Novel pathogenic VPS13A gene mutations in Japanese patients with chorea-acanthocytosis.

OBJECTIVE: To identify mutations in vacuolar protein sorting 13A (VPS13A) for Japanese patients with suspected chorea-acanthocytosis (ChAc). METHODS: We performed a comprehensive mutation screen, including sequencing and copy number variation (CNV) analysis of the VPS13A gene, and chorein Western blotting of erythrocyte ghosts. As the results of the analysis, 17 patients were molecularly diagnosed with ChAc. In addition, we investigated the distribution of VPS13A gene mutations and clinical symptoms in a total of 39 molecularly diagnosed Japanese patients with ChAc, including 22 previously reported cases. RESULTS: We identified 11 novel pathogenic mutations, including 1 novel CNV. Excluding 5 patients with the unknown symptoms, 97.1% of patients displayed various neuropsychiatric symptoms or forms of cognitive dysfunction during the course of disease. The patients carrying the 2 major mutations representing over half of the mutations, exon 60-61 deletion and exon 37 c.4411C>T (R1471X), were localized in western Japan. CONCLUSIONS: We identified 13 different mutations in VPS13A, including 11 novel mutations, and verified the clinical manifestations in 39 Japanese patients with ChAc.

The role of the thalamus in recovery from tactile extinction and crossed tactile extinction.

A 68-year-old man had a cerebral infarction affecting the right parietal lobe, right insula, and the left prefrontal region. On admission, left hand tactile extinction was noted when the hands were placed both in anatomical and crossed positions, but was noted only in crossed positions from day 20 and later. Five months later, the patient developed another cerebral infarction in the right thalamus, and left hand tactile extinction was again seen both in the anatomical and crossed positions. Our findings suggest that the thalamus was involved in the recovery from the tactile extinction in anatomical positions.

[Comparison and examination of stereotactic surgical complications in movement disorders].

The purpose of the present study was to determine exactly the incidence of surgical complications in patients for whom MRI-targeted, microelectrode recording (MER)-guided implantation of deep brain stimulation (DBS) or radiofrequency (RF)-coagulation surgery was performed. Between January, 1998 and September, 2002, a total of 110 stereotactic surgeries for movement disorders (57 RF-coagulations and 53 implantations of DBS) were performed. We investigated the type and number of complications for each of the following surgical targets; globus pallidus, thalamus, and subthalamic nucleus (STN). Twenty-four neurological complications in 22 patients and 16 radiological/instrumental complications in 16 patients were verified among the 110 surgeries. Among the neurological complications, hemiparesis and mental disturbances were observed at a high rate, while intraoperative hemorrhage frequently occurred among the radiological/instrumental complications. The rate of neurological and radiological/instrumental complications for each of the stereotactic targets; the globus pallidus, thalamus, and STN-targeted surgeries, was 32.4%, 16.7%, 18.8% and 16.2%, 20.0%, 12.5%, respectively. The reason for the high rate of intraoperative hemorrhage may be associated with technical problems resulting from the penetration of vessels by needles, as well as the destruction of small vessels due to heat ablation. As for the mental disturbances, visual hallucinations (VH) occurred a high rate, especially during STN-DBS. Peduncular damage and/or L-dopa toxicity due to STN-DBS may have been associated with VH, so the STN-DBS may therefore be thought to change the threshold of stimulus-induced hallucinations. We also found that the procedures for DBS surgery, especially in younger patients, have a lower risk of complication, while, on the other hand, coagulation surgery for elderly patients is accompanied by of high risks, from the standpoint of surgical complications.

Hemorrhagic complication of stereotactic surgery in patients with movement disorders.

OBJECT: Small, asymptomatic hemorrhages are easier to detect during stereotactic surgery when magnetic resonance (MR) imaging is used for targeting rather than when traditional approaches, such as ventriculography, are performed with contrast material. In the present study the authors examined the actual incidence of intraoperative hemorrhages in patients with movement disorders who had undergone MR imaging-targeted surgery, microelectrode recording (MER)-guided implantation of deep brain stimulation (DBS) electrodes, or radiofrequency-induced coagulation surgery performed. METHODS: Ninety-six consecutive patients underwent a total of 116 stereotactic operations for movement disorders (57 operations for radiofrequency-induced coagulation and 59 for DBS electrode implantation) between January 1998 and November 2002. The authors investigated the correlation between hemorrhages and other factors including the location of the hemorrhage and the type of surgery performed. Postoperative computerized tomography scans demonstrated the occurrence of intraoperative hemorrhages at 12 locations during 11 procedures (9.5% of all procedures). Nine hemorrhages occurred during 57 coagulation operations (15.8%). Within this group, the frequency of hemorrhages was highest during thalamotomy (five [21.7%] of 23 procedures) and lower during pallidotomy (four [11.8%] of 34 procedures). In contrast, only two intraventricular hemorrhages developed during 59 operations in which DBS electrodes were implanted (3.4%). In no case was hemorrhage detected in the main DBS target, that is, the subthalamic nucleus. CONCLUSIONS: When small, asymptomatic hemorrhages were included in the estimation, the actual rate of hemorrhage was higher than that previously reported. Judging from the incidence of hemorrhage during coagulation and DBS surgeries, the authors suggest that the heat induced by coagulation may play a larger role than microelectrode penetration in the development of hemorrhage.