Basal Ganglia activity in pathological gambling: a fluorodeoxyglucose-positron emission tomography study.
BACKGROUND
Pathological gambling (PG) is a disorder classified as an impulse control disorder (DSM-IV) bridging impulsive, compulsive and addictive behaviors. The striatum and thalamus are supposed to be involved in the pathophysiological substrate of these behaviors. An increased relative glucose metabolic rate (rGMR) in patients with a diagnosis of PG had previously been reported in the medial and orbitofrontal cortex. We extended our studies to include functional alterations of the striatum and thalamus in a cohort of patients with PG before and after treatment with lithium.


METHODS
Twenty-one patients with PG who met lifetime comorbid bipolar spectrum diagnoses and a comparison group of 21 age- and sex-matched controls underwent a baseline positron emission tomography (PET) scan. Sixteen of these patients entered a randomized double-blind placebo-controlled parallel-group-design trial of lithium and underwent a follow-up PET scan at week 10. Anatomical MRI were obtained and the structures outlined on consecutive axial slices. These individual hand-drawn templates were used to identify structures on the PET scan of each patient, and the rGMR was measured.


RESULTS
The PG patients had a decrement of the rGMR in the ventral parts of the striatum and thalamus, and an increment of the rGMR in the dorsal parts as compared with the controls. Lithium treatment increased the ventral caudate rGMR to a trend level in the patients, but had no effect on the metabolism of either the putamen or the thalamus.


CONCLUSIONS
Because of their extensive connectivity to the frontal cortex, striatal and thalamic functional alteration may contribute to faulty decision making processes in PG patients. By increasing the ventral rGMR of the caudate nucleus, lithium treatment may reduce cognitive dysfunction and symptoms in PG patients.
Pallanti
Stefano
S
Department of Psychiatry, Mount Sinai School of Medicine, New York, NY, USA. stefanopallanti@yahoo.it
Haznedar
M Mehmet
MM
Hollander
Eric
E
Licalzi
Elizabeth M
EM
Bernardi
Silvia
S
Newmark
Randall
R
Buchsbaum
Monte S
MS
D000328:Adult; D018692:Antimanic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001479:Basal Ganglia / Q000000981:diagnostic imaging* / Q000187:drug effects; D001931:Brain Mapping; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000523:psychology; D005260:Female; D019788:Fluorodeoxyglucose F18; D007839:Functional Laterality / Q000187:drug effects; D005715:Gambling; D006801:Humans; D018021:Lithium Chloride / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods
D018692:Antimanic Agents; D019788:Fluorodeoxyglucose F18; D018021:Lithium Chloride