GABRA1-Related Disorders: From Genetic to Functional Pathways.

OBJECTIVE: Variants in GABRA1 have been associated with a broad epilepsy spectrum, ranging from genetic generalized epilepsies to developmental and epileptic encephalopathies. However, our understanding of what determines the phenotype severity and best treatment options remains inadequate. We therefore aimed to analyze the electroclinical features and the functional effects of GABRA1 variants to establish genotype-phenotype correlations. METHODS: Genetic and electroclinical data of 27 individuals (22 unrelated and 2 families) harboring 20 different GABRA1 variants were collected and accompanied by functional analysis of 19 variants. RESULTS: Individuals in this cohort could be assigned into different clinical subgroups based on the functional effect of their variant and its structural position within the GABRA1 subunit. A homogenous phenotype with mild cognitive impairment and infantile onset epilepsy (focal seizures, fever sensitivity, and electroencephalographic posterior epileptiform discharges) was described for variants in the extracellular domain and the small transmembrane loops. These variants displayed loss-of-function (LoF) effects, and the patients generally had a favorable outcome. A more severe phenotype was associated with variants in the pore-forming transmembrane helices. These variants displayed either gain-of-function (GoF) or LoF effects. GoF variants were associated with severe early onset neurodevelopmental disorders, including early infantile developmental and epileptic encephalopathy. INTERPRETATION: Our data expand the genetic and phenotypic spectrum of GABRA1 epilepsies and permit delineation of specific subphenotypes for LoF and GoF variants, through the heterogeneity of phenotypes and variants. Generally, variants in the transmembrane helices cause more severe phenotypes, in particular GoF variants. These findings establish the basis for a better understanding of the pathomechanism and a precision medicine approach in GABRA1-related disorders. Further studies in larger populations are needed to provide a conclusive genotype-phenotype correlation. ANN NEUROL 2023.

Neurological assessment tool for screening infants during the first year after birth: The Brief-Hammersmith Infant Neurological Examination.

AIM: To develop a short version of the original Hammersmith Infant Neurological Examination (HINE) to be used as a screening tool (Brief-HINE) and to establish if the short examination maintains good accuracy and predictive power for detecting infants with cerebral palsy (CP). METHOD: Eleven items were selected from the original HINE ('visual response'; 'trunk posture'; 'movement quantity'; 'movement quality'; 'scarf sign'; 'hip adductor angles'; 'popliteal angle'; 'pull to sit'; 'lateral tilting'; 'forward parachute reaction'; 'tendon reflexes') identifying those items previously found to be more predictive of CP in both low- and high-risk infants. In order to establish the sensitivity of the new module, the selected items were applied to existing data, previously obtained using the full HINE at 3, 6, 9, and 12 months, in 228 infants with typical development at 2 years and in 82 infants who developed CP. RESULTS: Brief-HINE scores showed good sensitivity and specificity, at each age of assessment, for detecting infants with CP. At 3 months, a score of less than 22 was associated with CP with a sensitivity of 0.88 and a specificity of 0.92; at 6, 9, and 12 months, the cut-off scores were less than 25 (sensitivity 0.93; specificity 0.87), less than 27 (sensitivity 0.95; specificity 0.81), and less than 27 (sensitivity 1; specificity 0.86) respectively. The presence of more than one warning sign, or items that are not optimal for the age of assessment, imply the need for a full examination reassessment. INTERPRETATION: These findings support the validity of the Brief-HINE as a routine screening method and the possibility of its use in clinical practice.

Cerebral palsy and sex differences in children: A narrative review of the literature.

In the last years, new evidence has increased the attention on sex differences in the development of children with cerebral palsy (CP). Males seem to present with a higher risk for severe motor impairment and in the response to chirurgical and rehabilitative interventions. The published data confirmed a higher incidence of CP in males than in females. The aim of this literature review was to evaluate the impact of the sex on the most important areas that characterized CP: motor function, comorbidities (pain, cognitive impairment, communications skills, epilepsy, sleep, and behavior), and the different kind of interventions.

Hammersmith Infant Neurological Examination in infants born at term: Predicting outcomes other than cerebral palsy.

AIM: We explored the ability of the Hammersmith Infant Neurological Examination (HINE) to identify cognitive performance delay at 2 years in a large cohort of infants born at term. METHOD: We conducted a retrospective study of infants born at term at risk of neurodevelopmental impairments assessed using the HINE between 3 and 12 months post-term age and compared them with a cohort of typically developing infants born at term. All infants performed a neurodevelopmental assessment at 2 years of age using the Mental Development Index (MDI) of the Bayley Scales of Infant Development, Second Edition; the presence of cerebral palsy (CP) was also reported. The infants were classified as being cognitively normal/mildly delayed or significantly delayed (MDI < 70). The predictive validity of HINE scores for significantly delayed cognitive performance, in infants with and without CP, was calculated using specific cut-off scores according to age at assessment. RESULTS: A total of 446 at-risk and 235 typically developing infants (345 males, 336 females; mean [SD] gestational age 38.7 weeks [1.4], range 37-43 weeks) were included. Of the at-risk infants, 408 did not have CP at 2 years; 243 had a normal/mild delayed MDI and 165 had an MDI less than 70. Of the at-risk infants, 38 developed CP. HINE scores showed a good sensitivity and specificity, mainly after 3 months, for identifying significantly delayed cognitive performance in infants without CP. In those with CP, the score was associated with their cognitive performance. The comparison group had the highest HINE scores. INTERPRETATION: The HINE provides evidence about the risk of delayed cognitive performance at age 2 years in infants born at term with and without CP.

EXAMEN NEUROLÓGICO INFANTIL DE HAMMERSMITH EN BEBÉS NACIDOS A TÉRMINO: SU USO PARA PREDECIR OTRAS CONDICIONES ADEMÁS DE LA PARÁLISIS CEREBRAL: OBJETIVO: Valoramos la capacidad del examen neurológico infantil de Hammersmith (HINE) para identificar el retraso en el rendimiento cognitivo a los 2 años en una cohorte grande de bebés nacidos a término. MÉTODO: Realizamos un estudio retrospectivo de bebés nacidos a término con riesgo de trastornos del desarrollo neurológico evaluados mediante el HINE entre los 3 y los 12 meses de edad postérmino y los comparamos con una cohorte de bebés nacidos a término con un desarrollo típico. Todos los bebés realizaron una evaluación del desarrollo neurológico a los 2 años de edad utilizando el Índice de Desarrollo Mental (MDI) de las Escalas de Desarrollo Infantil de Bayley, Segunda Edición; también se informó la presencia de parálisis cerebral (PC). Los bebés se clasificaron como cognitivamente normales/levemente con retreaso o significativamente con retraso (MDI < 70). La validez predictiva de las puntuaciones HINE para el rendimiento cognitivo con retraso significativo, en bebés con y sin parálisis cerebral, se calculó utilizando puntuaciones de corte específicas según la edad en la evaluación. RESULTADOS: Se incluyeron un total de 446 lactantes en riesgo y 235 con desarrollo normal (345 varones, 336 mujeres; edad gestacional media [DE] 38,7 semanas [1,4], rango de 37 a 43 semanas). De los lactantes en riesgo, 408 no tenían parálisis cerebral a los 2 años; 243 tenían un MDI con retraso normal/leve y 165 tenían un MDI inferior a 70. De los bebés en riesgo, 38 desarrollaron PC. Las puntuaciones HINE mostraron una buena sensibilidad y especificidad, principalmente después de 3 meses, para identificar un rendimiento cognitivo severo en lactantes sin PC. En aquellos con PC, la puntuación se asoció con su rendimiento cognitivo. El grupo de comparación tuvo las puntuaciones HINE más altas. INTERPRETACIÓN: El HINE proporciona evidencia sobre el riesgo de retraso en el rendimiento cognitivo a los 2 años de edad en bebés nacidos a término con y sin parálisis cerebral.

Hammersmith Infant Neurological Examination in low-risk infants born very preterm: a longitudinal prospective study.

AIM: To describe the profile of global and single items of the Hammersmith Infant Neurological Examination (HINE) in a population of low-risk infants born very preterm during the first year of life. METHOD: The HINE was performed at 3, 6, 9, and 12 months' corrected age in a population of low-risk infants born preterm with a gestational age of fewer than 32 weeks and with normal or minimal changes on neuroimaging. RESULTS: A total of 174 infants born preterm (96 males, 78 females; mean gestational age = 27 weeks [SD = 1.8], range 23-31 weeks) fulfilled the inclusion criteria. The 10th centile cut-off score with median and range was reported for the HINE global and subsection scores. A progressive increase in global HINE scores was observed. Most of the single items, especially those related to tone, posture, and reflexes, showed progressive maturation. INTERPRETATION: Our results, which provide longitudinal data for single-item and global scores in a population of low-risk infants born very preterm, can be used as a reference in both clinical and research settings to monitor early neurological signs in these infants. These data could be used as normative data when examining low-risk infants born preterm.

Assessing floppy infants: a new module.

Our aim was to develop a new module for assessing the floppy infant, to describe the application of the module in a cohort of low-risk newborns and piloting the module in a cohort of floppy infants. The module was applied to a cohort of 143 low-risk newborns and piloted in in a cohort of 24 floppy infants. The new add-on module includes a neurological section and provides a section for recording information obtained by physical examination and antenatal history. For each item, column 1 reports abnormal findings, column 3 normal findings, and column 2 intermediate signs to be followed. Consistent with previous studies, in low-risk infants, none had definitely abnormal or mildly abnormal signs, with the exception of tendon reflexes that were not easily elicitable in 17.14% of term-born infants. CONCLUSION: Our study suggest that the module can be easily used in a clinical setting as an add-on to the regular neonatal neurological examination in newborns identified as hypotonic on routine examination. Larger cohorts are needed to establish the accuracy of the prognostic value of the module in the differential diagnosis of floppy infant. WHAT IS KNOWN: • Hypotonia is one of the key signs in newborns with neuromuscular disorders and can be associated with a wide range of other conditions (central nervous system involvement, genetic and metabolic diseases). • Weakness or/and contractures can identify infants with a neuromuscular disorder and help in the differential diagnosis of floppy infants. WHAT IS NEW: • To date, this is the first attempt to develop and apply a specific neurological module for the assessment of the floppy infant. • The module can be used in a routine clinical setting as an add-on to the regular neurological examination and has potential to differentiate the floppy infants from the low-risk infants.

Longitudinal Cognitive Assessment in Low-Risk Very Preterm Infants.

Background and Objectives: Preterm infants are at higher risk of neurodevelopmental impairment both at preschool and school ages, even in the absence of major neurological deficits. The early identification of children at risk is essential for early intervention with rehabilitation to optimize potential outcomes during school years. The aim of our study is to assess cognitive outcomes at preschool age in a cohort of low-risk very preterm infants, previously studied at 12 and 24 months using the Griffiths scales. Materials and Methods: Sixty-six low-risk very preterm infants born at a gestational age of <32 weeks were assessed at 12 and 24 months corrected age using the Griffiths Mental Development Scales (second edition) and at preschool age with the Wechsler Preschool and Primary Scales of Intelligence (third edition) (WPPSI-III). Results: At 12 and 24 months and at preschool age, low-risk very preterm infants showed scores within normal ranges with similar scores in males and females. A statistically significant correlation was observed in the general developmental quotient between 12 and 24 months; a further significant correlation was observed between the early cognitive assessments and those performed at preschool age, with a better correlation using the assessments at 24 months. Conclusion: The present study showed a favourable trajectory of cognitive development in low-risk very preterm infants, from 12 months to preschool age.

Hammersmith Infant Neurological Examination for infants born preterm: predicting outcomes other than cerebral palsy.

AIM: We explored the ability of the Hammersmith Infant Neurological Examination (HINE) to identify typical and delayed cognitive performance in a large population of infants born preterm, both with and without cerebral palsy (CP). METHOD: We conducted a retrospective study of infants born preterm who had repeated HINEs between 3 and 12 months corrected age. At 2 years, cognition was assessed using the Mental Development Index (MDI; from the Bayley Scales of Infant Development, Second Edition) and the presence and severity of CP was determined. All children were classified as cognitively typical/mildly delayed or significantly delayed (MDI <70) and CP. The predictive validity of HINE scores for significantly delayed cognitive performance, in children with and without CP, was calculated using specific cut-off scores according to age at assessment. RESULTS: Of 1229 eligible infants (gestational age 25-36wks, mean [SD] 34.9 [2.3]; 646 males, 583 females), 1108 did not develop CP, 891 had an MDI that was typical/mildly delayed, and 217 had an MDI less than 70. Of the 121 infants who developed CP, the MDI was typical in 28, mildly delayed in 27, and less than 70 in 66. HINE scores showed a good sensitivity and specificity, especially after 3 months, for detecting significantly delayed cognitive performance in infants without CP. In those who developed CP, the score was associated with their cognitive level. INTERPRETATION: The HINE provides information about the risk of delayed cognitive performance in infants born preterm with and without CP. What this paper adds The Hammersmith Infant Neurological Examination (HINE) can be used in the first year to identify infants born preterm at risk for delayed cognitive performance. Age-dependent HINE cut-off scores are proposed for detecting increased risk of delayed cognitive performance.

Visual Function in Children with GNAO1-Related Encephalopathy.

BACKGROUND: GNAO1-related encephalopathies include a broad spectrum of developmental disorders caused by de novo heterozygous mutations in the GNAO1 gene, encoding the G (o) subunit α of G-proteins. These conditions are characterized by epilepsy, movement disorders and developmental impairment, in combination or as isolated features. OBJECTIVE: This study aimed at describing the profile of neurovisual competences in children with GNAO1 deficiency to better characterize the phenotype of the disease spectrum. METHODS: Four male and three female patients with confirmed genetic diagnosis underwent neurological examination, visual function assessment, and neurovisual and ophthalmological evaluation. Present clinical history of epilepsy and movement disorders, and neuroimaging findings were also evaluated. RESULTS: The assessment revealed two trends in visual development. Some aspects of visual function, such as discrimination and perception of distance, depth and volume, appeared to be impaired at all ages, with no sign of improvement. Other aspects, reliant on temporal lobe competences (ventral stream) and more related to object-face exploration, recognition and environmental control, appeared to be preserved and improved with age. SIGNIFICANCE: Visual function is often impaired, with patterns of visual impairment affecting the ventral stream less.

pCO2 values in asphyxiated infants under therapeutic hypothermia after tailored respiratory management: a retrospective cohort study.

Background: Hypoxic-ischemic encephalopathy (HIE) represents one of the major causes of neonatal death and long-term neurological disability. Both hypoxic-ischemic insults and therapeutic hypothermia (TH) can affect respiratory function. Currently, there is no evidence regarding optimal respiratory management in these infants. Methods: This is a retrospective cohort study examining newborns with HIE treated with TH between January 2015 and September 2020. The study population was divided into two groups based on different respiratory assistance during TH: spontaneous breathing (Group A) or mechanical ventilation (Group B). The primary outcome of the study was the mean pCO2 ± SD evaluation during TH in ventilated and non-ventilated asphyxiated infants. The secondary outcome was the correlation between ventilation strategy and short-term neurologic outcome according to Rutherford et al.'s MRI scoring system. Results: A total of 126 newborns were enrolled, 75 in Group A and 51 in Group B. Respiratory management was individualized, and volume guarantee (VG) ventilation was the first choice for ventilated infants. Group B infants showed more severe conditions at birth. During TH, ventilated infants showed optimal mean pCO2 comparable with those breathing spontaneously (40.6 mmHg vs. 42.3 mmHg, respectively, p 0.091), with no significant difference in pCO2 standard deviation between (7.7 mmHg vs. 8.1 mmHg, respectively, p 0.522). Mean pH, pH standard deviation, mean pO2, pO2 standard deviation, and mean respiratory rate also did not differ between groups. MRI patterns of brain injury predictive of abnormal neurodevelopmental outcomes were similar in both groups. Logistic regression analysis demonstrated that only umbilical cord arterial blood pH-affected MRI lesions were associated with poor neurodevelopmental outcomes (OR 1.505; CI 95% 1.069-2.117). Conclusions: Infants cooled after HIE should receive individualized respiratory management, not necessarily involving intubation. In those infants requiring mechanical ventilation, a volume-targeted strategy appeared to be effective in maintaining stable blood gas levels. Short-term neurological outcomes appeared comparable in ventilated and non-ventilated infants.

Early Gross Motor Milestones in Duchenne Muscular Dystrophy.

BACKGROUND: Over the last few years there has been increasing attention to detect early signs of impairment in young Duchenne muscular dystrophy boys but less has been reported on whether the delay may also affect the very early aspects of motor development, such as gross motor milestones. OBJECTIVE: The aim of this study was to retrospectively assess the age when early motor milestones were achieved in Duchenne muscular dystrophy. METHODS: The study is a retrospective analysis of data collected as part of a larger natural history project. Information on past medical history, collected at the time the boys were seen for the first time, were recorded and re available on clinical notes and on electronic CRF. RESULTS: Data were collected in 134 DMD boys. Sitting was achieved at 7.04 months. The % of DMD boys not achieving sitting by 9.4 months was 10%, ranging from 2% in the boys with mutations before exon 44 to 33% in those beyond exon 63. Walking was achieved at a mean age of 16.35 months. The % of DMD boys not achieving independent walking by 18 months was 17%, ranging from 9% in the boys with mutations between 44 and 51 to 42% in those beyond exon 63. CONCLUSIONS: Our results showed that the risk of a delay in sitting and walking was increasingly high in patients with mutations predictive of the involvement of different brain dystrophin isoforms.

Cortical Thickness and Clinical Findings in Prescholar Children With Autism Spectrum Disorder.

The term autism spectrum disorder (ASD) includes a wide variability of clinical presentation, and this clinical heterogeneity seems to reflect a still unclear multifactorial etiopathogenesis, encompassing different genetic risk factors and susceptibility to environmental factors. Several studies and many theories recognize as mechanisms of autism a disruption of brain development and maturation time course, suggesting the existence of common neurobiological substrates, such as defective synaptic structure and aberrant brain connectivity. Magnetic resonance imaging (MRI) plays an important role in both assessment of region-specific structural changes and quantification of specific alterations in gray or white matter, which could lead to the identification of an MRI biomarker. In this study, we performed measurement of cortical thickness in a selected well-known group of preschool ASD subjects with the aim of finding correlation between cortical metrics and clinical scores to understand the underlying mechanism of symptoms and to support early clinical diagnosis. Our results confirm that recent brain MRI techniques combined with clinical data can provide some useful information in defining the cerebral regions involved in ASD although large sample studies with homogeneous analytical and multisite approaches are needed.

Respiratory function and therapeutic expectations in DMD: families experience and perspective.

OBJECTIVE: The aim of this study was to use a structured questionnaire in a large cohort of Duchenne Muscular Dystrophy (DMD) patients to assess caregivers and patients views on respiratory function and to establish if their responses were related to the patients' age or level of functional impairment. METHODS: Questionnaires were administered to caregivers in 205 DMD patients of age between 3 and 36 years (115 ambulant, 90 non-ambulant), and to 64 DMD patients (3 ambulant, 61 non-ambulant) older than 18 years, subdivided into groups according to age, FVC, ambulatory and ventilatory status. RESULTS: Some differences were found in relation to FVC % values (p = 0.014), ambulatory (p = 0.043) and ventilatory status (p = 0.014). Nearly half of the caregivers expected deterioration over the next years, with the perspective of deterioration more often reported by caregivers of non-ambulant (p = 0.018) and ventilated patients (p = 0.004). Caregivers appeared to be aware of the relevance of respiratory function on quality of life (84%) showing willingness to enter possible clinical trials if these were aiming to stabilize the progression of respiratory function with a very high number of positive responses across the spectrum of age, FVC, ambulatory and ventilatory status. The boys older than 18 years showed similar results. CONCLUSIONS: Our study showed that the concern for respiratory function increases with age and with the reduction of FVC or the need for ventilation, but the need for intervention was acknowledged across the whole spectrum of age and functional status.