Applicability and clinical utility of the German rivermead post-concussion symptoms questionnaire in proxies of children after traumatic brain injury: an instrument validation study.

BACKGROUND: The German Rivermead Post-Concussion Symptoms Questionnaire (RPQ) can be used to assess post-concussion symptoms (PCS) after traumatic brain injury (TBI) in adults, adolescents, and children. METHODS: In this study, we examined the psychometric properties of the German RPQ proxy version (N = 146) for children (8-12 years) after TBI at the item, total and scale score level. Construct validity was analyzed using rank correlations with the proxy-assessed Post-Concussion Symptoms Inventory (PCSI-P), the Patient Health Questionnaire 9 (PHQ-9), and the Generalized Anxiety Disorder Scale 7 (GAD-7). Furthermore, sensitivity testing was performed concerning subjects' sociodemographic and injury-related characteristics. Differential item functioning (DIF) was analyzed to assess the comparability of RPQ proxy ratings for children with those for adolescents. RESULTS: Good internal consistency was demonstrated regarding Cronbach's α (0.81-0.90) and McDonald's ω (0.84-0.92). The factorial validity of a three-factor model was superior to the original one-factor model. Proxy ratings of the RPQ total and scale scores were strongly correlated with the PCSI-P (ϱ = 0.50-0.69), as well as moderately to strongly correlated with the PHQ-9 (ϱ = 0.49-0.65) and the GAD-7 (ϱ = 0.44-0.64). The DIF analysis revealed no relevant differences between the child and adolescent proxy versions. CONCLUSIONS: The German RPQ proxy is a psychometrically reliable and valid instrument for assessing PCS in children after TBI. Therefore, RPQ self- and proxy-ratings can be used to assess PCS in childhood as well as along the lifespan of an individual after TBI.

Final Validation of the Quality of Life after Brain Injury for Children and Adolescents (QOLIBRI-KID/ADO) Questionnaire.

Until recently, no disease-specific health-related quality of life (HRQoL) questionnaire existed for pediatric traumatic brain injuries (TBIs). In this revalidation study, the psychometric properties and the validity of the 35-item QOLIBRI-KID/ADO questionnaire in its final German version were examined in 300 children and adolescents. It is the first self-reported TBI-specific tool for measuring pediatric HRQoL in individuals aged between 8 and 17 years. The six-factor model fits the data adequately. The questionnaire's internal consistency was excellent for the total score and satisfactory to excellent for the scale scores. Intraclass correlations indicated good test-retest reliability, and the measure's construct validity was supported by the overlap between the QOLBRI-KID/ADO and the PedsQL, which measures generic HRQoL. The discriminant validity tests showed that older children and girls reported a significantly lower HRQoL than comparison groups, and this was also true of children who were anxious or depressed, or who suffered from post-concussion symptoms, replicating the results of the questionnaire's first developmental study. Our results suggest that the QOLIBRI-KID/ADO is a reliable and valid multidimensional tool that can be used together with the adult version in clinical contexts and research to measure disease-specific HRQoL after pediatric TBI throughout a person's life. This may help improve care, treatment, daily functioning, and HRQoL after TBI.

Corrigendum: Psychometric evaluation and reference values for the German Postconcussion Symptom Inventory (PCSI-SR8) in children aged 8-12 years.

[This corrects the article DOI: 10.3389/fneur.2023.1266828.].

Recommendations for optimal interdisciplinary management and healthcare settings for patients with rare neurological diseases.

BACKGROUND: In 2017, the German Academy for Rare Neurological Diseases (Deutsche Akademie für Seltene Neurologische Erkrankungen; DASNE) was founded to pave the way for an optimized personalized management of patients with rare neurological diseases (RND) in all age groups. Since then a dynamic national network for rare neurological disorders has been established comprising renowned experts in neurology, pediatric neurology, (neuro-) genetics and neuroradiology. DASNE has successfully implemented case presentations and multidisciplinary discussions both at yearly symposia and monthly virtual case conferences, as well as further educational activities covering a broad spectrum of interdisciplinary expertise associated with RND. Here, we present recommendation statements for optimized personalized management of patients with RND, which have been developed and reviewed in a structured Delphi process by a group of experts. METHODS: An interdisciplinary group of 37 RND experts comprising DASNE experts, patient representatives, as well as healthcare professionals and managers was involved in the Delphi process. First, an online collection was performed of topics considered relevant for optimal patient care by the expert group. Second, a two-step Delphi process was carried out to rank the importance of the selected topics. Small interdisciplinary working groups then drafted recommendations. In two consensus meetings and one online review round these recommendations were finally consented. RESULTS: 38 statements were consented and grouped into 11 topics: health care structure, core neurological expertise and core mission, interdisciplinary team composition, diagnostics, continuous care and therapy development, case conferences, exchange / cooperation between Centers for Rare Diseases and other healthcare partners, patient advocacy group, databases, translation and health policy. CONCLUSIONS: This German interdisciplinary Delphi expert panel developed consented recommendations for optimal care of patients with RND in a structured Delphi process. These represent a basis for further developments and adjustments in the health care system to improve care for patients with RND and their families.

Health-Related Quality of Life after Pediatric Traumatic Brain Injury: A Quantitative Comparison between Children's and Parents' Perspectives of the QOLIBRI-KID/ADO Questionnaire.

Pediatric health-related quality of life (HRQoL) as a measure of subjective wellbeing and functioning has received increasing attention over the past decade. HRQoL in children and adolescents following pediatric traumatic brain injury (pTBI) has been poorly studied, and performing adequate measurements in this population is challenging. This study compares child/adolescent and parent reports of HRQoL following pTBI using the newly developed Quality of Life after Brain Injury in Children and Adolescents (QOLIBRI-KID/ADO) questionnaire. Three hundred dyads of 8-17-year-old children/adolescents and their parents were included in the study. The parent-child agreement, estimated using intraclass correlation coefficients and Cohen's κ, displayed poor to moderate concordance. Approximately two-fifths of parents (39.3%) tended to report lower HRQoL for their children/adolescents on the total QOLIBRI-KID/ADO score. At the same time, about one-fifth (21.3%) reported higher HRQoL Total scores for their children/adolescents. The best agreement for parents rating adolescents (aged 13-17 years) was found in terms of the Total score and the Cognition and Self scale scores. To date, parent-reported HRQoL has been the preferred choice in pediatric research after TBI. However, with a parent-child disagreement of approximately 60%, our results highlight the importance of considering self-reports for children/adolescents capable of answering or completing the HRQoL measures.

Psychometric evaluation and reference values for the German Postconcussion Symptom Inventory (PCSI-SR8) in children aged 8-12 years.

Background: Post-concussion symptoms (PCS) are a common consequence of pediatric traumatic brain injury (pTBI). They include cognitive, emotional, and physical disturbances. To address the lack of age-adapted instruments assessing PCS after pTBI, this study examines the psychometric properties of the German 17-item post-TBI version of the Postconcussion Symptom Inventory (PCSI-SR8) in children aged 8-12 years. The study also aims to establish reference values based on data from a pediatric general population sample to better estimate the prevalence and clinical relevance of PCS after pTBI in clinical and research settings. Methods: A total of 132 children aged 8-12 years from a post-acute TBI sample and 1,047 from a general population sample were included in the analyses. The questionnaire was translated from English into German and linguistically validated using forward and backward translation and cognitive debriefing to ensure comprehensibility of the developed version. Reliability and validity were examined; descriptive comparisons were made with the results of the English study. Measurement invariance (MI) analyses between TBI and general population samples were conducted prior to establishing reference values. Factors contributing to the total and scale scores of the PCSI-SR8 were identified using regression analyses. Reference values were calculated using percentiles. Results: Most children (TBI: 83%; general population: 79%) rated at least one symptom as "a little" bothersome. The German PCSI-SR8 met the psychometric assumptions in both samples and was comparable to the English version. The four-factor structure comprising physical, emotional, cognitive, and fatigue symptoms could be replicated. The MI assumption was retained. Therefore, reference values could be provided to determine the symptom burden of patients in relation to a comparable general population. Clinical relevance of reported symptoms is indicated by a score of 8, which is one standard deviation above the mean of the general population sample. Conclusion: The German version of the PCSI-SR8 is suitable for assessment of PCS after pTBI. The reference values allow for a more comprehensive evaluation of PCS following pTBI. Future research should focus on validation of the PCSI-SR8 in more acute phases of TBI, psychometric examination of the pre-post version, and child-proxy comparisons.

Quality of Life after Brain Injury in Children and Adolescents (QOLIBRI-KID/ADO)-The First Disease-Specific Self-Report Questionnaire after Traumatic Brain Injury.

The subjective impact of the consequences of pediatric traumatic brain injury (pTBI) on different life dimensions should be assessed multidimensionally and as sensitively as possible using a disease-specific health-related quality of life (HRQoL) instrument. The development and psychometrics of the first such self-report questionnaire for children and adolescents after TBI are reported here. Focus group interviews with children, adolescents, and their parents, cognitive debriefing, item pool generation and reduction using Delphi expert panels were performed. The resulting version was psychometrically tested on 300 individuals aged 8-17 years. After item reduction based on factor analyses, differential item functioning, reliability, and validity were investigated. The final 35 items were associated with six scales (Cognition, Self, Daily Life and Autonomy, Social Relationships, Emotions, Physical Problems). Internal consistency and construct validity were satisfactory. Health-related Quality of life (HRQoL) was significantly lower in older and in female participants, as well as those with cognitive disabilities, anxiety, depression and post-concussion symptoms, than in comparative groups. The new QOLIBRI-KID/ADO is a comprehensive, multidimensional, reliable, and valid instrument, comparable in content and items to the QOLIBRI adult version. Therefore, disease-specific HRQoL can now be measured across the lifespan and may support the amelioration of treatment, care, rehabilitation, and daily life of children and adolescents after TBI.

A Multidimensional Approach to Assessing Factors Impacting Health-Related Quality of Life after Pediatric Traumatic Brain Injury.

In the field of pediatric traumatic brain injury (TBI), relationships between pre-injury and injury-related characteristics and post-TBI outcomes (functional recovery, post-concussion depression, anxiety) and their impact on disease-specific health-related quality of life (HRQoL) are under-investigated. Here, a multidimensional conceptual model was tested using a structural equation model (SEM). The final SEM evaluates the associations between these four latent variables. We retrospectively investigated 152 children (8-12 years) and 148 adolescents (13-17 years) after TBI at the recruiting clinics or online. The final SEM displayed a fair goodness-of-fit (SRMR = 0.09, RMSEA = 0.08 with 90% CI [0.068, 0.085], GFI = 0.87, CFI = 0.83), explaining 39% of the variance across the four latent variables and 45% of the variance in HRQoL in particular. The relationships between pre-injury and post-injury outcomes and between post-injury outcomes and TBI-specific HRQoL were moderately strong. Especially, pre-injury characteristics (children's age, sensory, cognitive, or physical impairments, neurological and chronic diseases, and parental education) may aggravate post-injury outcomes, which in turn may influence TBI-specific HRQoL negatively. Thus, the SEM comprises potential risk factors for developing negative post-injury outcomes, impacting TBI-specific HRQoL. Our findings may assist healthcare providers and parents in the management, therapy, rehabilitation, and care of pediatric individuals after TBI.

The genetic spectrum of congenital ocular motor apraxia type Cogan: an observational study, continued.

BACKGROUND: The term congenital ocular motor apraxia (COMA), coined by Cogan in 1952, designates the incapacity to initiate voluntary eye movements performing rapid gaze shift, so called saccades. While regarded as a nosological entity by some authors, there is growing evidence that COMA designates merely a neurological symptom with etiologic heterogeneity. In 2016, we reported an observational study in a cohort of 21 patients diagnosed as having COMA. Thorough re-evaluation of the neuroimaging features of these 21 subjects revealed a previously not recognized molar tooth sign (MTS) in 11 of them, thus leading to a diagnostic reassignment as Joubert syndrome (JBTS). Specific MRI features in two further individuals indicated a Poretti-Boltshauser syndrome (PTBHS) and a tubulinopathy. In eight patients, a more precise diagnosis was not achieved. We pursued this cohort aiming at clarification of the definite genetic basis of COMA in each patient. RESULTS: Using a candidate gene approach, molecular genetic panels or exome sequencing, we detected causative molecular genetic variants in 17 of 21 patients with COMA. In nine of those 11 subjects diagnosed with JBTS due to newly recognized MTS on neuroimaging, we found pathogenic mutations in five different genes known to be associated with JBTS, including KIAA0586, NPHP1, CC2D2A, MKS1, and TMEM67. In two individuals without MTS on MRI, pathogenic variants were detected in NPHP1 and KIAA0586, arriving at a diagnosis of JBTS type 4 and 23, respectively. Three patients carried heterozygous truncating variants in SUFU, representing the first description of a newly identified forme fruste of JBTS. The clinical diagnoses of PTBHS and tubulinopathy were confirmed by detection of causative variants in LAMA1 and TUBA1A, respectively. In one patient with normal MRI, biallelic pathogenic variants in ATM indicated variant ataxia telangiectasia. Exome sequencing failed to reveal causative genetic variants in the remaining four subjects, two of them with clear MTS on MRI. CONCLUSIONS: Our findings indicate marked etiologic heterogeneity in COMA with detection of causative mutations in 81% (17/21) in our cohort and nine different genes being affected, mostly genes associated with JBTS. We provide a diagnostic algorithm for COMA.

Genotype-phenotype correlation and treatment effects in young patients with GNAO1-associated disorders.

BACKGROUND: Patients carrying pathogenic variants in GNAO1 often present with early-onset central hypotonia and global developmental delay, with or without epilepsy. As the disorder progresses, a complex hypertonic and hyperkinetic movement disorder is a common phenotype. A genotype-phenotype correlation has not yet been described and there are no evidence-based therapeutic recommendations. METHODS: To improve understanding of the clinical course and pathophysiology of this ultra-rare disorder, we built up a registry for GNAO1 patients in Germany. In this retrospective, multicentre cohort study, we collected detailed clinical data, treatment effects and genetic data for 25 affected patients. RESULTS: The main clinical features were symptom onset within the first months of life, with central hypotonia or seizures. Within the first year of life, nearly all patients developed a movement disorder comprising dystonia (84%) and choreoathetosis (52%). Twelve (48%) patients suffered life-threatening hyperkinetic crises. Fifteen (60%) patients had epilepsy with poor treatment response. Two patients showed an atypical phenotype and seven novel pathogenic variants in GNAO1 were identified. Nine (38%) patients were treated with bilateral deep brain stimulation of the globus pallidus internus. Deep brain stimulation reduced hyperkinetic symptoms and prevented further hyperkinetic crises. The in silico prediction programmes did not predict the phenotype by the genotype. CONCLUSION: The broad clinical spectrum and genetic findings expand the phenotypical spectrum of GNAO1-associated disorder and therefore disprove the assumption that there are only two main phenotypes. No specific overall genotype-phenotype correlation was identified. We highlight deep brain stimulation as a useful treatment option in this disorder.

Recurrent, founder and hypomorphic variants contribute to the genetic landscape of Joubert syndrome.

BACKGROUND: Joubert syndrome (JS) is a neurodevelopmental ciliopathy characterised by a distinctive mid-hindbrain malformation, the 'molar tooth sign'. Over 40 JS-associated genes are known, accounting for two-thirds of cases. METHODS: While most variants are novel or extremely rare, we report on 11 recurring variants in seven genes, including three known 'founder variants' in the Ashkenazi Jewish, Hutterite and Finnish populations. We evaluated variant frequencies in ~550 European patients with JS and compared them with controls (>15 000 Italian plus gnomAD), and with an independent cohort of ~600 JS probands from the USA. RESULTS: All variants were markedly enriched in the European JS cohort compared with controls. When comparing allele frequencies in the two JS cohorts, the Ashkenazim founder variant (TMEM216 c.218G>T) was significantly enriched in American compared with European patients with JS, while MKS1 c.1476T>G was about 10 times more frequent among European JS. Frequencies of other variants were comparable in the two cohorts. Genotyping of several markers identified four novel European founder haplotypes.Two recurrent variants (MKS1 c.1476T>G and KIAA0586 c.428delG), have been detected in homozygosity in unaffected individuals, suggesting they could act as hypomorphic variants. However, while fibroblasts from a MKS1 c.1476T>G healthy homozygote showed impaired ability to form primary cilia and mildly reduced ciliary length, ciliary parameters were normal in cells from a KIAA0586 c.428delG healthy homozygote. CONCLUSION: This study contributes to understand the complex genetic landscape of JS, explain its variable prevalence in distinct geographical areas and characterise two recurrent hypomorphic variants.

Hemifacial spasm through changes of cerebrospinal fluid pressure in idiopathic intracranial hypertension.

Hemifacial spasm (HFS) is a rare complication of idiopathic intracranial hypertension (IIH); hence, little is known about its pathophysiology and treatment options. Here, we report a 29-year-old woman with a 3-month history of IIH and HFS. Following a diagnostic and therapeutic lumbar puncture, she suffered from attacks of HFS for a few days every time she rose from a supine position. The relatively sudden drop in cerebrospinal fluid (CSF) pressure led to frequent HFS attacks, which, in contrast to the attacks in the previous months, were strictly observed only when getting up from the supine position. This observation suggests changes in CSF pressure as the likely pathophysiological mechanism responsible for HFS in IIH, rather than the absolute CSF pressure. She was then successfully treated with topiramate, a known therapeutic option in IIH, but not yet described for HFS in IIH.

Health-Related Quality of Life after Pediatric Traumatic Brain Injury: A Qualitative Comparison of Perspectives of Children and Adolescents after TBI and a Comparison Group without a History of TBI.

BACKGROUND: The assessment of the impact of pediatric traumatic brain injury (TBI) on the health-related quality of life (HRQoL) of the children and adolescents affected can be ameliorated by a disease-specific instrument. Such an instrument does not yet exist. This qualitative study investigates how children and adolescents after TBI subjectively perceive their HRQoL and whether and how this differs from the perspective of individuals without a history of TBI. METHODS: Eight problem-centered interviews were conducted with 11 children and adolescents around four years after mild TBI and with eight children and adolescents around three years after moderate to severe TBI. Nine problem-centered interviews were conducted with 25 participants without a history of TBI. The interviews were recorded and transcribed verbatim. The statements were assigned to inductively and deductively derived categories relevant to the HRQoL of children and adolescents after TBI and compared with those of individuals without a history of TBI. RESULTS: The HRQoL of children and adolescents after TBI tended to display both structural and content-related differences, independently of TBI severity, on several HRQoL dimensions, in contrast to the comparison group. For example, participants after TBI reported a broader range of negative emotions (such as worry, sadness, shame, and guilt), permanent physical impairments, felt that they were treated differently from others, and perceived cognitive limitations. CONCLUSIONS: The results of this qualitative study identified HRQoL dimensions that are relevant to children and adolescents after TBI and underlined the need for the development of a disease-specific instrument.

Efficacy, Tolerability, and Retention of Antiseizure Medications in PRRT2-Associated Infantile Epilepsy.

Background and Objectives: Pathogenic variants in PRRT2, encoding for the proline-rich transmembrane protein 2, were identified as the main cause of self-limiting sporadic and familial infantile epilepsy. Reported data on treatment response to antiseizure medications (ASMs) in defined monogenic epilepsies are limited. The aim of this study was to evaluate the treatment response of ASMs in children with monogenic PRRT2-associated infantile epilepsy. Methods: A multicenter, retrospective, cross-sectional cohort study was conducted according to the Strengthening the Reporting of Observational Studies in Epidemiology criteria. Inclusion criteria were occurrence of infantile seizures and genetic diagnosis of likely pathogenic/pathogenic PRRT2 variants. Results: Treatment response data from 52 individuals with PRRT2-associated infantile epilepsy with a total of 79 treatments (defined as each use of an ASM in an individual) were analyzed. Ninety-six percent (50/52) of all individuals received ASMs. Levetiracetam (LEV), oxcarbazepine (OXC), valproate (VPA), and phenobarbital (PB) were most frequently administered. Sodium channel blockers were used in 22 individuals and resulted in seizure freedom in all but 1 child, who showed a reduction of more than 50% in seizure frequency. By contrast, treatment with LEV was associated with worsening of seizure activity in 2/25 (8%) treatments and no effect in 10/25 (40%) of treatments. LEV was rated significantly less effective also compared with VPA and PB. The retention rate for LEV was significantly lower compared with all aforementioned ASMs. No severe adverse events were reported, and no discontinuation of treatment was reported because of side effects. Discussion: In conclusion, a favorable effect of most ASMs, especially sodium channel blockers such as carbamezepine and OXC, was observed, whereas the efficacy and the retention rate of LEV was lower in PRRT2-associated childhood epilepsy. Tolerability in these young children was good for all ASMs reported in the cohort. Classification of Evidence: This study provides Class IV evidence that in individuals with PRRT2-associated infantile epilepsy, sodium channel blockers are associated with reduced seizure frequency but levetiracetam is not.

Biallelic variants in ADAMTS15 cause a novel form of distal arthrogryposis.

PURPOSE: We aimed to identify the underlying genetic cause for a novel form of distal arthrogryposis. METHODS: Rare variant family-based genomics, exome sequencing, and disease-specific panel sequencing were used to detect ADAMTS15 variants in affected individuals. Adamts15 expression was analyzed at the single-cell level during murine embryogenesis. Expression patterns were characterized using in situ hybridization and RNAscope. RESULTS: We identified homozygous rare variant alleles of ADAMTS15 in 5 affected individuals from 4 unrelated consanguineous families presenting with congenital flexion contractures of the interphalangeal joints and hypoplastic or absent palmar creases. Radiographic investigations showed physiological interphalangeal joint morphology. Additional features included knee, Achilles tendon, and toe contractures, spinal stiffness, scoliosis, and orthodontic abnormalities. Analysis of mouse whole-embryo single-cell sequencing data revealed a tightly regulated Adamts15 expression in the limb mesenchyme between embryonic stages E11.5 and E15.0. A perimuscular and peritendinous expression was evident in in situ hybridization in the developing mouse limb. In accordance, RNAscope analysis detected a significant coexpression with Osr1, but not with markers for skeletal muscle or joint formation. CONCLUSION: In aggregate, our findings provide evidence that rare biallelic recessive trait variants in ADAMTS15 cause a novel autosomal recessive connective tissue disorder, resulting in a distal arthrogryposis syndrome.

Progressive frontal intraosseous lipoma: Detection of the mosaic AKT1 variant discloses Proteus syndrome.

Proteus syndrome is a very rare disorder with progressive, asymmetrical, and disproportionate overgrowth of body parts with a highly variable phenotype. It is associated with mosaicism for the recurrent heterozygous somatic gain-of-function variant c.49G>A (p.Glu17Lys) in the protein kinase AKT1. We report on a girl with a progressive intraosseous lipoma of the frontal bone and additional, nonspecific features including mild developmental delay, strabism, and a limbal dermoid of the left eye. She did not fulfill the criteria for a clinical diagnosis of Proteus syndrome. However, mutation analysis of AKT1 in a lipoma biopsy revealed this specific activating variant. Several cases of progressive intraosseous lipoma of the frontal bone have been reported in the literature. Only in two of these observations, a tentative diagnosis of Proteus syndrome was made, based on additional clinical features, although without molecular-genetic verification. We conclude that oligosymptomatic Proteus syndrome should be considered in progressive intraosseous lipoma, as recognition of this diagnosis has relevant implications for genetic counseling and opens novel treatment options with AKT1 inhibitors rather than surgical procedures.

Loss-of-function variants in DNM1 cause a specific form of developmental and epileptic encephalopathy only in biallelic state.

BACKGROUND: Developmental and epileptic encephalopathies (DEEs) represent a group of severe neurological disorders characterised by an onset of refractory seizures during infancy or early childhood accompanied by psychomotor developmental delay or regression. DEEs are genetically heterogeneous with, to date, more than 80 different genetic subtypes including DEE31 caused by heterozygous missense variants in DNM1. METHODS: We performed a detailed clinical characterisation of two unrelated patients with DEE and used whole-exome sequencing to identify causative variants in these individuals. The identified variants were tested for cosegregation in the respective families. RESULTS: We excluded pathogenic variants in known, DEE-associated genes. We identified homozygous nonsense variants, c.97C>T; p.(Gln33*) in family 1 and c.850C>T; p.(Gln284*) in family 2, in the DNM1 gene, indicating that biallelic, loss-of-function pathogenic variants in DNM1 cause DEE. CONCLUSION: Our finding that homozygous, loss-of-function variants in DNM1 cause DEE expands the spectrum of pathogenic variants in DNM1. All parents who were heterozygous carriers of the identified loss-of-function variants were healthy and did not show any clinical symptoms, indicating that the type of mutation in DNM1 determines the pattern of inheritance.

Psychometric Properties of the German Version of the Rivermead Post-Concussion Symptoms Questionnaire in Adolescents after Traumatic Brain Injury and Their Proxies.

The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) assesses post-concussion symptoms (PCS) after traumatic brain injury (TBI). The current study examines the applicability of self-report and proxy versions of the German RPQ in adolescents (13-17 years) after TBI. We investigated reliability and validity on the total and scale score level. Construct validity was investigated by correlations with the Post-Concussion Symptoms Inventory (PCSI-SR13), Generalized Anxiety Disorder Scale 7 (GAD-7), and Patient Health Questionnaire 9 (PHQ-9) and by hypothesis testing regarding individuals' characteristics. Intraclass correlation coefficients (ICC) assessed adolescent-proxy agreement. In total, 148 adolescents after TBI and 147 proxies completed the RPQ. Cronbach's α (0.81-0.91) and McDonald's ω (0.84-0.95) indicated good internal consistency. The three-factor structure outperformed the unidimensional model. The RPQ was strongly correlated with the PCSI-SR13 (self-report: r = 0.80; proxy: r = 0.75) and moderately-strongly with GAD-7 and PHQ-9 (self-report: r = 0.36, r = 0.35; proxy: r = 0.53, r = 0.62). Adolescent-proxy agreement was fair (ICC [2,1] = 0.44, CI95% [0.41, 0.47]). Overall, both self-report and proxy assessment forms of the German RPQ are suitable for application in adolescents after TBI. As proxy ratings tend to underestimate PCS, self-reports are preferable for evaluations. Only if a patient is unable to answer, a proxy should be used as a surrogate.