Changes in Midline Tremor and Gait Following Deep Brain Stimulation for Essential Tremor

Background: Essential tremor (ET) is a common movement disorder characterized by kinetic and postural tremor in the upper extremities and frequently in the midline. Persons with ET often also exhibit gait ataxia. Previous studies have observed associations between midline tremor severity and gait ataxia in persons with ET, suggesting a common pathophysiology distinct from that of upper extremity tremor. However, a causal link between midline tremor and gait impairment has not been established. Methods: We investigated tremor and gait in 24 persons with ET before and after implantation of unilateral deep brain stimulation into the ventralis intermedius nucleus of the thalamus. Results: Stimulation significantly improved tremor in the targeted upper extremity and midline. However, gait was unaffected at the cohort level. Furthermore, improvement in midline tremor was not significantly associated with gait improvement. Discussion: These findings revealed that midline tremor and gait impairment may be dissociable in persons with ET

Changes in Motor-related Cortical Activity Following Deep Brain Stimulation for Parkinson's Disease Detected by Functional Near Infrared Spectroscopy: A Pilot Study

It remains unclear how deep brain stimulation (DBS) modulates the global neuronal network involving cortical activity. We aimed to evaluate changes in cortical activity in six (two men; four women) patients with Parkinson's disease (PD) who underwent unilateral globus pallidus interna DBS surgery using a multi-channel near infrared spectroscopy (NIRS) system. As five of the patients were right-handed, DBS was performed on the left in these five cases. The mean age was 66.8 ± 4.0 years. The unified Parkinson's disease rating scale (UPDRS) motor scores were evaluated at baseline and 1- and 6-month follow-up. Task-related NIRS experiments applying the block design were performed at baseline and one-month follow-up. The mean of the total UPDRS motor score was 48.5 ± 11.1 in the off-medication state preoperatively. Postoperatively, total UPDRS motor scores improved to 26.8 ± 16.6 (p < 0.05) and 22.2 ± 8.6 (p < 0.05) at 1- and 6-month follow-up, respectively. A task-related NIRS experiment showed a postoperative increase in the cortical activity of the prefrontal cortex comparable to the preoperative state. To our knowledge, this is the first study to use a multi-channel NIRS system for PD patients treated with DBS. In this pilot study, we showed changes in motor-associated cortical activities following DBS surgery. Therapeutic DBS was concluded to have promoted the underlying neuronal network remodeling

Impact of an Interdisciplinary Deep Brain Stimulation Screening Model on Post-Surgical Complications in Essential Tremor Patients.

To investigate the relationship of our interdisciplinary screening process on post-operative unintended hospitalizations and quality of life.There are currently no standardized criteria for selection of appropriate Deep Brain Stimulation candidates and little hard data exists to support the use of any singular method.An Essential Tremor cohort was selected from our institutional Deep Brain Stimulation database. The interdisciplinary model utilized seven specialties who pre-operatively screened all potential Deep Brain Stimulation candidates. Concerns for surgery raised by each specialty were documented and classified as none, minor, or major. Charts were reviewed to identify unintended hospitalizations and quality of life measurements at 1 year post-surgery.Eighty-six percent (44/51) of the potential screened candidates were approved for Deep Brain Stimulation. Eight (18%) patients had an unintended hospitalization during the follow-up period. Patients with minor or major concerns raised by any specialty service had significantly more unintended hospitalizations when compared to patients without concerns (75% vs. 25%, p < 0.005). The rate of hospitalization revealed a direct relationship to the "level of concern"; ranging from 100% if major concerns, 42% if minor concerns, and 7% if no concerns raised, p = 0.001. Quality of life scores significantly worsened in patients with unintended hospitalizations at 6 (p = 0.046) and 12 months (p = 0.027) when compared to baseline scores. No significant differences in tremor scores between unintended and non-unintended hospitalizations were observed.The number and level of concerns raised during interdisciplinary Deep Brain Stimulation screenings were significantly related to unintended hospitalizations and to a reduced quality of life. The interdisciplinary evaluation may help to stratify risk for these complications. However, data should be interpreted with caution due to the limitations of our study. Further prospective comparative and larger studies are required to confirm our results

Correlation between the number of concerns and unintended hospitalizations (P < 0.001).

<p>Correlation between the number of concerns and unintended hospitalizations (P < 0.001).</p

Relationship between DBS-related and DBS-unrelated hospitalizations.

<p>Relationship between DBS-related and DBS-unrelated hospitalizations.</p

Primary reasons of reported unintended hospitalizations following DBS surgery.

<p>Primary reasons of reported unintended hospitalizations following DBS surgery.</p

The correlation between concerns and unintended hospitalization.

<p>The correlation between concerns and unintended hospitalization.</p

Issues cited as contributing to reservations reported by each service during screening.

<p>Issues cited as contributing to reservations reported by each service during screening.</p