Predictive value of intracranial high-density areas in neurological function.

BACKGROUND: Intracranial high-density areas (HDAs) have attracted considerable attention for predicting clinical outcomes; however, whether HDAs predict worse neurological function and mental health remains controversial and unclear, which requires further investigation. AIM: To investigate the predictive value of intracranial HDAs for neurological function and mental health after endovascular treatment. METHODS: In this prospective study, 96 patients with acute ischemic stroke (AIS) who accepted endovascular mechanical thrombectomy (EMT) were included. The enrolled patients underwent cranial computed tomography (CT) examination within 24 hours after EMT. Clinical data in terms of National Institutes of Health Stroke Scale (NIHSS), the 3-month modified Rankin Scale (mRS), self-rating depression scale (SDS), and self-rating anxiety scale (SAS) scores were collected and compared between patients with HDAs and non-HDAs and between patients with good and poor clinical prognosis. RESULTS: Compared to patients without HDAs, patients with HDAs presented severe neurological deficits (admission NIHSS score: 18 ± 3 vs 19 ± 4), were more likely to have post-stroke disabilities (mRS < 3: 35% vs 62%), and suffered more severe depression (SDS score: 58 ± 16 vs 64 ± 13) and anxiety disorder (SAS score: 52 ± 8 vs 59 ± 10). Compared to patients with a good prognosis, patients with a poor prognosis presented severe neurological deficits (admission NIHSS score: 17 ± 4 vs 20 ± 3), were more likely to have HDAs on CT images (64% vs 33%), and suffered more severe depression (SDS score: 55 ± 19 vs 65 ± 11) and anxiety (SAS score: 50 ± 8 vs 58 ± 12). Multivariate analysis revealed that HDAs were independent negative prognostic factors. CONCLUSION: In conclusion, HDAs on CT images predicted poor prognosis and severe depressive and anxiety symptoms in patients with AIS who underwent EMT.

Functional Investigation of a GRIN2A Variant Associated with Rolandic Epilepsy.

N-methyl-D-aspartate receptors (NMDARs), a subtype of glutamate-gated ion channels, play a central role in epileptogenesis. Recent studies have identified an increasing number of GRIN2A (a gene encoding the NMDAR GluN2A subunit) mutations in patients with epilepsy. Phenotypes of GRIN2A mutations include epilepsy-aphasia disorders and other epileptic encephalopathies, which pose challenges in clinical treatment. Here we identified a heterozygous GRIN2A mutation (c.1341T>A, p.N447K) from a boy with Rolandic epilepsy by whole-exome sequencing. The patient became seizure-free with a combination of valproate and lamotrigine. Functional investigation was carried out using recombinant NMDARs containing a GluN2A-N447K mutant that is located in the ligand-binding domain of the GluN2A subunit. Whole-cell current recordings in HEK 293T cells revealed that the N447K mutation increased the NMDAR current density by ~1.2-fold, enhanced the glutamate potency by 2-fold, and reduced the sensitivity to Mg2+ inhibition. These results indicated that N447K is a gain-of-function mutation. Interestingly, alternative substitutions by alanine and glutamic acid at the same residue (N447A and N447E) did not change NMDAR function, suggesting a residual dependence of this mutation in altering NMDAR function. Taken together, this study identified human GluN2A N447K as a novel mutation associated with epilepsy and validated its functional consequences in vitro. Identification of this mutation is also helpful for advancing our understanding of the role of NMDARs in epilepsy and provides new insights for precision therapeutics in epilepsy.

Paroxysmal hypnogenic dyskinesia is associated with mutations in the PRRT2 gene.

OBJECTIVE: To explore the potential causative genes of paroxysmal hypnogenic dyskinesia (PHD), which was initially considered a subtype of paroxysmal dyskinesia and has been recently considered a form of nocturnal frontal lobe epilepsy (NFLE). METHODS: Eleven patients with PHD were recruited. Mutations in proline-rich region transmembrane protein-2 (PRRT2), myofibrillogenesis regulator 1 (MR-1), solute carrier family 2, member 1 (SLC2A1), calcium-activated potassium channel alpha subunit (KCNMA1), cholinergic receptor, nicotinic, alpha 4 (CHRNA4), cholinergic receptor, nicotinic, beta 2 (CHRNB2), cholinergic receptor, nicotinic, alpha 2 (CHRNA2), and potassium channel subfamily T member 1 (KCNT1) were screened by direct sequencing. RESULTS: Two PRRT2 mutations were identified in patients with typical PHD. A mutation of c.649dupC (p.Arg217ProfsX8) was identified in a patient with PHD and his father who was diagnosed with paroxysmal kinesigenic dyskinesia. An additional mutation of c.640G>C (p.Ala214Pro) was identified in a sporadic patient and his asymptomatic mother. No mutations were found in the other screened genes. CONCLUSIONS: The present study identified PRRT2 mutations in PHD, extending the phenotypic spectrum of PRRT2 and supporting the classification of PHD as a subtype of paroxysmal dyskinesia but not NFLE. Based on the results of this study, screening for the PRRT2 mutation is recommended in patients with PHD.