Introduction[edit | edit source]
Neuromuscular scoliosis (NMS) is defined as a non-congenital spinal deformity present in conjunction with any type of pre-existing neuromuscular diagnosis.NMS is generally more severe than adolescent idiopathic scoliosis (AIS) and more progressive, typically continuing after the growth of the individual and spine has ceased.Its progressive nature is more often seen in conditions of neurologic and systemic involvement. While it can occur at any age, most diagnoses in the cerebral palsy population are made around 8 years of age.
Etiology[edit | edit source]
- Neuropathic with central or peripheral motor neuron involvement (or both).
- Myopathic. Which, according to the NIH (National Institute of Neurological Disorders and Stroke) can be defined as: "... neuromuscular disorders in which the primary symptom is muscle weakness due to dysfunction of muscle fiber." 
NMS is a common consequence of neuromotor disease. Examples of these include:
- Cerebral Palsy
- Spinal cord injury
- Motor neuron disease, e.g. Spinal muscular atrophy
- Muscle fibre disorders, e.g. Duchenne muscular atrophy
- Multifocal disorders, e.g. Spina Bifida
Orthopaedic manifestations can be similar amongst conditions but differ between underlying diagnoses.
In diseases of motor neuron and muscle fibre disease, the onset of scoliosis usually occurs once the individual loses ambulation. Age and onset have not been found to be a predictor of progression and severity of the deformity. NMS itself presents at any age.
Pathogenesis[edit | edit source]
Orthopaedic manifestations are often similar amongst different conditions but differ in their underlying conditions.
Conditions and their own aetiology vary widely, however, there are often common factors that contribute to spinal deformity. These include:
- Asymmetrical paraplegia
- Imbalance of mechanical forces
- Intraspinal and congenital abnormalities of the spine
- Altered sensory feedback
- Abnormal posture via central pathways
NMS is not always a simple result of trunk muscle weakness. Instead, truncal hypertonia is more often found to be the result of scoliosis in central neurologic conditions. Muscle imbalances, weakness, and poor coordination around the spinal axis produce a gradually worsening deformity because of a lack of effective muscle compensation. In this way, the deformity often resembles idiopathic scoliosis.
In the CP population, the typical presentation of the deformity is a long C-shaped curve, often with associated pelvic obliquity. If progression cannot be arrested, this most often leads to a collapsing kyphosis and eventual loss of sitting balance. Lower GMFCS levels show a more idiopathic-like scoliosis, while higher GMFCS levels presenting with the more typical neuromuscular pattern and prognosis.
Impairments[edit | edit source]
The result of NMS is often limitations or impairments to the individual involved.
- Compromised cardiopulmonary function (secondary to mechanical effects on thoracic volume and compliance).
- Alterations in skin integrity
- Limited or decreased...
- Limb movement
- General balance capacity
- Trunk stability
- Bimanual activities
- Functioning in Activities of Daily Living
- Complications in self image and social interactions
General management[edit | edit source]
Management of NMS is not simply the management of the scoliosis itself, but of the individual and the primary condition.
Components of management[edit | edit source]
Addressing scoliosis stemming from a neuromuscular disease or disorder requires various levels of intervention These can be summarised as the following:
- In CP scoliosis surveillance has been suggested, with radiographic observation to begin at 8 years of age. Under the age of 8 requiring only visual assessment of the back in supported sitting.
- Conservative treatment
In a 2019 study by Murphy and Mooney, it was highlighted that there remains a lack of high-level evidence that supports the positive effect of conservative treatment of NMS. The evidence is most supportive of improved sitting balance in patients with flexible curves. In general, as the deformity progresses, the effectiveness of bracing decreases. The study noted some improvements in Cobb angles and sitting stability with a 3-point molded brace.
- Seating systems
- Treatment of the underlying pathology. For example steroid administration to those diagnosed with DMD.
Assessment[edit | edit source]
Assessment of the individual includes both the clinical and radiological assessment.
Clinical assessment[edit | edit source]
- General health
- Wheelchair and seating supports
- Joint stiffness
- Around pelvis and in general
- Hip range of motion
- Important to consider pelvic positioning
- Best done in prone with legs off the end of the bed
- Pelvic obliquity
- Skin integrity
- Pressure points are to be noted
- Scabbed areas of hyper pressure
- Walking capacity
- Static examination of the deformity
- Hip positioning needs to be corrected before spinal deformity is addressed.
- Examination in prone, at the end of the table with the lower limb in flexion, shows residual deformity with the elimination of LLD (leg length discrepancy), pelvic asymmetry, and the influence of gravity.
- Dynamic examination of the deformity
- Performed in sitting
- Examines deformity reducibility
- The spine should be studied level by level in lateral inclination and for rotational movement.
- By lifting the patient's head gently upwards (while in sitting), curvature reducibility can also be assessed.
- Respiratory assessment
- Cardiac assessment
- FLACC scale may be used in cases where individuals may not be able to verbally communicate.
Radiological assessment[edit | edit source]
When imaging is performed with individuals with NMS it is important to consider the following:
- With non walking patients, images are done in a seated posture, but supine is preferable.
- Specific bending views can be done to assess the stiffening of different spinal levels.
- An AP view is done under asymmetric traction (manual pulling down on one side through the leg) to asses frontal reducibility of pelvic obliquity. Alignment, and therefore no pelvic obliquity is observed when the line passing through the base of the two sacroiliac interlines are parallel to the shoulder line.
- An angle greater than 15° is considered clinically significant.
- In terms of pre-operation management, an MRI is important in suspected medullary pathology.
- Thoracic CT scans are performed in cases where surgery is considered and the patient presents with thoracic hyperkyphosis or lordosis. This is important to assess how the lungs are affected in regards to the deformity. If in the presence of severe deformity, bronchial stretching following scoliosis correction may induce atelectasis and decrease lung volume.
Goals of management[edit | edit source]
In dealing with NMS the goals of management include:
- Preservation of function
- Facilitation of daily care
- Alleviation of pain
Management is best performed within a multidisciplinary team. While conservative management comprises of physiotherapy and bracing, correctly timed surgery often plays an essential role in the rehabilitative process.
Surgical management[edit | edit source]
Surgical intervention is usually prescribed when the measured Cobb's angle exceeds 40° (usually lying between 40-50°) but may be performed earlier in those diagnosed with conditions such as DMD. It has been noted that the time of surgery should not be too late; at a time which is most reducible and least severe, but not too early as limit hypertrophy and restrict lung volume.
Further indications for surgery are:
- Progressive deformity with an unacceptable truncal shift or pelvic obliquity that affects standing or sitting balance and/or positioning.
- Significant functional limitation
- A need to improve activities of daily living (ADLs)
Intraoperative and postoperative complications tend to be quite high in those with NMS. In a study by Weissmann et al. (2021) complication rates were between 33.1% and 40.1% with similar percentages being reported in other reviews. Despite this, the same study found a significant decrease in urinary tract infections, lower respiratory tract infections and even epilepsy after surgery.
An important component to reducing these complications is to do a thorough patient history (including complications/ conditions present before birth). This would be done to pick up possible co-morbidities.
The goal of surgical intervention is to obtain a solid bony arthrodesis of the spine and pelvis in order to restore seated or standing balance.Currently, the surgery with the most successful outcomes is segmental pedicular screwing. This type of surgery provides three dimensional control and allows some growth potential.
Principles of physiotherapy management[edit | edit source]
Principles of treatment:
- Pathologic posturing
- Pelvic obliquity
- Asymmetric hip posturing.
By avoiding and/or countering flexion contractures of the hips prevents lumbar-sacral stiffening which feeds further into hyperlordosis.
Hamstring shortening should also be managed as this leads to progressive anterior pelvic tilt and progressive kyphosis of the lumbar spine.
Further components to address include:
- Respiratory function: In this aspect, it is important to address the respiration
- Pain: A randomized control trial (RCT) published in 2017 showed that core stabilisation exercises were effective in decreasing pain and also decreasing rotational deformity. While the participants were diagnosed with idiopathic scoliosis, the principles and outcome should be considered.
Resources[edit | edit source]
References[edit | edit source]
- Murphy RF, Mooney JF. Current concepts in neuromuscular scoliosis. Current Reviews in Musculoskeletal Medicine. 2019 Jun;12(2):220-7.
- Allam AM, Schwabe AL. Neuromuscular scoliosis. PM&R. 2013 Nov 1;5(11):957-63.
- Howard J, Sees J, Shrader MW. Management of spinal deformity in cerebral palsy. JPOSNA®. 2019 Nov 3;1(1).
- Drs. Viral Jain and James McCarthy. Neuromuscular scoliosis. Available from:https://www.youtube.com/watch?v=WiRm0Fj8esw [last accessed 19/05/2022]
- Vialle R, Thévenin-Lemoine C, Mary P. Neuromuscular scoliosis. Orthopaedics & Traumatology: Surgery & Research. 2013 Feb 1;99(1):S124-39.
- National Institute of Neurological Disorders and Stroke. Myopathy. Available from: https://www.ninds.nih.gov/health-information/disorders/myopathy#:~:text=Publications-,Definition,cramps%2C%20stiffness%2C%20and%20spasm. (accessed 26 May 2022)
- Mullender MG, Blom NA, De Kleuver M, Fock JM, Hitters WM, Horemans AM, Kalkman CJ, Pruijs JE, Timmer RR, Titarsolej PJ, Van Haasteren NC. A Dutch guideline for the treatment of scoliosis in neuromuscular disorders. Scoliosis. 2008 Dec;3(1):1-4.
- Roberts SB, Tsirikos AI. Factors influencing the evaluation and management of neuromuscular scoliosis: a review of the literature. Journal of back and musculoskeletal rehabilitation. 2016 Jan 1;29(4):613-23.
- Kotwicki T, Jozwiak M. Conservative management of neuromuscular scoliosis: personal experience and review of literature. Disability and rehabilitation. 2008 Jan 1;30(10):792-8.
- Weissmann KA, Lafage V, Pitaque CB, Lafage R, Huaiquilaf CM, Ang B, Schulz RG. Neuromuscular Scoliosis: Comorbidities and Complications. Asian Spine Journal. 2021 Dec;15(6):778.
- Gür G, Ayhan C, Yakut Y. The effectiveness of core stabilization exercise in adolescent idiopathic scoliosis: A randomized controlled trial. Prosthetics and orthotics international. 2017 Jun;41(3):303-10.
- Paley Orthopaedics and Spine Institute. Neuromuscular Scoliosis. Available from: https://www.youtube.com/watch?v=1G1sGqu0IVY [last accessed: 19/05/2022]