Clinical phenotypes of infantile onset CACNA1A-related disorder.

BACKGROUND: CACNA1A-related disorders present with persistent progressive and non-progressive cerebellar ataxia and paroxysmal events: epileptic seizures and non-epileptic attacks. These phenotypes overlap and co-exist in the majority of patients. OBJECTIVE: To describe phenotypes in infantile onset CACNA1A-related disorder and to explore intra-familial variations and genotype-phenotype correlations. MATERIAL AND METHODS: This study was a multicenter international collaboration. A retrospective chart review of CACNA1A patients was performed. Clinical, radiological, and genetic data were collected and analyzed in 47 patients with infantile-onset disorder. RESULTS: Paroxysmal non-epileptic events (PNEE) were observed in 68% of infants, with paroxysmal tonic upward gaze (PTU) noticed in 47% of infants. Congenital cerebellar ataxia (CCA) was diagnosed in 51% of patients including four patients with developmental delay and only one neurological sign. PNEEs were found in 63% of patients at follow-up, with episodic ataxia (EA) in 40% of the sample. Cerebellar ataxia was found in 58% of the patients at follow-up. Four patients had epilepsy in infancy and nine in childhood. Seven infants had febrile convulsions, three of which developed epilepsy later; all three patients had CCA. Cognitive difficulties were demonstrated in 70% of the children. Cerebellar atrophy was found in only one infant but was depicted in 64% of MRIs after age two. CONCLUSIONS: Nearly all of the infants had CCA, PNEE or both. Cognitive difficulties were frequent and appeared to be associated with CCA. Epilepsy was more frequent after age two. Febrile convulsions in association with CCA may indicate risk of epilepsy in later childhood. Brain MRI was normal in infancy. There were no genotype-phenotype correlations found.

Sensory Tricks in Pantothenate Kinase-Associated Neurodegeneration: Video-Analysis of 43 Patients.

BACKGROUND: Sensory tricks are a classic hallmark of primary dystonia and result in specific maneuvers that temporarily improve dystonic posture or movement. Pantothenate kinase-associated neurodegeneration (PKAN) is a progressive neurological disorder that courses with prominent dystonia. Although previously described, sensory tricks are considered to be rare in PKAN. CASES: We reviewed videotaped motor examinations of 43 genetically confirmed patients with PKAN in order to identify and classify sensory tricks. All patients presented some feature of dystonia. Eighteen (42%) had one or more well-structured sensory tricks. Twelve different sensory tricks were identified, eight typical and four atypical (forcible motor): four in cervical dystonia, four in limb dystonia, three in oromandibular dystonia, and one in blepharospasm. A characteristic forcible motor maneuver for oromandibular dystonia (previously described as the "mantis sign") was present in 8 patients. CONCLUSIONS: Sensory tricks are common in PKAN, particularly for oromandibular dystonia. The mantis sign may be a useful clue for the diagnosis.