# Functional Neurosurgery Essentials — GCMD Library living collection

Updated: n/a · 13 episodes · 93 cited statements

## Episodes
### Core Concepts and Techniques
- [Functional Neurosurgery Explained: 1mm Matters in DBS | Amr Moursi posted on the topic](https://library.globalcastmd.com/watch/functional-neurosurgery-explained-1mm-matters-in-dbs-amr-moursi-posted-on-the-topic-13614) — article · [machine version](https://library.globalcastmd.com/watch/functional-neurosurgery-explained-1mm-matters-in-dbs-amr-moursi-posted-on-the-topic-13614.md)
- [Finding 1mm in the Brain | Functional Neurosurgery Explained – Episode 1](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636) — video · [machine version](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636.md)
- [The Geometry of Precision | Frames in DBS – Functional Neurosurgery Explained – Episode 2](https://library.globalcastmd.com/watch/the-geometry-of-precision-frames-in-dbs-functional-neurosurgery-explained-episode-2-13635) — video · [machine version](https://library.globalcastmd.com/watch/the-geometry-of-precision-frames-in-dbs-functional-neurosurgery-explained-episode-2-13635.md)
- [Neuromodulation vs. Neuroablation | Functional Neurosurgery Explained – Episode 3](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634) — video · [machine version](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634.md)
- [How Electrical Stimulation Changes Brain Circuits | Functional Neurosurgery Explained – Episode 4](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633) — video · [machine version](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633.md)
- [The Surgical Window: Why Timing Matters as Much as Skill | Functional Surgery Minute #05](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627) — video · 2:03 · [machine version](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627.md)

### Movement Disorders
- [3 Eras of Parkinson's Surgery: Destroy → Modulate → Respond](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628) — video · 2:08 · [machine version](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628.md)
- [Awake DBS: Why We Test the Patient in Real Time | Functional Surgery Minute #03](https://library.globalcastmd.com/watch/awake-dbs-why-we-test-the-patient-in-real-time-functional-surgery-minute-03-13630) — video · 1:38 · [machine version](https://library.globalcastmd.com/watch/awake-dbs-why-we-test-the-patient-in-real-time-functional-surgery-minute-03-13630.md)
- [Decoding DBS Target Selection in Parkinson's Disease | Functional Neurosurgery Explained – Episode 5](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632) — video · [machine version](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632.md)
- [Movement Disorder Exam Questions for Neurosurgeons | MCQs, Concepts and Key Topics](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623) — video · 9:40 · [machine version](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623.md)

### Epilepsy Surgery
- [Epilepsy Surgery Outcomes Explained 🧠](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625) — video · 2:16 · [machine version](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625.md)
- [Epilepsy Exam Questions for Neurosurgeons | MCQs, Concepts and Key Topics - part 1 out 3](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622) — video · [machine version](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622.md)

### Advanced Techniques
- [How LITT Reaches Deep Brain Tumours Through a 3-mm Hole | Functional Surgery Minute #04](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629) — video · 2:18 · [machine version](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629.md)

## Chapters
- [0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0) Introduction and Structure (Ep 12)
- [0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0) Definitions and Referral Thresholds (Ep 12)
- [0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0) Seizure Semiology and Localisation (Ep 12)
- [0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0) Named Epilepsy Syndromes (Ep 12)
- [0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0) EEG Patterns and Electrode Types (Ep 12)
- [0:00](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=0) Introduction to Functional Neurosurgery Examination Topics (Ep 10)
- [1:24](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=84) Symptom Response to Deep Brain Stimulation (Ep 10)
- [2:23](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=143) Target Selection for Deep Brain Stimulation (Ep 10)
- [4:12](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=252) Patient Selection Criteria and Levodopa Challenge (Ep 10)
- [6:15](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=375) Anatomical Side Effects During Macro-Stimulation (Ep 10)
- [8:24](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=504) Dopamine Transporter Scan and Summary (Ep 10)
- [0:00](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=0) Historical context and development of the Engel classification (Ep 11)
- [0:36](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=36) The four Engel classes explained (Ep 11)
- [1:37](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=97) Summary and key concept (Ep 11)
- [0:00](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=0) Introduction: The Surgical Window Concept (Ep 6)
- [0:28](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=28) Lumbar Disc Prolapse: Conservative Management and Missed Windows (Ep 6)
- [1:02](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=62) Parkinson's Disease: The Window for Deep Brain Stimulation (Ep 6)
- [1:31](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=91) Conclusion: Judgment and Timing in Neurosurgery (Ep 6)
- [0:00](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=0) Era 1: The Ablation Era (Ep 7)
- [0:44](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=44) Era 2: The Deep Brain Stimulation Era (Ep 7)
- [1:21](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=81) Era 3: The Adaptive Era (Ep 7)
- [0:00](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=0) Traditional Open Approach to Deep Brain Tumors (Ep 13)
- [0:47](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=47) LITT Technique and Real-Time MRI Guidance (Ep 13)
- [1:22](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=82) Clinical Outcomes and Expanding Indications (Ep 13)
- [1:45](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=105) Paradigm Shift in Surgical Access (Ep 13)
- [0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0) Introduction and Framework Overview (Ep 9)
- [0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0) Introduction and Episode Overview (Ep 5)
- [0:00](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634?t=0) Series introduction and episode overview (Ep 4)
- [0:00](https://library.globalcastmd.com/watch/the-geometry-of-precision-frames-in-dbs-functional-neurosurgery-explained-episode-2-13635?t=0) Introduction to Stereotactic Frames in DBS (Ep 3)
- [0:00](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636?t=0) Introduction to stereotactic targeting in functional neurosurgery (Ep 2)

## Statements
Every statement is attributed, typed, and timestamped; the link is the citation.
- Epilepsy surgery is one of the hardest functional topics in the exam (opinion) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- The best way to understand epilepsy surgery is to follow the structure: Diagnose, Investigate, Operate (opinion) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Two seizures are required to diagnose epilepsy (guideline) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Two failed appropriate drugs are required before referring for surgical assessment (guideline) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Absence epilepsy has a characteristic 3 Hz spike-and-wave pattern on EEG (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Lennox-Gastaut syndrome has a slow 1.5-2.5 Hz spike-and-wave pattern on EEG (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Juvenile myoclonic epilepsy has a 4-6 Hz polyspike-and-wave pattern on EEG (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- West syndrome is characterized by spasms, hypsarrhythmia, and developmental regression (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Hypothalamic hamartoma presents with gelastic seizures and precocious puberty (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Seizure classification includes focal, generalised, and unknown onset types (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Clinical seizure sequence can help localise and lateralise the seizure focus (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Normal posterior alpha rhythm is a recognized EEG pattern (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Frontal beta activity is a recognized EEG pattern (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Hypsarrhythmia is a recognized pathological EEG pattern (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Burst suppression is a recognized pathological EEG pattern (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Depth or stereo EEG and subdural grids are electrode types used in epilepsy evaluation (clinical) [Ep 12 · 0:00](https://library.globalcastmd.com/watch/epilepsy-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-part-1-out-3-13622?t=0)
- Functional neurosurgery is under-taught in basic training and most units don't do much of it (opinion) [Ep 10 · 0:29](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=29)
- Examiner expectations for functional neurosurgery are low and the basics are all you need (opinion) [Ep 10 · 0:36](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=36)
- Functional neurosurgery splits into three exam topics: movement disorders, pain surgery, and epilepsy (clinical) [Ep 10 · 0:49](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=49)
- Parkinson's disease has 4 cardinal features and bradykinesia is mandatory for the diagnosis (clinical) [Ep 10 · 1:28](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=88)
- Tremor responds best to deep brain stimulation in Parkinson's disease (clinical) [Ep 10 · 1:35](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=95)
- Gait freezing, speech and cognition respond poorly to deep brain stimulation (clinical) [Ep 10 · 1:44](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=104)
- Cognition can be worsened by deep brain stimulation (clinical) [Ep 10 · 1:48](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=108)
- Balance, speech, and postural instability all respond poorly to deep brain stimulation (clinical) [Ep 10 · 2:11](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=131)
- Subthalamic nucleus is the first choice target for deep brain stimulation in Parkinson's disease (guideline) [Ep 10 · 2:25](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=145)
- Globus pallidus internus is the second choice target for deep brain stimulation in Parkinson's disease (guideline) [Ep 10 · 2:29](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=149)
- When dyskinesia dominates, the globus pallidus internus is preferred because it smooths dyskinesia directly (clinical) [Ep 10 · 2:40](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=160)
- When tremor dominates, the ventral intermediate nucleus of the thalamus is the tremor target (clinical) [Ep 10 · 2:48](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=168)
- The anterior limb of the internal capsule is an obsessive compulsive disorder target, not a Parkinson's target (clinical) [Ep 10 · 3:19](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=199)
- Inclusion criteria for DBS include disease over 5 years, a meaningful levodopa response, disabling fluctuations, or refractory tremor (guideline) [Ep 10 · 4:12](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=252)
- Exclusion criteria for DBS include dementia, untreated depression or psychosis, and atypical Parkinsonism like progressive supranuclear palsy and multiple system atrophy (guideline) [Ep 10 · 4:29](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=269)
- The levodopa challenge predicts the response to deep brain stimulation, not severity (clinical) [Ep 10 · 4:51](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=291)
- Stimulation of the subthalamic nucleus roughly reproduces the patient's best medication on state, so a good levodopa response predicts a good stimulation response (clinical) [Ep 10 · 4:59](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=299)
- Atypical Parkinsonism doesn't respond to deep brain stimulation and is a contraindication (clinical) [Ep 10 · 5:48](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=348)
- At the subthalamic nucleus, medial spread hits the 3rd cranial nerve and red nucleus, giving diplopia (clinical) [Ep 10 · 6:22](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=382)
- At the subthalamic nucleus, lateral spread hits the internal capsule, giving contralateral twitching and dysarthria (clinical) [Ep 10 · 6:32](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=392)
- At the globus pallidus internus, ventral spread hits the optic tract, giving phosphenes (flashes of light) (clinical) [Ep 10 · 6:39](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=399)
- At the globus pallidus internus, posteromedial spread hits the capsule, giving muscle contraction (clinical) [Ep 10 · 6:48](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=408)
- The side effect tells you where the electrode is, and you correct by moving away from the structure you're hitting (clinical) [Ep 10 · 6:53](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=413)
- Motor fibers run in the internal capsule just lateral to the subthalamic nucleus (clinical) [Ep 10 · 7:09](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=429)
- Twitching during STN stimulation means you're too lateral and should move medially away from the capsule (clinical) [Ep 10 · 7:18](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=438)
- Reducing voltage just shrinks your therapeutic window and doesn't fix electrode position (clinical) [Ep 10 · 7:37](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=457)
- Red nucleus diplopia is the medial side effect from spread toward the 3rd cranial nerve and red nucleus (clinical) [Ep 10 · 7:50](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=470)
- The optic tract is ventral to the globus pallidus internus, so ventral spread produces flashes of light (phosphenes) (clinical) [Ep 10 · 8:10](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=490)
- The dopamine transporter scan separates Parkinson's from essential tremor and drug-induced tremor, showing reduced uptake in the posterior putamen (clinical) [Ep 10 · 8:30](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=510)
- The dopamine transporter scan does not distinguish Parkinson's from atypical Parkinsonism (clinical) [Ep 10 · 8:39](https://library.globalcastmd.com/watch/movement-disorder-exam-questions-for-neurosurgeons-mcqs-concepts-and-key-topics-13623?t=519)
- In neurosurgery, the brain and spine do not forgive timing errors. (clinical) [Ep 6 · 0:08](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=8)
- Timing is the most important lesson in neurosurgery. (opinion) [Ep 6 · 0:14](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=14)
- Operating too early in the surgical window represents unnecessary risk. (clinical) [Ep 6 · 0:23](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=23)
- Operating too late in the surgical window represents a lost opportunity. (clinical) [Ep 6 · 0:26](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=26)
- Most lumbar disc prolapse cases resolve with rest and medication without requiring surgery. (clinical) [Ep 6 · 0:28](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=28)
- When medication fails for lumbar disc prolapse, surgery can help and the surgical window is open. (clinical) [Ep 6 · 0:36](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=36)
- When lumbar disc prolapse patients present late with established foot weakness or lost bladder control, surgery can stop further damage but cannot restore what is already lost. (clinical) [Ep 6 · 0:42](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=42)
- In Parkinson's disease, medication works well at first, then tremor becomes uncontrolled with wearing-off phenomena that disable daily life. (clinical) [Ep 6 · 1:02](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=62)
- The optimal window for deep brain stimulation in Parkinson's disease is when medication fails with uncontrolled tremor and wearing-off phenomena that disable daily life. (clinical) [Ep 6 · 1:09](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=69)
- Deep brain stimulation performed at the right moment in Parkinson's disease changes lives. (clinical) [Ep 6 · 1:14](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=74)
- If deep brain stimulation is delayed until the Parkinson's patient no longer responds to dopamine or cognition declines, the same operation that could have helped will cause harm. (clinical) [Ep 6 · 1:20](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=80)
- Damage to the brain and spine is often permanent. (clinical) [Ep 6 · 1:31](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=91)
- Neurosurgery requires more than technical skill; it requires good judgment and honest decisions about timing. (opinion) [Ep 6 · 1:36](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=96)
- Good neurosurgical judgment includes having the honesty to say the surgical moment has passed, hasn't yet arrived, or is not indicated. (clinical) [Ep 6 · 1:45](https://library.globalcastmd.com/watch/the-surgical-window-why-timing-matters-as-much-as-skill-functional-surgery-minute-05-13627?t=105)
- DBS is not a reversible lesion (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- High-frequency stimulation disrupts pathological beta oscillations (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- Pathological beta oscillations cause bradykinesia and rigidity (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- The hyperdirect pathway carries antidromic spikes back to motor cortex within milliseconds (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- The connectivity profile of the active contact matters more than its coordinates (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- Dorsolateral STN and ventromedial STN produce completely different clinical outcomes (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- Chronic stimulation induces synaptic plasticity and neurochemical change (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- Dystonia takes months to respond to DBS (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- DBS mechanism operates through three layers: fast electrical effects, network remodelling, and plasticity (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- In DBS programming, you are programming axons not grey matter (clinical) [Ep 5 · 0:00](https://library.globalcastmd.com/watch/how-electrical-stimulation-changes-brain-circuits-functional-neurosurgery-explained-episode-4-13633?t=0)
- More than thirty percent of all DBS failures trace back to one mistake—the wrong patient, or the wrong target, chosen long before the operation even began. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- Target selection is the only step in DBS that cannot be corrected after surgery. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- The TARGET framework consists of six components that function as gates, not as a score: True diagnosis, Anatomy of symptoms, Response to levodopa, Goal, Evaluation of the brain, and Red lines. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- Atypical parkinsonism conditions to distinguish from true Parkinson's include MSA, PSP, Lewy body dementia, and Corticobasal Degeneration. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- The thirty percent levodopa response threshold is a meaningful criterion for DBS candidacy. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- DBS is a biological amplifier, not a generator. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- The TARGET framework can solve to STN, GPi, or Vim depending on patient characteristics. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- Cognitive reserve and mood are factors that determine whether to operate at all and which target is more forgiving when the brain is vulnerable. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- The EARLYSTIM trial changed the conversation about timing of DBS surgery. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- Both operating too late and operating too early are mistakes in DBS timing. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- There are six absolute red lines that collapse the entire TARGET equation to zero. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- A confident 'no' protects the patient far more than a hesitant 'yes' in DBS decision-making. (opinion) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- A five-evaluation multidisciplinary workup feeds every target decision. (clinical) [Ep 9 · 0:00](https://library.globalcastmd.com/watch/decoding-dbs-target-selection-in-parkinson-s-disease-functional-neurosurgery-explained-episode-5-13632?t=0)
- Stereotactic frames convert the head into a stable 3D coordinate system to place DBS electrodes within 1 mm of the target. (clinical) [Ep 3 · 0:00](https://library.globalcastmd.com/watch/the-geometry-of-precision-frames-in-dbs-functional-neurosurgery-explained-episode-2-13635?t=0)
- The concept of stereotaxis began with Horsley & Clarke and was later adapted for human use. (clinical) [Ep 3 · 0:00](https://library.globalcastmd.com/watch/the-geometry-of-precision-frames-in-dbs-functional-neurosurgery-explained-episode-2-13635?t=0)
- Arc-radius frames work on the principle that the target sits at the centre of the arc. (clinical) [Ep 3 · 0:00](https://library.globalcastmd.com/watch/the-geometry-of-precision-frames-in-dbs-functional-neurosurgery-explained-episode-2-13635?t=0)
- Frame-based systems remain the reference standard in DBS despite the availability of robotic and frameless systems. (opinion) [Ep 3 · 0:00](https://library.globalcastmd.com/watch/the-geometry-of-precision-frames-in-dbs-functional-neurosurgery-explained-episode-2-13635?t=0)
- Brain surgeons must hit deep targets only a few millimeters wide, buried more than 10 cm inside the brain, with less than 1 mm error. — Amr Moursi (clinical) [Ep 2 · 0:00](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636?t=0)
- 1 mm of error can change a patient's outcome in DBS and other functional procedures. — Amr Moursi (clinical) [Ep 2 · 0:00](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636?t=0)
- Functional neurosurgeons turn anatomy into a 3D coordinate system (X, Y, Z). — Amr Moursi (clinical) [Ep 2 · 0:00](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636?t=0)
- Skull landmarks and surface anatomy failed for deep targets. — Amr Moursi (clinical) [Ep 2 · 0:00](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636?t=0)
- Internal brain landmarks like the AC-PC line are important for targeting. — Amr Moursi (clinical) [Ep 2 · 0:00](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636?t=0)
- Stereotactic atlases and MRI work together in modern targeting. — Amr Moursi (clinical) [Ep 2 · 0:00](https://library.globalcastmd.com/watch/finding-1mm-in-the-brain-functional-neurosurgery-explained-episode-1-13636?t=0)

## Host summaries
Recaps by a host of what the experts said — not the host's own clinical position.
- Thalamotomy in the VIM silences tremor. — The host summarizing a resource [Ep 7 · 0:23](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=23)
- Pallidotomy in the GPi eases rigidity, slowness, and dyskinesias. — The host summarizing a resource [Ep 7 · 0:27](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=27)
- Ablative lesions are permanent and cannot be undone or adjusted as the disease progresses. — The host summarizing a resource [Ep 7 · 0:33](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=33)
- In 1987 in Grenoble, Benabbi switched on high frequency stimulation above 100 hertz, and the tremor vanished instantly, reversibly. — The host summarizing a resource [Ep 7 · 0:48](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=48)
- Stimulating the STN produced the same benefit as destroying it, so the benefit was never about the tissue. — The host summarizing a resource [Ep 7 · 1:01](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=61)
- With DBS, the structure stays intact and the surgeon can adjust amplitude, frequency, pulse width, and treat both sides safely. — The host summarizing a resource [Ep 7 · 1:08](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=68)
- The early STEM trial confirmed DBS beat medical therapy on quality of life. — The host summarizing a resource [Ep 7 · 1:17](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=77)
- Adaptive DBS devices record local field potentials from the STN, watching for pathological beta oscillations. — The host summarizing a resource [Ep 7 · 1:27](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=87)
- Pathological beta oscillations are a 13 to 30 Hz rhythm that suppresses movement. — The host summarizing a resource [Ep 7 · 1:36](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=96)
- When beta appears, stimulation fires; when it fades, it eases off. — The host summarizing a resource [Ep 7 · 1:40](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=100)
- Adaptive DBS results in less unnecessary current, longer battery life, and fewer side effects. — The host summarizing a resource [Ep 7 · 1:45](https://library.globalcastmd.com/watch/3-eras-of-parkinson-s-surgery-destroy-modulate-respond-13628?t=105)
- Hypothalamic hamartoma sits surrounded by the optic chiasm, the pituitary stalk, the mammillary bodies, and perforating vessels. — The host summarizing a resource [Ep 13 · 0:15](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=15)
- Traditional open approach to hypothalamic hamartoma meant splitting fissures, retracting the frontal lobe, working millimeter by millimeter around structures that could not be touched. — The host summarizing a resource [Ep 13 · 0:28](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=28)
- Open series for hypothalamic hamartoma reported complications in more than half of patients. — The host summarizing a resource [Ep 13 · 0:40](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=40)
- LITT uses a stereotactic bolt through a 3 millimeter burr hole, robotically guided, with a laser catheter advanced to the target inside the MRI scanner. — The host summarizing a resource [Ep 13 · 0:51](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=51)
- Real-time thermal map shows the ablation expanding second by second during LITT. — The host summarizing a resource [Ep 13 · 1:07](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=67)
- Safety markers are placed next to the optic tract and the fornix, and ablation is stopped the moment heat approaches them. — The host summarizing a resource [Ep 13 · 1:13](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=73)
- Across published hamartoma series, seizure freedom rates are 56 to 84%. — The host summarizing a resource [Ep 13 · 1:22](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=82)
- Hospital stay for LITT is just overnight. — The host summarizing a resource [Ep 13 · 1:28](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=88)
- LITT requires no craniotomy, just a small scalp incision. — The host summarizing a resource [Ep 13 · 1:32](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=92)
- LITT is expanding to mesial temporal epilepsy, insular cavernoma, and periventricular heterotopia. — The host summarizing a resource [Ep 13 · 1:36](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=96)
- LITT works from inside the lesion, leaving the healthy brain overlying untouched. — The host summarizing a resource [Ep 13 · 1:58](https://library.globalcastmd.com/watch/how-litt-reaches-deep-brain-tumours-through-a-3-mm-hole-functional-surgery-minute-04-13629?t=118)
- Before the 1980s, surgical outcomes for epilepsy were reported simply as improved or not improved, with every center using its own definition, preventing meaningful comparison of results. — The host summarizing a resource [Ep 11 · 0:10](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=10)
- In 1993, Jerome Engel and colleagues proposed a single standard scale for epilepsy surgery outcomes. — The host summarizing a resource [Ep 11 · 0:22](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=22)
- The Engel classification quickly became the international standard for reporting epilepsy surgery outcomes. — The host summarizing a resource [Ep 11 · 0:33](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=33)
- The Engel classification grades how close the patient is to complete seizure freedom rather than counting seizures. — The host summarizing a resource [Ep 11 · 0:37](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=37)
- Engel Class 1 means the patient is free of disabling seizures and essentially seizure-free — surgery worked. — The host summarizing a resource [Ep 11 · 0:54](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=54)
- Engel Class 2 means rare disabling seizures with long seizure-free stretches — almost seizure-free, surgery worked well but not perfectly. — The host summarizing a resource [Ep 11 · 1:01](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=61)
- Engel Class 3 means worthwhile improvement with seizures still happening but far less than before, where both patient and clinician agree the change was worth it — surgery helped but epilepsy remains active. — The host summarizing a resource [Ep 11 · 1:12](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=72)
- Engel Class 4 means no worthwhile improvement, with seizures continuing at similar frequency or worse — surgery did not achieve meaningful control. — The host summarizing a resource [Ep 11 · 1:27](https://library.globalcastmd.com/watch/epilepsy-surgery-outcomes-explained-13625?t=87)
- Parkinson's disease is a circuit disorder, not just a dopamine deficiency. — The host summarizing a resource [Ep 4 · 0:00](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634?t=0)
- The subthalamic nucleus becomes overactive in Parkinson's disease despite being structurally intact. — The host summarizing a resource [Ep 4 · 0:00](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634?t=0)
- Irreversibility was the fatal limitation of thalamotomy and pallidotomy. — The host summarizing a resource [Ep 4 · 0:00](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634?t=0)
- Benabid discovered in Grenoble in 1987 that high-frequency stimulation could replicate the effects of ablative lesions reversibly, shifting the entire question of surgery. — The host summarizing a resource [Ep 4 · 0:00](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634?t=0)
- Adaptive closed-loop DBS represents the future of the field. — The host summarizing a resource [Ep 4 · 0:00](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634?t=0)
- The first thalamotomies for Parkinson's disease were performed in the 1950s. — The host summarizing a resource [Ep 4 · 0:00](https://library.globalcastmd.com/watch/neuromodulation-vs-neuroablation-functional-neurosurgery-explained-episode-3-13634?t=0)

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