Neurological soft signs (NSS) are the non-localizing neurological abnormalities without diagnostic specificity.NSS occur in several psychiatric disorders. Studies of NSS in OCD are smaller and results inconsistent.
N. Jaafari et al reports the results of a metaanalysis addressing this question.15 studies met the inclusion criteria with a total of 1018 patients.Authors also report results of two empirical parallel studies conducted in the UK (74 participants) and Spain( 99 participants). In both samples, trained raters administered the Cambridge Neurological Inventory .
Patients with OCD have elevated scores on most NSS subscales.The effect size calculated for the total NSS was large at 1.27 . However heterogeneity among reported studies was large.Both empirical studies found elevated NSS scores in patients compared with matched controls. Patients have higher rates of NSS in the domains of motor coordination, sensory integration and primitive reflexes.
Is there more NSS in severe OCD?…Meta-regression analysis failed to confirm a significant association with symptom severity.
Do medication change the NSS? …Several studies found no influence of medication on NSS in OCD
Do NSS precede the development of OCD or is it a consequence of the disorder ? ..this is still unclear.Grisham et al. (2011) examined childhood risk factors for adult OCD diagnosis in a New Zealand birth cohort. They reported that poor motor skills in childhood (ages 3–9 years) specifically predicted the presence of OCD symptoms involving fears of harm and checking rituals.
There is some evidence that NSS can improve with successful treatment . Mergl et al. (2004) found that drawing speed was impaired in OCD compared with healthy controls but normalized after 10-week treatment with sertraline and behaviour therapy.
Conclusions: Individuals with OCD have more NSS.These subtle central nervous system alterations are broadly consistent with current neurobiological models of the disorder. Many crucial questions still remain unanswered.
Summary of the article:
Jaafari N, de la Cruz LF, Grau M, Knowles E, Radua J, Wooderson S, Segalas C, Alonso P, Phillips ML, Menchón JM, Mataix-Cols D. Psychol Med. 2013 May;43(5):1069-79.