1 – Serviço de Neurologia Pediátrica, 2 – Serviço de Neurorradiologia, Hospital Dona Estefânia, Centro Hospitalar Lisboa
– II Reunião Ibérica de Neurorradiologia, Lisboa 17-19 Out 2013 (Comunicação oral)
Introduction - Tubulin related disorders are rare neurological disorders with a wide spectrum of clinical presentation. After assembling, tubulin heterodimers form microtubules responsible for axon guidance and maintenance, neuronal migration and differentiation. The resulting nervous system malformations include different types of cortical malformations, defects in commissural fibber tracts, basal ganglia dysmorphism and degeneration of motor and sensory axons. Several mutations have been identified in the genes that encode α- and β-tubulin isotypes. Despite the rarity of these disorders, some phenotype-genotype correlation is possible. We aim to describe four patients with basal ganglia fusion identified in cranial MRI.
Results - Patient 1, female, currently 30 months old; neurodevelopmental delay and strabismus noted in the first year of life; refractory focal epilepsy disclosed by a statusepilepticus at age of 22 months old; diskinetictetraparesis. Patient 2, male, currently 5 years old; neonatal seizures controlled by monotherapy. Neurodevelopmental delay and autistic features. Dystonic postures in the upper limbs. Patient 3, male, currently 3 years old; ventricular asymmetry diagnosed in prenatal ultrasounds; neurodevelopmental delay and left hemiparesis noted in the second year of life. Patient 4, male, currently 12 years old; sickle cell anemia diagnosed by the age of 9 months old, never had stroke events. Neurodevelopmental delay evolving to cognitive deficit. Left hemiparesis (upper limb predominance). The four patients have cranial MRI’s disclosing caudate and lenticular nucleus fusion (uni or bilateral), rendering hard to identify the anterior harm of the internal capsule, as well as dysmorphic or hypoplasic corpus calosum. Patients 1 and 2 have subependymal heterotopies and focal polymicrogiral pattern. Patients 1 and 4 also have cerebellar and brain stem malformations, with a variable expression.
Conclusions - Despite the wide spectrum of neurological phenotypes associated to tubulin related disorders, some neuroradiological findings provide diagnostic clues. Our patients all have distinct clinical presentations but similar neuroadiological findings. The mutations in TUBB3 gene (a β-tubulin isotype) are typically associated to fusion of caudate and putamen nucleus and dysmorphy of corpus calosum; however, a disorganized gyral pattern polymicrogyria or agyria-pachigyria) and cerebellar malformations have also been described in these disorder. The genetic study for TUBB3 gene is in progress in the four patients
Palavras-chave: basal ganglia fusion, neuroradiology