Feature

Imagine you are an attorney in court. You look at the client sitting next to you and don't recognize him. Suddenly, you can't remember any details of the case or your strategy, and you don't know why.

When that exact scenario happened to Milwaukee lawyer Jeffrey Gingold, he was "literally speechless and disoriented," he says. "It was like having a word at the tip of your tongue, but in this case I had a whole category of information at the tip of my brain and couldn't access it."

Gingold had been diagnosed with multiple sclerosis but was completely unprepared for the episodes of "mental numbness" that he began to experience. That's not uncommon. According to the National Multiple Sclerosis Society, as many as half of all people with MS experience similar cognitive issues that are not discussed during diagnosis, leaving patients at a loss to understand or manage the symptoms.

MS is not the only illness that is accompanied by largely ignored neuropsychological conditions. Survivors of childhood cancer develop learning difficulties. Patients with hepatitis find it difficult to remember or follow medication instructions. Years after they leave intensive care, some people treated for critical cardiac or respiratory illness have deficits in executive functions such as planning or problem-solving.

The physicians who treat acute or chronic physical symptoms often don't pay attention to long-term outcomes that can include diminished behavioral and cognitive performance, experts say. However, psychologists are picking up that slack, and their work may inform diagnosis and treatment of chronic medical conditions.

Recent efforts involving HIV/AIDS, diabetes and multiple sclerosis illustrate the expanding role of psychological research in understanding and responding to a wide range of medical conditions.

HIV/AIDS

Clinicians and researchers have recognized the cognitive and behavioral effects of HIV since the epidemic began. In 1991 the American Academy of Neurology developed a scheme to characterize a suite of conditions that came to be known as HIV-associated neurocognitive disorders, or HAND. For a decade or more these definitions seemed adequate—if only barely—to researchers and clinicians. But there have been substantial changes to HIV disease, particularly since the advent of highly active anti-retroviral treatment (HAART) that have affected cognitive impairment in a number of areas, notes neurologist Justin McArthur, PhD, of Johns Hopkins University.

"We don't see the really severe dementia that we used to see 15 years ago," McArthur says. "Infectious disease doctors ask, 'So what's the problem with a little cognitive impairment?' But it's been conclusively shown that the impact of even the milder forms of cognitive impairment can have a substantial effect on survival, with about a three-fold increased risk of death."

McArthur was a member of a work group established in 2007 by the National Institute of Mental Health and the National Institute of Neurological Diseases and Stroke to consider how to refine the existing definitions and classification of HAND.

HIV's neurocognitive impact is now less severe than in the pre-HAART era, McArthur says in reporting the work group's findings. Patients survive longer, and clinicians now see cognitive and behavioral effects in patients who have no other symptoms of active HIV. This new category of HAND, which the group designates as asymptomatic neurocognitive impairment (ANI), can only be detected and accurately diagnosed through neuropsychological testing.

One obvious impact of recognizing ANI is to encourage frequent neurologic follow-up to monitor disease progression through standard behavioral and cognitive assessment tools. Such tests, the work group notes, could lead physicians to start pharmacological therapy earlier in the course of HIV/AIDS development and have a significant impact on patient outcomes.

The work group also noted that some HIV-infected patients—nearly 20 percent in some studies—had neurocognitive symptoms that fluctuated from normal to abnormal. This finding, too, might guide diagnosis as well as treatment that maximizes day-to-day functioning and long-term outcomes. These fluctuations of impairment appear to be independent of viral load or changes in HAART, McArthur says, and are comparable to fluctuations seen in relapsing-remitting multiple sclerosis.

Diabetes

Research by University of Alberta psychologist Roger Dixon, PhD, is helping sharpen our understanding of how diabetes exacerbates the inevitable decline aging brings to our mental function. In the January issue of Neuropsychology (Vol. 23, No. 1) Dixon showed a relationship between Type-2 diabetes and earlier appearance of decreased performance in two neurocognitive areas: speed and executive functioning.

"The differences we observed in diabetes patients are similar to those seen at an older age in men and women without the disease," Dixon says. "They aren't worse, but they show up at an earlier age and they could become progressively deeper and broader."

The study, supported by the National Institute on Aging, involved 465 adults age 53 to 90 (41 with Type-2 diabetes) who took tests to evaluate multiple aspects of episodic memory, semantic memory, verbal fluency, executive functioning and neurocognitive speed. The diabetes group performed significantly worse on one measure of executive function in which they were asked to complete a sentence with a single word or provide a word that didn't complete the sentence properly. Diabetes patients also took significantly longer than controls to respond correctly in two tests of neurocognitive speed. One test asked them to read a series of letters and then state whether the letters spelled an English word. The second test required that they read sentences and identify them as either "plausible or nonsensical."

The subjects in the study are part of the Victoria Longitudinal Survey, a large-scale, long-term project involving initially healthy older subjects who are evaluated at three-year intervals. Diabetes patients in the study described their conditions as mild to moderate.

"These are men and women who live in the community and whose diabetes is relatively well-controlled. Compared with other study groups of older adults, who are evaluated in clinics or nursing homes and whose illness is more severe, these people are probably much more representative of the diabetes population in North America," Dixon says.

Understanding the relationship between diabetes and functional declines of any severity will be increasingly important, Dixon says, because the incidence of diabetes is changing in two important ways. First, prevalence is increasing: The U.S. Centers for Disease Control and Prevention estimates that nearly a quarter (23.1 percent) of all people 60 years or older have diabetes, and diagnosis of Type-2 diabetes rose from 4.8 per 1,000 people between 1995 and 1997 to 9.1 per 1,000 people a decade later. Second, Type-2 diabetes—once called adult-onset diabetes because it was largely unknown in people younger than 40—now appears to be a sizable and growing problem in children and adolescents, according to the CDC.

Multiple sclerosis

Impaired memory is the most common neurocognitive deficit seen in people with MS, says psychologist Michael Basso, PhD, of the University of Tulsa.

"For MS patients—particularly for young patients in the prime of life—impaired memory has a significant impact on work and self-sufficiency, but there has been very little investigation of interventions that might remediate this condition,'' Basso says.

Basso and his colleagues have found that a technique called self-generated learning can help MS patients develop better memory skills. Moreover, the technique's benefits are seen in patients with moderate to severe impairments as well as those with mild to moderate memory deficits.

"These results represent the encouraging prospect that a relatively simple learning tool may enable these patients to function more confidently in a wide range of real-world situations,'' Basso says.

His studies were built on work reported in 2002 by Nancy Chiaravolloti, PhD, and colleagues at New York University. Basso's research involved controls and MS patients with and without memory impairment. Researchers asked subjects to remember word pairs with different relationships (such as love-hate, wheat-corn, sell-bell) presented didactically—they were told to pay attention to the second word, which they would later be asked to recall. Other word pairs were formed through self-generation: Subjects were given the semantic rule (e.g., opposite, similar, rhyming) and asked to provide the second word based on a first-letter clue (finish the pair, "love-h___'').

After being presented with five word pairs, subjects performed a free-recall test; they were told the first words and asked to recall as many second words as they could remember. A delayed-recall test assessed their memory again 20 minutes later. Finally, the researchers gave them a recognition test that asked participants to identify a target word originally included in a pair (the word "sheep," for example) presented in a trio that included two semantically related "distractors'' ("lamb" or "herd") not included in the original pair.

They found that all groups—controls as well as MS patients—better recalled the word pairs they had generated themselves. And to the researchers' surprise, the impaired and the unimpaired patient groups recalled essentially the same amount of self-generated information.

Follow-up studies by Basso and his colleagues show that this effect extends to MS patients' recall of names, appointments and the location of objects. Patients are vastly better at remembering self-generated material than information that is didactically presented.

The implications are significant, says Basso. "It's entirely possible that people with MS can be taught to use self-generation methods to learn important information that will help them maintain self-sufficiency in their daily lives,'' he notes. "They can develop skills to manage schedules, adhere to medication regimens or establish a tool kit of mechanisms to cope with the episodic lapses of recall that have profound and disruptive effects."

Basso now is investigating the role of self-generation in helping MS patients improve performance on other activities of daily living. "Improvements in learning can help these patients in a wide range of aspects of their day-to-day lives."


Patrick Zickler is a writer in Washington, D.C.