Why Don’t Psychiatrists Look at the Brain?

The Case for Greater Use of SPECT Imaging in Neuropsychiatry.

Psychiatrists are the only medical specialists who rarely look at the organ they treat. The odds are that if a patient is having serious problems with feelings (eg, depression), thoughts (eg, schizophrenia), or behavior (eg, violence), the psychiatrist will never order a brain scan. He or she will prescribe medication, psychotherapy, electroconvulsive therapy, or a host of other treatments that will change brain function—but will not know which areas of the patient’s brain work well, which areas work too hard, and which do not work hard enough. In my opinion, the lack of brain imaging has kept psychiatry behind medicine’s other specialties, reducing our effectiveness with patients and hindering our efforts to reduce stigma and improve compliance.

For the most part, psychiatrists base diagnosis and treatment on symptom clusters, not underlying brain dysfunction. Can you imagine the outcry if other medical specialties acted without looking? If orthopedists set fractures without taking x-ray films? If cardiologists diagnosed coronary artery blockages without doing angiograms or computed tomography (CT) scans? Imagine taking your car to a mechanic because it is smoking, using too much gas, and stalling in the middle of intersections. The mechanic listens to this list of symptoms, looks at the outside of the car, and decides to change the fuel pump without ever turning on the engine or popping the hood. What would you do? Probably go somewhere else. Yet, the state of the art in psychiatry is to not look at the organ we treat.

Researchers tell us that it’s not yet time to use imaging tools in psychiatric practice, even though high-resolution single-photon emission computed tomography (SPECT) and positron emission tomography (PET) scans of the brain have been available for more than 15 years. They say that more research is needed to determine the specificity and sensitivity of these imaging tools, even though there are hundreds of articles on functional brain imaging for a host of neuropsychiatric disorders (see Brain Science for a detailed reference list). And by the way, they ask, how would imaging tools help the practicing clinician? What would a SPECT scan do to change the clinical management of a patient?

This article will address these issues and discuss the practical use of SPECT imaging for three important neuropsychiatric areas: brain trauma, substance abuse, and violence. The views I’ve outlined in this article are based not only on the published research that I’ve cited but on my experience over the past 11 years with more than 10,000 SPECT studies, both as a treating psychiatrist and a physician licensed to perform these studies for others.

SPECT: A BRIEF OVERVIEW

Brain SPECT imaging is a nuclear medicine study that uses minute doses of isotopes bound to neurospecific pharmaceuticals to study regional cerebral blood flow (rCBF) and thus, indirectly, brain metabolic activity.(1) The instruments used to measure rCBF have evolved greatly over the past two decades. Imaging detectors have been developed that provide three-dimensional representations of rCBF, similar to the images created by PET technology. Like PET, more advanced SPECT cameras have multiple heads, which increases the resolution of images and reduces the time necessary to complete scans. Although some authors have argued that the value of SPECT is limited by poor resolution,(2) the resolution of contemporary multihead SPECT cameras has entered the same realm as PET, and at considerably less cost.(3) Also, SPECT cameras are located in many US hospitals, whereas PET cameras tend to be located in university research centers.

The radiation exposure from SPECT has been cited as another reason to avoid its use, especially with children. However, according to the American Academy of Neurology, SPECT is a safe procedure.(4) The average radiation exposure from one scan is 0.7 rem, an amount similar to that from a routine radionuclide bone scan or brain CT. Unfortunately, the radiation exposure concern has limited the collection of normative samples. To address this issue, the Society of Nuclear Medicine has established a large normative database at Yale University for clinical and research use. Also, Chiron et al have published a normative database of pediatric scans, which demonstrates that a SPECT study of a two-year-old child shows the same relative rCBF pattern as the adult brain.(5) Ultimately, symmetry is the hallmark of a normal study.(6)

Compared with PET, quantitative EEG, and functional magnetic resonance imaging (fMRI), brain SPECT imaging is more frequently covered by third party carriers—at least when properly ordered for medical indications (eg, to rule out frontal or temporal lobe disorders, dementia, and brain trauma). Moreover, SPECT is typically less expensive than PET or fMRI—in California, for example, approximately half the cost of the other techniques.

The Society of Nuclear Medicine currently lists the common indications for brain SPECT imaging as the evaluation of suspected brain trauma, evaluation of suspected dementia, localization of epileptic foci, and the detection and evaluation of cerebral vascular disease.(7) Brain SPECT imaging, like any kind of medical test, should be ordered only when it adds clinically relevant information that helps practitioners provide improved care. Below, I highlight the role that SPECT can play in the various phases of neuropsychiatric care, including diagnostic, prognostic, and treatment considerations.

BRAIN TRAUMA

Brain trauma frequently impacts behavior, cognition, and emotion. Documentation of the extent and location of brain injuries is essential for several reasons, including accurate diagnosis, prognosis, treatment planning, and forensic evaluation.

The literature indicates that SPECT is a sensitive and useful tool for evaluating perfusion abnormalities, not only in cases of blunt brain trauma but also postconcussion syndrome(8) and whiplash.(9) Minor injuries that leave brain tissues grossly intact may nonetheless cause perfusion abnormalities that can be seen on SPECT for extended periods, even if the patient never lost consciousness.(10) Indeed, researchers have demonstrated that functional imaging may be more sensitive than MRI or CT for detecting the effects of mild to moderate brain injury.(11,12) This sensitivity is important because patients with headaches, memory loss, concentration difficulties, dizziness, and emotional lability may be wrongly labeled as malingering if their EEG, CT, and MRI scans are normal after a brain injury.

Typically, SPECT findings in brain trauma include focal areas of decreased perfusion, often in a coup-contrecoup pattern (such as decreased perfusion in the left anterior prefrontal cortex and right occipital lobe, or the anterior and posterior aspects of a temporal lobe); in some instances there may be marked hyperperfusion over the site of the injury.

How can SPECT help in patient management? One often-overlooked contribution is that abnormal SPECT studies may improve treatment compliance; patients more readily accept help for something they can see. SPECT can also uncover, in clinically confusing or complex cases, the presence of forgotten brain trauma; it is common for patients to forget even significant incidents of brain injury. This may be due to amnesia surrounding the trauma, psychological repression, or the fact that the event occurred at a relatively young age. Finally, SPECT can help target medical treatment, guiding physicians to prescribe anticonvulsants if there are focal areas of hypo- or hyperperfusion in the temporal lobes; psychostimulants if there is diffuse hypoperfusion in the prefrontal cortex; antidepressants if there is hyperperfusion in the limbic system; or antidepressants with anti-obsessive properties if there is diffuse hyperperfusion in the anterior cingulate gyrus.

The following are two examples of how SPECT can be useful in the clinical evaluation of brain trauma.

Patient T, 15, exhibited severe conduct problems. From an early age, he had been hyperactive, impulsive, moody, and had learning difficulties. When he was 18 months old, he fell down a flight of stairs and briefly lost consciousness; he was taken to the hospital, where a CT scan was read as normal. However, after the incident he was never quite the same, according to his mother. By age 15, he had been arrested for shoplifting, often cut school, and was defiant and hostile toward his parents. His social development was poor. He had been treated with numerous medications without success; he had already been in two residential treatment programs and was on his way to a third when he arrived at our clinic for evaluation.

A SPECT study showed severe damage to T’s left prefrontal cortex, left occipital lobe, and both temporal lobes (see Figures 1, 2, 3 and 4). A combination of an anticonvulsant (to stabilize his temporal lobe) and a psychostimulant (to increase prefrontal cortex perfusion) was prescribed. The combination provided improved mood stability and impulse control. As a result, T was able to live at home with less turmoil. Moreover, T and his parents gained a better understanding of his problems, which allowed emotional healing to begin, and the school placed him in a program for brain-injured children rather than just labeling him with a behavioral disorder.

Figures 1-4: T’s , figures 1 and 2 are top down surface views, and figures 3 and 4 are underside surface views

The second patient, C, a 32-year-old dentist, was rear-ended by a truck on the freeway. Her head jerked back and forth forcefully but never hit anything. Nonetheless, she felt dazed for several days after the accident, and other problems emerged as well. She complained of a headache for months, had memory problems, struggled with her work, and was irritable. However, her insurance company denied disability benefits because the evaluating physician wrote that C had never hit her head and thus could not have had a brain injury.

C’s psychologist, whom she saw for family problems, referred her to our clinic for evaluation. Her SPECT study revealed markedly decreased perfusion in the anterior and posterior aspects of her left temporal lobe, a coup-contrecoup injury, and decreased activity in the inferior orbital prefrontal cortex (see Figure 5). This information proved useful for obtaining disability benefits, in helping C’s family understand that she had a brain injury, and in directing treatment (neurofeedback over the site of her left temporal lobe). Within six months, she was back to work with improved functioning.

VIOLENT OR AGGRESSIVE BEHAVIOR

In my experience, SPECT is a valuable tool for evaluating patients with violent behavior. SPECT helps to assess the functional integrity of brain systems frequently implicated in violence, such as the prefrontal cortex,(13-15) the temporal lobes,(14,16-18) and the anterior cingulate gyrus.(14) Different types of deficits may require different interventions. Thus, identifying the type of brain dysfunction a patient has may have a major impact on clinical management.(19)

According to Raine and colleagues, emotional and unplanned acts of violence may be the result of a person’s inability to utilize his or her prefrontal cortex to regulate the aggressive impulses that can be generated by subcortical structures of the brain.(20) In one study, Raine found structural deficits in the prefrontal cortex associated with antisocial personality disorders (APD).(15) The researchers studied 21 community volunteers with APD, half of whom had committed aggressive attacks on strangers. MRI revealed that the mean prefrontal gray matter volume was 11% lower in the subjects with APD than in two different control groups (34 healthy subjects and 26 matched individuals with other psychiatric disorders).

Although this study and others have linked structural deficits in the frontal lobes to violent behavior, a person can have a structural evaluation that is within normal limits and yet have significant functional abnormalities in these tissues. Thus, MRI, CT, and other structural techniques may not provide clinical information with the same sensitivity as SPECT and PET.

Many studies have reported blood flow and metabolic abnormalities in the temporal lobes of violent individuals, generally in the left hemisphere.(14,16-18) Amen and colleagues found temporal lobe abnormalities, usually left-sided, in 72.5% of 40 adolescents and adults who exhibited violent or aggressive behavior.(14) Soderstrom retrospectively compared violent subjects’ SPECT and MRI scans, taken from pretrial forensic psychiatric evaluations, with those of control subjects.(18) Even after the researchers adjusted for the presence of major mental disorders, substance abuse, and current medication use, the violent group displayed a significantly different functional brain pattern. Sixteen of the 21 impulsively violent subjects showed some hypoperfusion in the temporal and/or frontal lobes. However, MRI failed to show any corresponding structural damage or abnormalities. A similar study, by Volkow and Tancredi, of recidivistic violent offenders revealed that the largest functional deficits in the temporal lobe were found in their subjects whose structural CT scans were normal.(21)

Violent individuals have also shown atypical SPECT patterns in the medial aspects of the frontal lobes. Amen et al found not only decreased perfusion of the prefrontal cortex and left temporal lobe in violent psychiatric patients, but also increased perfusion of the anterior cingulate gyrus, a pattern associated with problems of cognitive inflexibility and repetitive negative thoughts.(14) Work by Tiihonen et al has also linked dysfunction of the medial frontal lobes with violent behavior.(22)

Given the different types of brain dysfunction associated with violent behavior, it is perhaps not surprising that the literature indicates that specific medications may be best suited for treating particular patterns of brain dysfunction. Several authors have suggested that selective serotonin reuptake inhibitors are effective in treating disorders that involve perfusion abnormalities in the medial aspects of the frontal lobes (eg, obsessive- compulsive disorder).(23,24) Significant rCBF reductions in the medial frontal lobes of violent patients may help reduce these patients’ tendency toward cognitive inflexibility and repetitive negative thoughts. Anticonvulsant medications have also been used successfully to treat violence and aggression.(25,26)

Here are two examples of how SPECT can be helpful in the clinical evaluation of this population.

For no obvious reason, patient A, a nine-year-old boy, attacked a young girl on the baseball field. He also began to experience spontaneous suicidal and homicidal thoughts, drawing pictures of himself hanging from a tree and shooting other children. In addition, for nine months prior to evaluation, he was negative, irritable, and moody. His family doctor recommended psychotherapy, which proved ineffective. When he was brought to our clinic for evaluation, a SPECT study revealed a complete lack of perfusion in the left temporal lobe region (see Figure 6). An MRI revealed an arachnoid cyst, the size of a golf ball, occupying his left middle cranial fossa. When the cyst was drained, the boy’s violent thoughts ceased and his mood and behavior improved dramatically.

Patient J, 16, had serious problems with aggression. He had been expelled from five schools for fighting; he was also oppositional, argumentative, and underachieved in school. There was a family history of violence (his father and uncle had spent time in prison for aggressive acts). J’s SPECT study was highly abnormal, showing marked hyperperfusion in the anterior cingulate gyrus as well as significant hypoperfusion in the prefrontal cortex and temporal lobes (see Figures 7, 8 and 9). He was placed, sequentially, on a combination of an anticonvulsant to stabilize his temporal lobes (our clinical experience tells us to do this first), an antiobsessive antidepressant to calm anterior cingulate gyrus hyperperfusion, and finally, a psychostimulant to enhance prefrontal cortex activity. Over the next year, his grades and behavior improved; he said that the scans helped him understand his problems and that he wanted to comply with treatment in order to "tune up" his brain.

SUBSTANCE ABUSE

I have found that SPECT can provide valuable information in the prevention, evaluation, and treatment of substance abuse. For example, three-dimensional SPECT images of brain damage caused by substance abuse can serve as striking visual aids in educational efforts, perhaps deterring persons (especially children and teenagers) from abusing drugs. SPECT studies may also help to break through the psychological barriers that people with substance abuse problems often erect: When patients are faced with vivid images of the abnormal cerebral perfusion in their own brains, it is harder for them to remain in denial about their problem. Moreover, SPECT can help clinicians determine the presence of other neuropsychiatric conditions (eg, brain trauma) that may be contributing to a patient’s drug abuse.

Several perfusion abnormalities in brain areas related to behavior (especially the frontal and temporal lobes) have been found in people with substance abuse problems.(27) Over time, many amphetamine and cocaine abusers develop multiple cerebral perfusion defects that are visible on SPECT, even after six months of abstinence.(28) Alcohol abuse is also associated with perfusion abnormalities, especially in the frontal and temporal regions. Nicolas et al performed SPECT studies on 40 patients with chronic alcoholism and found that, compared with normal controls, subjects who abused alcohol showed significantly decreased perfusion in all lobes of the brain.(29) Perfusion defects were most frequently seen in the frontal lobes (65% of subjects) and correlated with cognitive deficits on neuropsychologic testing. Chronic marijuana smoking and opiate abuse also seem to reduce cerebral blood flow, particularly in the frontal and temporal lobes.(30,31) These functional abnormalities are often found in tissues that are otherwise structurally intact. Fortunately, some authors report that the reductions in cerebral blood flow associated with chronic use of ethanol, nicotine, inhalants, and solvents are at least partially reversible with abstinence.

Here is an example of how SPECT can be helpful in the management of substance abuse patients.

Patient G, 37, was a corporate executive who used alcohol and cocaine daily. Although his work performance was poor and his family relationships strained, he did not acknowledge or even recognize his problem. His psychiatrist referred him for a SPECT study to confront him with the biologic evidence of potential brain impairment. His SPECT study indeed showed hypoperfusion in multiple brain regions, especially the prefrontal cortex and temporal lobes (see Figure 10). The scan helped convince G that his drug abuse was a problem, and he entered a treatment program. A scan taken a year later, when G was drug-free, showed improved perfusion, although the pattern was still not normal (see Figure 11).

CONCLUSION AND CAVEATS

When used properly, SPECT can be a useful tool in evaluating brain dysfunction in patients with brain trauma, violent behavior, or substance abuse, as well as numerous other indications not described here. However, a number of factors limit the wide-scale use of SPECT, including the sophistication of imaging equipment (single-head cameras are inferior to the newer multihead units) and the experience of the physicians interpreting the scans and utilizing the data. Finally, as with any medical test, SPECT should only be used in the context of a patient’s clinical history and examination. It is not a "doctor in a box," and findings need clinical correlation.

About the Author
Daniel G. Amen, MD, is a child and adult psychiatrist licensed in nuclear brain imaging. He is the Medical Director of the Amen Clinics, in Newport Beach and Fairfield, California, which have a database of over 10,000 brain SPECT studies for neuropsychiatric indications. Dr. Amen completed his psychiatric training at Walter Reed Army Medical Center in Washington, DC, and his child psychiatry training at Tripler Army Medical Center in Honolulu. He has won research and writing awards from the American Psychiatric Association and the Baltimore-DC Institute for Psychoanalysis. Dr. Amen has published numerous professional articles and 17 books, including Change Your Brain, Change Your Life (Random House, 1999) and Healing ADD (Putnam, 2001).

Dr. Amen’s SPECT work with substance abuse patients was featured on the television documentary The Truth About Drinking,which won an Emmy Award in 1999 for Outstanding Children’s Program.

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