Errors in the Spontaneous Language of Survivors of Pediatric Cerebellar Tumors

Pediatric cerebellar tumor survivors may present with spontaneous language impairments following treatment, but the nature of these impairments is still largely unclear. A recent study by Svaldi et al. (Cerebellum. 23:523-44, 2023) found a broad spectrum of spontaneous language impairments irrespective of postoperative cerebellar mutism syndrome (pCMS) diagnosis in long-term pediatric cerebellar tumor survivors. Several patients presented with reduced grammatical or lexical accuracy, but a detailed error analysis was lacking. The present study builds on this study by 1) investigating the error types in spontaneous language across three language processing levels in the same participant group and 2) by evaluating the possible association between pCMS and the processing nature of the language impairments. Spontaneous language was evaluated in 12 long-term survivors of pediatric cerebellar tumors (M(SD) = 4;8(3;8) years), of whom five were diagnosed with pCMS. The proportion of occurrence of each error type was compared between each patient and five matched controls using individual case statistics, reflecting (lexico-)phonological (i.e., phonemic paraphasias), lexical-semantic (e.g., empty speech) and morphosyntactic processing (e.g., verb inflection errors). Each patient showed a significantly higher proportion of at least one of the included error types across all language processing levels. A higher proportion of general-all-purpose verbs and inaccurate verb inflection were the most common errors and respectively reflected lexical-semantic and morphosyntactic processing. Additional language impairments were identified using the error analysis that were not identified with standard language measures and psycholinguistic analysis, suggesting the added diagnostic value of error analyses.