O.K., so the title is not very original. Akin to "you can tune a piano, but you can't tuna fish". Don't get me started; there's plenty of one-liners in my repetoire.
I enjoy a play on words; their meaning can differ by context. For neuropsychologists, "denial" has multiple meanings. Denial is a psychological defense mechanism used (consciously or unconsciously) to minimize or ward off conflicted feelings, urges or responsibility for behavior. In the hierarchy of psychological defenses (e.g., repression, projection, rationalization) it is arguably the most primitive and fragile. In early stages of recovery, alcoholics are said to be in denial of their illness. Stages of grief are said to begin with denial. When denial is breached, a flood of emotion will invariably emerge. At this point the psychological integrity of the individual depends on support from family, friends and professionals as well as an ability to marshal healthier defenses and a willingness to face the conflict.
Neurologically, "denial" is associated with brain damage, particularly to the right frontal-parietal regions. This is different from psychological denial. I observed a classic form of neurological denial during my first year of internship at Mt. Sinai Hospital's Department of Neurosurgery service. A patient was admitted for surgical removal of a brain tumor located on the right frontal-parietal brain region. The tumor was compressing the motor and sensory portion of the brain that caused the patient to experience no sensation and paresis of the (opposite side) left upper extremity. On morning rounds, the patient was alarmed that someone had played a cruel joke on him by placing someone else's left arm in his bed! To demonstrate his concern, he routinely raised the limp left arm, as if it was not his own. I was amazed that I was witnessing the classic "anosognosia" described by the French neurologist Babinski many years ago. A less severe form of neurologic denial is termed "neglect," wherein a person will neglect the left side of space. We had a patient with spatial neglect who would not eat from the left side of his plate or shave the left side of his face. Though vision (optic nerve) is functional, damage to right parietal regions can cause a neglect or inability to integrate visual information on the left side of each eye (not blindness). Not surprisingly, patients with slow growing tumors to right parietal brain regions may have a tendency to bump into objects on their left side. This can be of great concern when multiple car accidents result from left-sided inattention. Sometimes, a history of multiple car accidents to one side may alert an astute clinician to rule out neurological neglect of space. When patients are confronted with these facts (i.e., hemiparetic left arm, bumping into objects, motor vehicle accidents on the left side of the car), neurologic"denial" is the typical response (not their arm, someone else caused the car accidents). This condition should be differentiated from a recent syndrome (SMS-Soccer Mom Syndrome) caused by mini-vans rapidly backing out of the garage (clipping the side view mirror or knocking over the mailbox) to get a child to soccer practice. Denial in this case is often attributed to the garage opening being too narrow or the mailbox "getting in the way".
I became very interested in the role of parietal lobe dysfunction and denial when I evaluated more cases at the hospital. Critchley's 1950's book on the "Parietal Lobes" helped me understand neurologic denial. Critchley posited that body image perception was one function of the parietal lobe, particularly on the right side of the brain. Therefore, damage or dysfunction to this region could lead to altered body perception. So, denial of deficits could be the result of body misperception. I concluded this is likely on a continuum, as some patients were aware of their deficits but exhibited "la belle indifference". By contrast, patients with left parietal lobe damage may often exhibit a catastrophic reaction to their deficits. For example, neuropsychological testing can include immediate performance feedback (to the patient) measuring their learning curve on a new task. Left parietal lobe patients often cry, or become angry with their mistakes. The right parietal lobe patient may seem indifferent to their errors.
Right parietal lobe dysfunction, affecting body image perception, led me to think about anorexia. Some studies on anorexics had demonstrated their tendency to over-estimate body size. I hypothesized that perhaps anorexics had some parietal lobe dysfunction that could be measured on neuropsychological tests. I was very excited about pursuing this line of research. However, I already started a major study on frontal lobe dysfunction for my doctoral thesis. To this day, I believe the anorexic study would be a very fascinating topic (if not already done) for a budding graduate student.
Neurologic denial is not limited to hemiparetic arms or not shaving the left side of one's face. Its complexity is seen particularly with individuals who make a good recovery in a patient's adjustment to his permanent deficits. A few examples of this challenge are: denial of memory deficits, inability to safely operate a motor vehicle, and difficulty accepting vocational/educational limitations. The neuropsychologist, often called upon to conduct objective testing of a patient's abilities (and limitations), can become a target of patient frustration when a "reality check" is rendered. Patients who sustain right parietal lobe damage, can "neglect" the left side of space. Neuropsychological testing can assess a patient's reaction time, visual scanning speed and ability to make rapid visual judgments. Through the course of my career, I have had the unpleasant duty (on numerous occasions) of advising that an individual's driver's license be suspended. Though family members of the patient are relieved and grateful for this news, the patient usually feels otherwise. I always offer a patient the option of a second opinion. Some patients, upon hearing the same recommendation from colleagues, will seek out a 3rd, 4th and 5th opinion. Sadly, even when referred for counseling, neurologic denial can be life-long and intransient. Other patients begin to undertstand their limitations over time, but vehemently insist that, with additional physical or occupational therapy, they will drive again...get their old job back...or even regain full use of a hemiparetic limb.
I have compassion for these patients, even if I'm unpopular with them for taking their license away. When an individual's freedom and independence are limited, it is difficult to accept. This is true with the elderly as well, who must relinquish their freedoms when physical or mental demands exceed their abilities. This "hit home" for me a few years ago, when I received a frantic call from my oldest daughter who was watching the younger children while my wife and I were attending a jazz concert. She said, "Dad, grandma just drove through the garage door with her car." After hearing the children (and my mother) were unharmed, I advised my daughter to contact the fire department to inspect the integrity of the house. The damage was significant, but reparable. My mother's reaction was that a child on a tricycle could have caused the same damage. This is when I knew it was time to take the keys away. She, in her late 80s, simply did not have the coordination and reaction time to drive any longer. I knew she was in denial. Not neurologic denial, but I am your mother-tough-as-nails-who changed-your-diapers-smarty-pants-doctor denial. So, I left the decision to her. I would either take away the keys, or refer the issue to her primary care physician. Reluctantly, she conceded with grace, knowing it was the right thing to do.
So, denial is an overcrowded river with many people. Some have psychological issues, some neurologically based, and others, a mixture of both. Wading through the river, while keeping afloat, is part of our challenge. This week I saw a classic case of neurological denial for evaluation. It was also a week of remembrance for me; one of my mother's recent passing. Undeniably, she is missed by many.
Peter B. Sorman, PhD, ABN
Board Certified Clinical Neuropsychologist
Diplomate, American Board of Professional Neuropsychology
