Tiefe Hirnstimulation bei refraktärer Zwangsstörung

Subject randomized to this arm are initially "OFF" DBS (Deep Brain Stimulation) prior to the open label period for 16 weeks and then "ON" DBS for the next 16 weeks. This is then followed by an open-label period of DBS stimulation.

Deep brain stimulation is a surgery where bilateral electrodes are precisely inserted to specific brain targets affected by a disease state, and electrical stimulation is applied to achieve symptom relief. DBS is a reversible and adjustable treatment option and is now a preferred alternative to neurosurgical ablation. Sham Stimulation=DBS OFF

Deep brain stimulation is a surgery where bilateral electrodes are precisely inserted to specific brain targets affected by a disease state, and electrical stimulation is applied to achieve symptom relief. DBS is a reversible and adjustable treatment option and is now a preferred alternative to neurosurgical ablation. Therapeutic Stimulation= DBS ON

Subjects randomized to this arm are initially "ON" DBS prior to the open label period for 16 weeks and then "OFF" DBS for the next 16 weeks. This is followed by an open-label stimulation period.

Deep brain stimulation is a surgery where bilateral electrodes are precisely inserted to specific brain targets affected by a disease state, and electrical stimulation is applied to achieve symptom relief. DBS is a reversible and adjustable treatment option and is now a preferred alternative to neurosurgical ablation. Sham Stimulation=DBS OFF

Deep brain stimulation is a surgery where bilateral electrodes are precisely inserted to specific brain targets affected by a disease state, and electrical stimulation is applied to achieve symptom relief. DBS is a reversible and adjustable treatment option and is now a preferred alternative to neurosurgical ablation. Therapeutic Stimulation= DBS ON

All participants will transition to an open label stimulation phase for chronic therapy after the cross-over portion of this trial

Deep brain stimulation is a surgery where bilateral electrodes are precisely inserted to specific brain targets affected by a disease state, and electrical stimulation is applied to achieve symptom relief. DBS is a reversible and adjustable treatment option and is now a preferred alternative to neurosurgical ablation. Therapeutic Stimulation= DBS ON

Assessment of the efficacy of amSTN stimulation on OCD symptoms. This will be assessed by the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Possible scores range from 0-5 where lower scores indicate better outcome.

Safety will be assessed with cumulative serious adverse event rate that will be Frequency at which AEs occur that are directly related to the study device.

Hamilton Scale for Anxiety. A rating scale developed to measure the severity of anxiety symptoms. The scale consists of 14 items, each defined by a series of symptoms, and measures both psychic anxiety (mental agitation and psychological distress) and semantic anxiety (physical complaints related to anxiety). Each item is scored on a scale of 0 (not present) to 4 (severe), with a total score ranger of 0-56, where 17 indicates mild severity, 18-24 mild to moderate severity and 25-30 moderate to severe.

Hamilton Depression Rating Scale (HAM-D). A 21-item version of the HAM-D that includes 4 items intended to subtype the depression. The HAM-D is originally a 17 item questionnaire pertaining to symptoms of depression experienced over the past week. The patients score is determined using the first 17 questions. A score of 0-7 is generally accepted to be within the normal range (or in clinical remission), while a score of 20 or higher (indicating at least moderate severity) is usually required for entry into a clinical trial. Scoring on each question varies.

Brief Psychiatric Rating Scale (BPRS). An assessment that assesses the level of the following symptoms; somatic concern, anxiety, emotional withdrawal, conceptual disorganization, guilt feelings, tension, mannerisms and posturing, grandiosity, depressive mood, hostility, suspiciousness, hallucinatory behavior, motor retardation, uncooperativeness, unusual thought content, blunted affect, excitement, disorientation. Items are scored on a 1(not present) to 7 (extremely severe) scale. It is based on the clinicians interview with the patients and observations of the patient behavior over the previous 2-3 days.

Clinical Global Inventory- Severity scale is used to measure this outcome (CGI-S). This is a 3-item observer-rated scale that measures illness severity (CGI-S). The CGI is rated on a 7-point scale, with the severity of illness scale using a range of responses from 1 (normal) through 7 (amongst the most severely ill patients).

Mini-Mental State Examination (MMSE). A questionnaire comprised of 11 questions that is used by doctors and other health professionals to check for cognitive impairment. It is typically used to see if you have problems with ones thinking or communication. It can check for problems with understanding and amnesia. The MMSE checks 6 areas of mental ability including; knowing when one is (date and place), attention and concentration, short-term memory (recall), language skills, visual and spatial relationship between objects, ability to understand and follow instructions. The assessment is scored out of 30. A score of 25 or higher is normal, and score below 24 could indicate cognitive impairment.

The rate of neural activity will be measured via Hz.

Amplitude of neural activity will be measured via microamps.

A unit of measurement used to quantify the relationship between the temporal structures of signals in the brain, and are often used to study functional connectivity in neuroscience. This outcome measure will be measured in units of 0-2π.

Cross-frequency coupling (CFC) is a neuroscience measure that describes the statistical relationship between the frequency, amplitude, or phase of two different frequency bands in the brain. Its a type of neural oscillatory coupling that is been studied in the context of brain health and disease. This data point will be measured via the modulation index.