Giant anterior arachnoid cyst associated with syringomyelia: implications for treatment and follow-up.

STUDY DESIGN: A case report of a unique anterior intradural spinal arachnoid cyst (ISAC) associated with syringomyelia. OBJECTIVE: To discuss the surgical treatment and follow-up of anterior ISACs associated with syringomyelia. SUMMARY OF BACKGROUND DATA: Fenestration is commonly performed in arachnoid cysts with a large craniocaudal extension and in arachnoid cysts associated with syringomyelia. Particularly, excision of dorsal arachnoid cysts, without a shunting operation for the syrinx, achieves excellent results. However, anterior arachnoid cysts are different from dorsal cysts in having a greater craniocaudal extension and showing intracystic fibrous septae. METHODS: A 55-year-old man presented a small syringomyelic cavity at C1/C2 level and a giant anterior extramedullary intradural cystic cavity spreading from C1 to T11. A posterior laminectomy at C3 level was performed, and generous fenestration of the cyst was followed by the positioning of a cyst-subarachnoid shunt. RESULTS: After surgery, transitory relief was soon followed by a progressive worsening of symptoms. A specific kinematic-magnetic resonance imaging (K-MRI) was then carried out, showing a regular sisto-diastolic modulation of flow and normal shunt function. To define the real fluid dynamics within the cyst, the patient underwent a computed tomography-myelography (CT-M). Only a small quantity of contrast was found inside the pouch, confirming the clinical diagnosis of a poor communication within the shunt and the failure of previous surgery. CONCLUSION: This is the most extensive anterior ISAC associated with syringomyelia reported in literature until now. The treatment of extensive intradural extramedullary arachnoid cysts, especially for those located ventral to the spine and associated with syringomyelia, is still a matter of debate. In our case, fenestration and insertion of a cyst-subarachnoid shunt alone were not sufficient to restore normal CSF dynamics. In addition, we show that K-MRI may not be a proper method for postoperative follow-up of these lesions.

Postabsorptive and insulin-stimulated energy and protein metabolism in patients with myotonic dystrophy type 1.

BACKGROUND: Exaggerated insulin resistance was described as the major metabolic abnormality in myotonic dystrophy type 1 (DM1). We reported recently that the severity of the impairment in insulin-stimulated glucose metabolism in these patients was overestimated. OBJECTIVE: The aim was to dissect out insulin action with respect to whole-body energy homeostasis and glucose, protein, and lipid metabolism in patients with DM1 to assess the relevance of insulin resistance to the heterogeneous clinical manifestations of this syndrome. DESIGN: Ten nondiabetic patients with DM1 and 10 matched healthy control subjects were studied by means of 1) dual-energy X-ray absorptiometry; 2) a euglycemic-hyperinsulinemic clamp (40 mU. m(-2). min(-1)) combined with a primed, continuous infusion of [6,6-d(2)]glucose and [1-(13)C]leucine; 3) indirect calorimetry; and 4) localized (1)H magnetic resonance spectroscopy of the calf muscles. RESULTS: Patients with DM1 had less lean body mass, greater fat mass, and greater intramyocellular lipid contents than did healthy control subjects. Energy expenditure and glucose and lipid metabolism did not differ significantly between the groups. In contrast, markers of proteolysis were higher in DM1 patients in the postabsorptive and insulin-stimulated conditions and were associated with lower plasma concentrations of insulin-like growth factor 1 (P < 0.03) and higher plasma concentrations of tumor necrosis factor alpha receptor 2 (P = 0.04). CONCLUSIONS: Despite greater body fat and intramyocellular lipid contents in patients with DM1, insulin sensitivity was not significantly different between patients and control subjects. In contrast, the loss of lean body mass in patients with DM1 was associated with abnormal postabsorptive and insulin-stimulated regulation of protein breakdown. Lower plasma insulin-like growth factor 1 concentrations and higher tumor necrosis factor system activity might be involved in the muscle wasting of DM1.