Abbas Ali Mansour MD
Assistant Professor of Medicine, Department of Medicine, Basrah College of Medicine .
Murthatha Alawi Jabber MD

Correspondence to: Abbas Ali Mansour MD
Assistant Professor of Medicine, Department of Medicine,
Basrah college of Medicine, Hattin post office
P.O. Box: 142 Basrah, 42002, Iraq
Tel: +964 7801403706, Email aambaam@yahoo.com

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ABSTRACT Background: Diabetic foot ulceration is serious and with expensive complications with considerable morbidity that affects up to 15% of diabetic patients during their lifetime and 80-85% of amputations are preceded by foot ulcers. The aim of this work is to study the correlation between severity of clinical abnormalities and electrophysiological studies in diabetic foot ulcers. Patients and Methods: This was a cross sectional study of patients with diabetic foot ulcers seen in 2 hospitals in Basrah (Al-Faiha General and Basrah Teaching) from October 2003 to July 2004. All patients had type 2 diabetes mellitus, and there were 44 patients in total. The same examiner, according to general practice, did quantitative assessment of clinical findings. Nerve conduction studies were performed using standard protocols. Nerve conduction abnormalities were classified into normal and abnormal according to the common peroneal nerve conduction of each leg separately. Results: The sensitivity of numbness, burning feeling, pricking feeling, and symptoms worse at night was 84.6%, 69.2%, 61.5%, and 51.5% respectively. While sensitivity of decreased pin prick sensation, absent vibration, absent ankle jerk, decreased temperature sensations, and absent position sense was 100%, 87.2%, 71.8%, 56.5%, and 12.8% respectively. Sensitivity of combined clinical symptoms was 66.6%, with specificity of 40%, and predictive value of 89.6% while that of clinical signs 48.7% and 60% respectively and predictive value of 90.4 %. There was no significant difference in severity of electrophysiological abnormalities in the affected and non-affected feet. Conclusion: Clinical findings correlated with the severity of electrophysiological changes in patients with diabetic foot ulcers.

Key words: Diabetes, foot, ulcer, and electrophysiological studies.
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Neuropathy is present in 80% of patients with diabetic foot ulcers; it promotes ulcer formation by decreasing pain sensation and perception of pressure, by causing muscle imbalance that can lead to anatomic deformities, and by impairing the microcirculation and the integrity of the skin.1-5 Even in the face of non-obstructed vessels, impaired microvascular reactivity diminishes blood supply to the ulcerated areas.

About 20% of diabetic patients with foot ulcers will primarily have inadequate arterial blood flow, about 50% will primarily have diabetic neuropathy, and about 30% will be afflicted with both conditions.6
Diabetic foot ulceration is a serious and expensive complication with considerable morbidity that affects up to 15% of diabetic patients during their lifetime, and 80-85% of amputations are preceded by non-healing foot ulcers.7-10

There is increasing evidence that measures of neuropathy, such as electrophysiology (including motor nerve conduction velocity) and quantitative tests, are predictors of not only end points, including foot ulceration, but also of mortality.11

In Iraq, diabetic foot ulcers were reported in 17% of diabetics in a small series from Baghdad.12
The aim of this work is to study the correlation between severity of clinical abnormalities and electrophysiological studies in diabetic foot ulcer.

This was a cross sectional study of patients with diabetic foot ulcer seen in 2 hospitals in Basrah (Al-Faiha general and Basrah teaching) from October 2003 to July 2004. Patients from inpatient's clinic were included. All patients had type 2 diabetes mellitus (DM); there were 44 patients with diabetic foot ulcer.

Definitions: DM and degree of control was considered according to the American Diabetic Association (ADA) recommendations in 2002.13 For blood pressure, the average of second and third blood pressure measurements in the office were considered. Two blood pressure recordings were obtained from the right arm of patients in a sitting position after 30 minutes of rest at 5-minute intervals, and their mean value was calculated. Hypertension was considered if blood pressure was equal to 140/90 mmHg or above. Nephropathy was diagnosed on the basis of persistent frank proteinuria without erythrocytes or white blood cells in urine. Microalbuminuria detection was not feasible. Ophthalmologists diagnosed retinopathy.

Body mass index was calculated according to the formula weight (kg)/ht2 (m2).14 The women were non pregnant. Autonomic function tests were not done. Diabetic foot ulcer was defined as any full-thickness skin lesion distal to the ankle that required treatment in hospital, excluding minor abrasions and or blisters; presence of any other cause of diffuse peripheral neuropathy (malignancy, renal failure alcohol abuse, drug abuse, anemia, known vitamin B12 deficiency, or untreated hypothyroidism). Vibration sensation was measured on the plantar hallux using a 128-Hz tuning fork, and was graded as absent if the subject reported no vibration while the examiner could still sense vibration. Achilles tendon reflex was elicited with the subject in supine position. Neuropathy screening instruction questionnaire was done for all (appendix -1-).15

Quantitative assessment of clinical findings was done by the same examiner according to general practice (appendix -2-).1 Nerve conduction studies were performed using standard protocols.16 Nerve conduction abnormalities were classified into normal and abnormal according to the common peroneal nerve conduction of each leg separately (normal >44.4 m/second, mild 40-44.3m/second, moderate 36-39.9m/second,and severe <36 m/second). Using an electrophysiological study as a gold standard for the neuropathy, we calculate measures of validity, namely sensitivity and specificity. The results were expressed as percentages. For statistical analysis, a Chi -square test was used as appropriate. Level of significance was set to be <0.05 throughout analysis.

Major characteristics of patients are present in table I and feet findings in table II. Mean age was 58.7 ±8.7 years, and 54% of the study sample were females. Most ohad low qualification levels and average BMI. The most common treatment was oral hypoglycemia in 63.6 %. About two thirds of patients had non-optimal control of diabetes. Hypertension was seen in 38.6 %. Most were from low social classes. Past history of diabetic foot was seen in 56.8%. Fifty percent of ulcers were Wagner grade one and Pes cavus was seen in 50%.

The sensitivity of numbness, burning feeling, pricking feeling, and symptoms worse at night was 84.6%, 69.2%, 61.5%, and 51.5% respectively (table III). While sensitivity of decreased pin-prick sensation, absent vibration, absent ankle jerk, decreased temperature sensations, and absent position sense was 100%, 87.2%, 71.8%, 56.5%, and 12.8% respectively (table III). All patients had abnormal motor nerve conduction velocities (table IV).

Sensitivity of combined clinical symptoms was 66.6%, with specificity of 40%, and predictive value of 89.6%; while that of clinical signs was 48.7% and 60% respectively and predictive value of 90.4 % (table IV).

There was no significant difference in severity of electrophysiological abnormalities in the affected and non-affected foot (table V).

28.2 two percent of those with optimal diabetes control had severe electrophysiological study changes, versus 71.7% in those with non-optimal control (table VI).