Clinical Reasoning: Hyperventilation-Induced Alternating Hemiplegia With Concomitant Hemispheric EEG Slowing in a 7-Year-Old Girl With Headache.

A 7-year-old right-handed girl presented to the pediatric neurology outpatient clinic after 5 episodes of headache over the previous 3 months. Her family history was positive for migraine in the mother and maternal grandmother and for febrile seizures in the older sister. The neurologic examination and cognitive profile were normal. Five seconds after the end of hyperventilation, video-EEG showed high-amplitude delta waves predominantly over the left hemisphere with concomitant acute aphasia and right-sided weakness. After the event, which self-resolved over 8 minutes, the girl showed intact recall. A second instance of hyperventilation evoked the appearance of pseudo-rhythmic slow activity localized to the right hemisphere, associated with left-sided weakness, 20 seconds after the end of the test. This event spontaneously resolved in 3 minutes and was followed by headache.An exaggerated physiologic response to hyperventilation, the possible epileptic nature of the events, and a migraine variant were all considered in the differential. Nonetheless, the EEG slowing is shorter in duration and generalized in physiologic and paraphysiological conditions. A clear ictal morphology and evolution of the EEG activity were lacking in this case, and migraine attacks induced by hyperpnea have not been reported to date. Instead, EEG alterations similar to that observed in our patient are described in association with vascular abnormalities. We report the clinical presentation and diagnostic workup of a rare cerebrovascular disorder, highlighting the key features in the differential. Our case emphasizes the clinical value of the EEG rebuild-up phenomenon, which can help the clinician in achieving a prompt diagnosis.

Aicardi Syndrome: Key Fetal MRI Features and Prenatal Differential Diagnosis.

OBJECTIVE: This study was aimed to investigate the prenatal findings in Aicardi syndrome (AIC) by intrauterine magnetic resonance imaging (iuMRI) suggesting possible diagnostic criteria and differential diagnosis. METHODS: The iuMRI features of nine AIC confirmed cases were described and then compared with those of postnatal MRI. Furthermore, all iuMRI cases with both corpus callosum (CC) agenesis-dysgenesis and cortical malformation (AIC mimickers) were retrospectively reviewed and compared with iuMRI AIC cases, in order to identify possible neuroradiological predictors of AIC syndrome. For this purpose, Chi-square statistic and binary logistic regression analysis were performed. RESULTS: In all AIC cases, iuMRI was able to detect CC agenesis-dysgenesis and cortical development anomalies. Postnatal MRI revealed some additional findings mainly including further cystic lesions and in two cases small coloboma. A statistically significant difference between AIC and AIC mimicker were found regarding sex, nodular heterotopias, posterior fossa abnormalities, coloboma, and cortical gyration abnormalities. The most predictive variables in the logistic regression model were cortical gyration abnormalities, coloboma, and sex. CONCLUSION: The iuMRI findings may suggest prenatal diagnosis of AIC syndrome with significant impact on parental counseling. Among possible differential diagnoses, tubulinopathies emerged.