Metabolic and Toxic Myelopathies

Area of Science:

• Neurology
• Toxicology
• Nutritional Science

Background:

• Metabolic and toxic myelopathies arise from diverse causes including nutritional deficiencies (e.g., vitamin B12, copper), environmental toxins, substance abuse, systemic diseases, and cancer treatments.
• The incidence of certain myelopathies is changing due to factors like increased bariatric surgery, climate change impacting food security, and advancements in cancer therapy leading to longer survival and reirradiation risks.
• Emerging treatments like immune checkpoint inhibitors introduce new neurological risks, including immune-mediated myelitis.

Approach:

• This review synthesizes current knowledge on the clinical presentation, diagnostic pathways, and therapeutic strategies for metabolic and toxic myelopathies.
• It emphasizes the importance of a thorough patient history, physical examination, and targeted laboratory and neuroimaging studies for accurate diagnosis.
• The article highlights specific risk factors and clinical syndromes associated with various causes of myelopathy.

Key Points:

• Nutritional deficiencies, particularly after bariatric surgery, and dietary toxins (konzo, lathyrism) are significant causes of myelopathy.
• Radiation therapy and newer cancer treatments like immune checkpoint inhibitors present unique challenges in managing myelopathy.
• Prompt diagnosis and intervention are critical, as some metabolic and toxic myelopathies are reversible.

Conclusions:

• Metabolic and toxic myelopathies necessitate a high index of suspicion in patients presenting with relevant clinical and imaging findings.
• A comprehensive diagnostic approach integrating clinical, laboratory, and radiological data is essential for timely and effective management.
• Early treatment of these myelopathies can significantly improve prognosis and potentially reverse neurological deficits.