Infection-Induced Elevated Plasma Perampanel in a Patient with Hemimegalencephaly.

Perampanel is a noncompetitive, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptor antagonist. Herein, we report a case of increased perampanel plasma concentration and impaired consciousness triggered by an infection. The patient had refractory epilepsy associated with hemimegalencephaly. During adolescence, perampanel (maximum dose, 10 mg, oral), valproic acid, clobazam, and lacosamide were administered for seizure control. He was admitted to our hospital with high fever, impaired consciousness, and elevated perampanel plasma level (from 1,300 to 1,790 ng/mL), but with no increase in the concentration of other antiseizure medications. Further examinations (blood, cerebrospinal fluid, brain magnetic resonance images, and electroencephalogram) revealed no physical cause for impaired consciousness. After discontinuation of perampanel, his level of consciousness gradually improved. The pharmacokinetics of perampanel may be modified by both hemimegalencephaly and infection, resulting in an elevated plasma concentration of perampanel. This case underlines the importance of monitoring perampanel plasma concentration in patients with underlying brain disease who develop an infection.

Different pharmacoresistance of focal epileptic spasms, generalized epileptic spasms, and generalized epileptic spasms combined with focal seizures.

OBJECTIVE: Among standard treatments for infantile spasms, adrenocorticotropic hormone (ACTH) is reported as the best treatment, but ACTH is ineffective in one-half of the patients. To establish precision medicine, we examined pharmacoresistance of focal epileptic spasms (ES), generalized ES, and generalized ES combined with focal seizures, diagnosed based on the revised seizure classification of ILAE in 2017. METHODS: We conducted a retrospective nationwide study in Japan on the long-term seizure outcome of ES. Long-term seizure outcome was evaluated by seizure-free rate, seizure-free period, and Kaplan-Meier curve. Seizure-free was defined as seizure control for longer than 2 months. RESULTS: From the medical history of 501 patients, 325 patients had generalized ES only (GES group) at the start of the first treatment, 125 patients had generalized ES after focal seizure onset (FS-GES group), seven patients had focal ES after focal seizure onset (FS-FES group), and 24 patients had generalized ES combined with focal seizures after focal seizure onset (FS-GES + FS group). Seizure-free period of ES (generalized ES and focal ES) [mean (95% confidence interval)] was 2.7 (0.0-5.4) months in GES group, 1.1 (0.1-2.2) months in FS-GES group, 1.0 (0.2-1.9) months in FS-GES + FS group, and 0.1 (-0.2-0.5) months in FS-FES group. Seizure-free rate, seizure-free period, and Kaplan-Meier curve of generalized ES were almost the same in GES group and FS-GES group, with characteristics of superior response to ACTH. Mean seizure-free period of generalized ES combined with focal seizures was significantly shorter in FS-GES + FS group than in GES group. Mean seizure-free period of focal ES in FS-FES group was extremely short with exceedingly early relapse. SIGNIFICANCE: Pharmacoresistance was different in generalized ES, focal ES, and generalized ES combined with focal seizures. ES with focal features or with focal seizures may have focal lesions, thus consider surgical options earlier in the course.

Paroxysmal sympathetic hyperactivity and the later development of epilepsy in a chemotherapy-associated brain damage.

BACKGROUND: Chemotherapy in childhood leukemia potentially induces brain lesions and neurological sequelae. Paroxysmal sympathetic hyperactivity (PSH) is known as a treatment-associated complication; however, the full clinical spectra of PSH remain to be elusive. CASE REPORT: A 5-year-old girl was diagnosed of acute myeloid leukemia (AML) M5. After the intensification therapy, she developed recurrent symptoms of episodic tachycardia, hypertension and perspiration lasting for several hours per day. The low-frequency-high-frequency ratio on Holter electrocardiography was rapidly increased from 0.84 to 2.24 at the onset of the paroxysmal event, whereas the video-monitoring electroencephalography (EEG) never identified ictal patterns of epileptiform discharges during the episodes. Thus, the diagnosis of PSH was given at 7 years of age. Myoclonic and generalized tonic-clonic seizures frequently appeared from 10 years of age, which poorly responded to anticonvulsants. EEG showed diffuse slow-wave bursts with multifocal spikes. Serial head magnetic resonance imaging (MRI) revealed diffuse cerebral and hippocampal atrophy, but not inflammatory lesions in the limbic system. CONCLUSION: We first demonstrate a pediatric case with PSH who developed drug-resistant epilepsy 3 years after the onset of PSH. Our data suggest the pathophysiological link of persistent PSH with chemotherapy-associated brain damage.

POLR1C variants dysregulate splicing and cause hypomyelinating leukodystrophy.

OBJECTIVE: To further clarify the molecular pathogenesis of RNA polymerase III (Pol III)-related leukodystrophy caused by biallelic POLR1C variants at a cellular level and potential effects on its downstream genes. METHODS: Exome analysis and molecular functional studies using cell expression and long-read sequencing analyses were performed on 1 family with hypomyelinating leukodystrophy showing no clinical and MRI findings characteristic of Pol III-related leukodystrophy other than hypomyelination. RESULTS: Biallelic novel POLR1C alterations, c.167T>A, p.M56K and c.595A>T, p.I199F, were identified as causal variants. Functional analyses showed that these variants not only resulted in altered protein subcellular localization and decreased protein expression but also caused abnormal inclusion of introns in 85% of the POLR1C transcripts in patient cells. Unexpectedly, allelic segregation analysis in each carrier parent revealed that each heterozygous variant also caused the inclusion of introns on both mutant and wild-type alleles. These findings suggest that the abnormal splicing is not direct consequences of the variants, but rather reflect the downstream effect of the variants in dysregulating splicing of POLR1C, and potentially other target genes. CONCLUSIONS: The lack of characteristic clinical findings in this family confirmed the broad clinical spectrum of Pol III-related leukodystrophy. Molecular studies suggested that dysregulation of splicing is the potential downstream pathomechanism for POLR1C variants.

Effects of low-dose hydrochlorothiazide on urolithiasis and bone metabolism in severely disabled individuals: a pilot study.

To clarify the effects of hydrochlorothiazide (HCT) on calcium metabolism in subjects with severe motor and intellectual disabilities (SMID), we examined four patients (16-48years old) with a history of urolithiasis and/or bone fracture and increased urinary calcium/creatinine ratio (U-Ca/Cr). U-Ca/Cr, blood markers of bone turnover, and bone-mineral density (BMD) were measured before and after administration of low-dose HCT (0.25-0.5mg/kg/day). Three months after the initiation of HCT, U-Ca/Cr decreased in all patients, but this effect was less evident at 9-18months. Bone-turnover marker of bone-specific alkaline phosphatase also showed a tendency to decrease, but BMD remained unchanged during the follow-up period. In SMID patients, HCT is beneficial for the treatment of hypercalciuria but its effects can be transient in certain cases. HCT may also ameliorate the increase in bone turnover, but its effects on the prevention of bone fractures remain uncertain. Hyponatremia is the most frequent and significant adverse effect of HCT, for which a close observation is mandatory in HCT application for patients with SMID.

Atrioventricular block and diastolic dysfunction in a patient with Sanfilippo C.

A 39-year-old woman with Sanfilippo C syndrome was referred to our department for the treatment of bradycardia. An electrocardiogram revealed a second degree atrioventricular block, and pacemaker implantation was performed with the patient under general anesthesia. A transthoracic echocardiogram showed normal left ventricular systolic function, moderate mitral regurgitation due to mitral valve prolapse, and a high E/e' ratio, indicating left ventricular diastolic dysfunction. The present patient exhibited a rare case of Sanfilippo syndrome complicated with conduction disturbances, mitral regurgitation, and diastolic dysfunction.