurological deficits.
  • Imaging: usually several ring-enhancing lesions with oedema on scanning in the cortex and deep brain - basal ganglia and thalamus and is the cause of over 90% of focal CNS lesions.
  • Investigations: Check IgG serology which is 90% positive.
  • Treatment: Combination therapy with pyrimethamine, sulfadiazine, and folinic acid.
• Cryptococcal Meningitis:
  • Caused by Cryptococcus neoformans, a fungal infection affecting the meninges.
  • Symptoms: Headache, fever, neck stiffness, and altered mental status.
  • LP: CSF a budding yeast. Use Indian ink stain. Cryptococcal antigen in blood and serum.
  • CT/MRI and LP are obligatory in most patients with HIV and neurological signs.
  • Treatment: Antifungal therapy with amphotericin B and flucytosine, followed by fluconazole.
• Progressive Multifocal Leukoencephalopathy (PML):
  • Caused by JC virus reactivation, leading to demyelination in the brain.
  • Symptoms: Progressive weakness, visual disturbances, speech difficulties, and cognitive impairment.
  • Imaging: diffuse white matter disease due to JC virus in those with very low CD4. MRI shows non enhancing white matter but no oedema.
  • Treatment: Antiretroviral therapy (ART) to control HIV replication and stabilize the immune system. The incidence of PML has not fallen markedly with the extensive use of HAART and is even seen in those with a CD4+ count > 200.
• CMV Encephalitis:
  • Caused by Cytomegalovirus, leading to inflammation of the brain.
  • Symptoms: Confusion, fever, seizures, and focal neurological signs.
  • Treatment: Antiviral medications such as ganciclovir or valganciclovir.

Peripheral Neuropathies

• Distal Symmetric Polyneuropathy (DSPN):
  • Most common HIV-related neuropathy, affecting the hands and feet.
  • Symptoms: Pain, numbness, tingling, and weakness in affected areas.
  • Treatment: Pain management, antiretroviral therapy, and supportive care.
• Inflammatory Demyelinating Polyneuropathy:
  • Immune-mediated neuropathy resembling Guillain-Barré syndrome.
  • Symptoms: Rapid onset of weakness, sensory loss, and areflexia.
  • Treatment: Immunoglobulin therapy or plasmapheresis, and antiretroviral therapy.

Other Neurological Conditions

• HIV Myelopathy:
  • Damage to the spinal cord caused by HIV infection.
  • Symptoms: Weakness, spasticity, and sensory disturbances in the lower extremities.
  • Treatment: Antiretroviral therapy and supportive care.
• HIV-Associated Vacuolar Myelopathy:
  • A subtype of HIV myelopathy with characteristic vacuolar changes in the spinal cord.
  • Symptoms: Gait disturbances, weakness, and sensory deficits.
  • Treatment: Antiretroviral therapy and physical rehabilitation.

Prevention and Management

• Early initiation and adherence to antiretroviral therapy (ART) to maintain immune function.
• Regular monitoring of neurological symptoms and cognitive function.
• Prophylactic medications for high-risk patients to prevent opportunistic infections.
• Comprehensive management of neurological symptoms through a multidisciplinary approach.