Mononeuropathies, Diagnosis and Treatment

**3**

**Chapter 1**

**Abstract**

Focal Upper Limb

*Tayir Alon and Vera Bril*

with Diabetes Mellitus

efficacy of cubital tunnel release in DM patients.

**in patients with DM**

**Keywords:** mononeuropathy, diabetes mellitus, carpal tunnel syndrome, nerve compression, diabetic sensorimotor polyneuropathy, median nerve,

**1. What causes the increased vulnerability to entrapment neuropathies** 

Entrapment neuropathies are more prevalent among patients with DM, and carpal tunnel syndrome (CTS) can guide a better understanding of the pathophysiology of entrapment neuropathies in this patient population. CTS is the most commonly studied entrapment syndrome and changes in the small arteries, such as vascular hypertrophy and intimal thickening, and noninflammatory fibroses of connective tissue are key pathologic features as discussed earlier in this book. In patients with DM, the reasons for the higher susceptibility to entrapment neuropathies are likely the combination of increased vulnerability of the nerves to compression arising from underlying diffuse DM-related nerve fiber injury and the presence of altered connective tissue structures within the carpal tunnel causing additional compression [1]. These two mechanisms are most likely relevant to all entrapment neuropathies in DM. Axonal, metabolic, and structural changes in DM that can

ulnar nerve, carpal tunnel syndrome, cubital tunnel syndrome

Mononeuropathies in Patients

In this chapter, we describe the prevalence, diagnostic methods, and treatment efficacy of compressive neuropathies of the median and the ulnar nerves in patients with diabetes mellitus (DM). Median neuropathy at the wrist is found in up to onethird of patients with DM, when demonstrated electrophysiologically, but is symptomatic as carpal tunnel syndrome (CTS) in a smaller proportion of these patients. It is clear that diabetes increases the risk of having clinical CTS. Diagnosis of CTS using nerve conduction studies is difficult in patients with DM and diabetic sensorimotor polyneuropathy (DSP) as median nerve conduction studies are affected predominantly by the diabetes state. We will discuss different electrodiagnostic and ultrasonography techniques for diagnosis and the outcomes of carpal tunnel release decompressive surgery in this special patient population. It is controversial whether DM is a risk factor for cubital tunnel syndrome or ulnar neuropathy at the elbow (UNE) or at the wrist (UNW). In this chapter, we will review the ultrasonographic and electrophysiological diagnostic techniques used in UNE and UNW and the

#### **Chapter 1**
