Evaluation of Short-Term Psychological Functions in Opiate Addicts after Ablating the Nucleus Accumbens via Stereotactic Surgery

Abstract

Objective: To investigate the short-term psychological function of opiate addicts who have undergone ablative stereotactic surgery targeting the nucleus accumbens (NAc) for alleviating opiate drug psychological dependence. Methods: The psychological functional status of 14 opiate addicts was assessed by standardized psychological tests both before and approximately 3 months after stereotactic surgery. Standardized tests included the Wechsler Adult Intelligence Scale-Revised Chinese (WAIS-RC), the Clinical Memory Scale of Chinese (CMS), the Eysenck Personality Questionnaire (EPQ) and the Symptom Checklist 90 (SCL-90). The evaluation of psychological dimensions included intelligence, memory, personality characteristics and mental health symptoms. Results: Compared with the preoperative state, there was no statistically significant difference in full-scale intelligence quotient (IQ) postoperatively, but without Bonferroni correction a significant decline by 13.55% (p < 0.05) was observed in the Digit Symbol-Substitution subtest of WAIS-RC. The memory quotient (MQ) of CMS demonstrated a significant decline of 10.65% (p < 0.05) postoperatively. Concerning the participants’ personality characteristics, a significant postoperative increase (p < 0.05) was detected in the Psychoticism (P) trait of EPQ. The mental healthy severity indexes of SCL-90 were decreased postoperatively. After Bonferroni correction, however, there was no statistical difference between pre- and postoperative results on all assessments. Conclusions: Although the patients’ intelligence measures were not changed significantly, their short-term memory and attention appeared to decline postoperatively. In addition, there was a trend towards change in some personality characteristics postoperatively. The postoperative mental health levels of the patients increased, indicating a trend towards improvement. Stereotactic ablation of the NAc in opiate addicts may be associated with short-term negative psychological functions. Advisement regarding the safety of the new surgical modality and recommendations for further investigation are necessary.

The Nucleus Accumbens: A Comprehensive Review

“…While some studies have used the AC posterior border [305,306], the posterior commissure (PC) [307], or the mid-commissural point [308,309] as a reference point for determining DBS coordinates, the most often reported reference point is the anterior border of the AC at the midline [303,304,310,311,312,313,314], which has been recognized as the most reliable reference point because it is less affected by ventricular anatomy or the AC-PC distance [35] (see Mavridis and Anagnostopoulou [315]). A comprehensive anatomical examination has been done comparing both gross anatomical specimens and T2-weighted MR images in order to localize the NAc within the ventral striatum [41].…”

“…Bilateral ablation of the NAc has been attempted for the treatment of opiate [309,318] and alcohol [319] addiction with evidence of efficacy, although following surgery, changes in personality characteristics, short-term memory, and attention have been noted [308]. Long-term follow-up notes continued effectiveness [318], but a lack of extensive long-term data has halted the use of ablative treatments, especially in light of the ethical concerns of intentionally causing irreversible damage to brain structures with as many cognitive and behavioral functions as the NAc.…”

Associations between personality changes and nucleus accumbens ablation in opioid addicts

“…By November 2004, this operation had been performed on a total of 272 opiate addicts, and short-term follow-ups revealed satisfactory results [7,8] . However, this treatment was halted due to ethical problems associated with irreversible damage to the brain structure and the lack of long-term follow-up data.…”

Hashimoto’s Encephalopathy with Reversible Diffuse Leukoencephalopathy

“…3,6,7 and 12), including memory, calculation, orientation and language. The cognitive abilities of these patients were evaluated by at least one cognitive scale (Table 1), including the Mini-Mental State Examination (MMSE) [13], the Clinical Memory Scale (CMS) [14] and the Wechsler Adult Intelligence Scale-Revise Chinese (WAIS-RC) [14], except for patient No. 6, who could not cooperate with the detailed cognitive tests on admission.…”