title: Ferritin levels and their association with regional brain volumes in Tourette's syndrome.
abstract: OBJECTIVE
  A previous small study showed lower serum ferritin levels in subjects with Tourette's syndrome than in healthy subjects. The authors measured peripheral iron indices in a large group of Tourette's syndrome and comparison subjects and explored associations of ferritin levels with regional brain volumes.
  
  
  METHODS
  Ferritin was measured in 107 children and adults (63 Tourette's syndrome, 44 comparison); serum iron was measured in 73 (41 Tourette's syndrome, 32 comparison). Magnetic resonance imaging scans were used to measure volumes of the basal ganglia and cortical gray matter.
  
  
  RESULTS
  Ferritin and serum iron were significantly lower in the Tourette's syndrome subjects, although still within the normal range. No association was found between tic severity and either iron index. In the Tourette's syndrome subjects, ferritin did not correlate significantly with caudate volume but did correlate positively with putamen volume. In the comparison subjects, ferritin correlated inversely with caudate volume but did not correlate significantly with putamen volume. Irrespective of diagnosis, ferritin correlated positively with volumes of the sensorimotor, midtemporal, and subgenual cortices.
  
  
  CONCLUSIONS
  The lower peripheral ferritin and iron levels in persons with Tourette's syndrome are consistent with findings in other movement disorders and suggest that lower iron availability may have a causal role in the pathophysiology of tic disorders. Lower iron stores may contribute to hypoplasia of the caudate and putamen, increasing vulnerability to developing tics or to having more severe tics. Lower iron stores may also contribute to smaller cortical volumes and consequently to reduced inhibitory control of tics.
authors.affiliation: Department of Psychiatry, The Hospital for Sick Children, 555 University Ave., Toronto, ON M5G 1X8, Canada. daniel.gorman@sickkids.ca
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Gorman
authors.forename: Hongtu
authors.initials: H
authors.lastname: Zhu
authors.forename: George M
authors.initials: GM
authors.lastname: Anderson
authors.forename: Mark
authors.initials: M
authors.lastname: Davies
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Peterson
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001479:Basal Ganglia / Q000473:pathology; D001921:Brain / Q000473:pathology*; D002421:Caudate Nucleus / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology; D002648:Child; D004298:Dopamine / Q000502:physiology; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D007501:Iron / Q000097:blood / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D012737:Sex Factors; D009435:Synaptic Transmission / Q000502:physiology; D005879:Tourette Syndrome / Q000097:blood* / Q000175:diagnosis / Q000473:pathology*
chemical_list: D005293:Ferritins; D007501:Iron; D004298:Dopamine