Subacute combined degeneration

Subacute Combined Degeneration of Spinal Cord (SCD), also known as Subacute Combined Degeneration of the Cord, is a medical condition characterized by the degeneration of the spinal cord, specifically affecting the posterior and lateral columns. This condition is most commonly associated with a deficiency in Vitamin B12 (cobalamin), which is essential for the proper functioning and maintenance of the nervous system. The deficiency leads to demyelination, or the loss of the myelin sheath, of the spinal cord nerves, resulting in a combination of neurological symptoms.

Causes

The primary cause of Subacute Combined Degeneration is a deficiency in Vitamin B12, which can result from various factors including:

• Pernicious Anemia - an autoimmune condition affecting the stomach's ability to produce intrinsic factor, necessary for the absorption of Vitamin B12.
• Dietary deficiency - particularly in strict vegetarians or vegans who do not consume enough B12-containing foods.
• Malabsorption syndromes - such as Celiac Disease or Crohn's Disease, which impair the absorption of nutrients from the diet.
• Medications - certain medications can interfere with B12 absorption, including proton pump inhibitors and metformin.

Symptoms

Symptoms of Subacute Combined Degeneration can vary but typically include:

• Neuropathy - numbness, tingling, or pain in the hands and feet.
• Muscle weakness and atrophy.
• Difficulty with coordination and balance (Ataxia).
• Mental changes - including memory loss, confusion, or depression.
• Visual disturbances.

Diagnosis

Diagnosis of Subacute Combined Degeneration involves a combination of clinical evaluation, laboratory tests, and imaging studies. Key diagnostic steps include:

• Blood tests to measure levels of Vitamin B12, methylmalonic acid, and homocysteine.
• Magnetic Resonance Imaging (MRI) of the spinal cord to identify the characteristic pattern of degeneration.
• Neurological examination to assess sensory and motor deficits.

Treatment

Treatment for Subacute Combined Degeneration focuses on addressing the underlying Vitamin B12 deficiency and alleviating symptoms. Treatment options include:

• Vitamin B12 supplementation, either through oral supplements or intramuscular injections.
• Dietary advice to increase intake of B12-rich foods.
• Management of symptoms through physical therapy and medications for neuropathic pain.

Prognosis

With timely diagnosis and treatment, many individuals with Subacute Combined Degeneration can experience significant improvement in symptoms. However, prolonged deficiency of Vitamin B12 before treatment can lead to irreversible damage to the nervous system.

Prevention

Prevention of Subacute Combined Degeneration involves ensuring adequate intake of Vitamin B12 through diet or supplements, especially in populations at risk of deficiency such as the elderly, vegetarians, and individuals with malabsorption syndromes.