Pop diva Ariana Grande recently surprised her fans with an Instagram post that purportedly showed images of her brain in comparison with scans of a "healthy brain" and the "brain of a person with PTSD" (posttraumatic stress disorder). The only words in the post say: "hilarious and terrifying" and "not a joke." For those of you who may have forgotten, on May 22, 2017, a suicide bomber detonated an improvised explosive device packed with shrapnel in front of the Manchester Arena in England where Grande had just finished performing. Twenty-two people died and 139 were wounded. More than half of the victims were children. On June 4, 2017, Grande hosted a benefit concert in Manchester entitled "One Love Manchester" at Old Trafford Cricket Ground, which was broadcast live on television, radio, and social media. At the concert, Grande performed along with several other high-profile artists. Free tickets were offered to those who had attended the May 22 show. The benefit concert and associated Red Cross fund raised £17 million for victims of the attack. In an interview in Elle magazine, Grande says how that experience fundamentally changed her: "You hear about these things. You see it on the news, you tweet the hashtag. It's happened before, and it'll happen again. It makes you sad, you think about it for a little, and then people move on. But experiencing something like that firsthand, you think of everything differently. Everything is different." Although we have no reason to doubt Ms. Grande's self-disclosure of PTSD, whether the brain scans she shared on Instagram can diagnose this condition is another question. There is and has been a great deal of interest in the use of functional neuroimaging methods to elucidate the underlying "circuitry" involved in mental disease states such as dementia, posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI). These are significant problems that affect a great number of people, in both civilian and military settings. Technologies and Techniques Some of the functional neuroimaging methods currently in use include functional MRI, single-photon emission computerized tomography (SPECT), diffusion magnetic resonance imaging (D-MRI), and arterial spin labeling (ASL). Functional MRI measures brain activity by detecting changes associated with blood flow. Neuronal activation is coupled with cerebral blood flow- increased activity is associated with increased blood flow to that area of the brain. Functional MRI uses blood oxygenation level-dependent contrast, which is useful in research because it does not require people to undergo injections or surgery, to ingest substances, or to be exposed to ionizing radiation. ASL, also known as arterial spin tagging, is a magnetic resonance imaging technique used to quantify cerebral blood perfusion by labeling blood water as it flows throughout the brain. ASL uses arterial blood water, which is magnetically "labeled" using radio-frequency pulses, as a diffusible flow tracer. ASL techniques are noninvasive and do not require an exogenous contrast agent. D-MRI uses the diffusion of water molecules to generate contrast in MR images. Molecular diffusion refers to the random translational motion of molecules (remember Brownian motion?) as a result of the thermal energy carried by these molecules. Molecular diffusion in tissues is not free, but reflects interactions with many obstacles, such as macromolecules, fibers, and membranes. Water molecule diffusion patterns can therefore reveal microscopic details about tissue architecture, either normal or in a diseased state. It has been especially useful in cases of acute brain ischemia. SPECT is a nuclear imaging test which uses an injected radioisotope (99mTc-HMPAO- hexamethylpropylene amine oxime) to measure blood flow in different areas of the brain. It is very similar to conventional nuclear medicine planar imaging using a gamma camera (that is, scintigraphy) but can provide true 3D information. It has been used as a brain scan, particularly in dementia, epilepsy, and head injuries as well as for heart problems and bone disorders. Of all the above modalities, SPECT is the least sensitive. Research and Clinical Applications Two reviews of functional neuroimaging techniques in patients with PTSD (Van Boven, et al. and Hughes and Shin) have focused on elucidating the neurocircuitry involved and the clinical applications of various imaging techniques. A proposed neurocircuitry model of PTSD involves the amygdala, medial prefrontal cortex (mPFC), and hippocampus. According to Hughes and Shin (2011), "the amygdala is hyperresponsive, leading to an exaggerated fear response. By contrast, regions of the ventral mPFC (vmPFC; including rostral anterior cingulate cortex [rACC] and ventral medial frontal gyrus) are hyporesponsive and fail to inhibit the amygdala. This hyperresponsivity may also be related to impaired fear extinction in PTSD." Van Boven, et al. (2009) stress that modern neuroimaging needs to be able to detect subtle but significant abnormalities in mild TBI [traumatic brain injury] and PTSD. "Several MRI methods have excellent potential to help visualize metabolic, microstructural and functional network changes related to resting and cognitive states." In addition, "Multimodal techniques may emerge as helpful orthogonal approaches to enhance the yield of detection and characterization of abnormalities. These methods may provide complementary information about the neural, glial, vascular, and network conditions that subserve cognitive and behavioral states." The take-away lesson from these reviews is that neuroimaging studies are becoming useful for detecting abnormalities and errors in circuitry in disease states such as TBI and PTSD, but are not yet at the stage of being routine diagnostic tools. Currently, the American Psychiatric Association does not support the use of functional brain imaging for the diagnosis of neuropsychiatric disorders (except in the case of the judicious use of PET scans in patients suspected of having dementia). Dr. Susan Bookheimer, director of the Intellectual and Developmental Disabilities Research Center at UCLA's David Geffen School of Medicine, cautioned, in a recent Washington Post article, about the use of low-resolution scans in the diagnosis of PTSD: "If one studies a large group of individuals with PTSD and compares them with those without trauma using a much higher resolution brain scanning technique such as functional MRI at 3 Tesla, or possibly PET with a sensitive new radioligand, one may see brain differences at the group level. But without diminishing the truly awful events that she [Ariana Grande] experienced, and those of the many individuals with PTSD experience, the changes that occur in the brain are far too subtle to be imaged using today's techniques, and especially SPECT if that is what this is, even though there are practitioners out there who will make such claims (and often, will charge a lot of money). There is no FDA-approved imaging technique for diagnosis or revelation of PTSD, and nothing similar in the U.K." In 2013, the National Institutes of Health joined with several other federal agencies to launch the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative. The project is slated to invest $4.5 billion over 10 years to map brain circuits, understand patterns of electrical and chemical activity in those circuits, and explore how their interplay creates cognitive and behavioral capabilities. Perhaps, then, functional neuroimaging may be advanced to the point of being a tool in the diagnosis of a variety of mental health conditions. Source
