• diabetic peripheral neuropathy
• entrapment neuropathy
• nerve entrapment
• neuropathic pain
• peripheral nerve decompression

• Natural Science Foundation of Shanghai Municipality
• National Natural Science Foundation of China
• Medical Innovation Research Project of the Shanghai Science and Technology Commission

• Carpal tunnel syndrome
• diabetes mellitus
• diagnosis
• median nerve
• nerve conduction study
• treatment

• Carpal Tunnel Syndrome/complications
• Carpal Tunnel Syndrome/diagnosis
• Diabetes Mellitus
• Diabetic Neuropathies/complications
• Diabetic Neuropathies/diagnosis
• Diabetic Neuropathies/therapy
• Humans
• Median Nerve
• Quality of Life
• Vascular Endothelial Growth Factor A

Neuropathy is a common complication of diabetes mellitus (DM) with a wide clinical spectrum that encompasses generalized to focal and multifocal forms. Entrapment neuropathies (EN), which are focal forms, are so frequent at any stage of the diabetic disease, that they may be considered a neurophysiological hallmark of peripheral nerve involvement in DM. Indeed, EN may be the earliest neurophysiological abnormalities in DM, particularly in the upper limbs, even in the absence of a generalized polyneuropathy, or it may be superimposed on a generalized diabetic neuropathy. This remarkable frequency of EN in diabetes is underlain by a peculiar pathophysiological background. Due to the metabolic alterations consequent to abnormal glucose metabolism, the peripheral nerves show both functional impairment and structural changes, even in the preclinical stage, making them more prone to entrapment in anatomically constrained channels. This review discusses the most common and relevant EN encountered in diabetic patient in their epidemiological, pathophysiological and diagnostic features.

• Diabetes mellitus
• Neuropathy
• Diabetic neuropathy
• Median entrapment neuropathy at the wrist
• Ulnar entrapment neuropathy at the elbow
• Ulnar entrapment neuropathy at the wrist
• Carpal tunnel syndrome
• Electrodiagnosis
• Tarsal tunnel syndrome

• Antidromic nerve conduction test
• Carpal tunnel syndrome
• Orthodromic nerve conduction test
• Sensory nerve action potential

• Adult
• Aged
• Aged, 80 and over
• Carpal Tunnel Syndrome/complications
• Carpal Tunnel Syndrome/physiopathology
• Diabetic Neuropathies/complications
• Diabetic Neuropathies/physiopathology
• Electromyography
• Female
• Guillain-Barre Syndrome/complications
• Guillain-Barre Syndrome/physiopathology
• Humans
• Male
• Middle Aged
• Young Adult

To elucidate the clinical significance of median neuropathy at the wrist (MN) in patients with diabetes.

In total, 340 patients with diabetes who were hospitalized for glycemic control were enrolled in the present study. The diagnoses of MN and diabetic polyneuropathy (DPN) were based on electrophysiological criteria. A total of 187 patients were divided into four subgroups: patients without MN or DPN; patients with MN without DPN; patients with MN and DPN; and patients with DPN without MN. Intergroup comparisons of clinical characteristics and results of nerve conduction studies were carried out.

A total of 71 patients had neither MN nor DPN; 25 had MN, but no DPN; 55 had MN and DPN; and 36 had DPN, but no MN. In comparison with the MN and DPN group, the MN without DPN group included more patients in the early phase of diabetes (diagnosed within the past 5 years) and fewer patients with diabetic microangiopathy. Comparative median nerve conduction studies showed significantly lower motor and sensory nerve conduction velocities, longer F-wave latencies, and smaller sensory nerve action potentials in patients with MN and DPN than in those without DPN.

MN in patients with diabetes could be attributed to an impairment in axonal function at common entrapment sites, and could be used to identify an early manifestation of diabetic neuropathy.

• Carpal tunnel syndrome
• Diabetic neuropathy
• Median neuropathy

• Carpal tunnel syndrome
• Diabetes mellitus
• Diabetic neuropathy
• Median entrapment neuropathy at the wrist
• Polyneuropathy
• Ulnar entrapment neuropathy at the elbow
• Ulnar entrapment neuropathy at the wrist

• Diabetes Mellitus, Type 2/complications
• Diabetes Mellitus, Type 2/physiopathology
• Diagnosis, Differential
• Electrodiagnosis/methods
• Female
• Follow-Up Studies
• Humans
• Male
• Middle Aged
• Neural Conduction/physiology
• Polyneuropathies/physiopathology
• Retrospective Studies
• Ulnar Nerve/physiopathology
• Ulnar Nerve Compression Syndromes/diagnosis
• Ulnar Nerve Compression Syndromes/etiology
• Ulnar Nerve Compression Syndromes/physiopathology

Using high-resolution ultrasonography (US) to measure the median nerve cross-sectional areas (CSAs) such as in the “inching test” conducted in nerve conduction studies is a valuable tool to assess carpal tunnel syndrome (CTS). However, using this US measurement method to assess the median nerve CSA in diabetic patients with CTS has rarely been reported. Therefore, we used this US measurement method in this study to measure median nerve CSAs and to compare the CSAs of idiopathic, diabetic and diabetic polyneuropathy (DPN) patients with CTS.

124 hands belonging to 89 participants were included and assigned into four groups: control (32), idiopathic (38), diabetic (38) and DPN (16) CTS. In the latter two groups, only patients with mild and moderately severe CTS were included. The median nerve CSAs were measured at 8 points marked as i4, i3, i2, i1, w, o1, o2, and o3 in the inching test. The measured CSAs in each group of participants were compared.

Compared with the CSAs of the control group, enlarged CSAs were found in the idiopathic, diabetic and DPN CTS groups. The CSAs were larger at i4, i3 and i2 in the diabetic CTS group compared to the idiopathic CTS group. The CSAs measured at the i1 and w levels of the DPN CTS group were smaller than those of the diabetic CTS group. In the diabetic CTS group, the cut-off values of CSAs measured at the inlet, wrist crease, and outlet were 15.3 mm², 13.4 mm² and 10.0 mm², respectively, and 14.0 mm², 12.5 mm² and 10.5 mm², respectively, in the DPN CTS group.

Compared with the median nerve CSAs of the control and idiopathic CTS groups, the median nerve CSAs of the diabetic patients with CTS were significantly enlarged. However, compared with the diabetic CTS group, the CSAs were significantly smaller in the DPN CTS group. This US 8-point measurement method can be of value as an important complementary tool for CTS studies and diagnosis among diabetic patients.

• Aged
• Carpal Tunnel Syndrome/diagnosis
• Diabetic Neuropathies/diagnosis
• Electrodiagnosis/methods
• Female
• Humans
• Male
• Middle Aged
• Neural Conduction
• Prospective Studies
• Severity of Illness Index