D. Di Lenola

Migraine improvement during short lasting ketogenesis: a proof-of-concept study.

Ketogenesis is a physiological phenomenon due to starvation or a ketogenic diet (KD), a drastic restricted carbohydrate dietary regimen that induces lipid metabolism and ketone body synthesis. Two patients whose migraines disappeared only during, and not outside, cycles of very‐low‐calorie KD performed to reduce their weight were recently observed. To confirm our observation, in a dietitian clinical setting two parallel groups of migraineurs, one receiving a 1‐month very‐low‐calorie KD prescription followed by a 5‐month standard low‐calorie diet (SD) and the other a 6‐month SD, were followed.

58. Clinical efficacy of short-lasting ketogenic diet in migraine might be due to a general normalization of cortical hyperresponsivity rather than to a direct modulation of the brainstem activity

We previously reported that a short-lasting period of ketogenic diet (KD) regimen can help to prevent migraine and can normalize its interictally abnormal cortical hyperresponsivity. Here, we aimed to verify whether cerebral cortex is the primary site of KD-related changes or if the latter are the expression of ketones ability to modulate brainstem subcortical structures. We simultaneously recorded the nociceptive specific blink (nBR, a marker of the brainstem trigeminal activity) and cortical pain-related evoked potentials (PREP) elicited by the stimulation of right the supraorbital division of the trigeminal nerve in 18 migraine without aura patients before and after 1-month of KD, during ketogenesis. We measured nBR R2 component as well as PREP amplitude habituations over 2 blocks of 5 averaged responses. We confirmed the ability of 1-month KD of significantly decreasing mean attack frequency and duration. KD significantly induced normalization of the interictally reduced PREP habituation (pre: +1.8, post: −9.1), while nBR habituation remained unchanged. Here, we provided evidence that the clinical efficacy of a short-lasting KD regimen in migraine can be principally due to a general normalization of the interictal cortical dysfunction, and not to a direct modulation of the subcortical brainstem activation.

EHMTI-0182. Positive family history of migraine predisposes to a reduced migraineurs visual cortical reactivity

Results We recruited 85 patients with and 24 without a positive family history of migraine. Patients who had one parent affected (mother or father) had significantly lower N75-P100 VEP amplitude blocks overall than those had no parents affected, the latter resulting not different from HV. Lack of VEP N75-P100 amplitude habituation was found in overall migraineurs compared with HV, irrespectively of whether they had a parent affected or not. Conclusion These findings suggest that familial occurrence of migraine may predispose to a general reduced cortical reactivity to visual stimulation. No conflict of interest.

EHMTI-0181. Fast recovery of visual evoked potential amplitude after photostress in migraine patients between attacks

Results VEP parameters did not differed between groups at the baseline. In all groups, the VEPs recorded after PS showed a significant increase in latency at 20s. In HV, N75-P100 amplitude significantly decreased 20s after PS, and recovered subsequently. There was no effect in the migraine groups. In fact, the percentage reduction in N75-P100 amplitude observed at 20s after photostress in MO and MA patients were lower than in HV (MO & MA vs. HV P<0.05). When data of migraine patients were combined, the percentage of amplitude change at 20s was negatively correlated with number of days since the last migraine attack (r=-0.525, p=0.02).

EHMTI-0375. Central mechanisms of migraine improvement with ketogenic diet: an evoked potentials study

Ketogenic diet (KD) is a dietetic regimen that mimics fasting in producing ketone bodies, which seems to have a potential role in treating migraine. From animal and human models emerges that KD might affects CNS at multiple levels: it is able to normalize cortical dysexcitability and to reduce cortical spreading depression velocity of propagation, which mechanisms are potentially of interest in migraine pathophysiology.

EHMTI-0177. Evidence for plastic brain morphometric changes during the migraine cycle

Background Neurophysiological investigations have demonstrated that there are distinctive fluctuations in the brain’ se lectric signals between the ictal and interictal periods of recurrent migraine. Whether structural plasticity of the brain is also an important feature of episodic migraine remains unresolved. Aim We therefore investigated the possibility that there are fluctuations over time in whole brain grey matter morphometry of patients affected by episodic migraine without aura (MO). Method Twenty-four patients with untreated MO underwent MRI scans (3-Tesla Siemens Verio) during (n = 10) or between attacks (n = 14) and were compared to a group of 15 healthy volunteers (HV). We then performed voxelbased-morphometry (VBM) analysis of structural T1-weighted MRI scans to determine if changes in brain structure were observed over the course of the migraine cycle. Results During the interictal phase, MO patients had a significantly lower grey matter (GM) density within the right inferior parietal lobule, right temporal inferior gyrus, right superior temporal gyrus, and left temporal pole than did HV. During attacks, GM density increased within the left temporal pole, bilateral insula, and right lenticular nuclei, but no areas exhibited decreased GM density. Conclusion The morphometric GM changes between ictal and interictal phases reported in the present study suggest that abnormal structural plasticity may be an important mechanism of migraine pathology. Given the functional neuroanatomy of these areas, our findings suggest that migraine is a condition associated with global dysfunction of multisensory integration and memory processing. No conflict of interest.