CONCLUSIONS. The systematic review shows some limitations. Firstly, it includes a small number of studies, which is also a small sample of participants. In addition, among the studies, there is a great clinical diversity and many articles did not described relevant data exactly for critical reading. PMID: 20645264 [PubMed - in process] (Source: Revista de Neurologia)<div id="medworm"><p><b><i>MedWorm Message:</i></b> Register for <b><a href="http://www.medmatcha.com" target ="_self">MedMatcha, MedWorm's medical advertising network</a></b>, and receive $5 free advertising.</p></div>