Rigid Spine Syndrome - Causes, Symptoms, and Management

Introduction

Muscular dystrophies are conditions in which the muscles weaken over time and lead to decreased function and mobility of the muscles. Muscular dystrophies are usually inherited and progressive at varying rates. Rigid spine syndrome is a form of congenital muscular dystrophy affecting the neck and torso muscles. It is a rare disease, the prevalence of which is unknown.

What Is Rigid Spine Syndrome?

Rigid spine syndrome is a rare congenital muscular dystrophic condition. The disease is characterized by slowly progressive rigidity of the spinal muscles leading to an abnormal posture or curvature of the spine and muscle weakness. Rigid spine syndrome is also known as severe spine muscular dystrophy.

What Causes Rigid Spine Syndrome?

• Rigid spine syndrome is a genetic disease, meaning the syndrome is caused due to one or more genes that are not working correctly.

• Rigid spine syndrome is caused due to the mutations of SEPN1 (SELENON) and ACTA1 genes.

• SELENON gene mutations cause about 40 percent of rigid spine syndrome cases.

• SELENON gene produces information for the production of a protein called selenoprotein N. The exact function of this protein is not established, but it is believed to play a role in the formation of muscle tissue before birth and muscle function after birth.

• The mode of inheritance of rigid spine syndrome is autosomal recessive, which means one copy of the mutated gene from both parents is inherited for the individual to develop the disease.

What Are the Signs and Symptoms of Rigid Spine Syndrome?

Symptoms of rigid spine syndrome start appearing in newborn and infant stages. The severity and number of symptoms differ among individuals affected by this syndrome. Symptoms of rigid spine syndrome affect different body systems. Some of the signs and symptoms associated with this syndrome are listed below.

Very Frequent Symptoms

• Abnormal skeletal morphology with abnormalities in the bones' form, size, or structure.

• Spinal rigidity results in reduced ability to move the spine and reduced neck and trunk movements.

• Scoliosis refers to an atypical lateral curvature of the spine.

• Myopathy is a disease of the muscles affecting the muscle fibers and their functions.

• Generalized muscle hypotonia ( decreased muscle tone).

• Neck muscle weakness results in reduced strength of the neck muscles.

• Respiratory insufficiency causes impairment of the gas exchange and breathing difficulties.

Other Frequent Symptoms

• Poor head control with difficulty in maintaining the correct position of the head while standing or sitting.

• Muscle contractures refer to the tightening and stiffness of the muscles and the shortening of the muscle length. Muscles commonly affected by contractures in rigid spine syndrome are hip muscles, hamstrings, and elbow muscles.

• Hyperlordosis is when the lumbar or cervical spine has an abnormally increased anterior concavity.

• Hyporeflexia indicates decreased or absent muscle reflex responses.

• Cardiac conduction abnormality with abnormal electrical impulses of the heart.

• Skeletal muscle atrophy decreases muscle mass due to increased protein degradation.

• Pneumonia is an infection in the lungs that may be due to breathing difficulties, increasing the risk of respiratory illness.

Rare Symptoms

• Gower's sign indicates the weakness of the proximal muscles in the legs. The patient is not able to stand up without the use of their hands.

• Developmental delay affecting both the motor and mental skills of the affected child

• The waddling gait is characterized by an abnormal walking pattern resulting from the weakened muscles of the pelvic girdle.

Other Common Symptoms Experienced by the Affected Individual

• Severe persistent back pain that worsens over time.

• The restricted range of motion hampers the patient's ability to flex their back or engage in forward bending. Consequently, routine tasks such as dressing and lifting objects become challenging.

• Difficulty in standing and walking as the spine becomes rigid.

• Difficulty in performing strength activities as there is muscle weakness.

• Other joints, like the hand and feet joints, are also affected due to rigid spine syndrome and may result in stiffness and swelling of hands and feet.

• Children with rigid spine syndrome may have difficulty breathing at night.

How Is Rigid Spine Syndrome Diagnosed?

• Diagnosis of rigid spine syndrome is made through clinical evaluation, imaging studies, and genetic tests.

• Family history also plays a vital role in diagnosis.

• The doctor does a clinical evaluation to check for physical symptoms like spinal rigidity, muscle weakness, and limited range of motion.

• Imaging tests like X-rays, MRIs, and CT scans can be taken to evaluate the spine's rigidity and rule out other conditions with similar symptoms.

• A muscle biopsy may be done to observe the abnormalities in the muscles. A muscle biopsy involves collecting a small sample of the muscle tissue using a needle.

• A genetic test can help confirm the diagnosis by checking for specific genetic mutations.

• Genetic counseling for the affected individual and their families may provide information about the inheritance pattern of the syndrome and the potential risks to the family members.

How Is Rigid Spine Syndrome Managed?

Rigid spine syndrome currently has no cure, but various treatment options are available to reduce the symptoms and improve patient well-being. Some of them are listed below.

• Physical Therapy - Physiotherapy helps strengthen muscles, slow down muscle loss, prevent joint contractures, and improve the range of motion. Physiotherapists implement stretches and exercises according to the needs of the affected individual.

• Orthopedic Management

  • Orthopedic braces are used to support the spine in children with scoliosis.

  • Surgery is done in some cases to correct spinal deformities and joint contractures.

• Respiratory Support - Breathing difficulties are common in people with rigid spine syndrome due to the weakening of the respiratory muscles. Respiratory support is provided using additional oxygen or a non-invasive ventilator.

• Medications - Healthcare providers may prescribe pain relievers, muscle relaxants, and anti-inflammatory drugs to alleviate muscle stiffness and pain.

• Assistive Devices - Assistive devices such as wheelchairs, walking aids, and other adaptive equipment help improve mobility and independence.

• Counseling and Support - People with rigid spine syndrome and their families may benefit from counseling and support groups to help cope with the emotional and psychological impact of the condition.

Conclusion.

Rigid spine syndrome is a rare genetic disorder requiring a multidisciplinary team approach to manage the syndrome according to every individual's needs. Appropriate management strategies can help alleviate symptoms and maintain the affected individual's functioning abilities.