TY - JOUR
T1 - Myophosphorylase deficiency affects muscle mitochondrial respiration as shown by 31P-MR spectroscopy in a case with associated multifocal encephalopathy
AU - Siciliano, Gabriele
AU - Rossi, Bruno
AU - Martini, Antonio
AU - Angelini, Corrado
AU - Martinuzzi, Andrea
AU - Lodi, Raffaele
AU - Zaniol, Paolo
AU - Barbiroli, Bruno
AU - Muratorio, Alberto
PY - 1995
Y1 - 1995
N2 - We report here a glycogen storage myopathy type V associated with multifocal encephalopathy. The patient, a 43-year-old male with increased serum CK, a heavy drinker and smoker, had been affected by generalized epilepsy since age 24, after a cranial injury. He had had a right hemiparesis 2 years before coming to our observation and a transient left hemiparesis the following year. CT and MRI of the brain showed multiple hemispheric lesions consistent with an ischemic process, as suggested by single photon emission tomography of the brain. Muscle biopsy showed a vacuolar myopathy, and myophosphorylase activity was 13% of the normal mean. Phosphorus magnetic resonance spectroscopy (31P-MRS) performed on resting calf muscles showed increased PCr to ATP and decreased PCr to Pi ratios. During both aerobic and ischemic exercise 31P-MRS failed to show any cytosolic acidification and phosphomonoesters (PME) accumulation, two MRS findings in agreement with McArdle's syndrome diagnosis. Mitochondrial respiration was also affected as shown by a low PCr to Pi ratio at rest and by a low rate of PCr re-synthesis during recovery from aerobic exercise. This latter finding in McArdle's disease can be explained by decreased mitochondrial substrate availability, which in turn can contribute to the phenotypic manifestations of the disease.
AB - We report here a glycogen storage myopathy type V associated with multifocal encephalopathy. The patient, a 43-year-old male with increased serum CK, a heavy drinker and smoker, had been affected by generalized epilepsy since age 24, after a cranial injury. He had had a right hemiparesis 2 years before coming to our observation and a transient left hemiparesis the following year. CT and MRI of the brain showed multiple hemispheric lesions consistent with an ischemic process, as suggested by single photon emission tomography of the brain. Muscle biopsy showed a vacuolar myopathy, and myophosphorylase activity was 13% of the normal mean. Phosphorus magnetic resonance spectroscopy (31P-MRS) performed on resting calf muscles showed increased PCr to ATP and decreased PCr to Pi ratios. During both aerobic and ischemic exercise 31P-MRS failed to show any cytosolic acidification and phosphomonoesters (PME) accumulation, two MRS findings in agreement with McArdle's syndrome diagnosis. Mitochondrial respiration was also affected as shown by a low PCr to Pi ratio at rest and by a low rate of PCr re-synthesis during recovery from aerobic exercise. This latter finding in McArdle's disease can be explained by decreased mitochondrial substrate availability, which in turn can contribute to the phenotypic manifestations of the disease.
KW - Encephalomalacia
KW - Energy metabolism
KW - Glycogen storage disease, type V
KW - Glycolysis
KW - McArdle's disease
KW - Nuclear magnetic resonance spectroscopy
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U2 - 10.1016/0022-510X(94)00207-5
DO - 10.1016/0022-510X(94)00207-5
M3 - Article
C2 - 7722538
AN - SCOPUS:0028888573
VL - 128
SP - 84
EP - 91
JO - Journal of the Neurological Sciences
JF - Journal of the Neurological Sciences
SN - 0022-510X
IS - 1
ER -