Characteristics of number transcoding errors of Chinese- versus English-speaking Alzheimer's disease patients.

Number processing disorder is an acquired deficit in mathematical skills commonly observed in Alzheimer's disease (AD), usually as a consequence of neurological dysfunction. Common impairments include syntactic errors (800012 instead of 8012) and intrusion errors (8 thousand and 12 instead of eight thousand and twelve) in number transcoding tasks. This study aimed to understand the characterization of AD-related number processing disorder within an alphabetic language (English) and ideographical language (Chinese), and to investigate the differences between alphabetic and ideographic language processing. Chinese-speaking AD patients were hypothesized to make significantly more intrusion errors than English-speaking ones, due to the ideographical nature of both Chinese characters and Arabic numbers. A simplified number transcoding test derived from EC301 battery was administered to AD patients. Chinese-speaking AD patients made significantly more intrusion errors (p = 0.001) than English speakers. This demonstrates that number processing in an alphabetic language such as English does not function in the same manner as in Chinese. The impaired inhibition capability likely contributes to such observations due to its competitive lexical representation in brain for Chinese speakers.

Small Incidental Pheochromocytoma Presenting With Normal or Borderline High 24-hour Urine Fractionated Metanephrines.

A 73-year-old man was found to have a 2-cm lipid-poor right adrenal incidentaloma on computed tomography imaging for hematuria. Twenty-four-hour urine metanephrine was 1.1-fold elevated, then normal on repeat measurement. Paired with the second urine collection, plasma metanephrine measured by liquid chromatography tandem mass spectrometry after a 30-minute supine rest was 3.3-fold elevated. Plasma normetanephrine was 1.2-fold elevated. The 24-hour urine catecholamines and normetanephrine, measured twice, were normal. He received low-dose phenoxybenzamine and underwent successful resection of right pheochromocytoma. Postoperatively, both plasma metanephrine and normetanephrine levels normalized, using an age-appropriate upper reference limit for plasma normetanephrine. Patients who harbor small lipid-poor adrenal incidentalomas have a relatively high risk (>5%) of having pheochromocytoma, indistinguishable from adenomas or carcinomas on computed tomography scan. In such cases when 24-hour urine fractionated metanephrines are normal, plasma free metanephrines measured by liquid chromatography tandem mass spectrometry under optimal sampling conditions that are 2-fold or more elevated confirm the diagnosis of pheochromocytoma. Preoperative alpha blockade followed by surgical resection is then appropriate, rather than continued monitoring with repeat urine measurements.

Megacolon as an atypical presentation of cervical myelopathy.

A 61-year-old gentleman was admitted with progressive symptoms of cervical myelopathy. An MRI performed showed severe compression from C3-6 with cord signal changes. He was offered surgical intervention but the operation had to be delayed because of worsening abdominal distension. X-rays performed showed a severely dilated colon measuring >12 cm. A CT did not show any obstructive cause. He was managed conservatively for more than 2 weeks but did not improve. As his symptoms continued to worsen, a decision was made to proceed with a C3-6 posterior decompression and fusion, despite the theoretical risk of bacterial translocation predisposing him to infection. Postoperatively, he improved significantly. Interestingly, his abdominal distention had also improved and a repeat X-ray showed complete resolution of the megacolon. In conclusion, this case highlights that long standing cervical cord compression may be a cause for an "atonic" megacolon. Once all causes of intestinal obstruction are excluded, surgical decompression of the cervical stenosis should proceed, and need not be delayed for the megacolon resolve spontaneously.

Characteristics of Chinese-English bilingual dyslexia in right occipito-temporal lesion.

Current literature suggests that right hemisphere lesions produce predominant spatial-related dyslexic error in English speakers. However, little is known regarding such lesions in Chinese speakers. In this paper, we describe the dyslexic characteristics of a Chinese-English bilingual patient with a right posterior cortical lesion. He was found to have profound spatial-related errors during his English word reading, in both real and non-words. During Chinese word reading, there was significantly less error compared to English, probably due to the ideographic nature of the Chinese language. He was also found to commit phonological-like visual errors in English, characterized by error responses that were visually similar to the actual word. There was no significant difference in visual errors during English word reading compared with Chinese. In general, our patient's performance in both languages appears to be consistent with the current literature on right posterior hemisphere lesions. Additionally, his performance also likely suggests that the right posterior cortical region participates in the visual analysis of orthographical word representation, both in ideographical and alphabetic languages, at least from a bilingual perspective. Future studies should further examine the role of the right posterior region in initial visual analysis of both languages.