Cognitive
impairment in people with HIV has multiple causes and HIV-associated
neurocognitive disorder is being over-diagnosed, clinicians from Brighton
report in Brain Sciences. Assessment
of patients attending a specialist HIV memory clinic showed that only 31% met
the criteria for HIV-associated neurocognitive disorder (HAND) with an almost
equal proportion (27%) having impairment due to mental health problems, sleep
disorders or drug use.
Patients attending the Orange Clinic – a collaboration between HIV specialists and
memory services in Brighton – were assessed and cared for by a
multidisciplinary team. Interventions offered to patients included changing
antiretroviral therapy, specialist case-management and follow-up, as well as signposting and referral to other services.
“HIV clinics have
always been active in adapting and innovating care models to provide for the
changing needs of their patients,” comment the authors. “The Orange Clinic
represents such a model – a novel, needs-driven, efficient and coordinated
service for the ageing population of PLWH [people living with HIV] who
experience neurocognitive issues.”
Cases of HIV associated
dementia are now very rare, but some studies have suggested that over a quarter of
HIV-positive people aged 50 years and older have the less severe HAND. Assessment for
HAND is made using the Frascati criteria (an assessment based on neuropsychological testing). Some researchers have
pointed out that these criteria lack precision and do not take into the account the complexity of pathogenic mechanisms that contribute to cognitive impairment, potentially resulting in HAND being
over-diagnosed.
Regardless of the
precise diagnosis, HIV-positive people with cognitive and memory problems
require specialist support. HIV clinicians in Brighton therefore collaborated
with local memory services and the Brighton and Sussex Medical School to
establish a specialist clinic to assess, manage and support HIV-positive
people with suspected cognitive impairment.
The Orange Clinic is
multidisciplinary, its staff including an HIV consultant, a consultant old-age
psychiatrist skilled in dementia assessment and management, a neuropsychologist, a clinical psychologist and an HIV nurse
consultant. Support is provided by neurology and neuroimaging.
Patients undergo a
range of neuropsychological tests, including assessment of IQ, memory,
attention, language processing, visuo-spatial processing and executive
function. Medical histories are thoroughly reviewed. Care also involves a
thorough assessment of mental health.
Diagnoses are based on clinical interpretation of an individual's test results, along with factors
that can affect cognitive performance, such as mood, mental health and sleep.
Between June 2016
and May 2018 the clinic cared for 52 patients. Their median age was 55 years,
79% were male, 83% were white and the median time since HIV diagnosis was 17 years. The average
current viral load was 690 cells/mm3. Only one patient was not
currently taking antiretroviral therapy and four individuals had a detectable
viral load. A third of the patients reported recreational drug use. On average,
patients were taking a mean of five non-HIV medications and 46% were being
treated with antidepressants.
Of the 52 people seen, 42 (81%) had HAND using Frascati criteria. However, when the clinicians used their own more sophisticated diagnostic criteria:
- 16 individuals (31%) were diagnosed with HAND.
- 2 people (4%) were diagnosed with dementia, one due to Alzheimer's disease and one of unspecified cause.
- 14 people (27%) had cognitive impairment due to a secondary mental health
issue, such as depression, anxiety, drug/alcohol use or poor sleep.
- 7 people (14%) had cognitive impairment due to a non-HIV-related cause, such as cerebrovascular disease or brain injury.
- 11 people (21%) had no objective
cognitive impairment.
“It is significant that 27% of those who
attended the clinic had a mental health condition which was likely to be
responsible for their objective cognitive impairment,” note the authors. “In
our clinic it has been vital to be able to address the mental health issues of
patients.”
MRI brain imaging
showed that two-thirds of patients had some sort of abnormality.
The general
intelligence of the patients was comparable to that expected in the wider
population. Anxiety, depression and stress scores were all higher than established averages in the general population.
The mean scores for immediate memory, visuo-spacial assessment,
language, attention and delayed memory were were all lower than established norms.
The authors suggest that the pattern of cognitive impairment has changed with the availability of combination therapy. In the years before effective treatment, HIV-associated dementia was "characterized by progressive subcortical dementia with prominent degeneration of cognitive and motor functions". Their patients diagnosed with HAND have subtler impairments in tests of immediate and delayed memory, with mild impairments in attention, visuospatial skills and language.
As regards
management, 23 patients have been discharged from the clinic. Of those
discharged, nine had no objective cognitive impairment and eight had impairment
due to mental health problems that could be managed using another service.
Three of the discharged patients had mild HAND.
A total of 29
patients are still receiving care at the clinic. Of these, 15 have undergone
repeat cognitive assessment and a further eight have been followed up after
implementation of a management plan (e.g. psychological therapy, in-clinic
advice on mental health/lifestyle/sleep, changes in HIV medication, stricter
control of cardiovascular disease risk factors). Other patients are awaiting
repeat assessment after further diagnostic tests or remain on the clinic’s
books and will be followed-up as warranted.
“Recent modelling
work predicts that by 2030 73% of PLWH will be aged over 50 years of age.
Multidisciplinary working is vital to the successful management of such
patients where complex multimorbidity is likely to be the norm,” conclude the
authors. “This service evaluation provides tentative evidence that the need
exists, that the model of care we have developed is feasible and that there may
be value in establishing similar models of working in HIV care for those with
impairment in cognitive function.”