Yuichi Oka

Subthalamic nucleus stimulation for Parkinson disease with severe medication-induced hallucinations or delusions.

OBJECT Subthalamic nucleus deep brain stimulation (STN DBS) improves cardinal motor symptoms of Parkinson disease (PD) and reduces antiparkinsonian medication. Therefore, STN DBS seems to be well indicated for patients suffering from medication-induced psychotic symptoms. However, there are few available data dealing with the effect of STN DBS in this kind of patient. The authors studied the effect of STN DBS in patients with PD and severe medication-induced hallucinations or delusions. METHODS The authors retrospectively reviewed the clinical course of 10 patients who suffered from severe medication-induced hallucinations or delusions and underwent bilateral STN DBS. Patients whose preoperative thought disorder score (Unified Parkinsons Disease Rating Scale Part I, item 2) was 3 or more were enrolled in this study. All patients underwent cognitive function examination and brain perfusion SPECT preoperatively to exclude dementia with Lewy bodies. RESULTS Subthalamic nucleus DBS yielded significant improvement of motor function in all patients. In 8 patients, psychotic symptoms completely disappeared with significant reduction of dopaminergic medication. In 2 patients, hallucinations and delusions deteriorated immediately after surgery despite complete withdrawal of antiparkinsonian medication. However, these psychotic symptoms completely disappeared after a few months with administration of antipsychotics, and no recurrence was observed afterward in either patient. CONCLUSIONS Subthalamic nucleus DBS is a good treatment option for patients with PD who are suffering severe medication-induced hallucinations or delusion. However, vigilance is needed, because temporary deterioration of psychotic symptoms may occur after surgery.

Apraxia of eyelid opening after subthalamic deep brain stimulation may be caused by reduction of levodopa.

Apraxia of eyelid opening (ALO) is an infrequent side effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinsons disease (PD). However, the pathogenesis of ALO after STN DBS is not well understood. We report on two patients who suffered from disabling ALO after bilateral STN DBS. Their ALO improved by resuming the levodopa medication that had been discontinued after the surgery. Although ALO after STN DBS is considered as an adverse effect of STN stimulation, postoperative modification of dopaminergic medication may be a cause of ALO after STN DBS.

Temporary deterioration of executive function after subthalamic deep brain stimulation in Parkinson's disease.

OBJECTIVE Selective impairment of executive function has been shown in Parkinsons Disease (PD) patients undergoing Deep Brain Stimulation (DBS) of the Subthalamic Nucleus (STN). However, some patients experience difficulties in daily life, such as dissension in interpersonal relationships or a loss of lifestyle balance, in the short term after surgery. Our hypothesis is that these difficulties might be related to executive dysfunction. To elucidate the involvement of executive dysfunction in these difficulties, we assessed motor and executive function in the short term and long term after surgery. METHODS We examined motor function and executive function in 30 patients who underwent bilateral STN-DBS for medically refractory PD. Patients were evaluated for executive function 1 month before surgery, 1 month after surgery, and 12 months after surgery using the Trail Making Test (TMT), the Modified Stroop Color Word Interference Test (MST) and tests of Verbal Fluency (VF). RESULTS TMT-B, TMT (B/A), MST-B, VF-phonemic and VF-semantic scores were significantly poorer 1 month after STN-DBS. TMT-B, TMT (B/A) and VF-phonemic recovered to preoperative levels by 12 months after surgery. A reduction in dopaminergic medication 1 month after surgery was significantly correlated with deterioration of TMT (B/A). CONCLUSION Temporary deterioration of executive function may occur in the short term after STN-DBS, whereas motor function is usually improved. PD patients undergoing STN-DBS should be managed during this period to better predict temporary executive dysfunction. Excessive reduction of dopaminergic medication after surgery might, at least in part, result in this deterioration of executive function.

Predictive factors affecting early deterioration of axial symptoms after subthalamic nucleus stimulation in Parkinson's disease.

Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment option for medically refractory Parkinsons disease (PD). However, some patients show deterioration of axial symptoms within a short time after surgery. We studied 43 patients who underwent bilateral STN-DBS and investigated predictive factors affecting early deterioration of axial symptoms. Among 43 patients, 16 patients showed obvious deterioration of axial symptoms within three years of surgery. Multiple logistic regression analysis indicated that the significant independent variables related to early deterioration of axial symptoms were rapidly progressive short duration of the disease and advanced age at surgery. These results suggest that patients with rapidly progressing PD, who need early surgical intervention, tend to show early deterioration of axial symptoms after STN-DBS.

Validity of single tract microelectrode recording in subthalamic nucleus stimulation.

In surgery for subthalamic nucleus (STN) deep brain stimulation (DBS), precise implantation of the lead into the STN is essential. Physiological refinement with microelectrode recording (MER) is the gold standard for identifying STN. We studied single tract MER findings and surgical outcomes and verified our surgical method using single tract MER. The number of trajectories in MER and the final position of lead placement were retrospectively analyzed in 440 sides of STN DBS in 221 patients. Bilateral STN DBS yielded marked improvement in the motor score, dyskinesia/fluctuation score, and reduced requirement of dopaminergic medication in this series. The number of trajectories required to obtain sufficient activity of the STN was one in 79.0%, two in 18.2%, and three or more in 2.5% of 440 sides. In 92 sides requiring altered trajectory, the final direction of trajectory movement was posterior in 73.9%, anterior in 13.0%, lateral in 5.4%, and medial in 4.3%. In 18 patients, posterior moves were required due to significant brain shift with intracranial air caused by outflow of CSF during the second side procedure. Sufficient STN activity is obtained with minimum trajectories by proper targeting and precise interpretation of MER findings even in the single tract method. Anterior–posterior moves rather than medial–lateral moves should be attempted first in cases with insufficient recording of STN activity.

Upregulation of the P2X7 receptor after cryogenic injury to rat brain.

The P2X7 receptor is a member of the P2X family of adenosine triphosphate-gated ion channels. It is expressed in the central nervous system and is associated with several pathological conditions. Here, we examined the expression of P2X7 with immunohistochemistry after cryogenic injury to the rat cortex. One day after cortical cryogenic injury, P2X7 immunoreactive cells were increased in regions surrounding the cold-injured site. These P2X7 positive cells were also immunoreactive for OX42, a microglial marker, and possessed the short, thick processes that are characteristic of activated microglia. These results suggest that the increased local expression of P2X7 may be associated with microglial activation, contributing to detrimental and/or protective functions around the cold-injured site.

Identification of novel SNORD118 mutations in seven patients with leukoencephalopathy with brain calcifications and cysts

Leukoencephalopathy with brain calcifications and cysts (LCC) is neuroradiologically characterized by leukoencephalopathy, intracranial calcification, and cysts. Coats plus syndrome is also characterized by the same neuroradiological findings together with defects in retinal vascular development. Indeed, LCC and Coats plus were originally considered to be the same clinical entity termed cerebroretinal microangiopathy with calcifications and cysts, but evidence suggests that they are genetically distinct. Mutations in CTS telomere maintenance complex component 1 (CTC1) and small nucleolar RNA, C/D box 118 (SNORD118) genes have been found to cause Coats plus and LCC, respectively.

Corrective surgery for Parkinson's disease (PD) deformity following Deep Brain Stimulation (DBS) - Is DBS a last resort?

Spinal deformity related to Parkinson’s disease (PD) is severe. Due to reported high complication rate, some authors reported that PD deformity with no neurological symptoms should not undergo surgery and also reported deep brain stimulation (DBS) should be considered instead of corrective surgery for their postural disorders. However, almost of previous reports did not consider spino-pelvic parameters. If spino-pelvic harmonization is achieved even in PD deformity surgery, there is a possibility of obtaining much better surgical results. We analyzed the surgical results of PD deformity surgery focused in spino-pelvic parameters and we here report minimum two years follow up of PD deformity surgery. Patients and methods Six patients with Parkinson’s deformity following DBS underwent corrective surgery were enrolled this study. Mean age at surgery was 67.8 y.o. and there were 3 men and 3 women. Pelvic incidence, Pelvic tilt, SVA, lumbar lordosis, thoracic lordosis, JOA score were analyzed pre-, and post-surgery. Results