Mateusz Andrzej Zajączkowski

Hemolytic-uremic syndrome (HUS) is a thrombotic microangiopathy that is most commonly caused by infection with Shiga toxin-producing Escherichia coli (STEC-HUS). Atypical HUS (aHUS) is associated with inappropriate activation of the alternative complement pathway caused by infections, including SARS-CoV-2, malignancies, medications, or other triggering factors in genetically predisposed individuals. Assessment of the impact of the COVID-19 pandemic on epidemiology, course, complications, and outcome of HUS in children in a single tertiary nephrological center in Poland. It is a retrospective study, in which a total number of 74 pediatric patients with HUS were analyzed, including 16 cases in 5-year period before the outbreak of the COVID-19 pandemic (HUS-5) and 58 cases in 5-year period after the outbreak of the pandemic (HUS+5). A more than 3.6-fold increase in HUS cases and a 7-fold higher incidence of STEC-HUS were reported in the HUS+5 population. Strokes and persistent neurological complications were observed only in this group. 91.9% of patients presented with abnormal renal ultrasound (USG) findings at admission, and these findings improved significantly more frequently in the HUS-5 (68.75% vs 25.9%, p = 0.002) group. Mortality did not differ significantly between the 2 analyzed groups and was 6.8% for the entire population. The COVID-19 pandemic has had a significant impact on the incidence of HUS in the pediatric population. SARS-CoV-2 infection most markedly increases the risk of neurological complications but does not affect overall mortality.

Introduction: Drug-resistant epilepsy (DRE) affects up to 40% of pediatric patients and continues to be a major therapeutic challenge. Vagus nerve stimulation (VNS) is an established neuromodulatory therapy; however, the impact of genetic etiology on treatment efficacy and antiseizure medication (ASM) burden remains unclear. Conclusions: VNS provides clinically observable seizure reduction in pediatric DRE regardless of etiology, though responses appear more pronounced in non-genetic cases. Genetic etiology should not preclude VNS consideration, as it remains a safe and effective adjunctive therapy for refractory epilepsy. Aim: To evaluate the clinical effectiveness of VNS in pediatric DRE, comparing seizure reduction and ASM burden between genetically and non-genetically determined epilepsies. Materials and methods: We retrospectively analyzed 18 pediatric patients (aged 4–18 years) with DRE who underwent VNS implantation between 2021 and 2025. Patients were stratified into genetic (n = 8) and non-genetic (n = 10) cohorts. Seizure frequency and ASM exposure were in comparison to before and after implantation using nonparametric tests. The significance level was set at p < 0.05. Median duration of VNS therapy was 15 months (interquartile range [IQR] width: 16 months). Results: Overall, 67% of individuals exhibited clinical improvement, and 61% achieved a ≥ 50% reduction in seizure frequency. Median seizure reduction appeared greater in the non-genetic cohort (60%) than in the genetic cohort (20%), although this difference did not reach statistical significance (p = 0.088). Reduction in ASM burden occurred in 50% of non-genetic cases versus 13% of genetic cases. Post-implantation exposure to calcium-channel modulators was significantly more frequent amongst non-genetic patients (p = 0.036). Conclusions: VNS provides clinically observable seizure reduction in pediatric DRE regardless of etiology, though responses appear more pronounced in non-genetic cases. Genetic etiology should not preclude VNS consideration, as it remains a safe and effective adjunctive therapy for refractory epilepsy.

Super-refractory status epilepticus (SRSE) is a rare and life-threatening neurological emergency associated with substantial morbidity and mortality. Defined as persistent or recurrent seizures lasting beyond 24 h despite anaesthetic and antiseizure pharmacotherapy, SRSE poses significant therapeutic challenges. Management strategies aim to suppress seizures, provide neuroprotection, and mitigate excitotoxic injury. While emergency epilepsy surgery is traditionally reserved as a last resort due to limited supporting evidence, it has demonstrated efficacy in selected cases. We report the case of an 8-year-old girl with cerebral palsy, drug-resistant epilepsy, cortical visual impairment, and bilateral hearing loss, who developed SRSE unresponsive to maximal antiepileptic and anaesthetic therapy. Following multidisciplinary evaluation, a sequential multimodal neurosurgical approach was implemented, comprising left selective amygdalohippocampectomy (SAH), vagus nerve stimulation (VNS), and anterior corpus callosotomy. SAH targeted the epileptogenic mesial temporal structures while preserving surrounding neocortex and neurovascular anatomy, resulting in immediate seizure cessation. Subsequent VNS implantation and callosotomy were performed following recurrent episodes, achieving sustained reduction in seizure frequency and severity, with Engel class II outcome. This case underscores the potential role of integrating resective, neuromodulatory, and disconnection procedures in paediatric SRSE when conventional treatments fail. Early consideration of sequential surgical strategies may enhance seizure control and improve quality of life in this high-risk patient group.

Background: Cerebrospinal fluid (CSF) shunting remains a crucial intervention in the treatment of paediatric hydrocephalus. Overdrainage syndrome is a well-recognised but potentially severe complication, in which hyperostosis cranii ex vacuo—diffuse thickening of the cranial bones—emerges as an adaptive response to chronic intracranial hypotension. Currently, no established diagnostic criteria exist to reliably identify and classify this phenomenon, nor are there defined strategies to prevent associated complications of reduced intracranial compliance. Objective: This study aimed to characterise the morphoradiological and clinical phenotype of hyperostosis cranii ex vacuo in paediatric patients with long-term shunt dependency and to propose its classification as a fifth subtype of CSF overdrainage syndrome with direct implications for long-term neurosurgical care. Methods: A retrospective observational study was conducted on nine paediatric patients with radiologically confirmed diffuse calvarial thickening secondary to surgical treatment of hydrocephalus. Quantitative morphometric analysis of frontal, parietal, and occipital bones, sella turcica dimensions, and dural enhancement was performed using high-resolution neuroimaging. Clinical records were reviewed for hydrocephalus aetiology, shunt revision history, and neurological impairment. Results: All patients exhibited a mean two-fold increase in age-adjusted calvarial thickness. Premature craniosynostosis was identified in 33.3% of cases. Diffuse pachymeningeal enhancement was noted in all patients with contrast-enhanced imaging. Neurological comorbidities included epilepsy, spastic paraparesis, and features of Chiari type I malformation. Conclusions: Hyperostosis cranii ex vacuo represents a distinct and underrecognised consequence of chronic CSF overdrainage. We propose preliminary diagnostic criteria and a structured management pathway—from radiological recognition through ICP assessment to tiered surgical intervention. Formal recognition of this entity as a fifth subtype of CSF overdrainage syndrome may enhance early diagnosis, improve risk stratification, and guide long-term surveillance of shunted children.

Background: Cerebrospinal fluid (CSF) shunting remains a crucial intervention in the treatment of paediatric hydrocephalus. Overdrainage syndrome is a well-recognised but potentially severe complication, in which hyperostosis cranii ex vacuo-diffuse thickening of the cranial bones-emerges as an adaptive response to chronic intracranial hypotension. Currently, no established diagnostic criteria exist to reliably identify and classify this phenomenon, nor are there defined strategies to prevent associated complications of reduced intracranial compliance. Objective: This study aimed to characterise the morphoradiological and clinical phenotype of hyperostosis cranii ex vacuo in paediatric patients with long-term shunt dependency and to evaluate its classification as a distinct nosological entity within the spectrum of CSF overdrainage syndromes. Methods: A retrospective observational study was conducted on nine paediatric patients with radiologically confirmed diffuse calvarial thickening secondary to surgical treatment of hydrocephalus. Quantitative morphometric analysis of frontal, parietal, and occipital bones, sella turcica dimensions, and dural enhancement was performed using high-resolution neuroimaging. Clinical records were reviewed for hydrocephalus aetiology, shunt revision history, and neurological impairment. Results: All patients exhibited a mean two-fold increase in age-adjusted calvarial thickness. Premature craniosynostosis was identified in 33.3% of cases. Diffuse pachymeningeal enhancement was noted in all patients with contrast-enhanced imaging. Neurological comorbidities included epilepsy, spastic paraparesis, and features of Chiari type I malformation. Conclusion: Hyperostosis cranii ex vacuo represents a distinct and underrecognised consequence of chronic CSF overdrainage. Its formal classification as a fifth subtype of CSF overdrainage syndrome may improve diagnostic accuracy and inform long-term neurosurgical management in shunted paediatric populations.