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Volume 8, Issue 4 (Suppl)
J Addict Res Ther
ISSN: 2155-6105 JART, an open access journal
Alcoholism 2017
July 03-04, 2017
Page 35
conference
series
.com
July 03-04, 2017 Kuala Lumpur, Malaysia
7
th
International Conference on
Addictive Disorders and
Alcoholism
Evidence of brain damage in chronic ketamine users – A brain imaging study
Background &Objectives:
The objectives of this study were to ascertain the pattern of grey and white matter volume reduction
and regional metabolic and activation abnormalities in chronic ketamine users, and to evaluate the correlations between these
brain abnormalities and cognitive impairments in chronic ketamine users in Hong Kong.
Design:
The design was a cross-sectional observational study.
Setting:
Counselling Centre for Psychotropic Substance Abusers in Hong Kong was taken as a setting for this study.
Participants:
136 participants were recruited from October 2011 to April 2014. The participants were divided into two groups:
Ketamine users (79) and healthy controls (57).
Main Outcome Measures:
Psychiatric assessments included screening with self-rating questionnaires and face-to-face
interviews. All of the participants completed a detailed cognitive battery that covered general intelligence, verbal and visual
memory, executive functions, motor speed and language. All of the participants underwent magnetic resonance imaging of
the brain.
Results:
Many of the participants in the ketamine group also frequently used cocaine and cannabis. Among the ketamine
users, 12.6% were diagnosed with a mood disorder and 8.9% with an anxiety disorder. The participants in the ketamine group
had worse performance than the healthy controls on tests of general intelligence, verbal, visual and working memory and
executive functioning. In terms of grey matter volumes, the right orbitofrontal cortex, right medial prefrontal cortex, left and
right hippocampus and possibly the left orbitofrontal cortex were smaller in the ketamine group. In contrast, the volumes
of the left basal ganglia, left putamen and possibly the left caudate were higher in the ketamine group. In terms of white
matter volumes, the ketamine group had a lower periventricular white matter volume in the right hemisphere. The grey matter
volumes of the left and right orbitofrontal cortex, right medial prefrontal cortex, left basal ganglia and left putamen, and right
periventricular white matter volume were negatively correlated with the severity of ketamine dependence. The hippocampal
volumes were correlated with performance on the arithmetic, information and digit span tests. The periventricular white
matter volume also correlated with the information score. A functional connectivity examination of the default mode network
revealed significantly decreased connectivity in the medial part of the bilateral superior frontal gyrus, left middle frontal gyrus,
bilateral gyrus rectus, left superior temporal pole, left inferior temporal gyrus, bilateral angular gyrus and bilateral cerebellum
crus II in the ketamine group. This group also displayed increased connectivity in the bilateral precuneus and right inferior
occipital gyrus.
Conclusions:
The results provide imaging evidence of brain damage in chronic ketamine users. Chronic ketamine use was
associated with reduced grey and white matter volumes in certain regions of the brain. Chronic ketamine use was also associated
with altered functional connectivity with the default mode network. Abnormal brain structures and altered functional
organisation of the brain network may underlie the hypersensitivity towards drug related cues but weakened cognitive control
in those with ketamine addiction. Longitudinal or prospective studies would help to strengthen the evidence on the reversibility
of the structural and functional brain damage caused by ketamine.
Wai Kwong Tang
The Chinese University of Hong Kong, China
Wai Kwong Tang, J Addict Res Ther 2017, 8:4 (Suppl)
DOI: 10.4172/2155-6105-C1-029