Oral Symptoms and Bone Observations in Odonto-Hypophosphatasia

Hypophosphatasia (HPP) is an inherited skeletal disease caused by mutation of the gene encoding tissue non-specific alkaline phosphatase (TNSALP). Odonto-HPP is well known as the mildest of HPP. The manifestations involve only the teeth, such as premature primary teeth exfoliation caused by reduction of alveolar bone, enlarged dental pulp chamber, and dental defects. We report a case of a 9-years-old boy who developed HPP. He was observed from the primary dentition to the mixed dentition period. At initial presentation at our hospital, he had multiple premature exfoliation of primary teeth and reduction of the alveolar bone. HPP was suspected due to the low level of ALP activity in serum, his oral manifestation, and dental history. He was referred to a physician for the final diagnosis. Therefore his compound heterozygote mutations, c.1559 delT (T/delT) and c.407G > A (G/A), were found in TNSALP and he diagnosed with odonto-HPP. Even though these mutations were reported as being involved in odonto-HPP, his mineral densities tended to be lower than that of his age. It is therefore necessary to investigate the bone mineralization level in odonto-HPP without other bone symptoms. Moreover, ongoing enzyme-replacement therapy in odonto-HPP might improve dental abnormality and bone disorders.

Factors affecting early decline of executive function after subthalamic nucleus stimulation in Parkinson’s disease

Subthalamic nucleus deep brain stimulation (STN DBS) is an effective treatment for medically refractory Parkinson’s disease (PD). However, a minority of patients develop cognitive problems, particularly a decline of executive function in the early period after STN DBS. Although this problem is usually transient, it may cause social maladjustment. We investigated factors affecting early decline of executive function after STN-DBS. Fifty-seven patients whose preoperative global cognitive screening was normal (MMSE score;28 or more) were enrolled in this study. Executive function was evaluated with the Trail-Making Test (TMT) preoperatively and 1-month after surgery. We considered a patient to have decline in executive function if the TMT (B-A) was prolonged more than 30 seconds after STN DBS. Among 57 patients, 25 patients were categorized as having decline of executive function. Univariate analysis revealed that high preoperative UPDRS III motor score in the medication-off period and a depressive state evaluated with BDI-II correlated significantly with decline in executive function. Multiple logistic regression analysis revealed that the only significant independent variable related to early decline of executive function was the preoperative BDI-II score. Postoperative factors such as active contact location or dopaminergic medication reduction had no relation with the decline of executive function. Even in cognitively well-selected patients, STN DBS causes early decline in executive function in a significant number of patients. Preoperative simple cognitive screening alone could not predict early decline in executive function. More detailed neuropsychological evaluation, including mood status, should be undertaken before surgery.