How common is peripheral neuropathy (damage to nerves in arms and legs) in children with cystic fibrosis aged 1-18 years on high dose vitamin E supplementation?
Is the blood level of vitamin E linked to peripheral neuropathy in children with cystic fibrosis aged 1-18 years on vitamin E supplementation?
Why is this important?
With increasing life expectancy, diseases of the peripheral nerves could be a significant problem for people with CF as they are associated with various complications in upper and lower limbs like decrease in strength, reduced ability to feel and so problems with ulcers caused by small amounts of damage in the feet.
What did you do?
The study was conducted in New Delhi, India. In this study, children with cystic fibrosis were evaluated for any features of peripheral nerve damage (by clinical examination and evaluation of nerve function by electrical stimulation) along with measurement of serum levels of Vitamin B12, folic acid, vitamin E and copper, as deficiency of these can cause peripheral neuropathy.
What did you find?
At examination, 46.7% had evidence of peripheral nerve involvement (all related to touch and feel). Overall 22 out of 45 (48.88%) had evidence of peripheral neuropathy based on nerve conduction studies. We could find no link between status of vitamins and peripheral neuropathy. Those with peripheral neuropathy were older children.
What does this mean and reasons for caution?
The current study implies that beyond 5 years of age, cystic fibrosis patients should be periodically assessed for involvement of peripheral nerves. Symptoms like abnormal or reduced sensation, recurrent ulcers should be looked for. Special attention should be paid to balanced and proper nutrition, enzyme and fat soluble vitamins (vitamin E) supplementation. Factors which may be responsible for development of peripheral neuropathy with increasing age in these patients are impaired glucose metabolism, frank diabetes and repeated airway infections causing decreased oxygenation of peripheral nerves. This means that periodic evaluation of blood sugar levels and appropriate and early management of lung infections may be important in preventing peripheral nerve damage.
Long term studies evaluating the evolution of the process with follow up clinical examination and nerve conduction studies should be planned.
Minimally invasive punch skin biopsies can be performed examining the superficial nerve fibres just below the skin to study the cellular and molecular basis of the process.
Intervention studies should be planned like prescribing micronutrients and then following up the status of nerve damage in patients with documented nutritional deficiencies.
Studies should be planned to see if glucose metabolism and lung function tests are linked to peripheral nerve damage in these patients.