Solutions to everyday challenges for spinal muscular atrophy patients

Many patients with spinal muscular atrophy have a remarkable imagination for solving problems that hinder their mobility and independence. Many often resort to creating homemade devices to carry out tasks which many of us take for granted.

Their active imaginations coupled with their drive to better their day-to-day lives are big reasons they persevere in fashioning makeshift devices, to reach objects in a cupboard, or to put on a hat, for example. But their resourcefulness is also a testament to the lack of commercially available solutions for their mobility challenges.

Enter the Gravity Neutral Orthosis (GNO) pioneered by a cross-disciplinary team of Columbia University physician-scientists dedicated to finding solutions for people with spinal muscular atrophy or SMA.

A devastating neurological disease that affects an estimated 10 to 16 out of 100,000 infants and children, SMA is marked by a progressive muscle weakness caused by degeneration of lower motor neurons in the spinal cord and brainstem. It can make even the simplest gestures, such a wave "hello", difficult or impossible without assistance.

Working with Columbia Technology Ventures, a team of individuals ranging from professors at Columbia University College of Physicians and Surgeons to undergraduate students at Columbia’s School of Engineering and Applied Science has developed a device meant to improve arm function in patients with SMA. The GNO is a sling-like mechanism that may make it possible for patients to accomplish simple but vital activities of daily living.

Many of these activities force patients to use their extremities against the forces of gravity. A pulley system created by a physical therapist to suspend the weak limbs of a patient and facilitate movement served as the basis for the development of the GNO device.

"We formed a team to help solve a problem with our disabled neuromuscular patient population, a team with members that cross many disciplines, all working together on a common goal: to improve upper extremity function in weak patients with neuromuscular disease," says Nancy E. Strauss, MD, executive vice chair and clinical professor in the Department of Rehabilitation and Regenerative Medicine. "Innovative and creative ideas have translated into functional improvements for our disabled patients through this collaboration."

Jackie Montes, a physical therapist in the Department of Neurology has probably the most experience of anyone at Columbia working directly with SMA patients on the 5th floor of Harkness Pavilion.

Montes says that SMA patients generally have difficulty initiating and following through with the vertical and side-to-side motions of their arms, and that’s where the powered vertical motion assistance of the GNO can help.

The concept of commercially available assistive devices is not entirely new. Current assistive devices, however, do not adequately address the wide range of muscle weakness in children with SMA. Passive, or non-powered, orthosis devices may be favoured because they have a simple design, are cost effective, and allow for free three-dimensional movement of the arms for certain patients.

One example of a commercially available device is the Wilmington Robotic Exoskeleton (WREX). Passive orthosis devices, such as the WREX, normally use the elastic energy of rubber bands or springs to achieve anti-gravity motions. However, an inherent limitation is that the user must possess some minimum muscle strength to overcome friction and balancing forces. This is not an issue with the anti-gravity forces harnessed by the GNO.

Through the Irving Institute for Clinical and Translational Research, the GNO team became a recipient of the Collaborative and Multidisciplinary Pilot Research (CaMPR) award, which focuses on developing interdisciplinary approaches to develop biomedical technology to solve a clinical problem, said Dr Strauss, who is also director of the Residency Training Program in Physical Medicine and Rehabilitation at NewYork-Presbyterian Hospital. As the leader of the clinical rehabilitation arm of the research, Dr Strauss was able to share a medical perspective with engineers; at the same time, the clinicians gained insight into the preclinical research process by learning about the engineering components of the device.

"As doctors, we tend to approach a potential solution working from the needs of the patient, whereas those with an engineering background on the project worked from a ground-up perspective, taking into account what was mechanically possible within the constraints of a certain design," Dr Strauss said.

Petra Kaufmann, MD, formerly in the Department of Neurology, now at NIH, and Elisa Konofagou, PhD, in the Departments of Biomedical Engineering and Radiology, are responsible for assembling this talented team. The collaboration was made possible through federal funding awarded to Henry Ginsberg, MD, director of the Irving Institute for Clinical and Translational Research, Columbia University’s Clinical and Translational Science Award (CTSA). The project described was supported by Grant Number UL1 RR024156 from the NCRR, a component of the National Institutes of Health (NIH) and NIH Roadmap for Medical Research, and its contents are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH.

The research was also made possible with a grant from the SMA Foundation and that organization’s support of Columbia’s SMA Clinical Research Center. The CTSA-funded work first began with individuals with SMA, and has expanded with trials of the device among individuals with Duchenne muscular dystrophy. In every case, the patient’s curiosity and intellect has surprised Montes, who says she is constantly amazed by her patient’s resourcefulness in overcoming physical challenges.

Unlike some other spinal-neural disorders, there is no cognitive decline associated with SMA. In fact, quite the opposite, Montes says.

"Instead of watching TV or wasting time thinking about nothing, my patients’ minds always seem engaged in navigating their environment," Montes said. "I think these challenges and the need to be perpetually aware actually play a large role in keeping their minds strong and vital."

The benefits have been far-reaching, according to the researchers.

"Something as simple as a patient scratching an itch on his or her face – something for which they now are dependent on a caregiver, but with the device may do with their own hand – is a tremendous advance for patients living with neuromuscular disease," Dr Strauss said.

(Source: Columbia University Medical Center: May 2010)