Discussion, Functional Impairments in ....

FUNCTIONAL IMPAIRMENTS IN PATIENTS WITH BORDERLINE PERSONALITY DISORDERS DEMONSTRATED BY NEUROSPECT HMPAO Tc 99 m IN BASAL CONDITIONS AND UNDER FRONTAL ACTIVATION

DISCUSSION

In a previous publication from our group ^*(http://www.alasbimnjournal.cl/revistas/3/pradoia.htm) we have described the complex, but well defined web of cortical-subcortical circuits that participate in human behavior. These lead to conclude that frontal lobes can be envisioned as structures of rich interconnectivity that integrates information between the external environment and the internal milieu of the subject.

These facts make us remember the significant refinements experienced by the dorso-lateral prefrontal cortex at the time of adolescence in all subjects. In the case of pathological conditions that begin their manifestations in that period of life, like schizophrenia and also borderline personality disorders these facts may have an influence in the clinical manifestation of the respective clinical conditions.

During adolescence normally, there is a diminution of connectivity of the pyramidal cells of the third layer of the cerebral cortex. The activity of this layer is modulated by local inhibitory GABA input circuitry and afferent fibers of dopamine (34). In schizophrenia this area has a diminution in the size of the pyramidal cells in comparison to normal subjects.

Furthermore, if we consider the high sensitivity and specificity parameters used in Scales of neurobehavioral performance such as Levin (35) for brain lesions, we find that these can be correlated with the semiology described by the DSM-IV for borderline personality disorders that are listed ahead (9 of 12 items abnormal and highlighted in bold). These facts allow us to state that there is a functional and anatomical correlation also in borderline patients.

Diminution of initiative/motivation (lack of normal initiative in work or during the use of free time, difficulty to keep performing a task, resistance to accept new changes) (anterior cyngulate gyrus).
Emotional lability. Sudden changes of mood that are disproportionate to the trigger (dorsolateral prefrontal area).
Disinhibition. Inappropriate socialization, commentaries and actions, including sexual, aggressive comments, comments inappropriate to the situation and temperamental explosions (related to orbito frontal area).
Hostility/Lack of cooperation. Animosity, irritability, belligerence, disregard for others, challenge of authority (dysfunction of orbito frontal and dorso lateral prefrontal cortex).
Excitability. Emotional tone increased, increase of reactivity to environment (orbito frontal/dorso lateral prefrontal cortex).
Poor planning/unrealistic targets, failure to take into account personal incapacity, poor definition of plans for future, etc. (dorso lateral prefrontal dysfunction).
Difficulty for insight. Excessive autovaloration with exaggerated opinions with regards to oneself. Increased or subvaloration of the personal capabilities. Differences in the evaluation of personality between psychiatrist and family (dorso lateral prefrontal dysfunction).
Lack of spontaneous interaction. Isolation, difficulties in relations with other people (dorso lateral area and prefrontal dorsal medial area and anterior cyngulate gyrus).
Sadness, pessimism, disappointment (dysfunction of area 25 and anterior cyngulate gyrus).
Motor impairment.
Depressive mood.
Incapacity to confront stressful conditions and to become aware of environmental aspects.

Finally, it is important to consider that this research opens an area of interest for the study of human behavior in the definition of conduct. The present findings although preliminary, shed some light into this matter. Furthermore, these results are concordant with diagnostic and semiologic instruments such are those suggested by Kandel (36) and Kaplan (37), among others.

Furthermore, this could also become a contribution to the approach (38) of understanding personality disorder as manifestations of changes of structure and functions in specific circuitry in the CNS, while in psychotic disorders we would observe exclusively structural changes in cerebral cortex such as in schizophrenia. In the genesis of these clinical conditions we must consider genetic factors as well as environmental issues such as parental relations (39, 40), social stressors, work-related stressors, familiar stressors (41) etc. It is important to consider that an improvement in these factors would have a structural and functional cerebral outcome. For this reason, a successful psychotherapeutic work or pharmacologic approach could temporally or permanently revert changes which are observed under clinical conditions of the Borderline Personality. These statements look forward to the pre and post treatment imagenologic study that we will entertain in the near future.