Does visual cortex lactate increase following photic stimulation in migraine without aura patients? A functional 1H-MRS study

Abstract

Proton magnetic resonance spectroscopy (1H-MRS) has been used in a number of studies to assess noninvasively the temporal changes of lactate (Lac) in the activated human brain. Migraine neurobiology involves lack of cortical habituation to repetitive stimuli and a mitochondrial component has been put forward. Our group has recently demonstrated a reduction in the high-energy phosphates adenosine triphosphate (ATP) and phosphocreatine (PCr) in the occipital lobe of migraine without aura (MwoA) patients, at least in a subgroup, in a phosphorus MRS (31P-MRS) study. In previous studies, basal Lac levels or photic stimulation (PS)-induced Lac levels were found to be increased in patients with migraine with aura (MwA) and migraine patients with visual symptoms and paraesthesia, paresia and/or dysphasia, respectively. The aim of this study was to perform functional 1H-MRS at 3 T in 20 MwoA patients and 20 control subjects. Repetitive visual stimulation was applied using MR-compatible goggles with 8 Hz checkerboard stimulation during 12 min. We did not observe any significant differences in signal integrals, ratios and absolute metabolite concentrations, including Lac, between MwoA patients and controls before PS. Lac also did not increase significantly during and following PS, both for MwoA patients and controls. Subtle Lac changes, smaller than the sensitivity threshold (i.e. estimated at 0.1–0.2 μmol/g at 3 T), cannot be detected by MRS. Our study does, however, argue against a significant switch to non-aerobic glucose metabolism during long-lasting PS of the visual cortex in MwoA patients.

Magnetic resonance spectroscopy in migraine: What have we learned so far?

“…Additionally, low magnesium levels were observed during migraine attacks without changes in pH i (7). These early 31 P-MRS studies in migraine failed to support the prevailing concept at that time that migraine pain was caused by brain ischemic acidosis, but rather suggested a disordered energy metabolism during a migraine attack.…”

“…Montagna et al performed 31 P-MRS in a large cohort of migraine patients including MwoA patients, MwA patients and a group of 'complicated' migraine patients, the latter comprising both migrainous stroke and migraine with prolonged aura (9).…”

31P‐MRS in Migraine: Fallen Through the Cracks

“…In a retrospective study on patients with subacute daily headache (1-4 weeks durations), we observed that patients with a prior history of febrile illness are more likely to have neck pain and signs of meningismus (in addition to headache). 4 Our observation, 4 Almazov and Brand's observation, 2 and a few other observations 5 suggest a possibility of postinfectious pathology (most likely immunological) in meninges in patients who have a prior history of infections before the onset of headache. We further suggest that the interrelation between meninges and infections may be like the interrelation of synovial membrane to various viral infections for the development of reactive arthritis, as synovial membranes and meninges are of same type of tissue (membranous connective tissue).…”

“…We further suggest that the interrelation between meninges and infections may be like the interrelation of synovial membrane to various viral infections for the development of reactive arthritis, as synovial membranes and meninges are of same type of tissue (membranous connective tissue). 4 We speculate a local immune reaction in the meninges in a subset of patients with NDPH who have a prior history of febrile illness. Moreover, as immune reaction may begin within 2 days after an antigenic challenge, postinfectious symptoms may start within febrile periods.…”

“…• in fact the most consistent findings in migraine were generated with the 31 P-MRS technique pointing at an interictal disturbed brain energy metabolism, • an accurate detection of lactate by 1 H-MRS, let alone accurate quantification of lactate, is cumbersome at low field strength (both 1 H-MRS studies mentioned were performed on a 1.5 Tesla scanner); potential lactate changes should be confirmed at higher field strength (7 Tesla); lactate was not detected in migraine without aura patients, both in the resting and stimulated occipital lobe, in recent 3 Tesla 1 H-MRS studies, 3,4 • the significance of the N-acetylaspartate (NAA) signal is unclear; NAA is considered a marker of neuronal (in particular axonal) integrity, is synthesized predominantly in neuronal mitochondria, and assumed to be involved in mitochondrial/cytosolic carbon transport.…”