Split-belt Treadmill as Therapy for Brain-injured Patients

CNN has an interesting article about a split-belt treadmill that is being used for stroke survivors and other people with brain injuries.

Story here

The treadmill’s two belts can move independently and even in opposite directions. Doctors and researchers are trying to find any underlying intact neural circuitry by providing unique motor challenges to brain injury patients.

War-related traumatic brain injuries

An article in the most recent Monitor on Psychology (published by the American Psychological Association) [here’s a link to the article that is accessible for free online: Link) reminded me of something one of my professors in graduate school told our class a couple years ago. He is a clinical neuropsychologist who occasionally does some consulting for the military. After he returned from a consultation with the military he told us that between the war in Afghanistan and the Iraq war there had been 18,000 central nervous system (brain and spinal cord) injuries of soldiers and contract employees serving in those two countries. The majority of the injuries were minor and many were not combat related but there are still thousands of people with moderate to severe CNS injuries that were acquired in war zones. Quoting from the Monitor article:

“Psychologists, particularly neuropsychologists, are stepping in to assess the damage, help patients learn new strategies to compensate while their brains recover, and raise public awareness of the increasing number of servicemen and women with TBIs. In fact, 1,977 service members were treated for them at Defense and Veterans Brain Injury Center (DVBIC) sites from January 2003 to February 2007.”Soldier Helmet

One reason for high rates of traumatic brain injury in the Iraq (and Afghanistan) war(s) is the improved (compared to previous wars) body armor and other life-saving devices. The downside to fewer fatalities is that there are higher rates of people with severe injuries who survive. The mild TBI rates are shown to be: “between 10 and 20 percent [in some surveys] of soldiers returning from deployments” (Source). It’s great to have fewer fatalities but TBIs can have profound effects on people. Clinical neuropsychologists can help people with TBIs learn how to best cope with their injuries as well as understand how their lives might be different and what they can do to compensate for any difficulties. Most people with mild to moderate TBIs seem to have complete or nearly complete recoveries; however, those with moderate to severe TBIs may have deficits, many very severe, that last the rest of their lives.

There can be myriad short-term problems associated with TBIs (e.g., mental slowing, memory problems, personality changes, concentration and attentional difficulties, etc.) but there are also long-term ones. Research has shown that a person with a history of multiple TBIs is more likely to get Alzheimer’s Disease in old age (well, the research actually shows that there is an over-representation of people with multiple TBIs in the Alzheimer’s population). There is a great need for clinical neuropsychologists currently and in the future to work with and help all of our war veterans who have acquired brain injuries.

Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome is a common cause of mortality and morbidity, affecting an estimated 150,000 people per year in the United States (Rubenfeld, Doyle, & Matthay, 1995) however, recent evidence suggests the incidence may be higher (Rubenfeld, 2003). Compared to 20 years ago mortality has decreased from 80% to 30% of ARDS participants (Milberg, Davis, Steinberg, & Hudson, 1995; Brower et al., 2000) resulting in approximately 100,000 people who survive ARDS each year in the United States (Bersten, Edibam, Hunt, & Moran, 2002). Acute respiratory distress syndrome occurs in response to a variety of insults including sepsis, trauma, pneumonia, massive transfusion and other medical/surgical conditions. Treatment of ARDS requires aggressive supportive care including positive pressure ventilation (Brower et al., 2000) and increased oxygen concentrations with risks of barotrauma, oxygen toxicity, and nosocomial infection.

Acute respiratory distress syndrome may be a consequence of multiple organ system dysfunction, including the central nervous system (Bell, Coalson, Smith, & Johanson, 1983; Montgomery, Stager, Carrico, & Hudson, 1985). Participants who survive ARDS are at risk for neuropsychological deficits (Hopkins et al., 1999; Rothenhausler, Ehrentraut, Schelling, & Kapfhammer, 2001; Al-Saidi et al., 2003; Hopkins, Weaver, Chan, & Orme, 2004) 6 to 12 months following hospital discharge. Approximately 33% of general medical ICU survivors, some with ARDS, have cognitive impairments (Jackson et al., 2003) 6 months after hospital discharge. In 1999, Hopkins and colleagues found that 45% of ARDS survivors had neurocognitive impairments including impaired memory, attention, concentration, mental processing speed, and global intellectual decline one year post-discharge.

Others have since made similar observations (Marquis et al. 2000; Rothenhausler et al., 2001; Al-Saidi et al., 2003; Jackson et al., 2003). The prevalence of neurocognitive impairments varies from 25% (Rothenhausler et al., 2001) to 78% in participants with more severe ARDS (Hopkins et al., 1999). Neurocognitive impairments are a major determinant in return to work, work productivity, and life satisfaction following ARDS (Rothenhausler et al., 2001).


Al-Saidi, F., McAndrews, M. P., Cheunt, A. M., Tansey, C. M., Matte-Martyn, A., Diaz-Granados, N., et al. (2003). Neuropsychological sequelae in ARDS survivors. American Journal of Respiratory and Critical Care Medicine, 167, A737.

Bell, R. C., Coalson, J. J., Smith, J. D., & Johanson, W. G., Jr. (1983). Multiple organ system failure and infection in adult respiratory distress syndrome. Annals of Internal Medicine, 99, 293–298.

Bersten, A. D., Edibam, C., Hunt, T., & Moran, J. (2002). Incidence and mortality of acute lung injury and the acute respiratory distress syndrome in three Australian States. American Journal of Respiratory and Critical Care Medicine, 165, 443–448.

Brower, R. G., Matthay, M. A., Morris, A., Schoenfeld, D., Thompson, B. T., & Wheeler, A. (2000). Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. New England Journal of Medicine, 342, 1301–1308.

Hopkins, R. O., Weaver, L. K., Chan, K. J., & Orme, J. F. (2004). Quality of life, emotional, and cognitive function following acute respiratory distress syndrome. Journal of the International Neuropsychological Society, 10, 1005–1017.

Hopkins, R. O., Weaver, L. K., Pope, D., Orme, J. F., Bigler, E. D., & Larson-Lohr, V. (1999). Neuropsychological sequelae and impaired health status in survivors of severe acute respiratory distress syndrome. American Journal of Respiratory and Critical Care Medicine, 160, 50–56.

Jackson, J. C., Hart, R. P., Gordon, S. M., Shintani, A., Truman, B., May, L., et al. (2003). Six-month neuropsychological outcome of medical intensive care unit participants. Critical Care Medicine, 31, 1226–1234.

Marquis, K., Curtis, J., Caldwell, E., Davidson, T., Davis, J., Sanchez, P., et al. (2000). Neuropsychological sequelae in survivors of ARDS compared with critically ill control participants. American Journal of Respiratory and Critical Care Medicine, 161, A383.

Milberg, J. A., Davis, D. R., Steinberg, K. P., & Hudson, L. D. (1995). Improved survival of participants with acute respiratory distress syndrome (ARDS): 1983-1993. Journal of the American Medical Association, 273, 306–309.

Montgomery, A. B., Stager, M. A., Carrico, C. J., & Hudson, L. D. (1985). Causes of mortality in participants with the adult respiratory distress syndrome. American Review of Respiratory Disease, 132, 485–489.

Rothenhausler, H. B., Ehrentraut, S., Stoll, C., Schelling, G., & Kapfhammer, H. P. (2001). The relationship between cognitive performance and employment and health status in long-term survivors of the acute respiratory distress syndrome: Results of an exploratory study. General Hospital Psychiatry, 23, 90–96.

Rubenfeld, G. D. (2003). Epidemiology of acute lung injury. Critical Care Medicine, 31, S276–S284.

Rubenfeld, G. D., Doyle, R. L., & Matthay, M. A. (1995). Evaluation of definitions of ARDS. American Journal of Respiratory and Critical Care Medicine, 151, 1270–1271.

Brain Injury Video

Here’s a decent video about brain injury that does a good job of showing how brain injury affects people.

Unfortunately, we don’t have the ability to completely reverse the effects of acquired brain injury. Therapy and rehabilitation can help but if the injuries are severe, completely normal functioning is unlikely ever to return. Prevention is the best medicine in this case; it is unfortunate that prevention is not always possible.The parts of the brain that are most often affected with brain injury are those that have to do with memory.

Another common outcome of brain injury is cognitive slowing – people just don’t seem to think or move or act as quickly after brain injury as they did before. This slowing is due in part to the diffuse axonal injury that occurs (the connections between brain cells {neurons} are broken or twisted as the brain compresses and stretches) with traumatic brain injuries. Even non traumatic brain injuries (e.g., carbon monoxide poisoning) can result in overall cognitive slowing (this slowing often greatly improves over time with mild to moderate brain injuries).It is also fairly common to see personality changes in someone with a recent brain injury – this is mainly due to damage to the frontal lobes. These changes in personality can be the source of great frustration and concern for family, friends, and everyone around the injured person. Dealing with a severe brain injury requires a lot of loving, patience, and care.

Ventromedial prefrontal cortex damage results in impaired moral judgments

Click on the following link to read the news article from New Scientist: Moral judgment

The researchers found that people with ventromedial prefrontal cortex (which is involved in emotional regulation) damage have impaired judgment regarding moral dilemmas in which they are personally involved. Their judgment is not impaired compared to people without ventromedial prefrontal cortex (VMPC) damage in situations in which they are not personally involved. The likely pathway of this impairment is: damage to VMPC –> impaired emotional regulation –> impaired moral judgment in personal moral dilemmas.

The study of brain-injured individuals

The brain is an interesting organ. Its complexity is far beyond any other part of the body, which is what makes studying it so difficult. Individual differences affect how the brain functions – to an extent – and how it reacts to stressors, damage, or decay. When the brain is injured or dysfunctions, we can learn about its normal functioning. There have been some widely publicized cases of brain damage and the effect that damage has on cognition and life. One such case was the Terry Schiavo case that caught widespread national attention two years ago. The lessons we learned from Terry were mostly political, legal, and moral ones. What about cases where there is more than minimal higher-order brain functioning as in Terry’s case?

A number of years ago some researchers reported the case of a man who had damage to his thalamus, a structure in the middle of the brain that is viewed as a “relay center” for the brain, among other functions. In this man’s case he had an anomia (i.e., lack of ability to name) for medical instruments and terms. He was not a doctor or other health care professional, he just had great difficulty naming medically-related terms. There have been other similar cases where people have had random category naming difficulties following brain injury. It is cases like this that make the study of the brain so interesting.

Over the years there have been a number of famous brain injury patients. Gage was a railroad foreman in the 1800s whose personality and emotionality changed after a tamping rod was blasted through his frontal lobes in a horrific accident. H.M. is a man whose medial temporal lobes were removed in surgery. Following the surgery he had severe anterograde amnesia (that roughly means he doesn’t remember anything that happened after his surgery) and mild retrograde amnesia (he doesn’t remember the few days prior to his surgery either). From HM researchers learned a lot about the memory system and how the medial temporal lobes are involved in memory processes (although the theories are still under development and some ideas about how information is processed into long-term memory are controversial). Then there have been cases of people with temporal lobe damage who have lost the ability to recognize objects or people. The study of brain dysfunction is fascinating and informative. Sometimes one doesn’t know what to expect.

Learn also: How personal injury affects employment.

Reference: Rear End Accident Attorney Louisiana.