ABSTRACT
Charcot-Marie-Tooth disease type 1A (CMT1A) is the most common type of hereditary neuropathy worldwide and diabetes mellitus (DM) is the most frequent cause of peripheral neuropathy in the Western world. CMT1A typically manifest as a predominant motor neuropathy, while, DM-related neuropathy often manifests as a predominant sensory disorder. There are some evidences that CMT1A patients that also had DM had a more severe neuropathy. Although the real frequency and the underlying mechanisms related to this association has not yet been addressed in the literature. We sought to characterize the phenotypic variability of CMT1A patients with persistent high glucose levels (DM or impaired glucose tolerance [IGT]). Nineteen patients with CMT1A and DM (CMTdiab), seven with CMT1A and IGT (CMTintol) and 27 with CMT1A without comorbidities were analyzed. They were evaluated through clinical assessment, application of the following scales: visual analogue scale, McGill, CMTNS, SF-36 and COMPASS 31 and electrophysiological studies. Patients CMTdiab had a more severe motor and sensory neuropathy, more intense autonomic symptoms and worse quality of life. Surprisingly, proximal weakness and temporal dispersion on nerve conduction studies are frequently observed in this group. Patients CMTintol also had a more severe neuropathy. Curiously, we observed that the association of CMT1A and glucose metabolism disorders (CMTglic) clustered in some families. Patients CMTglic develop a more severe neuropathy. As there is yet no cure to CMT1A, a strict blood sugar control may be a useful measure.
Subject(s)
Autonomic Nervous System Diseases , Charcot-Marie-Tooth Disease , Diabetes Mellitus , Diabetic Neuropathies , Glucose Intolerance , Adult , Autonomic Nervous System Diseases/blood , Autonomic Nervous System Diseases/epidemiology , Autonomic Nervous System Diseases/etiology , Autonomic Nervous System Diseases/physiopathology , Charcot-Marie-Tooth Disease/blood , Charcot-Marie-Tooth Disease/complications , Charcot-Marie-Tooth Disease/epidemiology , Charcot-Marie-Tooth Disease/physiopathology , Comorbidity , Diabetes Mellitus/blood , Diabetes Mellitus/epidemiology , Diabetes Mellitus/physiopathology , Diabetic Neuropathies/blood , Diabetic Neuropathies/epidemiology , Diabetic Neuropathies/etiology , Diabetic Neuropathies/physiopathology , Female , Glucose Intolerance/blood , Glucose Intolerance/complications , Glucose Intolerance/epidemiology , Glucose Intolerance/physiopathology , Humans , Male , Middle Aged , Neural Conduction/physiology , Neurologic Examination , Quality of LifeABSTRACT
We report an 18-month-old Charcot-Marie-Tooth type 1A (CMT1A) patient who developed a rapid-onset neuropathy, with proximal and distal weakness, and non-uniform nerve conduction studies. The neuropathy responded well to immunomodulation, confirming the coexistence of an inherited and an inflammatory neuropathy. Unexpected clinical and/or electrophysiological manifestations in CMT1A patients should alert clinicians to concomitant inflammatory neuropathy. In addition, this association raises reflections about disease mechanism in CMT1A.