We report the clinical and MR manifestations of an 18 year-old girl with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Recurrent status epilepticus caused reversible cytotoxic edema on diffusion-weighted images (DWI). Initial and one month follow-up MR spectroscopy, after seizure control, showed some discrepancies in the ratio of metabolites. N-acetylaspartate (NAA) partially recovered (NAA/creatine (Cr) ratio: 1.27-->1.84). This was because of a normalization of decreased NAA due to cellular dysfunction as a result of status epilepticus. A low ratio of NAA/Cr due to abnormal mitochondria remained in the decreased state. Reversible NAA/Cr ratios in the acute lesion suggested that NAA reflects the neuronal function as well as the level of neuronal structural damage. The altered NAA/Cr ratio better correlated with the abnormal signal intensity area of T2-weighted images (T2WI) and DWI than the lactate (Lac)/Cr ratio. With conservative treatment with anti-epileptics not accompanied by coenzyme Q or sodium dichloroacetate, lactate persistently increased (Lac/Cr ratio: 1.01-->1.21) because of the continued production of lactate in cells with respiratory deficiency, which is the main pathology of MELAS.
Adolescence ; Aspartic Acid/metabolism ; Aspartic Acid/analogs & derivatives* ; Brain/metabolism ; Case Report ; Creatine/metabolism ; Diffusion ; Female ; Human ; MELAS Syndrome/metabolism ; MELAS Syndrome/diagnosis* ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy

OBJECTIVEThis study examined the biochemical metabolism by proton magnetic resonance spectroscopy ('H-MRS) in order to explore the value of 'H-MRS in idiopathic epilepsy in children.

METHODSThirty-three children with idiopathic epilepsy (14 cases with history of febrile seizures and 19 cases without) and six normal controls experienced MRI of the skull and brain and single-voxel 'H-MRS examinations of the hippocampi-temporal lobe. The signal intensities of N-acetylaspartate (NAA), eatine+phosphocreatine (Cr), choline-containing compounds (Cho) and lactate (Lac) and the ratios of NAA/ (Cho+Cr) and Lac/Cr were compared between the patients and normal controls.

RESULTSMRI examination showed that only one child with epilepsy had myelin dysplasia. 'H-MRS examination showed that the ratio of NAA/ (Cho+Cr) in the epilepsy group was lower than that in the control group (0.64+/-0.07 vs 0.73+/-0.05; P<0.01). The epileptic children with history of febrile seizures had a more decreased ratio of NAA/ (Cho+Cr) compared with those without the history (0.61+/-0.07 vs 0.66+/-0.06; P<0.05). There were no significant differences in the ratio of Lac/Cr between the epilepsy and the control groups.

CONCLUSIONS'H-MRS may provide early information on brain injury sensitively and non-invasively in children with epilepsy. It may be used for diagnosis and prognosis evaluation of epilepsy.

Aspartic Acid ; analogs & derivatives ; analysis ; Child ; Child, Preschool ; Choline ; analysis ; Epilepsy ; diagnosis ; metabolism ; Female ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; methods ; Male ; Phosphocreatine ; analysis ; Protons

BACKGROUNDIn vivo proton magnetic resonance spectroscopy (MRS) provides a noninvasive method of examining a wide variety of cerebral metabolites in both healthy subjects and patients with various brain diseases. Absolute metabolite concentrations have been determined using external and internal standards with known concentrations. When an external standard is placed beside the head, variations in signal amplitudes due to B1 field inhomogeneity and static field inhomogeneity may occur. Hence an internal standard is preferable. The purpose of this study was to quantitatively analyze the metabolite concentrations in normal adult brains and gliomas by in vivo proton MRS using the fully relaxed water signal as an internal standard.

METHODSBetween January 1998 and October 2001, 28 healthy volunteers and 16 patients with gliomas were examined by in vivo proton MRS. Single-voxel spectra were acquired using the point-resolved spectroscopic pulse sequence with a 1.5 T scanner (TR/TE/Ave = 3000 ms/30 ms/64).

RESULTSThe calculated concentrations of N-acetyl-asparatate (NAA), creatine (Cre), choline (Cho), and water (H2O) in the normal hemispheric white matter were (23.59 +/- 2.62) mmol/L, (13.06 +/- 1.8) mmol/L, (4.28 +/- 0.8) mmol/L, and (47,280.96 +/- 5414.85) mmol/L, respectively. The metabolite concentrations were not necessarily uniform in different parts of the brain. The concentrations of NAA and Cre decreased in all gliomas (P < 0.001). The ratios of NAA/Cho and NAA/H2O showed a significant difference between the normal brain and gliomas, and also between the high and low grades (P < 0.001).

CONCLUSIONSQuantitative analysis of in vivo proton MR spectra using the fully relaxed water signal as an internal standard is useful. The concentrations of NAA and the ratios of NAA/H2O and NAA/Cho conduce to discriminating between the glioma and normal brain, and also between the low-grade glioma and high-grade glioma.

Adult ; Aspartic Acid ; analogs & derivatives ; metabolism ; Brain ; metabolism ; Choline ; metabolism ; Creatine ; metabolism ; Female ; Glioma ; metabolism ; Glycine ; metabolism ; Humans ; Inositol ; metabolism ; Magnetic Resonance Spectroscopy ; Male

OBJECTIVE: To detect metabolic changes of bilateral frontal lobe in patients with multiple system atrophy (MSA) and cognitive dysfunction by 1H-proton magnetic resonance spectroscopy (1H-MRS).
 METHODS: N-acetylaspartate (NAA)/creatine(Cr), choline (Cho)/Cr, myoinositol (mI)/Cr in three sides of frontal lobe were detected by 1H-MRS in 48 healthy controls, 23 patients with MSA and cognitive dysfunction and 19 patients with MSA but without cognitive dysfunction.
 RESULTS: NAA/Cr of bilateral frontal lobes in patients with MSA and cognitive dysfunction was significantly decreased compared with MSA patients without cognitive dysfunction and healthy controls (P<0.05). mI/Cr of right frontal lobes was significantly increased in patients with MSA and cognitive dysfunction compared with healthy controls (P<0.05). There was a negative correlation between NAA/Cr of bilateral frontal lobes and duration while a positive correlation between NAA/Cr of bilateral frontal lobes and MoCA score in patients with MSA and cognitive dysfunction.
 CONCLUSION There is a decrease in NAA/Cr and an increase in mI/Cr in frontal lobes in patients with MSA and cognitive dysfunction, which may be associated with cognitive dysfunction in MSA patients.
Aspartic Acid ; analogs & derivatives ; metabolism ; Choline ; metabolism ; Cognition Disorders ; physiopathology ; Creatine ; metabolism ; Frontal Lobe ; metabolism ; Humans ; Inositol ; metabolism ; Multiple System Atrophy ; physiopathology ; Proton Magnetic Resonance Spectroscopy

AIMTo evaluate N-acetylaspartate reflecting the neuronal lesion in middle cerebral artery occlusion and reperfusion rat by magnetic resonance spectroscopy (MRS).

METHODSSixteen adult Wistar rats with MCAO reperfusion and ten pseudooperation rats were performed MRS in vivo at the sixth weeks, then pathologic examination of HE staining and immunohistochemical staining were made. We compared hippocampus modality, cell density and immunohistochemical results with N-acetylaspartate, creatine changes and ration of NAA/Cr.

RESULTSThe values of NAA, Cr and NAA/Cr of ipsilateral hippocampus lesion in MCAO reperfusion rats (2.05 +/- 0.33, 2.42 +/- 0.41 and 0.86 +/- 0.10) were visiblly decreased than contralateral hippocampus (3.45 +/- 0.58, 3.10 +/- 0.93, 1.18 +/- 0.32) and control group (3.42 +/- 0.43, 3.57 +/- 0.47, 0.98 +/- 0.14). But the level of decreased NAA is not corresponding to the degree of neuronal death in ipsilateral region of hippocampus in histochemistry.

CONCLUSIONMRS has perfect explanation of cell metabolic changes in CA1 region. Decrease of NAA represented neuron delayed injury. But the decreased level of NAA is not perfectly corresponded to the degree of neuron lost. This change has closed correlation with reactive astrocytes proliferation.

Animals ; Aspartic Acid ; analogs & derivatives ; metabolism ; Brain Ischemia ; metabolism ; pathology ; Female ; Hippocampus ; cytology ; pathology ; Magnetic Resonance Spectroscopy ; methods ; Male ; Neurons ; metabolism ; pathology ; Rats ; Rats, Wistar

OBJECTIVETo assess the value of (1)H-magnetic resonance spectroscopy ((1)H-MRS) in evaluating cerebral vasospasm resulting from subarachnoid hemorrhage (SAH).

METHODSSix dogs were subjected to autologous non-heparinized blood injection via cisternal puncture twice at one-day interval to establish models of SAH, and another 6 received injections with normal saline in an identical manner. (1)H-MRS scan was performed on the 3rd, 7th and 14th days after the injections to measure the changes of N-acetylaspartate (NAA), creatine (Cr) and choline (Cho). After the (1)H-MRS scan, all the dogs underwent brain digital subtraction angiography (DSA) for determining the basilar artery diameter.

RESULTSDSA results on day 3 presented development of obvious vasospasm of the basilar artery, which was most evident on day 7 and recovered obviously on day 14. (1)H-MRS results demonstrated obvious changes of NAA, Cho and Cr on days 3 and 7 in SAH model group, and NAA declined to the lowest level on day 3 followed by gradual ascending till reaching the normal level on day 14. Cho decreased slightly on day 3, then increased and reached the peak level on day 7 and then decreased. Cr rose steadily from day 3 to 14, but since day 7, the rise slowed down obviously and Cr maintain a level not significantly different from that on day 14 (P>0.05). The functional results of (1)H-MRS were consistent with the DSA results.

CONCLUSION(1)H-MRS can be used to monitor the development of cerebral vasospasm resulting from SAH as a good evaluation method for functional imaging.

Animals ; Aspartic Acid ; analogs & derivatives ; metabolism ; Choline ; metabolism ; Creatine ; metabolism ; Dogs ; Female ; Magnetic Resonance Spectroscopy ; methods ; Male ; Protons ; Subarachnoid Hemorrhage ; complications ; Time Factors ; Vasospasm, Intracranial ; diagnosis ; etiology ; metabolism

BACKGROUNDIn head and neck neoplasm survivors treated with brain irradiation, metabolic alterations would occur in the radiation-induced injury area. The mechanism of these metabolic alterations has not been fully understood, while the alternations could be sensitively detected by proton (1H) nuclear magnetic resonance spectroscopy (MRS). In this study, we investigated the metabolic characteristics of radiation-induced brain injury through a long-term follow-up after radiation treatment using MRS in vivo.

METHODSA total of 12 adult Sprague-Dawley rats received a single dose of 30 Gy radiation treatment to semi-brain (field size: 1.0 cm × 2.0 cm; anterior limit: binocular posterior inner canthus connection; posterior limit: external acoustic meatus connection; internal limit: sagittal suture). Conventional magnetic resonance imaging and single-voxel 1H-MRS were performed at different time points (in month 0 before irradiation as well as in the 1st, 3rd, 5th, 7th, and 9th months after irradiation) to investigate the alternations in irradiation field. N-acetylaspartate/choline (NAA/Cho), NAA/creatinine (Cr), and Cho/Cr ratios were measured in the bilateral hippocampus and quantitatively analyzed with a repeated-measures mixed-effects model and multiple comparison test.

RESULTSSignificant changes in the ratios of NAA/Cho (F = 57.37, P_{g < 0.001), NAA/Cr (F = 54.49, Pg < 0.001), and Cho/Cr (F = 9.78, Pg = 0.005) between the hippocampus region of the irradiated semi-brain and the contralateral semi-brain were observed. There were significant differences in NAA/Cho (F = 9.17, Pt < 0.001) and NAA/Cr (F = 13.04, Pt < 0.001) ratios over time. The tendency of NAA/Cr to change with time showed no significant difference between the irradiated and contralateral sides. Nevertheless, there were significant differences in the Cho/Cr ratio between these two sides.}

CONCLUSIONSMRS can sensitively detect metabolic alternations. Significant changes of metabolites ratio in the first few months after radiation treatment reflect the metabolic disturbance in the acute and early-delayed stages of radiation-induced brain injuries.

Animals ; Aspartic Acid ; analogs & derivatives ; metabolism ; Brain ; radiation effects ; Choline ; metabolism ; Male ; Proton Magnetic Resonance Spectroscopy ; methods ; Radiation Injuries ; diagnosis ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the clinical efficacy of electroacupuncture (EA) on mild cognitive impairment (MCI) for patients of Uygur and Han nationality and explore the national diversity among the patients with MCI.

METHODSTwenty-five cases were divided into Han nationality group (15 cases) and Uygur nationality group (10 cases) according to patient's nationality. In either group, EA was applied to Baihui (GV 20), Fengchi (GB 20), Xuanzhong (GB 39), Fuliu (KI 7), Sanyinjiao (SP 6) and Taixi (KI 3), once per day, 15 treatments made one session and there were 5 days at the interval among the sessions. Totally, 3 sessions of treatment were required. The proton magnetic resonance spectroscopy (1H-MRS) was used to observe the changes in the ratio of N-acetylaspartate and creatine (NAA/Cr) on the left hippocampus for the patients in two groups before and after treatment as well as the changes in the results of the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA) separately.

RESULTSNAA/Cr in Uygur nationality group was higher than that in Han nationality group before treatment (1.659 +/- 0.418 vs 1.137 +/- 0.190, P < 0.05). After treatment, MMSE and MoCA scores all increased apparently as compared with those before treatment in two groups (P < 0.05, P < 0.01), and NAA/Cr on the left hippocampus in either group was up-regulated as compared with that before treatment (both P < 0.01).

CONCLUSIONEA can improve the overall cognitive function for the patients with MCI. There is the national diversity in the partial brain metabolite level between Uygur patients and Han patients with MCI.

Aged ; Aged, 80 and over ; Aspartic Acid ; analogs & derivatives ; analysis ; China ; ethnology ; Cognition Disorders ; metabolism ; therapy ; Creatine ; analysis ; Electroacupuncture ; Female ; Hippocampus ; chemistry ; Humans ; Magnetic Resonance Spectroscopy ; Male ; Middle Aged

OBJECTIVETo determine whether there are in vivo differences of metabolites levels in bilateral cortical masticatory area(CMA) of patients with sleep bruxism, compared with healthy controls using proton magnetic resonance spectroscopy(1H-MRS). Accordingly to explore if cortical control of the central jaw motor system is abnormal in sleep bruxism patients.

METHODSFifteen sleep bruxism patients and fifteen age- and gender-matched healthy controls underwent 1H-MRS of bilateral CMA using J-difference edited point-resolved spectroscopy sequence(MEGA-PRESS) technique. Levels of metabolites were quantified from the ratio of the metabolite integral to the unsuppressed water signal. Differences of levels of γ-aminobutyric acid(GABA), glutmate(Glu) and N-acetyl aspartate(NAA) in bilateral CMA between sleep bruxism patients and healthy controls were tested using two-way ANOVA.

RESULTSEdited spectra were successfully obtained from the bilateral CMA in all of the participants. Levels of GABA+, glutmate and NAA in right and left CMA in sleep bruxism patients were (2.45±0.48)×10(-3), (2.35±0.62)×10(-3), (10.65±1.84)×10(-3), (10.49±2.37)×10(-3), (10.70±3.61)×10(-3), and (11.26±4.01)×10(-3) respectively. In contrast, levels of GABA+, glutmate and NAA in right and left CMA in healthy controls were (2.63±0.68)×10(-3), (2.65±0.97)×10(-3), (11.19± 1.34)×10(-3), (10.58±3.14)×10(-3), (11.82±1.80)×10(-3), and (11.95±3.23)×10(-3). There were no differences in levels of GABA+(P=0.196), Glu(P=0.590), and NAA(P=0.292) between sleep bruxism patients and healthy controls, nor in inbilateral CMA(GABA+: P=0.837; Glu: P=0.510; NAA: P=0.628).

CONCLUSIONSThe results indicate the absence of any alteration of the cortical control of the central jaw motor system in the levels of GABA, Glu and NAA in patients with sleep bruxism.

Analysis of Variance ; Aspartic Acid ; analogs & derivatives ; analysis ; metabolism ; Case-Control Studies ; Glutamic Acid ; analysis ; metabolism ; Humans ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; methods ; Masticatory Muscles ; metabolism ; physiopathology ; Motor Neurons ; metabolism ; Sleep Bruxism ; metabolism ; physiopathology ; gamma-Aminobutyric Acid ; analysis ; metabolism

OBJECTIVETo study the metabolic changes of auditory cortex in patients with presbycusis by using proton magnetic resonance spectroscopy ((1)H-MRS).

METHODSTen normal hearing volunteers (youth group), 10 normal hearing of elderly (aged group) and 8 patients with presbycusis (presbycusis group) were checked with proton magnetic resonance spectroscopy. N-acetylaspartic acid (NAA), creatine (Cr), choline (Cho), γ-aminobutyric acid (GABA), glutamic acid (Glu) compound were measured. The differences between the groups were semi-quantitatively analyzed.

RESULTSWhen compared with youth group, reduced NAA/Cr, increased Cho/Cr were found in the aged group and presbycusis group (P < 0.05). GABA/Cr ratio and Glu/Cr ratio were significant difference between presbycusis group and youth group (P < 0.05). There were no significant difference in the GABA/Cr and Glu/Cr ratios in the bilateral auditory cortex between the youth group and the aged group (P > 0.05). When compared with aged group, the metabolic changes of auditory cortex in patients with presbycusis were remarkable (P < 0.05).

CONCLUSIONS(1)H-MRS is a noninvasive technique that can provide useful information concerning the metabolic changes of auditory cortex in human. In comparison to the aged group and the youth group, the changes of NAA, GABA, Cho and Glu is found in auditory cortex in patients with presbycusis.

Adult ; Aged ; Aspartic Acid ; analogs & derivatives ; metabolism ; Auditory Cortex ; metabolism ; Case-Control Studies ; Choline ; metabolism ; Creatine ; metabolism ; Female ; Glutamic Acid ; metabolism ; Humans ; Magnetic Resonance Spectroscopy ; Male ; Middle Aged ; Presbycusis ; metabolism ; pathology ; Young Adult ; gamma-Aminobutyric Acid ; metabolism