ORIGINAL ARTICLE The human nucleus accumbens suffers parkinsonism-related shrinkage: a novel finding Ioannis Mavridis • Efstathios Boviatsis • Sophia Anagnostopoulou Received: 18 May 2010 / Accepted: 3 March 2011 / Published online: 15 March 2011 Ó Springer-Verlag 2011 Abstract Purpose The human nucleus accumbens (NA) plays an important role in motivation and emotional processes and is involved in some of the most disabling neuropsychiatric disorders such as Parkinson’s disease (PD). The purpose of our study was to check out the potential existence of a statistically significant difference in NA size between parkinsonian and non-parkinsonian individuals, through studying brain magnetic resonance images (MRIs). Methods For our study we used 52 NAs from 26 cerebral MRIs from neurosurgical patients. Of these MRIs, 15 were preoperative from patients with advanced PD who under- went bilateral deep brain stimulation of the subthalamic nucleus. The group of non-parkinsonian MRIs came from the rest 11 individuals. We measured the absolute and relative NA maximum transverse diameter (D max ), and absolute and relative NA width at a specific transverse plane. Results We found a statistically significant difference of the mean value of the D max (absolute and relative) between the two groups. The mean percentage reduction of the NA size was 11.77% represented by the relative D max . Conclusions To our knowledge, this is the first report of parkinsonism-related shrinkage of the human NA. Further research is needed to identify whether a respective shrinkage is also observed in patients with early PD and whether this atrophy is correlated with dopaminergic neu- ropsychiatric symptoms (perhaps mediated by a malfunc- tioning NA) that occur in PD. Keywords Magnetic resonance imaging Á Nucleus accumbens Á Parkinson’s disease Á Shrinkage Introduction The basal ganglia form a complex network that is involved in the selection and facilitation or the inhibition of move- ments, acts and emotions [17]. The components of the basal ganglia system are the striatum, globus pallidus, substantia nigra and subthalamic nucleus. The striatum is formed by the caudate nucleus, putamen and nucleus accumbens (NA) [12]. The NA, an integral and important part of limbic and prefrontal cortico-striatopallidal-thalamic circuits, seems to function as a limbic-motor interface and is involved in several cognitive, emotional and psychomotor functions altered in some psychopathology [11]. It belongs to the subcortical telencephalic structures that play an important role in motivation and emotional processes, and it is involved in some of the most disabling neuropsychiatric disorders such as Alzheimer’s disease, Parkinson’s disease (PD), depression, schizophrenia, obsessive–compulsive disorder, anxiety disorders, as well as in drug abuse and addiction [11]. Parkinson’s disease, a common neurologic disease, is an archetypal disorder of dopamine dysfunction characterised by motor, cognitive, behavioural and autonomic symptoms. With disease progression, non-dopaminergic nuclei such as the locus coeruleus, the nucleus basalis of Meynert and the I. Mavridis (&) Á S. Anagnostopoulou Department of Anatomy, University of Athens School of Medicine, Mikras Assias str. 75, Goudi, 11527 Athens, Greece e-mail: pap-van@otenet.gr E. Boviatsis 2nd Department of Neurosurgery, Attikon Hospital, University of Athens School of Medicine, Rimini str. 1, Haidari, 12462 Athens, Greece 123 Surg Radiol Anat (2011) 33:595–599 DOI 10.1007/s00276-011-0802-1