Fragile X syndrome. Clinical, electroencephalographic and neuroimaging characteristics.
We studied 11 patients (9 males) with cytogenetic diagnosis of fragile X syndrome (FXS) with the purpose of investigating the neural circuitry involved in this condition. The ages ranged from 8 to 19. All the individuals presented large ears, elongated faces and autistic features. Ten patients had severe mental retardation. Attention disorder was found in 10 individuals. Electroencephalographic recordings were abnormal in 6 of 10 patients examined, showing focal epileptiform discharges predominantly in frontal and parietal areas. All patients underwent magnetic resonance imaging studies which were abnormal in 8 of them. The most important abnormalities were reduction of the cerebellar vermis and enlargement of the IV ventricle. Single photon emission computerized tomography (SPECT) was performed in 7 patients and was abnormal in all of them, the most frequent finding being a hypoperfusion of the inferior of the frontal lobes. Based on the clinical picture, neuropsychological findings and functional and structural imaging studies we suggest that FXS presents with a dysfunction involving a large area of the central nervous system: cerebellum-basal frontal regions-parietal lobes. The literature points to a disturbance involving the same neural circuitry in patients with autism.
Departamento de Neurologia, Faculdade de Ciências Médicas (FCM) da Universidade Estadual de Campinas (UNICAMP), Brasil.
M M
MM
Guerreiro
E E
EE
Camargo
M
M
Kato
A P
AP
Marques-de-Faria
S M
SM
Ciasca
C A
CA
Guerreiro
J R
JR
Netto
M V
MV
Moura-Ribeiro
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology; D002648:Child; D004569:Electroencephalography; D005260:Female; D005600:Fragile X Syndrome / Q000175:diagnosis* / Q000523:psychology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D015899:Tomography, Emission-Computed, Single-Photon