In order to clarify the clinical and genetic features of SCA6, we retrospectively analyzed 140 patients. We observed an inverse correlation between the age of onset and the length of the expanded allele, and also between the age of onset and the sum of CAG repeats in the normal and the expanded alleles. The ages of onset of four homozygous patients correlated better with the sum of CAG repeats in both alleles rather than with the expanded allele calculated from heterozygous SCA6 subjects. Clinically, unsteadiness of gait was the main initial symptom, followed by vertigo and oscillopsia, and cerebellar signs were detected in nearly 100% of the patients. In contrast, extracerebellar signs were relatively mild and infrequent. The results of neuro-otological examination performed in 22 patients suggested the purely cerebellar abnormalities of ocular movements in nature. There was a close relationship between downbeat positioning nystagmus (DPN) and positioning vertigo, which became more common in the later stage. We conclude that total number of CAG repeat-units in both alleles is a good parameter for assessment of age of onset in SCA6 including homozygous patients. In addition, clinical and neuro-otological examinations suggested that SCA6 is a disease with predominantly cerebellar dysfunction.

Background: The aim of the present study was to estimate the prevalence of impaired cognitive function and Alzheimer's disease (AD) in diabetic subjects from Japan. Methods: In the present study, 386 Japanese diabetic subjects aged more than 50 years were initially screened with the 'brief screening test' for AD, and were diagnosed with AD and vascular dementia (VaD) according to the criteria of the NINCDS-ADRDA and the NINDS-AIREN. We compared the prevalence of dementia in diabetic patients with that in ordinary subjects, and analyzed the association of the status of diabetes with dementia including AD and VaD. Results: Forty-six (11.9%) patients were diagnosed with dementia, including 13 (3.4%) patients with AD and nine (2.3%) patients with VaD. Of the 221 subjects aged more than 65 years, 39 (17.6%) patients had dementia, including 13 (5.9%) patients with AD and eight (3.6%) patients with VaD. Compared with ordinary subjects, the prevalence of dementia in the present study was more frequent than the prevalence of dementia for the general population in almost each age group examined. There was also a greater prevalence of AD and VaD in subjects aged over 65 years in the present study. In the present study, AD subjects had significantly higher levels of fasting plasma glucose (FPG; 247.5 1 116.3 mg/dL; P < 0.05) and glycosylated hemoglobin (HbA1c; 8.8 1 1.9%; P < 0.01) compared with nondemented subjects. In AD patients, the odds ratios of FPG and HbA1c were also significantly higher (1.02 and 2.07, respectively; both P < 0.01).Conclusion: The present study shows that diabetes can be associated with impaired cognitive function, particularly AD, in Japanese subjects.

A 36-year-old Japanese woman complained of right hypochondralgia followed by ascites. Paracentesis showed a turbid, straw-colored sterile exudate. Computed tomography and magnetic resonance imaging of the abdomen revealed a left periuteric mass and ascites. The mass and ascites spontaneously regressed within a month with no specific treatment. Later, after the patient had been discharged from hospital, immunofluorescence antibody titers for Chlamydia trachomatis were successfully determined using stored ascitic fluid and serum. Though the number of cases of Chlamydia trachomatis peritonitis has increased, few cases with ascites have been reported, and spontaneous regression of the ascites is also rare. (Internal Medicine 31: 835-839, 1992)

The white matter lesions in a patient with late adult onset dentatorubropallidoluysian atrophy (DRPLA) were studied in detail by MRI using the fluid attenuation inversion recovery (FLAIR) technique. The patient was a 60 year old woman with a family history of DRPLA, in whom the number of CAG repeats in the DRPLA gene on chromosome 12 was expanded to 59 (normal allele 10). In addition to atrophy of the cerebral cortex, cerebellum, and pontomesencephalic tegmentum, the cerebral white matter and a part of the white matter tracts within the brainstem showed prominent high signal intensities on FLAIR images. These MR findings suggest that, in addition to the degeneration of the dentatorubral and pallidoluysian systems, the pathological process extends to the white matter in DRPLA. This could be important for diVerentiating DRPLA from other clinically similar diseases such as Machado-Joseph disease or Huntington's disease. (J Neurol Neurosurg Psychiatry 1998;65:396-399)

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant spinocerebellar degeneration, associated with extended repeats of the trinucleotide CAG in the ATXN2 gene on the long arm of chromosome 12. Magnetic resonance imaging (MRI) of SCA2 showed significant atrophies of the brainstem, middle cerebellar peduncles, and cerebellum. We report two genetically proven SCA2 patients who showed hypertrophy of the inferior olivary nuclei on proton density- and T2-weighted MRI. This pattern has never been reported in patients with SCA1, SCA3, or SCA6, and may make it possible to differentiate SCA2 from other hereditary spinocerebellar ataxias.