HIV-Associated Delirium
HIV-Associated Delirium
Clinical Manifestations of Delirium in HIV-Infected Patients
Relevant history and examination
Introduction
HIV enters the central nervous system (CNS) soon after initial infection and is responsible for a range of neuropsychiatric complications.
Delirium is the most common neuropsychiatric complication in hospitalised patients with AIDS. Early stages of delirium are often subtle, difficult to recognise, and may resemble primary psychiatric disorders. Delirium may be life-threatening and requires immediate medical attention.
The following patients are at risk for developing delirium:
- Those in advanced stages of immunosuppression
- Those with a history of opportunistic infections, substance use, head/brain injuries, or episodes of delirium
- Those with HIV-associated dementia or infections and malignancies of the CNS
Diagnosis
The hallmarks of delirium are:
- Impaired level of consciousness
- A reduced ability to maintain attention
- Cognitive changes or development of perceptual disturbances (not explained by a pre-existing dementia).
These symptoms/disturbances may develop over a short period of time, and can fluctuate in severity.
Delirium is often difficult to diagnose. When patients appear hypo-active, depression is a frequent misdiagnosis for delirium. The clinical manifestations of HIV-associated delirium is summarised in the table below.
Clinical Manifestations of Delirium in HIV-Infected Patients |
Impairment of memory, orientation, prefrontal "executive" functions Difficulty with abstraction Difficulty with sequential thinking Impaired temporal memory Impaired judgement |
Disturbances in thought and language Decreased verbal fluency |
Disturbances in perception Hallucinations (primarily visual) Illusions (misinterpretation of visual cues, e.g. mistaking shadows for people) |
Disturbances in psychomotor function Hypo-active Hyperactive Mixed hypo- and hyperactive |
| Disturbances in sleep-wake cycle Daytime lethargy Night time agitation |
Delusions (usually paranoid but more disorganised than those seen in psychoses) |
Affective lability |
| Neurologic abnormalities Tremors Ataxia Myoclonus Cranial nerve palsies Asterixis Cerebellar signs Nystagmus |
Delirium is generally caused by an underlying medical condition (Box 1). CNS infections are common and substance use in HIV-infected patients (especially methamphetamine) is associated with significant changes in cognitive impairment and brain structure.
Possible Causes of Delirium
- Alcohol intoxication and withdrawal
- Almost all HIV-related and psychotropic medications
- Anaemia
- CNS infections
- CNS malignancies
- Metabolic abnormalities
- Hypoxemia
- Methamphetamine use
- Opioids
- Sepsis
Differential Diagnosis
- Toxoplasmosis
- Cryptococcal meningitis
- Cytomegalovirus (CMV) encephalitis
- HIV encephalopathy
- Progressive multifocal leucoencephalopathy (PML)
- Primary cerebral lymphoma (also known as primary CNS lymphoma (PCNSL)
- Aseptic meningitis/encephalitis
- Cerebral abscess
- Space-occupying lesion of unknown cause
- HIV-associated Dementia
- Leucoencephalopathy
Management based on Severity
- Immediate action
Correcting the underlying conditions remains the primary treatment.
Non-drug treatment
- Immediate referral of patients with signs and symptoms of delirium to a hospital
- Consultation with a psychiatrist if medical conditions excluded
Drug treatment
- Low dose neuroleptics (useful for confusion or agitation)
- Low dose lorazepam (if agitation put patient or others at risk)
- HIV-infected patients (especially older patients or those with advanced disease) may be more sensitive to the side effects of psychotropic medications.
Relevant history and examination
- Clinicians should assess for delirium when there is a sudden change in a patient's cognitive functioning, consciousness, or behaviour.
Investigations
- Complete evaluation including biochemical tests, neuroimaging studies and lumbar puncture
Referral criteria
- Immediate referral of patients with signs and symptoms of delirium to a hospital
References:
1. New York State Department of Health. Cognitive disorders and HIV/AIDS: HIV-associated dementia and delirium 2007; (2007 Sep 12): Available from: http://files.imd. com/medinfo/material/157/4eb1f8e844aea51d6a389157/4eb1f90244aea51d6a38915a.pdf.
2. Baggaley R. HIV for non-HIV specialists - Diagnosing the undiagnosed: Medical Foundation for AIDS & Sexual Health; 2008 [cited 2012 18 October]. Available from: http://www.medfash.org.uk/publications/documents/HIV_for_non_HIV_specialists.pdf.
3. Regensberg L, Whitelaw C, editors. Clinical guidelines 2010/2011. 8th ed. Cape Town: Aid for Aids; 2010.
4. New York State Department of Health AIDS Institute. HIV Clinical Resource. Cognitive Disorders and HIV/AIDS, [serial on the Internet]. 2007: Available from: http://www.hivguidelines.org/clinicalguidelines/ HIV-and-mental-health/cognitive-disorders-and-HIV-aids/.