A patient known to AIDS is admitted to hospital for treatment for mania. During the admission they begin to complain of a headache and have an associated fever. You request a CT scan which shows multiple contrast-enhancing lesions in the grey matter of the cortex, these are described in the radiologists report as ring enhancing. Which of the following would you suspect?
Exam Question Jul 2014
The patient is likely to have Toxoplasmic encephalitis caused by the protozoan Toxoplasma gondii. The most common clinical presentation of T. gondii infection is focal encephalitis with headache, confusion, or motor weakness and fever. Computed tomography (CT) scan or magnetic resonance imaging (MRI) of the brain will typically show multiple contrast-enhancing lesions in the grey matter of the cortex or basal ganglia, often with associated edema. On imaging studies, lesions are usually ring-enhancing (have the appearance of a ring).
Mycobacterium tuberculosis19%Cryptosporidiosis20%Herpes simplex virus20%Toxoplasma gondii21%Candidiasis20%
Exam Question Jul 2014
The patient is likely to have Toxoplasmic encephalitis caused by the protozoan Toxoplasma gondii. The most common clinical presentation of T. gondii infection is focal encephalitis with headache, confusion, or motor weakness and fever. Computed tomography (CT) scan or magnetic resonance imaging (MRI) of the brain will typically show multiple contrast-enhancing lesions in the grey matter of the cortex or basal ganglia, often with associated edema. On imaging studies, lesions are usually ring-enhancing (have the appearance of a ring).
HIV
The Acquired Immunodeficiency Syndrome (AIDS) is a multi-system disorder that can have psychiatric manifestations. These may be due to infection as well as from its management.
AIDS was first reported in the USA in 1981. In 1983 it was shown to be due to infection with the human immunodeficiency virus, HIV-1. This is a single-stranded retrovirus which is destructive of CD4 lymphocytes. The virus also destroys neuronal cells.
Modes of transmission:
- sexual
- parenteral blood or blood product recipients
- vertical from mother to child in utero
Clinical presentation
Main clinical manifestations:
- candidiasis
- cryptococcus
- cryptosporidiosis
- cytomegalovirus
- herpes simplex virus
- Kaposi's sarcoma
- mycobacterium avium
- mycobacterium tuberculosis
- pneumocystis jiroveci (formally known as pneumocyctis carinii)
- toxoplasma gondii
Approximately two to four weeks after infection, the majority of patients develop a flu-like syndrome, characterised by:
- a self-limiting fever
- fatigue
- rash
- pharyngitis with cervical adenitis
- arthralgia
- myalgia
Following initial infection, there is usually an asymptomatic period before the onset of the various opportunistic infections
Diagnosis
Diagnosis is based on the detection of the P24 antigen, HIV nucleic acid or direct virus detection. Antibodies are detectable within about six weeks of infection and persist for life.
Severity of disease and response to treatment are monitored by measuring the CD4 count and viral load. Decreases in CD4 counts correlate with opportunistic infections.
Most individuals are asymptomatic when their CD4 counts are >500 x 10^6/l. They are at greatest risk when this count falls below 200 x 10^6/l.
Antiretroviral drugs
These are not curative but are effective in reducing viral loads and increasing CD4 counts.
The following table illustrates the classification of antiretrovirals:
| Class | Examples |
|---|---|
| Non-nucleoside reverse-transcriptase inhibitors | efavirenz nevirapine |
| Nucleoside reverse-transcriptase inhibitors | abacavir didanosine |
| Protease inhibitors | retinovir indinavir |
| Others | enfuvirtide |
Side effects from antiretrovirals are common (see table below taken from the Maudsley Guidelines):
| Side effect | Antiretroviral |
|---|---|
| Abnormal dreams | Atazanavir Efavirenz Emtricitabine Etravirine Lopinavir Raltegravir Ritonavir Stavudine |
| Agitation | Efavirenz |
| Anxiety | Atazanavir Efavirenz Enfurvirtide Etravirine Lopinavir Raltegravir Ritonavir Stavudine Zidovudine |
| Delusions 'psychosis like behaviour' | Efavirenz |
| Depression | Atazanavir Efavirenz Maraviroc Raltegravir Stavudine Zidovudine |
| Fatal suicide | Efavirenz |
| Mania | Efavirenz |
Don't panic (too much) from seeing this table. As you can see the main one to remember is Efavirenz as it causes most problems and is most likely to appear in the exam.
Co-morbidity and prescribing
Most psychiatric conditions can co-occur.
The most prevalent psychiatric illness in people with HIV is depression (35.6%), followed by substance misuse, anxiety, psychosis, adjustment disorder and bipolar affective disorder (Knights, 2017).
The following table lists the suggestions by the Maudsley Guidelines in cases of HIV.
| Problem | Suggestions |
|---|---|
| Psychosis | Atypicals are suggested. Risperidone is the most widely studied |
| Delirium | Atypicals and low-dose short acting benzodiazepines |
| Depression | SSRIs, especially citalopram. Note that the following have also been specifically recommended (Knight, 2017) as first-line; selective serotonin reuptake inhibitors (SSRIs), selective noradrenaline reuptake inhibitors (SNRIs), mirtazapine and bupropion |
| Bipolar | Valproate, lamotrigine, gabapentin are the best options, lithium ok but poorly tolerated. Carbamazepine is to be avoided. Atypical antipsychotics may also be used |
Knights (2017) HIV infection and its psychiatric manifestations: a clinical overview. BJPsych Advances Jul 2017, 23 (4) 265-277.
