Early-onset cognitive impairment: Less-known aspects of dementia

December 9, 2022

Healthcaretoday, Acquired brain injury, alcohol-related dementia, HIV-associated neurocognitive disorders, dementia, HIV-associated dementia,

Acquired brain injury (ABI) can lead to chronic cognitive impairment, significantly affecting an individual's quality of life.

Dementia is a complex condition that affects millions worldwide, but certain populations experience early-onset cognitive impairment for specific reasons, including acquired brain injury, alcohol-related dementia, and HIV-associated neurocognitive disorders (HANDs). Understanding these conditions is crucial for effective management and support.

Acquired brain injury
Acquired brain injury (ABI) can lead to chronic cognitive impairment, significantly affecting an individual's quality of life. A Cochrane systematic review focusing on traumatic brain injury (TBI) found that rivastigmine, a medication used to treat cognitive decline, showed a significant improvement in verbal memory functioning compared to a placebo. However, this was the only primary measure that demonstrated effectiveness, and there were no notable differences in safety profiles.

The Clinical Practice Guidelines (2021) by the Ministry of Health, Malaysia, highlight the findings from two systematic reviews on non-pharmacological interventions for ABI:

Cognitive rehabilitation: This approach did not prove effective in improving return to work, independence in activities of daily living (ADL), community integration, or overall quality of life for adults with TBI when compared to no intervention or conventional rehabilitation.

Music interventions: Some evidence suggests that music interventions may enhance communication and speech repetition in individuals with post-stroke aphasia, although these findings are based on a limited number of studies with small sample sizes.

Alcohol-related dementia
Alcohol-related dementia (ARD) is a significant concern, with prevalence rates ranging from 0.12% to 25.6%, predominantly affecting males. It is notably more prevalent in early-onset dementia cases, occurring in approximately 10% of such patients.

Heavy alcohol consumption can lead to ARD through several mechanisms:

Neurotoxic effects: Chronic alcohol use can cause permanent structural and functional damage to the brain.
Thiamine deficiency: This deficiency can result in Wernicke-Korsakoff syndrome, a serious brain disorder.
Comorbid conditions: Heavy drinking increases the risk of other conditions that can damage the brain, such as hepatic encephalopathy in patients with liver disease.
Cardiovascular issues: These can lead to vascular dementia indirectly.

HIV-associated neurocognitive disorders (HANDs)
HANDs present another layer of complexity in cognitive impairment. Various diagnostic criteria exist, with the 2007 Frascati criteria being the most widely used. This classification includes three categories:

Asymptomatic neurocognitive impairment (ANI): Mild cognitive impairment in at least two domains without affecting daily functioning.
Mild neurocognitive disorder (MND): Mild impairment in at least two domains with some interference in daily functions.
HIV-associated dementia (HAD): Severe impairment in at least two domains, significantly impacting daily activities.

Research from the Malaysian HIV and Aging (MHIVA) study indicates that HAD is rare in Malaysia, with no reported cases among participants, suggesting that most individuals with HIV experience milder forms of HAND, such as ANI.

The prevalence of HANDs globally ranges from 39.1% to 44.4%, with lower rates of MND and HAD observed in individuals with higher income levels. A meta-analysis assessing cognitive screening tools for diagnosing HANDs found that the HIV Dementia Scale and International HIV Dementia Scale generally exhibited poor and moderate pooled sensitivities.

As HIV-associated dementia is more prevalent among those under 65, addressing cognitive issues alone is insufficient. These individuals require enhanced psychological and social support, particularly concerning employment, financial stability, and social integration.