Wednesday, December 14, 2011

Born This Way?



A group of investigators from the University of Iowa have published a case report about a 14 year old boy with severe antisocial behavior (Boes et al., 2011):
He is aggressive, manipulative, and callous; features consistent with psychopathy. Other problems include: egocentricity, impulsivity, hyperactivity, lack of empathy, lack of respect for authority, impaired moral judgment, an inability to plan ahead, and poor frustration tolerance.
MRI findings revealed a small congenital malformation in his left ventromedial prefrontal cortex (vmPFC), which has been associated with decision making and the regulation of emotional behavior (Grabenhorst & Rolls, 2011; Mitchell, 2011).

Figure 1 (Boes et al., 2011). MRI Images. 1A. This is an oblique coronal T2 image at the level immediately anterior to the horn of the lateral ventricles. Note the hyperintense white matter just deep to the gyrus rectus (indicated by arrow) with a linear extension tapering as it courses toward the anterior horn of the ventricle. Also note the cortical thickening of the left gyrus rectus relative to the right gyrus rectus. 1B. This coronal T1 MPRAGE image shows thickening of the left ventromedial prefrontal cortex [PFC] and blurring of the gray-white interface in this same region. 1C. This is a surface rendering of B.W.'s brain viewing the medial left hemisphere surface with thickened cortex highlighted, which approximates the lesion site.


The boy (patient B.W.) had MRI scans at the ages of 4, 11, and 13. The three main neuroanatomical findings remained stable across the three scans. Although the abnormalities appear to be relatively minor, the authors described them as consistent with a focal cortical dysplasia affecting portions of Brodmann areas 11, 12, 25, and 32.

Did these anatomical anomalies cause B.W.'s aberrant behavior? He reached normal developmental milestones until the age of 4, when he started having seizures. He was prescribed divalproate, an anticonvulsant (and mood stabilizer) which temporarily controlled his seizures. But they returned between the ages of 6-11 yrs, when he started having complex partial seizures every few months. Complex partial seizures are typically associated with an alteration of consciousness and foci in the medial temporal lobes, although they can also originate in the frontal lobes (Williamson et al., 1985). More details of B.W.'s behavior from the case history:
At age six B.W.'s parents reported the onset of defiance at home and at school, including: stealing, lying, aggression, rage, rude language, and disobedience. His parents referred to this as his 'contraband' period because he would consistently bring prohibited items to school (e.g. a pocketknife). He also stole cookies and would sell them to peers. The parents were very concerned about this behavior because it did not seem characteristic of B.W.‟s previous temperament. Moreover, neither parent nor any sibling of B.W. had similar behavioral problems. He was seen by a child psychologist and diagnosed with oppositional defiant disorder and started counseling, which was discontinued after a few visits.

During ages seven to nine B.W.'s parents describe a 'cause and effect problem' in which he would behave badly and be punished and the following day would engage in the same behavior that led to the punishment. Along with his lack of response toward punishment, B.W. was impulsive and showed a lack of respect toward authority, including teachers and parents. In an effort to provide greater structure and discipline than the school could provide the parents decided to begin home-schooling B.W. and his siblings when he was nine years old... Despite behavioral problems and lack of self-motivation he was noted to be intelligent and academically capable. The following year a child psychiatrist diagnosed B.W. with attention deficit hyperactivity disorder and bipolar disorder, for which he was prescribed carbemazepine, topiramate,1 and dexmethylphenidate [the d-enantiomer of Ritalin]. Counseling was again attempted briefly without effect.

At age 11 B.W. presented to the emergency room of a large tertiary care center with his mother for suicidal ideation. While at a nearby shopping mall he expressed feelings of hopelessness, unworthiness, and wanting “to kill myself… I would cut or burn myself.” The talk of suicide had been ongoing for two months and had been accompanied by suicidal gestures such as jumping from a second story deck onto a trampoline and a superficial laceration to the left hand because “I wanted to kill myself.” Along with the suicidal gestures the parents were alarmed about escalating aggression, destructive behavior, wandering off, and hypersexual behavior that included masturbation, accessing porn sites on the web, and asking younger peers to disrobe in a domineering manner (despite being pre-pubescent at the time). During the admission interview he reported that he had been hearing voices at night from God and the devil motivating him to do good and bad things, respectively.
When he was hospitalized, B.W. admitted that he was fabricating the psychotic and suicidal symptoms, along with his self-reported levels of high anxiety and depression. Hospital staff found him manipulative and easily angered. He was given the diagnoses of oppositional defiant disorder, ADHD, and mood disorder not otherwise specified. He was no longer considered bipolar. After discharge his antisocial behavior escalated. He started fires, assaulted the principle, resisted arrest, threatened his mother with a knife, and hit his father over the head with a wrench "in cold blood, without any emotion."

Neuropsychological testing revealed his IQ and cognitive functioning to be in the average range, although he had problems with planning and with the Iowa Gambling Task, where he could not learn which decks were safe (vs. risky). He was also given a moral judgment task:
On his first attempt, B.W. skipped several questions and scribbled over the entire second sheet and drew a goblin. He completed the task at a later date.
He eventually tested at a “relatively immature, preconventional, stage of moral development, in which moral dilemmas were approached primarily from the perspective of avoiding negative consequences for one's self.”

On the Antisocial Process Screening Device filled out by his parents, his scores were at the 99-100th percentile for callous-unemotional, narcissism, impulsivity, and total score.

Recently (summer 2011), B.W. underwent intracranial mapping of the left ventromedial frontal and anterior temporal regions for monitoring of seizure foci, and subsequent surgical resection of left prefrontal and left temporal regions (including the amygdala). Pathological examination of this tissue revealed dysplastic neurons. Post-surgery, B.W. is on lamotrigine and has remained seizure-free.

The authors concluded that B.W.’s bad behavior was caused by the vmPFC abnormality for the following reasons:
1) The behavioral and neuropsychological profile described in the results section is strikingly consistent with prior cases of focal vmPFC lesions. … The severity of behavioral problems is more extreme than previously reported following vmPFC damage but this may represent an extension of prior reports of more severe outcomes following early-onset lesions... 2) There is a complete absence of externalizing and antisocial behavioral problems in B.W.’s family, suggesting a lower likelihood of a genetic predisposition. … 3) B.W. has exceptionally few social risk factors. He has intelligent, extraordinarily caring and motivated parents. They are raising his five siblings without behavioral problems. 4) One could argue that microscopic dysplastic tissue of the left amygdala and anteromedial temporal cortex may also have contributed significantly to B.W.’s behavioral problems. … [but] we believe it is safe to attribute the severe behavioral impairment to B.W.’s vmPFC malformation or the combination of the vmPFC and anteromedial pathology...
My assumption is that all of the testing took place before surgery, which was only mentioned as an afterthought. So we have no measure of long-term outcome. And since he is only 14 yrs old, he cannot (or should not) be diagnosed as a psychopath:
... psychopathy is not normally diagnosed in children or adolescents, and some jurisdictions explicitly forbid diagnosing minors with psychopathy and similar personality disorders. This is because such a diagnosis "fails to capture the emotional, cognitive, and interpersonality traits — egocentricity and lack of remorse, empathy, or guilt — that are so important in the diagnosis of psychopathy."[65]
However, Boes et al. explicitly asked, “Is B.W. a psychopath?” They seem to think he is but then backed off with the following statement:
We used the Antisocial Process Screening Device, a tool to evaluate “psychopathic tendencies” in children. B.W. scored high in all domains of the test with an overall score in the 99.8 percentile. The authors of this screening tool caution against applying the label psychopath to any child because of its derogatory connotations. In this regard we agree and will instead say that B.W. shares several of the interpersonal and affective characteristics commonly seen in developmental psychopathy.
At any rate, this was the first report of antisocial behavior in an adolescent with congenital abnormalities in this specific region. Although most previously reported patients with vmPFC damage have acquired the lesions as adults, an earlier study by the Iowa group tested two individuals whose lesions occurred before the age of 16 months (Anderson et al., 1999). Those two patients were said to have “defective social and moral reasoning” and “a syndrome resembling psychopathy.” Or as so charmingly stated in the headline of a news article at the time:
Brain Damage Found to Impair Morals

October 19, 1999 | Sandra Blakeslee, New York Times

Scientists have identified rare cases in which injuries to the brain in infancy prevented people from learning normal rules of social and moral behavior in childhood and adolescence. When the infants reached adulthood, they showed no guilt or remorse for their bad behavior and seemed destined never to get along in social situations.

In the case of B.W., it is critical to follow up with additional observation and testing. Did removal of the anatomically and electrically abnormal brain tissue have a positive effect on his behavior?


Footnote

1 Presumably, the divalproate (Depakote) that controlled his seizures wasn't helping his "bipolar disorder" symptoms, so two different anticonvulsants/mood stabilizers were prescribed. His diagnosis was later changed to "mood disorder not otherwise specified" along with ADHD and oppositional defiant disorder.


References

Anderson SW, Bechara A, Damasio H, Tranel D, Damasio AR. (1999). Impairment of social and moral behavior related to early damage in human prefrontal cortex. Nat Neurosci. 2:1032-7.

Boes, A., Hornaday Grafft, A., Joshi, C., Chuang, N., Nopoulos, P., & Anderson, S. (2011). Behavioral effects of congenital ventromedial prefrontal cortex malformation BMC Neurology, 11 (1) DOI: 10.1186/1471-2377-11-151

Grabenhorst F, Rolls ET. (2011). Value, pleasure and choice in the ventral prefrontal cortex. Trends Cogn Sci. 15:56-67.

Mitchell DG. (2011). The nexus between decision making and emotion regulation: a review of convergent neurocognitive substrates. Behav Brain Res. 217:215-31.

Williamson PD, Spencer DD, Spencer SS, Novelly RA, Mattson RH. (1985). Complex partial seizures of frontal lobe origin. Ann Neurol. 18:497-504.

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