RT Journal Article SR Electronic T1 When a clear crystal makes a case crystal clear JF Practical Neurology JO Pract Neurol FD BMJ Publishing Group Ltd SP 345 OP 346 DO 10.1136/jnnp.2009.193839 VO 9 IS 6 A1 Rudolf Benz A1 Max Züger A1 Tamara Pung A1 Evelyn Gallus A1 Christian Weisshaupt A1 Martin Krause YR 2009 UL http://pn.bmj.com/content/9/6/345.abstract AB