The syndrome of diabetic amyotrophy

Abstract

Changes in the electromyograms and motor nerve conduction velocities in 12 patients with diabetic amyotrophy suggested mild distal and moderate proximal neuropathy in the lower limbs. Histological and histochemical findings in the vastus medialis muscles were consistent with denervation. Electron microscopical examination of the vastus medialis muscles in 6 patients revealed myofibrillar degeneration. One patient had abnormal mitochondria and tubular aggregates. The basement membranes of the intramuscular capillaries were thickened in all but 1 patient. Histochemical staining of the myoneural junctions showed changes consistent with degeneration and regeneration. We conclude that diabetic amyotrophy is a distinct clinical entity and is secondary to metabolic derangement rather than diabetic microangiopathy.

Proximal skeletal muscle alterations in streptozotocin‐diabetic rats: A histochemical and morphometric analysis

“…The pathogenesis of this syndrome is not known. Although it seems to be neurogenic, the site of nerve involvement is not yet known (Locke et al, 1963;Chokroverty et al, 1977). Furthermore, several researchers (Redwood, 1962;Armstrong et al, 1975;Chao et al, 1976;Ianuzzo and Armstrong, 1976;Asbury, 1977Asbury, , 1987Grodsky et al, 1982) prefer the hypothesis of metabolic damage to explain the muscle pathology in experimental as well as clinical studies.…”

Focal and multifocal diabetic neuropathies

“…This syndrome, which was originally described by Bruns in 1890 17 , has been subsequently reported under the terms of diabetic myelopathy 18 , diabetic amyotrophy 19 , femoral neuropathy 20,21 , proximal diabetic neuropathy 22,23 , femoral-sciatic neuropathy 24 and the Bruns-Garland syndrome 25,26 . The neurological picture is limited to the lower limbs and is usually asymmetrical 27 .…”

Diabetic Proximal Neuropathy: Therapy and Prognosis

“…Has subsequent experience justified this euphoric view? In previous studies, many patients were followed up merely for months, rather than the periods in excess of three years that would be required to assess the slow recovery from diabetic proximal neuropathy [4,7,10]. Now Coppack and Watkins have reviewed hospital case records of 27 patients covering periods of 1-14 years following their diagnosis of diabetic proximal neuropathy.…”

“…Furthermore, any theory that proximal diabetic neuropathy represents nerve infarction due to diabetic microvascular disease would have to account for the rarity with which it is accompanied by diabetic retinopathy or nephropathy, [4] the excellent recovery achieved by many patients, and the marked tendency for abnormalities to develop symmetrically on the two sides within a few weeks of one another [4,5]. The other end of the clinical spectrum is less well recognized: symmetrical proximal muscle weakness of slow onset, which is relatively painless and is presumed to be metabolic in origin [6][7][8].A paper in this issue of the journal by Coppack and Watkins [5] addresses two important issues concerning the treatment and prognosis of diabetic proximal neuropathy. First, does hypoglycaemic therapy really aid recovery of the leg weakness?…”

“…the use of insulins is almost invariably essential' a view supported by Casey and Harrison [10]. However it is clear that diabetic proximal neuropathy can develop in patients with rather mild glucose intolerance, and that recovery can coincide merely with the institution of a low calorie diet, without additional hypoglycaemic medication [7,10]. …”