Case report: oculomotor apraxia in ataxia telangiectasia

Introduction: Ataxia telangiectasia (AT) belongs to the autosomal recessive cerebellar ataxias and is due to a mutation on the chromosome 11q22.23 in the ATM gene, which is necessary for the recognition and repair of the DNA damage. A progressive cerebellar ataxia, an oculomotor apraxia, an immunodeficiency, ocular telangiectasias, and malignancies characterize AT.

Case Report: A 7-year-old girl, conspicuous at the age of 2 years, because of a psychomotor retardation. Besides a slight clumsiness, the motor development was unremarkable. She suffered from frequent infections, especially otitis media. At the age of 7 years, after an acute otitis media with mastoiditis, the girl complained about dizziness without nausea, but with clear ataxia and an oculomotor disorder (having difficulties in looking active at objects). In addition, she had daytime enuresis more often than before, and sometimes she seemed like absent, but she answered when addressed. At the clinical examination, the ocular motility was free and moved easily by vestibule ocular reflex, but slowly by guidance. Saccades initiation was delayed and of slow velocity. There was also slowed smooth pursuit. There were no compensating head movements. There were short periods of ocular flutter. The Halmagyi head impulse test was normal on both sides. Moderated stance ataxia, trunk ataxia, and clear gate ataxia. In the finger sequence test, she seemed insecure, but without clear dysmetria. Moderate dysdiadochokinesia. No telangiectasias. MRT of the scull: Clear atrophy of both cerebellum hemispheres as also of the cerebellum worm, pronounced basal cisterns. Laboratory: α-fetoprotein elevated (115 ng/mL). IgG subclasses 2, 3, and 4 lowered. Analysis of cells: For the age pronounced little mitogenic reaction of the lymphocytes, compatible with a cellular or combined Immunodeficiency. Blockage of the proliferating cells in the G2-phase of the first cell cycle after irradiation with 1.5 Gy. The below average cell growth rate and the high G2/Gf-Ratio (after irradiation) are consisted with the suspected ataxia telangiectasia.