Table 1.
HSV-1 exposure and temporal trajectory of cognitive function in published studies.
| First author / Reference | Study sample (N) | Cognitive tests | Follow up duration | Key results |
|---|---|---|---|---|
| Strandberg (Strandberg et al., 2003) | Random sample of Helsinki residents with cardiovascular disease (383) | MMSE, CDR | 1 year | Reduction in MMSE scores proportional to viral burden due to HSV-1, CMV and HSV-2 |
| Aiello (Aiello et al., 2008) | Community-dwelling elderly Latino sample (1204) | MMSE, episodic memory (word list-learning test) | 4 years | Rate of cognitive decline significantly related to CMV titers, but not HSV-1 titers |
| Prasad (Prasad et al., 2012) | First-episode antipsychotic-naive SZ patients (26); Healthy subjects (38) | WCST | 1 year | Greater reduction in perseverative errors in HSV-1 seronegative SZ patients than in the HSV-1-seropositive patients. No significant associations with CMV, or in healthy subjects. |
| Barnes (Barnes et al., 2014) | 3 cohorts of elderly community members (N=849) | MMSE, tests of working memory, episodic memory, visuospatial function | 5 years | No significant temporal associations with HSV-1 status. CMV seropositivity associated with greater risk of Alzheimer disease and faster rate of cognitive decline in global cognition. |
| Nimgaonkar (Nimgaonkar et al., 2016) | Representative community sample of elders | MMSE, tests of complex attention, executive functions, memory, language, visuospatial function | 5 years | IgG titers of antibodies to CMV, HSV-2 and Tox associated with differing patterns of greater cognitive decline. No temporal associations with HSV-1. |
MMSE: Mini-Mental State Examination; CDR: Clinical Dementia Rating scale; HSV-1: herpes simplex virus, type 1 (HSV-1); CMV: cytomegalovirus; HSV-2: herpes simplex virus, type 2 (HSV-2); Tox: Toxoplasma Gondii.