A case of a girl with poor school achievement, ataxia and neurological deterioration

The patient was born uneventfully at 40 weeks gestation and weighed 3000 g. She was able to walk alone at the age of 12 months and to speak several words at 10 months. Her developmental milestones were normal until the age of 6 years. After she entered elementary school, she had difficulty keeping up with school studies. At the age of 9, her school achievement became worse. In addition, she showed slurred speech and was prone to falls. Incontinence, drooling and memory disturbance were apparent at the age 13 years, and thus she was referred to our clinic. On examination, she showed no abnormalities in the chest and abdomen, which included no hepatosplenomegaly. Neurological examination revealed alternating exotropia, scanning speech, bilateral pes excavatus, increased deep tendon reflexes in the lower extremities and no pathologic reflexes. She also had finger oscillation in the finger-to-finger test and the finger-to-nose test, truncal instability during one-leg standing and a positive Romberg test. We interpreted these findings as cerebellar symptoms and funiculus posterior symptoms of the spinal cord. MRI showed atrophy of the cerebellar vermis (Fig. 1). She was diagnosed as having spinocerebellar degeneration transiently and received a close follow-up in the out-patient clinic. Her electroencephalography turned abnormal at the age of 14, and she was administered an anticonvulsant although no seizure attacks occurred. At age 15, her cerebellar symptom aggravated, deep tendon reflexes increased markedly, and she suffered a dystonic posture. She showed athetotic movements in her neck and upper extremities and disturbance of vertical eye movements. She was admitted to our clinic again. Laboratory examination revealed no abnormalities in complete blood count, chemistry, WBC, CSF, urine and lysosomal enzyme assay, including arylsulfatase A, betagalactosidase, beta-hexosaminidase, alpha-mannosidase, alpha-galactosidase, beta-glucronidase, alpha-glucosidase and beta-glucosidase. We detected no CAG repeat in the DNA analysis. Motor nerve conduction velocity was 51.7 m/sec in the median nerve and 41.9 m/sec in the peroneal nerve. Fundoscopy showed no abnormalities. Her intelligence quotient was 40 by the Wechsler Intelligence Scale for Children – Revised. After discharge from the hospital, her illness progressed relentlessly. She lost the ability to walk independently at the age of 16. Generalized tonic-clonic convulsions commenced. At age 17, she had affective incontinence and dysphasia and underwent gastrostomy. Her neurological symptoms, such as involuntary movements and pyramidal tract signs, aggravated further, and she became bedridden. At age 19, she received a tracheostomy owing to the sticking of sputum to her throat and frequent pneumonia. She expired at the age of 20 years.