A 39-year-old HIV seropositive man

A 39-year-old HIV seropositive man was referred to the neurology clinic with altered personality and progressive speech problems.
His partner, who had accompanied him to clinic, said that he had noticed a marked difference in his demeanour and that he had become aggressive towards him in the last few weeks. The patient had also noticed increasing stiffness in his legs and had been dragging his left leg whilst walking.
The patient was diagnosed with HIV approximately 10 years ago. He had been offered the opportunity to start antiretroviral therapy several times, but had declined due to his concerns about the possible side-effects of drugs. Otherwise he had no other past medical history, was a smoker of 10 cigarettes per day and drank 20 units of alcohol per week.
On examination he appeared thin and drawn. He weighed 50 kg in his clothes. His temperature was 36.1°C, blood pressure was 135/75 mmHg and pulse was 78/minute and regular. He had several cold sores around his mouth. He was alert and orientated. He scored 27/30 on mini-mental state examination with deficiencies in naming objects. Cranial nerve examination was normal.
On examination of the peripheral nervous system, there was a mild left-sided hemiparesis and the right plantar reflex was extensor. He walked with a spastic gait and appeared to be leaning to the left.
The results of further investigations are detailed below:
MRI brain scan: Multiple, non-enhancing white-matter lesions within the frontal and temporal lobes with no oedema or mass-effect.
Blood tests showed:
Serum oligoclonal bands Present
CD4 count 96 cells/mm3
HIV quantitative PCR (viral load)100,000 copies/ml
Lumbar puncture showed:
Opening pressure16 cm H2O (5-18)
CSF protein 0.42 g/L(0.15 - 0.45)
CSF white cell count 4 per ml (5)
CSF red cell count 3 per ml(5)
CSF oligoclonal bands Present
What is the most likely diagnosis?
(Please select 1 option)
CNS lymphoma
HIV encephalopathy
Primary progressive multiple sclerosis (MS)
Progressive multifocal leukoencephalopathy
Toxoplasma encephalitis

This patient presents with a left hemiparesis, expressive dysphasia and behavioural changes in clear consciousness.
The most likely diagnosis is progressive multifocal leukoencephalopathy.
Progressive multifocal leukoencephalopathy (PML) is the result of infection of oligodendrocytes with JC virus, which is a papovavirus found latent in most healthy adults. With CD4 counts of less than 100 this virus becomes active leading to progressive neurological deterioration. Hemiparesis, visual field defects, ataxia and mental change are characteristic.
The diagnosis can be established either
By demonstrating the presence of JC virus genetic material in the cerebrospinal fluid (by polymerase chain reaction), or
Through a brain biopsy (showing asymmetric foci of demyelination and intranuclear inclusions containing the JC virus).
There is no effective treatment, but progression can be slowed by initiation of antiretroviral therapy.

Primary central nervous system lymphoma usually presents with a solitary space-occupying lesion with mass effect.
Toxoplasma encephalitis typically presents as multiple ring-enhancing lesions with mass effect; the patient is often febrile and the presentation is usually more acute.
HIV encephalopathy is frequently associated with behavioural changes, but radiological changes are usually limited to cerebral atrophy.
In primary progressive MS there is intrathecal oligoclonal band synthesis only, and the white matter lesions are periventricular in location.