Investigating Muscle Function After Stroke Rehabilitation with 31P-MRS: A Preliminary Study

Abstract

BackgroundNew evidence reveals significant metabolic changes in skeletal muscle after stroke. However, it is unknown if 31P magnetic resonance spectroscopy (31P-MRS) can evaluate these metabolic changes. Our objective here was to investigate: (a) if muscle energy metabolism changes in the affected side; (b) if muscle energy metabolism changes after rehabilitation; and (c) if energy metabolism measured by 31P-MRS can reflect changes in the Modified Modified Ashworth Scale (MMAS) and Fugl-Meyer assessment-lower extremity (FMA-LE) scores after rehabilitation.Material/MethodsWe enrolled 13 patients with stroke symptoms and hemiplegia. Lower-limb motor status on the affected side was evaluated by FMA-LE and MMAS. The 31P-MRS measures included phosphocreatine (PCr), inorganic phosphate (Pi), PCr/Pi, and pH. We statistically compared these measures in the affected and unaffected lower leg muscles before rehabilitation and after rehabilitation on the affected side. Spearman correlational analyses was performed to determine correlations between change in energy metabolism and change in FMA-LE score and MMAS score after rehabilitation.ResultsPCr and PCr/Pi were significantly lower in the affected muscle compared to the unaffected muscle; however, there were no significant differences in Pi or pH. After rehabilitation, PCr, Pi, PCr/Pi, and pH did not significantly change. However, FMA-LE and MMAS score improved significantly after rehabilitation. Changes in energy metabolism measured by 31P-MRS had no correlation with FMA-LE change after rehabilitation. However, changes in PCr and PCr/Pi were correlated with change in MMAS score after rehabilitation.Conclusions31P-MRS can evaluate changes in muscle energy metabolism in patients with stroke. PCr measured by 31P-MRS can reflect changes in MMAS after rehabilitation.

Different energy transfer efficiencies and buffering capabilities in quadriceps and calves muscles with low-load isotonic exercise detected by dynamic localized phosphorus-31 magnetic resonance spectroscopy

“…Our study had several limitations. Firstly, relatively lower temporal resolution (50 s per spectrum) compared to 7T ultra-high field three-dimensional 31 P-MRS research [29,30] restricted the exact calculation of PCr recovery constants; however, it had been best designed to gain the better signal-to-noise ratio in conventional hospitals (3T magnetic resonance scanner) which was consistent with some previous studies [19,20]. Secondly, a motion artifact during 31 P-MRS acquisition could be caused by the exercise, potentially adverse factor for generating highquality and stable phosphate metabolite signal, which had been controlled in this study as much as possible by firmly placing the surface coil under the muscles and hold it tightly to reduce the relative movement for increasing the signal-to-noise ratio.…”

“…c Statistically significant difference between during exercise and end exercise. previously published research [12,19,22]. The PCr/ATP ratio likewise had a downtrend in during exercise.…”

“…Quadriceps and calves muscles are the two most representative muscles of the thigh and calves, respectively [3,4]. In former studies, many 31 P-MRS studies showed the high-energy phosphate metabolism of quadriceps or calves muscles in state of health, training, aging or illness [10,[18][19][20][21][22][23]. Among them, a 31 P-MRS study of quadriceps muscles from Japan exhibited that muscle phosphate metabolism is different between deep and superficial parts during dynamic exercise [22].…”

Intervention Effect of Rehabilitation Robotic Bed Under Machine Learning Combined With Intensive Motor Training on Stroke Patients With Hemiplegia

“…After stroke hemiplegia, the upper motor neuron of patients will be damaged, and the motor reflex of the lower center will be released, resulting in motor dysfunction. The main clinical manifestations are weakened muscle strength, increased muscle tone, and tendon hyperreflexia (Zhang et al, 2018 ; Kimura et al, 2019 ; Ratanapinunchai et al, 2019 ). The FMA-LE motor function scale was used to evaluate the lower extremity motor function of stroke patients with hemiplegia.…”

Magnetic Field Dependence of Spectral Correlations between 31P-Containing Metabolites in Brain

“…Phosphorous ( 31 P) magnetic resonance spectroscopy (MRS) is an important technique enabling noninvasive assessment of many aspects of bioenergetics and metabolism in vivo [ 1 ]. 31 P MRS has been widely used to study numerous diseases such as Parkinson’s disease [ 2 ], tumor [ 3 ], diabetes [ 4 ], stroke [ 5 ], hepatobiliary disease [ 6 ], and neuromuscular disorders [ 7 ]. In many clinical applications of 31 P MRS, metabolite signals such as adenosine triphosphate (ATP), phosphocreatine (PCr), inorganic phosphate (P i ), and phosphoesters are measured in vivo and then correlated with clinical metrics such as disease severity and/or treatment.…”