The associated manifestations of insulin and noninsulin dependent diabetes include, but are not limited to, retinopathy, nephropathy, cardiovascular disease, and peripheral neuropathy. The most common necrologie sequela is bilateral and distal sensorineural deficit.
Diabetic amyotrophy is a less common sequela of diabetes mellitus. However, due to a combination of its variable presentation and a lack of familiarity of this condition within the medical community, the correct diagnosis may not be determined until an extensive and costly evaluation is performed.
This article presents a case of diabetic amyotrophy presenting as severe hip pain as an example of Bruns-Garland syndrome.
A 56-year-old woman with a 10-year history of insulin dependent diabetes mellitus presented with progressive, incapacitating left groin and thigh pain of 10 days' duration.
Deep vein thrombosis was diagnosed and anticoagulation therapy was started. The patient reported sharp excruciating pain in the left groin and anteromedial thigh with radiation to the medial knee. The pain was exacerbated by hip or knee motion and was partially relieved by sitting and immobilization of the left lower extremity in hip and knee flexion.
Medical history was significant for insulin dependent diabetes mellitus, sarcoidosis, and mild degenerative joint disease of both knees. On presentation, the patient was afebrile with stable vital signs.
Physical examination revealed exquisite pain to palpation of the left groin and medial thigh as well as pain with passive thigh or knee motion. Weakness of the hip flexors and adductors and quadriceps to a greater degree than the other motor groups of the left lower extremity was noted. Reflexes showed a slightly decreased patellar on the left.
Laboratory values on admission included elevated white blood cell count (14,000) and blood glucose (268 mg/dL). Creatine kinase values were normal. Lower extremity doppler examination also was normal.
Bone scan revealed slightly increased uptake in the left medial thigh on blood pool images only. Computed tomography of both hip joints and bilateral thighs to knee level as well as abdominal examination was normal.
Magnetic resonance imaging was attempted; however, the patient could not tolerate the required position of extended hips and knees for sufficient time to obtain data. Computed tomography myelogram revealed only L3-L4, L4-L5 bulging disks without nerve root compression.
Electromyography and nerve conduction studies showed denervation potentials in multiple muscles supplied by L2 through L4 nerve roots, particularly those muscles supplied by femoral and obturator nerves. Paraspmals from T9 to S 1 revealed increased activity.
The clinical presentation and electromyography and nerve conduction studies were consistent with diabetic amyotrophy. Aggressive blood glucose control and pain management were instituted. The pain was eventually controlled by oral medication and die patient discharged. Over the subsequent 6 months, her symptoms improved and she returned to her normal level of activity. Follow-up electromyography and nerve conduction studies 6 months after onset of symptoms were normal.
Diabetic amyotrophy was first cited by Bruns1 in 1890 in 3 patients with diabetes mellitus who had progression of proximal thigh weakness and pain. The next description of the disorder was in 1953 by Garland and Tavemer.2 They reported a series of 5 patients and used the term "diabetic myelopathy" due to their uncertainty regarding spinal cord involvement in the pathophysiology of the disorder. In 1955, the term diabetic amyotrophy was first used by Garland.3 In 1961, Garland summarized data from 27 patients and noted that most symptoms involved the proximal thigh musculature and usually were asymmetrical.4
The typical diabetic amyotrophic patient was male and insulin or noninsulin dependent for a long time. Findings usually were asymmetrical with decreased strength and deep tendon reflexes, and a decrease in muscle bulk in the affected limb often was present. Cerebrospinal fluid protein levels usually were elevated.4"9 If electromyography and nerve conduction studies were performed, denervation usually was demonstrated at several levels. Frequently the onset of pain was acute and followed a period of poor blood glucose control.7,10
The two most widely held theories on the pathogenesis of diabetic amyotrophy are fundamentally based on ischemia and metabolic dysfunction of the involved nerves.7-11 The sudden onset of symptoms in many patients was believed by some authors to indicate an acute loss of blood flow to the symptomatic nerve root. This was believed to result from long-term hyperglycemia and its resulting microvascular changes and prompted the name ischemic mononeuropathy multiplex used by some to describe the disorder.7,12,13
The second theory presumes derangements in nerve cell metabolism resulting from poor blood glucose control.14,15 A paucity of direct evidence for either theory exists; however, one postmortem study of the nerves of more severe human diabetics has shown depressed levels of myo-inositol in nerve cell bodies.16
Myo-inositol is incorporated into the myelin sheath of the nerve and, as a component of phosphatidylinositol, is important in the maintenance and function of nerve cell membranes. In animal studies with experimentally induced diabetic rats with neuropathy, myo-inositol appears to be the critical step in deteirnining conduction problems in the nerve. Oral replacement of this compound in one study caused a reversal in the conduction delays.17,18 Myo-inositol is critical for nerve cell ATPase function and regulation of intracellular concentrations of ions and osmotic grathents necessary for normal nerve function.19
Clinical evidence suggests a metabolic derangement as a component of the disorder as most patients have improvement of their symptoms with improved blood glucose control. Electromyography and nerve conduction studies are noted to lag the improvement in symptoms; however, with continued control, these findings return to baseline. A correlation also exists between severity of symptoms and incidence of the disorder, and postmortem changes are directly correlated with the degree of blood glucose control.2-4,20,21
Controversy exists regarding the precise anatomic location of the lesion in diabetic amyotrophy. Every site from the spinal cord to the muscle itself has been implicated.21 According to some authors, the lesion is located in the peripheral nerves, with more severe involvement proximally.7,21,24 Discrepancies between the clinical examination and electromyography and nerve conduction studies make precise location of the lesion impossible. Multiple sites of involvement may be noted.
Diabetic amyotrophy treatment consists of pain management, physical therapy, and most importantly, rigorous control of blood glucose levels. The typical course of the condition is one of gradual improvement over months correlating with the degree of compliance with blood glucose levels. Pain usually is the first symptom to improve, with weakness and normalization of electromyography and nerve conduction studies progressively following. Most authors report improvement in the 90% subjective range for return to functional activities.2-4,20,21
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2. Garland H, Tavemer D. Diabetic myelopathy. Br Med J. 1953; 1:1405-1408.
3. Garland H. Diabetic amyotrophy. Br Med J. 1955;2:1287-1290.
4. Garland H. Diabetic amyouophy. Br J Clin Praci. 1961; 15:9-13.
5. Bastron JA, Thomas JE. Diabetic polyradiculopathy: clinical and electromyographic findings in 105 patients. Mayo Clin Proc. 1981; 56:725-732.
6. Bradley WG, Chad D, Verghese JP. et al. Painful lumbosacral plexopathy with elevated erythrocyte sedimentation rate: a treatable inflammatory syndrome. Ann Neurol. 1984; 15:457-464.
7. Chokroverty S. AAEE case report 13: diabetic amyotrophy. Muscle Nerve. 1987; 10:679-684.
8. Raff MC, Asbury AK. Ischemic mononeuropathy and mononeuropathy multiplex in diabetes mellitus. N Engl J Med. 1968; 279:17-21.
9. Subramony SH, Wilboum AJ. Diabetic proximal neuropathy. Clinical and electromyographic studies. J Neurol Sci. 1982; 53:293-304.
10. Gregersen G. Diabetic amyotrophy - a well-defined syndrome? Acta Med Scand. 1969; 185:303-310.
11. Tuck RR, Schmelzer JD, Low PA. Endoneurial blood flow and oxygen tension in the sciatic nerves of rats with experimental diabetic neuropathy. Brain. 1984; 107:935-950.
12. Asbury AK. Proximal diabetic neuropathy. Ann Neurol. 1977; 2:179-180.
13. Raff MC, Sangalang V, Asbury AK. Ischemic mononeuropathy multiplex associated with diabetes mellitus. Arch Neurol. 1968; 18:487-499.
14. Duncan LJP, Macfariane A, Robson JS. Diabetic retinopathy in pancreatic diabetes. Lancet. 1958; 1:822-826.
15. Osuntokun BO. The neurology of non-alcoholic pancreatic diabetes mellitus in Nigerians. J Neurol Sci. 1970; 11:17-43.
16. Mayhew JA, Gillon KR Hawthorne JN. Free and lipid inositol, sorbitol and sugars in sciatic nerve obtained post-mortem from diabetic patients and conimi subjects. Diabewlogia. 1983; 24:13-15.
17. Greene DA, De Jesus PV Jr, Winegrad AI. Effects of insulin and dietary myo-inositol on impaired peripheral motor nerve conduction velocity in adult streptozotocin diabetes. J Clin Invest. 1975:55:1326-1336.
18. Greene DA, Lewis RA, Lattimer SA. Brawn MJ. Selective effects on myo-inositol administration on sciatic and tibial motor nerve conduction parameters in the streptozotocin-diabetic rat. Diabetes. 1982; 31:573-578.
19. Greene DA, Lattimer SA. Na/K ATPase defect in diabetic ral peripheral nerve: correction by myo-inositol administration. J Clin Invest. 1983;72:1058-1063.
20. Casey EB1 Harrison MJ. Diabetic amyotrophy: a follow-up study. Br Med Jr. 1972; 1:656-659.
21. Chokroverty S, Reyes MG, Rubino FA. Tonaki H. The syndrome of diabetic amyotrophy. Ann Neurol 1977; 2:181-194.
22. Chokroverty S. Diabetic proximal amyotrophy. In: Canal N, Pazza G, eds. Peripheral Neuropathies. 1978; 257-268.
23. Chokroverty S. Proximal nerve dysfunction in diabetic proximal amyotrophy. Elecrrophysiology and and electron microscopy. Arch Neurol. 1982; 39:403-407.
24. Chokroverty S, Reyes MG, Rubino FA. Bruns-Garland syndrome of diabetic amyotrophy. Tram Am Neurol Assoc, 1977; 102:173-177.