To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Background: Patients with Rett syndrome (RTT) may demonstrate parkinsonian
features. Here, we report a preliminary cross-sectional and prospective
evaluation of the evolution, regional distribution, and eventual incidence
of rigid tone in a cohort of MECP2 mutation-positive
patients. Methods: In 51 participants, muscle tone rigidity in extremity regions and
neck plus hypomimia were quantified using an RTT rigidity distribution
(RTTRD) score with a range of 0 to 15. RTTRD scores were correlated with
age, ability to walk and speak, mutation type, and, in a small subgroup
(n=9), cerebrospinal fluid (CSF) homovanillic acid (HVA) and
5-hydroxyindole-acetic acid levels. Results: Participant ages ranged from 2 years and 5 months, to 54 years.
Rigidity was found in 43/51 (84.3%); it appeared as early as age 3,
increased in extent with age, and was present in all participants aged ≥13.
Ankle region rigidity appeared first, followed by proximal legs, arms, neck,
and face. Ambulatory participants (n=21) had lower RTTRD scores than
nonambulatory (n=30; p=0.003). We found a trend to lower scores in
participants with retained speech (n=13) versus those with none (n=38;
p=0.074), and no difference in scores for those with truncating (n=25)
versus missense mutations (n=22; p=0.387). RTTRD scores correlated
negatively with CSF HVA levels (R=−0.83; p=0.005), but not with
5-hydroxyindole-acetic acid levels (R=−0.45; p=0.22). Conclusions: Although assessment of muscle tone is somewhat subjective and the
RTTRD has not been validated, this study nevertheless suggests that
parkinsonian rigidity in RTT is common and frequently increases in extent
with age; its severity correlates directly with impaired ambulation and
inversely with CSF HVA levels.
Neuropsychological assessment aims to identify individual performance profiles in multiple domains of cognitive functioning; however, substantial variation exists in how deficits are defined and what cutoffs are used, and there is no universally accepted definition of neuropsychological impairment. The aim of this study was to derive and validate a clinical case definition rule to identify neuropsychological impairment in children and adolescents. An existing normative pediatric sample was used to calculate base rates of abnormal functioning on eight measures covering six domains of neuropsychological functioning. The dataset was analyzed by varying the range of cutoff levels [1, 1.5, and 2 standard deviations (SDs) below the mean] and number of indicators of impairment. The derived rule was evaluated by bootstrap, internal and external clinical validation (orthopedic and traumatic brain injury). Our neuropsychological impairment (NPI) rule was defined as “two or more test scores that fall 1.5 SDs below the mean.” The rule identifies 5.1% of the total sample as impaired in the assessment battery and consistently targets between 3 and 7% of the population as impaired even when age, domains, and number of tests are varied. The NPI rate increases in groups known to exhibit cognitive deficits. The NPI rule provides a psychometrically derived method for interpreting performance across multiple tests and may be used in children 6–18 years. The rule may be useful to clinicians and scientists who wish to establish whether specific individuals or clinical populations present within expected norms versus impaired function across a battery of neuropsychological tests. (JINS, 2015, 21, 596–609)
Email your librarian or administrator to recommend adding this to your organisation's collection.