Breakthrough study identifies possible cause of scoliosis

A nagging suspicion that the brain of scoliosis patients might be wired differently led to a breakthrough study that found a link between imbalances in the brain and an abnormal curvature of the spine. Singapore General Hospital (SGH) surgeons and National Neuroscience Institute (NNI) neurologists operating on the spines of patients with adolescent idiopathic scoliosis (AIS) had noticed in recent years that the wave signals from the left and right sides of their brains were somewhat assymetric.

To check out their observations, the SGH-NNI team used a high-resolution and specialised magnetic resonance imaging (MRI) technique — the first to do so — to map the brains of 34 participants in 2020. “We found asymmetric measurements in the nerve pathway between the right and left side of the brain in patients who have AIS, unlike the symmetrical pattern in participants without,” said Professor Ling Chan , Senior Consultant, Department of Neuroradiology, SGH, and the study’s corresponding author.

The study, published in the international Clinical Radiology journal in February 2024, used a high-resolution diffusion tensor imaging (DTI) brain MRI technique for mapping brain pathways. Besides asymmetry, the scans also showed an enlargement or swelling of pons in the brainstem, the bottom part of the brain linked to the spinal cord. In those without AIS, the pathways showed symmetric quantitative measurements, and the pons was not enlarged.

“This discovery suggests that scoliosis is fundamentally related to our brain and spinal cord. It could bring about changes in the way AIS is diagnosed or treated. For example, neurological interventions may potentially be employed to prevent worsening of spine curvature. These could include the use of magnetic fields or low electrical currents to stimulate or modulate brain activity,” said Professor Lo Yew Long, Senior Consultant, Department of Neurology, NNI@SGH, and senior author of the study.

AIS affects about 3 per cent of adolescents in Singapore, mostly girls. Symptoms include spine curvature, and uneven shoulders, hips and waist. Most patients manage their condition with physiotherapy and bracing.

“Currently there is no cure for AIS, but the custom-made brace pushes on the spine to prevent it from getting worse. Patients will usually need bracing until the pubertal growth spurt has completed. At that point, the situation stabilises and they no longer need the brace,” said Associate Professor Reuben Soh , Senior Consultant, Department of Orthopaedic Surgery, SGH, and the study’s first co-author.

If the scoliosis continues to advance despite the braces, which happens in about 5–10 per cent of patients, the patients may experience nerve damage and breathing problems. Complex surgery involving the use of metal rods, hooks and screws will then be needed to hold the bones in place.

“Most scoliosis patients are picked up very early by the school health services, and they continue to be monitored by the Health Promotion Board. If the condition worsens, they are referred to SGH’s scoliosis clinic,” said Assoc Prof Soh.

The scoliosis clinic’s specially trained physiotherapists help 300 patients the clinic manages each year to improve their mobility and muscular symmetry through exercise and core strengthening, which in turn help to reduce the degree of spine curvature.

“We see patients as young as 10 years old and parents often have the misconception that it’s bad habits or lifestyle factors that cause scoliosis. We embarked on this study to try uncovering the real reason; in doing so, we hope to be able to better care for patients and support them and their families in managing the condition,” said Assoc Prof Soh.

The team intends to conduct further studies to identify markers in patients who are at risk of AIS progression with imaging and electrical methods. “We are hopeful that one day, there could be a non-invasive mode for managing the spinal curvature, and that would really change things for the patients,” said Assoc Prof Soh.

This article was first published in Singapore Health Nov/Dec 2024 issue.