From the Guidelines
Axonal nutritional neuropathy should be treated immediately with thiamine supplementation if the patient presents with rapid weight loss, poor dietary intake, vomiting, alcohol abuse, oedema, or symptoms of neuropathy, without waiting for blood results. This condition is a nerve disorder caused by nutritional deficiencies that damage the axons, which are the long fibers of nerve cells that transmit signals. The most recent and highest quality study, published in 2020, emphasizes the importance of prompt treatment for thiamine deficiency in patients undergoing bariatric surgery 1.
Causes and Treatment
Axonal nutritional neuropathy commonly results from deficiencies in B vitamins (particularly B1/thiamine, B6/pyridoxine, B12/cobalamin), vitamin E, copper, or essential fatty acids. Treatment focuses on identifying and correcting the underlying nutritional deficiency. For B12 deficiency, treatment typically involves intramuscular injections of 1000 mcg cyanocobalamin daily for one week, then weekly for one month, followed by monthly maintenance doses. Thiamine deficiency requires 100 mg thiamine daily for 3-5 days, then 50-100 mg daily until symptoms improve, as recommended by the British Obesity and Metabolic Surgery Society guidelines 1.
Prevention and Recovery
A balanced diet rich in fruits, vegetables, whole grains, and lean proteins helps prevent recurrence. Recovery can take months to years as damaged nerves slowly regenerate, and some patients may require pain management with medications like gabapentin (300-1200 mg daily) or duloxetine (30-60 mg daily). The condition improves with proper nutritional supplementation because nerve cells require specific nutrients for axonal maintenance and repair of the myelin sheath that insulates and protects nerve fibers. Additionally, addressing contributing factors like alcoholism, malabsorption disorders, or restrictive diets is essential, as noted in a study on the relationship between vitamin B6 intake and the risk of developing disability in elderly women 1.
Key Considerations
- Prompt treatment for thiamine deficiency is crucial in patients with rapid weight loss, poor dietary intake, vomiting, alcohol abuse, oedema, or symptoms of neuropathy.
- A balanced diet and addressing contributing factors are essential for preventing recurrence and improving outcomes.
- The condition can take months to years to recover from, and some patients may require pain management.
- Vitamin B6 deficiency has been linked to an increased risk of osteoporotic fractures and related falls, particularly in older women, highlighting the importance of adequate nutrition in preventing related complications 1.
From the Research
Axonal Nutritional Neuropathy
- Axonal nutritional neuropathy is a condition that can result from nutritional deficiencies, particularly in patients with alcohol use disorder, bariatric surgery, or anorexia 2, 3.
- The clinical spectrum of axonal nutritional neuropathy can range from pure sensory neuropathy to pure motor neuropathy, and mixed sensorimotor axonal polyneuropathy 2.
- Vitamin B1 (thiamine) deficiency is the most common micronutrient deficiency associated with axonal nutritional neuropathy, followed by vitamin B6 and folate deficiencies 2, 3.
- Other nutritional deficiencies, such as vitamin B12 (cobalamin) deficiency, can also cause isolated sensory axonal neuropathy or mixed axonal and demyelinating neuropathy 4, 5.
- Early recognition and treatment of nutritional deficiencies are essential to prevent or minimize neurologic morbidity in patients with axonal nutritional neuropathy 2, 6.
- The prognosis of axonal nutritional neuropathy is guarded, with residual neuropathic pain and slow recovery of independent ambulation being common outcomes 2.