Early-onset cerebellar ataxia,myoclonus and hypogonadism in a case of mitochondrial complex III deficiency treated with vitamins K3 and C

A 16-year-old girl presented with early-onset cerebellar ataxia, myoclonus, elevated lactic acidosis and hypogonadotropic hypogonadism. Muscle biopsy specimens revealed fibres with a ragged appearance with increased mitochondria and lipid droplets. Biochemical investigation revealed a deficiency of complexbc ₁ (complex III) of the mitochondrial respiratory chain. Genetic analysis did not show either deletions or known mutations of mitochondrial DNA (mtDNA). Phosphorus magnetic resonance spectroscopy (³¹P-MRS) showed defective energy metabolism in brain and gastrocnemius muscle. A decreased phosphocreatine (PCr) content was found in the occipital lobes accompanied by normal inorganic phosphate (Pi) and cytosolic pH. These findings represented evidence of a high cytosolic adenosine diphosphate concentration and a relatively high rate of metabolism accompanied by a low phosphorylation potential. Muscle³¹P-MRS showed a high Pi content at rest, abnormal exercise transfer pattern and a low rate of PCr post-exercise recovery. These findings suggested a deficit of mitochondrial function. Therapy with vitamins K₃ and C normalized brain³¹P-MRS indices, whereas it did not affect muscle bioenergetic metabolism. In this patient, the endocrinological disorder is putatively due to a mitochondrial cytopathy. Although an unknown mtDNA mutation cannot be ruled out, the genetic defect may lie in the nuclear genome.     

In vivo skeletal muscle mitochondrial function in Leber's hereditary optic neuropathy assessed by 31P magnetic resonance spectroscopy

We used ³¹P magnetic resonance spectroscopy (³¹P-MRS) to asses in vivo skeletal muscle mitochondrial function in 10 Leber's hereditary optic neuropathy patients/carriers with a mitochondrial DNA (mtDNA) mutation at one of three nucleotide positions, 11,778, 14,484, and 3,460. We studied one affected patient for each mutation and two unaffected carriers with the 11,778 or 3,460 mutation and three carriers with 14,484. All subjects were homoplasmic except the two 3,460 carriers, who showed 80% and 15% of mutated mtDNA. ³¹P-MRS at rest disclosed some abnormalities in all subjects. In particular, the phosphorylation potential was below the normal range in all cases. During recovery from exercise, the maximum rate of mitochondrial ATP production (V_max) was reduced to 27% of normal in the 11,778 mutation and to 53% in the 14,484 mutation patient/carrier groups. Mitochondrial V_max was within the normal range in all subjects with the 3,460 mutation but correlated inversely with the percentage of mutated mtDNA. This in vivo study shows that the 11,778 mutation causes a mitochondrial impairment more severe than the 14,484 and that the 3,460 mutation results in only a mild depression of muscle mitochondrial function.     

Lipoic (thioctic) acid increases brain energy availability and skeletal muscle performance as shown by in vivo31P-MRS in a patient with mitochondrial cytopathy

A woman affected by chronic progressive external ophthalmoplegia and muscle mitochondrial DNA deletion was studied by phosphorus magnetic resonance spectroscopy (³¹P-MRS) prior to and after 1 and 7 months of treatment with oral lipoic acid. Before treatment a decreased phosphocreatine (PCr) content was found in the occipital lobes, accompanied by normal inorganic phosphate (Pi) level and cytosolic pH. Based on these findings, we found a high cytosolic adenosine diphosphate concentration [ADP] and high relative rate of energy metabolism together with a low phosphorylation potential. Muscle MRS showed an abnormal work-energy cost transfer function and a low rate of PCr recovery during the post-exercise period. All of these findings indicated a deficit of mitochondrial function in both brain and muscle. Treatment with 600 mg lipoic acid daily for 1 month resulted in a 55% increase of brain [PCr], 72% increase of phosphorylation potential, and a decrease of calculated [ADP] and rate of energy metabolism. After 7 months of treatment MRS data and mitochondrial function had improved further. Treatment with lipoate also led to a 64% increase in the initial slope of the work-energy cost transfer function in the working calf muscle and worsened the rate of PCr resynthesis during recovery. The patient reported subjective improvement of general conditions and muscle performance after therapy. Our results indicate that treatment with lipoate caused a relevant increase in levels of energy available in brain and skeletal muscle during exercise.     

Slower recovery of muscle phosphocreatine in malignant hyperthermia-susceptible individuals assessed by 31P-MR spectroscopy

Our aim was to develop an exercise protocol using ³¹P-magnetic resonance spectroscopy (³¹P-MRS), which can discriminate between malignant hyperthermia-susceptible (MHS) individuals and controls. MRS spectra of the forearm muscles were recorded at rest, during and after a standardized exercise protocol in 10 MHS patients and compared with spectra obtained in 10 controls. There was no difference in resting intracellular pH (pHi) or PCr/ (Pi+PCr) ratio between the groups (PCr = phosphocreatine, Pi = inorganic phosphorus). At the end of the exercise and during the initial recovery phase, the pHi and PCr/(Pi+PCr) ratio were significantly lower in the MHS group ([pHi: 6.37 (0.07) for MHS vs 6.70 (0.05) for controls, P < 0.005; PCr/(Pi+PCr): 0.784 (0.017) for MHS vs 0.954 (0.020) for controls, P < 0.0005]). For PCr/ (Pi+PCr), complete separation between the two groups was observed during the initial recovery phase. The mean recovery time of PCr/ (Pi+PCr) was 0.57 min for the control group and 1.28 min for the MHS group. The slower recovery of PCr/ (Pi+PCr) is likely to be caused by a combination of several factors, including the lower pHi in MHS subjects at the start of recovery (inhibiting ATP production) and excessive sarcoplasmic calcium overload (causing continued enzyme activation and ATP consumption). Our exercise protocol can be a valuable adjunct to discriminate between MHS and non susceptible subjects. Received: 10 July 1996 Received in revised form: 7 August 1997 Accepted: 11 August 1997     

Leber's hereditary optic neuropathy: genetic, biochemical, and phosphorus magnetic resonance spectroscopy study in an Italian family

Three siblings of a family affected with Leber's hereditary optic neuropathy (LHON) showed a mitochondrial DNA mutation at position 11778. The lactate response to a standardized effort was increased in only one case. Muscle biopsies and biochemistry of muscle and platelet mitochondrial enzymes were normal. All patients showed an altered energy metabolism during exercise and during recovery after exercise on phosphorus 31-magnetic resonance spectroscopy (31P-MRS) of muscle. Brain 31P-MRS showed a decreased energy reserve (decreased PCr/Pi ratio) in all patients. 31P-MRS noninvasively demonstrated an altered mitochondrial energy metabolism in muscle and, for the first time, in the brains of LHON patients.     

Skeletal muscle oxidative capacity in amyotrophic lateral sclerosis

Introduction: Mitochondrial dysfunction in the motor neuron has been suspected in amyotrophic lateral sclerosis (ALS). If mitochondrial abnormalities are also found in skeletal muscle, assessing skeletal muscle could serve as an important biomarker of disease progression. Methods: Using ³¹P magnetic resonance (³¹P‐MRS) and near infrared (NIRS) spectroscopy, we compared the absolute values and reproducibility of skeletal muscle oxidative capacity in people with ALS (n = 6) and healthy adults (young, n = 7 and age‐matched, n = 4). Results: ALS patients had slower time constants for phosphocreatine (PCr) and muscle oxygen consumption (mVO₂) compared with young, but not age‐matched controls. The coefficient of variation for the time constant was 10% (SD = 2.8%) and 17% (SD = 6.2%) for PCr and mVO₂, respectively. Conclusions: People with ALS had, on average, a small but not statistically significant, impairment in skeletal muscle mitochondrial function measured by both ³¹P‐MRS and NIRS. Both methods demonstrated good reproducibility. Muscle Nerve 50 : 767–774, 2014     

31P magnetic resonance spectroscopy in the frontal lobe of major depressed patients

Most research with ³¹P-magnetic resonance spectroscopy (³¹P-MRS) in affective disorders has been done in the field of bipolar disturbances. Reduced frontal and temporal lobe phosphomonoester (PME) concentrations were measured in the euthymic state, whereas increased values were found in the depressed state. In bipolar-II patients reduced phosphocreatine (PCr) concentrations were reported in the euthymic, depressed, and manic state. The aim of the present study was to explore whether PME and PCr were also altered in the frontal lobe of major depressed, unipolar patients. Therefore, we used ³¹P-MRS to investigate the relative phospholipid and high-energy phosphate concentrations in the frontal lobe of 14 unipolar patients, mostly medicated, and 8 age-matched controls. We found increased PME and decreased ATP values. Other ³¹P-MRS parameters were not different in both groups. Phosphomonoester percentages correlated negatively with the degree of depression. Thus, the main alterations found in bipolar depressed patients could also be demonstrated in unipolar depressed patients. The results are discussed with regard to disturbed phospholipid and intracellular high-energy phosphate metabolism in depressed patients. Received: 2 December 1997 / Accepted: 14 July 1998     

Brain and skeletal muscle bioenergetic failure in familial hypobetalipoproteinaemia.

OBJECTIVE: To determine whether a multisystemic bioenergetic deficit is an underlying feature of familial hypobetalipoproteinaemia. METHODS: Brain and skeletal muscle bioenergetics were studied by in vivo phosphorus MR spectroscopy (31P-MRS) in two neurologically affected members (mother and son) and in one asymptomatic member (daughter) of a kindred with familial hypobetalipoproteinaemia. Plasma concentrations of vitamin E and coenzyme Q10 (CoQ10) were also assessed. RESULTS: Brain 31P-MRS disclosed in all patients a reduced phosphocreatine (PCr) concentration whereas the calculated ADP concentration was increased. Brain phosphorylation potential was reduced in the members by about 40%. Skeletal muscle was studied at rest in the three members and during aerobic exercise and recovery in the son and daughter. Only the mother showed an impaired mitochondrial function at rest. Both son and daughter showed an increased end exercise ADP concentration whereas the rates of postexercise recovery of PCr and ADP were slow in the daughter. The rate of inorganic phosphate recovery was reduced in both cases. Plasma concentration of vitamin E and CoQ10 was below the normal range in all members. CONCLUSIONS: Structural changes in mitochondrial membranes and deficit of vitamin E together with reduced availability of CoQ10 can be responsible for the multisystemic bioenergetic deficit. Present findings suggest that CoQ10 supplementation may be important in familial hypobetalipoproteinaemia.     

Direct measurement of high-energy phosphate compounds in patients with neuromuscular disease.

Several neuromuscular disorders are associated with reductions in intramuscular adenosine triphosphate (ATP) and/or phosphocreatine (PCr). These alterations have been primarily characterized using (31)P-magnetic resonance spectroscopy ((31)P-MRS). We prospectively measured total creatine, PCr, and ATP in muscle biopsies from 81 patients: normal controls (n = 33), mitochondrial cytopathy (n = 8), neuropathic (n = 3), dystrophy/congenital myopathies (n = 7), inflammatory myopathy (n = 12), and miscellaneous myopathies (n = 18) using direct biochemical analysis. Intramuscular concentrations of PCr and ATP were lower for the dystrophy/congenital myopathy, inflammatory myopathy, and mitochondrial disease patients with ragged red fiber (RRF) as compared with normal controls (P < 0.05). Total creatine was lower for the dystrophy/congenital myopathy group as compared with the normal control group (P < 0.05). These values compare favorably to results from other studies using (31)P-MRS and provide external validation for the values obtained using that method. Given the reductions in high-energy phosphate compounds in these patients, there is the potential for therapeutic intervention with creatine monohydrate supplementation.     

Mitochondrial dysfunction in myotonic dystrophy type 1

The pathophysiological mechanism linking the nucleotide expansion in the DMPK gene to the clinical manifestations of myotonic dystrophy type 1 (DM1) is still unclear. In vitro studies demonstrate DMPK involvement in the redox homeostasis of cells and the mitochondrial dysfunction in DM1, but in vivo investigations of oxidative metabolism in skeletal muscle have provided ambiguous results and have never been performed in the brain. Twenty-five DM1 patients (14M, 39 ± 11years) underwent brain proton MR spectroscopy (¹H-MRS), and sixteen cases (9M, 40 ± 13 years old) also calf muscle phosphorus MRS (³¹P-MRS). Findings were compared to those of sex- and age-matched controls. Eight DM1 patients showed pathological increase of brain lactate and, compared to those without, had larger lateral ventricles (p < 0.01), smaller gray matter volumes (p < 0.05) and higher white matter lesion load (p < 0.05). A reduction of phosphocreatine/inorganic phosphate (p < 0.001) at rest and, at first minute of exercise, a lower [phosphocreatine] (p = 0.003) and greater [ADP] (p = 0.004) were found in DM1 patients compared to controls. The post-exercise indices of muscle oxidative metabolism were all impaired in DM1, including the increase of time constant of phosphocreatine resynthesis (TC PCr, p = 0.038) and the reduction of the maximum rate of mitochondrial ATP synthesis (p = 0.033). TC PCr values correlated with the myotonic area score (ρ = 0.74, p = 0.01) indicating higher impairment of muscle oxidative metabolism in clinically more affected patients. Our findings provide clear in vivo evidence of multisystem impairment of oxidative metabolism in DM1 patients, providing a rationale for targeted treatment enhancing energy metabolism.     

Energy metabolism measured by 31P magnetic resonance spectroscopy in the healthy human brain

Background and purposePhosphorous magnetic resonance spectroscopy (31P-MRS) allows a non-invasive analysis of phosphorus-containing compounds in vivo. The present study investigated the influence of brain region, hemisphere, age, sex and brain volume on 31P-MRS metabolites in healthy adults.Materials and methodsSupratentorial brain 31P-MRS spectra of 125 prospectively recruited healthy volunteers (64 female, 61 male) aged 20 to 85 years (mean: 49.4 ± 16.9 years) were examined with a 3D-31P-MRS sequence at 3T, and the compounds phosphocreatine (PCr), inorganic phosphate (Pi) and adenosine triphosphate (ATP) were measured. From this data, the metabolite ratios PCr/ATP, Pi/ATP and PCr/Pi were calculated for different brain regions. In addition, volumes of gray matter, white matter and cerebrospinal fluid were determined.ResultsFor all metabolite ratios significant regional differences and in several regions sex differences were found. In some brain regions and for some metabolites hemispheric differences were detected. In addition, changes with aging were found, which differed between women and men.ConclusionsThe present results indicate that 31P-MRS metabolism varies throughout the brain, with age and between sexes, and therefore have important practical implications for the design and the interpretation of future 31P-MRS studies under physiological conditions and in patients with various cerebral diseases.     

In vivo phosphorus nuclear magnetic resonance (31P-NMR) study of dystrophic hamster muscle

Skeletal muscle bioenergetics of dystrophic hamsters (DH) were studied by in vivo 31P-NMR in order to evaluate possible metabolic impairment. 31P-NMR data were obtained during rest, during muscle work that was induced by nerve stimulation at 3 frequencies (0.2, 0.4 and 1.0 Hz) and during postexercise recovery. At rest, phosphocreatine-to-inorganic phosphate ratio (PCr/Pi) was significantly (P less than 0.02) lower in adult DH (5.3 +/- 1.1; +/- 2 SD) compared with control hamsters (6.55 +/- 0.5). An increased PCr depletion was found in DH muscle during nerve stimulation and the steady-state PCr/Pi was significantly (P less than 0.05) lower at 0.4 and 1.0 Hz. Slow PCr/Pi recovery was observed in DH (0.5 +/- 0.2 units per min compared with 1.42 +/- 0.28 for control, +/- 2 SD, P less than 0.02). These findings suggest a significant in vivo mitochondrial malfunction in DH muscle that may result from either mitochondrial abnormalities or cardiac insufficiency or a combination of both.     

31P magnetic resonance spectroscopy study of cerebral metabolism in developing dog brain and its relationship to neuronal function.

Cerebral metabolism and neuronal function of prefrontal brain cortex were studied in 6 dog litters from birth to 3 months of age. Noninvasive phosphorus magnetic resonance spectroscopy (31P-MRS) was used to observe longitudinal biochemical changes in the phosphorus compounds associated with cerebral metabolism. Neurological tests, examining reflex, motor and sensory nerve function, were performed in conjunction with the 31P-MRS study. During the neonatal period, exponential increases in PCr, Pi, and phophodiesters preceded neurological changes. Phosphomonoesters showed an exponential, nearly linear, decrease and PCr/Pi was maintained during the 3-month period. Developmental increases in high energy phosphates and the maintenance of PCr/Pi indicate that the increased energy demands of the developing animal are met by increased mitochondrial function (ATP turnover).     

Abnormal in vivo skeletal muscle energy metabolism in Huntington's disease and dentatorubropallidoluysian atrophy

We studied in vivo muscle energy metabolism in patients with Huntington's disease (HD) and dentatorubropallidoluysian atrophy (DRPLA) using 31P magnetic resonance spectroscopy (MRS). Twelve gene-positive HP patients (4 presymptomatic patients) and 2 gene-positive DRPLA patients (1 presymptomatic patient) were studied. 31P-MRS at rest showed a reduced phosphocreatine-to-inorganic phosphate ratio in the symptomatic HD patients and DRPLA patient. Muscle adenosine triphosphate/(phosphocreatine + inorganic phosphate) at rest was significantly reduced in both groups of symptomatic and presymptomatic HD subjects and was below the normal range in the 2 DRPLA subjects. During recovery from exercise, the maximum rate of mitochondrial adenosine triphosphate production was reduced by 44% in symptomatic HD patients and by 35% in presymptomatic HD carriers. The maximum rate of mitochondrial adenosine triphosphate production in muscle was also reduced by around 46% in the 2 DRPLA subjects. Our findings show that HD and DRPLA share a deficit of in vivo mitochondrial oxidative metabolism, supporting a role for mitochondrial dysfunction as a factor involved in the pathogenesis of these polyglutamine repeat-mediated neurodegenerative disorders. The identification of 31P-MRS abnormalities may offer a surrogate biochemical marker by which to study disease progression and the effects of treatment in HD and DRPLA.     

Creatine has no beneficial effect on skeletal muscle energy metabolism in patients with single mitochondrial DNA deletions: a placebo-controlled, double-blind 31P-MRS crossover study

The purpose of our randomized, double-blind, placebo-controlled crossover study in 15 patients with chronic progressive external ophthalmoplegia (CPEO) or Kearns-Sayre syndrome (KSS) because of single large-scale mitochondrial (mt) DNA deletions was to determine whether oral creatine (Cr) monohydrate can improve skeletal muscle energy metabolism in vivo. Each treatment phase with Cr in a dosage of 150 mg/kg body weight/day or placebo lasted 6 weeks. The effect of Cr was estimated by phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS), clinical and laboratory tests. (31)P-MRS analysis prior to treatment showed clear evidence of severe mitochondrial dysfunction. However, there were no relevant changes in (31)P-MRS parameters under Cr. In particular, phosphocreatine (PCr)/ATP at rest did not increase, and there was no facilitation of post-exercise PCr recovery. Clinical scores and laboratory tests did not alter significantly under Cr, which was tolerated without major side-effects in all patients. Cr supplementation did not improve skeletal muscle oxidative phosphorylation in our series of patients. However, one explanation for our negative findings may be the short study duration or the limited number of patients included.     

<Superscript>31</Superscript>P-MRS of skeletal muscle is not a sensitive diagnostic test for mitochondrial myopathy

Clinical phenotypes of persons with mitochondrial DNA (mtDNA) mutations vary considerably. Therefore, diagnosing mitochondrial myopathy (MM) patients can be challenging and warrants diagnostic guidelines. (31)phosphorous magnetic resonance spectroscopy ((31)P-MRS) have been included as a minor diagnostic criterion for MM but the diagnostic strength of this test has not been compared with that of other commonly used diagnostic procedures for MM. To investigate this, we studied seven patients with single, large-scale deletions-, nine with point mutations of mtDNA and 14 healthy subjects, who were investigated for the following: 1) (31)P-MRS of lower arm and leg muscles before and after exercise, 2) resting and peak-exercise induced increases of plasma lactate, 3) muscle morphology and -mitochondrial enzyme activity, 4) maximal oxygen uptake (VO(2max)), 5) venous oxygen desaturation during handgrip exercise and 6) a neurological examination. All MM patients had clinical symptoms of MM, > 2% ragged red fibers in muscle, and impaired oxygen desaturation during handgrip. Fourteen of 16 patients had impaired VO(2max), 10/16 had elevated resting plasma lactate, and 10/11 that were investigated had impaired citrate synthase-corrected complex I activity. Resting PCr/P(i) ratio and leg P(i) recovery were lower in MM patients vs. healthy subjects. PCr and ATP production after exercise were similar in patients and healthy subjects. Although the specificity for MM of some (31)P-MRS variables was as high as 100%, the sensitivity was low (0-63%) and the diagnostic strength of (31)P-MRS was inferior to the other diagnostic tests for MM. Thus, (31)P-MRS should not be a routine test for MM, but may be an important research tool.     

Abnormal brain and muscle energy metabolism shown by 31P magnetic resonance spectroscopy in patients affected by migraine with aura.

We studied brain and muscle energy metabolism by phosphorus 31 magnetic resonance spectroscopy (31P-MRS) in 12 patients affected by migraine with aura (classic migraine) in interictal periods. Brain 31P-MRS disclosed a low phosphocreatine content in all patients, accompanied by high adenosine diphosphate concentration, a high percentage of V/Vmax (adenosine triphosphate), and a low phosphorylation potential--features showing an unstable state of metabolism in classic migraine. Abnormal muscle mitochondrial function, in the absence of clinical signs of muscle impairment, was present in nine of the 12 patients examined.     

Tai Chi Improves Brain Metabolism and Muscle Energetics in Older Adults

BACKGROUND AND PURPOSE

Tai Chi is a mind‐body exercise that has been shown to improve both mental and physical health. As a result, recent literature suggests the use of Tai Chi to treat both physical and psychological disorders. However, the underlying physiological changes have not been characterized. The aim of this pilot study is to assess the changes in brain metabolites and muscle energetics after Tai Chi training in an aging population using a combined brain‐muscle magnetic resonance spectroscopy (MRS) examination.

METHODS

Six healthy older adults were prospectively recruited and enrolled into a 12‐week Tai Chi program. A brain ¹H MRS and a muscle ³¹P MRS were scanned before and after the training, and postprocessed to measure N‐acetylaspartate to creatine (NAA/Cr) ratios and phosphocreatine (PCr) recovery time. Wilcoxon‐signed rank tests were utilized to assess the differences between pre‐ and post‐Tai Chi training.

RESULTS

A significant within‐subject increase in both the NAA/Cr ratios (P = .046) and the PCr recovery time (P = .046) was observed between the baseline and the posttraining scans. The median percentage changes were 5.38% and 16.51% for NAA/Cr and PCr recovery time, respectively.

CONCLUSIONS

Our pilot study demonstrates significant increase of NAA/Cr ratios in posterior cingulate gyrus and significantly improved PCr recovery time in leg muscles in older adults following short‐term Tai Chi training, and thus provides insight into the beneficial mechanisms.     

A case of mitochondrial myopathy,lactic acidosis and complex I deficiency

Summary A 34-year-old man affected by exercise intolerance, mild proximal weakness and severe lactic acidosis is described. Muscle biopsy revealed mitochondrial abnormalities and an increase of cytochrome c oxidase histochemical reaction. Biochemical investigations on isolated muscle mitochondria as well as polarographic studies revealed a mitochondrial NADH-CoQ reductase (complex I) deficiency. Mitochondrial dysfunction was confirmed by ³¹P nuclear magnetic resonance spectroscopy. Immunological investigation showed a generalized reduction of all complex I polypeptides. Genetic analysis did not reveal mitochondrial DNA deletions. The biochemical defect was not present in the patient's muscle tissue culture. Metabolic measurements and functional evaluation showed a reduced mechanical efficiency during exercise.     

Muscle energy metabolism in female DMD/BMD carriers: a 31P-MR spectroscopy study.

31P nuclear magnetic resonance spectroscopy (31P-MRS) was used to investigate the energy metabolism of the gastrocnemius muscle in 16 DMD/BMD female carriers. No significant difference was found with the controls in the resting muscle, while all carriers showed a decreased ability to perform work, and a higher Pi/PCr ratio for comparable relative levels of steady-state work. The rate of postexercise recovery of PCr/Pi ratio was lower in all carriers. The decreased rate of PCr/Pi recovery appears to be mainly due to a decreased rate of Pi recovery. Our findings show abnormal muscle energy metabolism in DMD/BMD female carriers.