Upper thoracic myelopathy caused by delayed neck extensor weakness in myotonic dystrophy

Area of Science:

• Neurology
• Orthopedics
• Genetics

Background:

• Myotonic dystrophy is a common adult-onset autosomal dominant myopathy.
• Neck weakness, ptosis, and a characteristic facial appearance are common in myotonic dystrophy.
• Spinal complications are less frequently reported but can significantly impact patient health.

Purpose of the Study:

• To report a rare case of upper thoracic myelopathy in a patient with myotonic dystrophy type 1.
• To investigate the association between neck muscle weakness and spinal cord compression.
• To highlight the importance of considering spinal complications in the management of myotonic dystrophy.

Main Methods:

• Case report of a 41-year-old female with diagnosed myotonic dystrophy type 1.
• Clinical assessment including neurological examination and symptom evaluation.
• Diagnostic imaging (MRI) of the cervical and thoracic spine.
• Genetic and electrodiagnostic studies to confirm myotonic dystrophy type 1.

Main Results:

• The patient presented with motor weakness, sensory changes, pain below T4, and urinary incontinence.
• MRI revealed spinal cord compression at T1-T3 due to hypertrophy of the ligamentum flavum and posterior longitudinal ligament.
• The myelopathy was attributed to repetitive mechanical stress on the neck from muscle weakness.

Conclusions:

• Upper thoracic myelopathy is a potential complication of myotonic dystrophy type 1, linked to neck muscle weakness.
• Hypertrophy of the ligamentum flavum and posterior longitudinal ligament can cause significant spinal cord compression.
• Early recognition and management of spinal complications are crucial for patients with myotonic dystrophy.