Page 330 - Encyclopedia of Nursing Research

MILD COGNITIVE IMPAIRMENT n 297

remains intact. It is thought that this type Both genetic and nongenetic factors,
of MCI may be a prodrome of Lewy Body such as APOE e4 alleles, depression, social
dementia (Petersen & Morris, 2005). isolation, chronic kidney disease, thyroid M
To date, no Diagnostic and Statistical dysfunction, testosterone deficiency, estro-
Manual of Mental Disorders, fourth edition, or gen levels, and vitamins B 12 and D, have been
International Statistical Classification of Diseases, implicated in the etiology of MCI (Etgen,
10th revision, international diagnostic crite- Bickel & Förstl, 2010; Gauthier et al., 2006);
ria have been established for MCI (Dierckx, however, so far no definitive links have been
Engelborghs, De Raedt, De Deyn, & Ponjaert- established. One certainty is that age is the
Kristofferson, 2007), and there is much dis- most significant risk factor, and cardiovas-
agreement in the literature about the status cular risks such as hypertension and dia-
of the MCI concept; however, most authori- betes are also thought to play a prominent
ties recommend that a diagnosis is reached role (Molinuevo et al., 2010). Although some
through a process of clinical judgment, promising work is underway into the use of
usually based on the Mayo clinic criteria biomarkers in AD, work of this nature in the
(Chertkow et al., 2007; Petersen, 2004). Others MCI context is in its infancy (Prabhavalkar &
suggest that this may be augmented by the Chintamaneni, 2010).
use of standard cognitive functional assess- A number of studies have been con-
ments (Prabhavalkar & Chintamaneni, 2010). ducted into the effectiveness of a variety of
Petersen (2004) proposes that most people pharmacological and nonpharmacological
with MCI fall 1.5 standard deviations below therapies in both the prevention of the con-
norms on memory tests, and hence these tests version of MCI to dementia and the improve-
may be used in the objective assessment of ment of cognitive functioning in persons
MCI. However, many of the assessments that with MCI. Clearly, such a discovery would
are used in AD may not be valid or sensitive have significant social and economic benefits.
enough to detect MCI (Raschetti, Albanese, In a recent review, Chertkow et al. (2008) con-
Vanacore, & Maggini, 2007); hence, in the cluded that only leisure activities, treatment
last decade, a number of more MCI-specific of sleep disorders, cognitive stimulation,
instruments such as the Montreal Cognitive physical activity, opportunities for social
Assessment (Petersen, 2004) and the DemTect interaction, and control of vascular risk fac-
(Kalbe et al., 2004) have emerged. tors can be recommended at this time. They
Data from prevalence studies vary con- found insufficient evidence to recommend
siderably for MCI chiefly because of dif- any of the drugs reviewed (cholinesterase
ferences in definition and classification. inhibitors [ChEIs], estrogen therapy, vitamin
Gauthier et al. (2006) report that prevalence E, nonsteroidal anti-inflammatory drugs,
in population-based epidemiological studies and ginkgo biloba). Similarly, a review by
ranges from 3% to 19% in those over the age Massoud et al. (2007) recommended a gen-
of 65 but that this increases significantly with eral healthy lifestyle combined with close
age. Other research has focused on the rate monitoring and treatment of vascular disor-
of progression of MCI to dementia; however, ders and, in addition, gave some support for
again, results have varied considerably. One vitamin B 6 , vitamin B 12 , folate supplements,
recent meta-analysis concluded that although omega fatty acids, and antioxidants. Other
the annual conversion rate from MCI to work has indicated that the ChEI galan-
dementia was approximately 5% to 10%, a tamine is associated with increased mortal-
majority of individuals will not progress to ity in MCI patients (Loy & Schneider, 2006).
dementia even after a 10-year follow-up, and Accordingly, ChEIs are not currently recom-
some individuals will revert from MCI back mended in the treatment of MCI (Chertkow
to normal (Mitchell & Shiri-Feshki, 2009). et al., 2008; Massoud et al., 2007).