The “crab sign”: an imaging feature of spinocerebellar ataxia type 48

Cocozza, Sirio; Pontillo, Giuseppe; Michele, G. De; Perillo, Teresa; Guerriero, Elvira; Ugga, Lorenzo; Salvatore, Elena; Galatolo, Daniele; Riso, Vittorio; Saccà, Francesco; Quarantelli, Mario; Brunetti, Arturo

doi:10.1007/s00234-020-02427-7

Cited by 15 publications

(16 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2). This finding has already been described in other degenerative ataxias, such as ataxia with oculomotor apraxia (AOA) [20], SPG7 [21] and SCA48 [22]. Pieperhoff et al (2020) [23] reported constant dentate hyperintensity in T2-weighted images in twenty SCA14 and nine AOA2 patients.…”

Section: Discussionsupporting

confidence: 68%

Episodic ataxia and severe infantile phenotype in spinocerebellar ataxia type 14: expansion of the phenotype and novel mutations

et al. 2021

Self Cite

View full text Add to dashboard Cite

Introduction Spinocerebellar ataxia type 14 (SCA14) is a dominantly inherited neurological disorder characterized by slowly progressive cerebellar ataxia. SCA14 is caused by mutations in PRKCG, a gene encoding protein kinase C gamma (PKCγ), a master regulator of Purkinje cells development. Methods We performed next-generation sequencing targeted resequencing panel encompassing 273 ataxia genes in 358 patients with genetically undiagnosed ataxia. Results We identified fourteen patients in ten families harboring nine pathogenic heterozygous variants in PRKCG, seven of which were novel. We encountered four patients with not previously described phenotypes: one with episodic ataxia, one with a spastic paraparesis dominating her clinical manifestations, and two children with an unusually severe phenotype. Conclusions Our study broadens the genetic and clinical spectrum of SCA14.

show abstract

Section: Discussionsupporting

confidence: 68%

Episodic ataxia and severe infantile phenotype in spinocerebellar ataxia type 14: expansion of the phenotype and novel mutations

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…57 Brain T2 hyperintensity with corresponding T1 hypointensity has been proposed to indicate myelin degradation. 58 In SCA-PRKCG, 59 Signal alterations confined to the dentate nucleus have recently been described in few genetic (ataxia) movement disorders [60][61][62] but have not been systematically investigated and T2 hyperintensity of the dentate nucleus is currently not considered a characteristic imaging finding in neurodegenerative ataxia. 63,64 Although it is possibly not specific, our results suggest the T2 hyperintense dentate sign as a supporting criterion for PRKCG variant classification in cases with typical phenotype.…”

Section: Discussionmentioning

confidence: 99%

Spinocerebellar ataxia type 14: refining clinicogenetic diagnosis in a rare adult‐onset disorder

Schmitz‐Hübsch

Lux

Bauer

et al. 2021

Ann Clin Transl Neurol

View full text Add to dashboard Cite

Objectives Genetic variant classification is a challenge in rare adult‐onset disorders as in SCA‐PRKCG (prior spinocerebellar ataxia type 14) with mostly private conventional mutations and nonspecific phenotype. We here propose a refined approach for clinicogenetic diagnosis by including protein modeling and provide for confirmed SCA‐PRKCG a comprehensive phenotype description from a German multi‐center cohort, including standardized 3D MR imaging. Methods This cross‐sectional study prospectively obtained neurological, neuropsychological, and brain imaging data in 33 PRKCG variant carriers. Protein modeling was added as a classification criterion in variants of uncertain significance (VUS). Results Our sample included 25 cases confirmed as SCA‐PRKCG (14 variants, thereof seven novel variants) and eight carriers of variants assigned as VUS (four variants) or benign/likely benign (two variants). Phenotype in SCA‐PRKCG included slowly progressive ataxia (onset at 4–50 years), preceded in some by early‐onset nonprogressive symptoms. Ataxia was often combined with action myoclonus, dystonia, or mild cognitive‐affective disturbance. Inspection of brain MRI revealed nonprogressive cerebellar atrophy. As a novel finding, a previously not described T2 hyperintense dentate nucleus was seen in all SCA‐PRKCG cases but in none of the controls. Interpretation In this largest cohort to date, SCA‐PRKCG was characterized as a slowly progressive cerebellar syndrome with some clinical and imaging features suggestive of a developmental disorder. The observed non‐ataxia movement disorders and cognitive‐affective disturbance may well be attributed to cerebellar pathology. Protein modeling emerged as a valuable diagnostic tool for variant classification and the newly described T2 hyperintense dentate sign could serve as a supportive diagnostic marker of SCA‐PRKCG.

show abstract

“…It is also interesting to note that, although a relatively limited literature is to date available, peculiar magnetic resonance imaging findings could help in distinguishing between the 2 conditions. In particular, although the presence of cerebellar atrophy is significant and constant in both diseases, a T2‐weighted hyperintense signal extending from the dentate nuclei to the middle cerebellar peduncles, coupled to atrophy of the most posterior cerebellar regions, has been recently reported in 90% of SCA48 patients, 5 whereas no data on its possible presence are available yet in SCAR16.…”

mentioning

confidence: 99%