Increased Metabolic Activity in the Spinal Cord of Patients with Long-Standing Lhermitte’s Sign

Abstract

These data suggests a close direct relationship between regional perfusion and metabolism of the spinal cord, similarly as in the brain. The postirradiation recovery may be related to energy-demanding conduction, explaining the increased metabolism and perfusion. The increased radiosensitivity and higher spinal cord BED may have contributed to the more severe sequelae in case 1.

Lhermitte sign and myelopathy after irradiation of the cervical spinal cord in radiotherapy treatment of head and neck cancer

“…This can be resolved by a higher sodium channel density, but this causes increased glucose metabolism and, therefore, greater tissue perfusion. Increased FDG and O 15 butanol uptake as well autopsy findings with lack of structural damage of LS patients support this view [12,13]. …”

“…First, LS is usually reversible. Only late onset LS may develop into CPRM [6,10,12,20,28,32]. Second, LS developed at maximum doses as low as 38.2 Gy.…”

“…Chronic progressive radiation myelopathy (CPRM) can be preceded by delayed onset of Lhermitte sign (LS; 9-15 months after radiotherapy treatment) [6,10,12,20,28,32]. LS is a transient myelopathy with shock-like sensations from the neck to the extremities, typically after flexion of the neck, and can be evoked by different factors including radiotherapy [2,21,27,30].…”

Prognostic Value of 18F-FDG PET in Monosegmental Stenosis and Myelopathy of the Cervical Spinal Cord

“…After initially increased 18 F-FDG uptake (SUV max # 2.7) within the area of demyelination, a slow normalization of glucose utilization can be observed. The decline of the increased glucose metabolism is accompanied by a good clinical recovery under treatment with glucocorticoids (31)(32)(33)(34). These authors suggest that the regionally increased 18 F-FDG uptake is caused by reparative processes in radiation-induced damage to the spinal cord.…”

Clinical value of 2-deoxy-[18F]fluoro-d-glucose positron emission tomography in patients with cervical spondylotic myelopathy

“…Increased glucose uptake has been observed within the areas of demyelination, and, furthermore, the glucose metabolism decreased correspondingly to clinical recovery during corticosteroid treatment. 7,11,12,38 It was assumed that regional hypermetabolism in radiation-related myelopathy is caused by reparative processes.…”