Functional

Question 1

Which of the following is a physiologic side effect of T2 sympathetic ganglionectomy?

A. Tachycardia
B. Urinary Retention
C. Compensatory Hyperhidrosis
D. Hypotension
E. Tachypnea

Answer 1

**C. Compensatory Hyperhidrosis
**

Compensatory hyperhidrosis is a common side effect after T2 sympathetic ganglionectomy. Studies have reported rates as high as 86-100%. The distribution of hyperhidrosis varies significantly. The other choices are not known to be significant side effects after T2 ganglionectomy. Nonsurgical treatment options include oral anticholinergics such as glycopyrrolate, oxybutynin, botox injections, and iontophoresis.

Question 2

Which of the following symptoms of Parkinson disease is expected to improve the most from deep brain stimulation of the subthalamic nucleus?

A. Resting Tremor
B. Cognitive dysfunction
C. Bowel/Bladder Dysfunction
D. Imbalance
E. Freezing

Answer 2

A. Resting Tremor

The cardinal symptoms of Parkinson’s disease are resting tremor, rigidity, and bradykinesia. These are typically responsive to both levodopa and deep brain stimulation, typically recommended once disease becomes refractory to levodopa. There are many other symptoms of Parkinson’s that do not respond to DBS, including freezing, falling, speech difficulty, cognitive decline, and bowel/bladder dysfunction.

Question 3

In the treatment of convulsive status epilepticus in adults, which of the following intravenous medications should be co-administered with benzodiazepines?

A. fosphenytoin
B. valproic acid
C. 10% dextrose
D. keppra
E. mannitol

Answer 3

A. fosphenytoin

Status epilepticus (SE) is defined as 2 or more consecutive seizures without return to baseline or more than 30 minutes of continuous seizure activity. SE constitutes a medical emergency and is managed by ABC evaluation. Benzodiazepines are the mainstay of medical management, lorazepam 4-8mg IV bolus is often first-line therapy, SE refractory to IV bolus of benzodiazepine should be treated with fosphenytoin 15-20mg/kg IV load. Reversible causes of SE should be sought and rapidly treated, including hypoglycemia, hyponatremia, toxic substance screen etc.

Question 3

Which of the following types of epilepsy is best described as a “primary generalized epilepsy”?

A. Rasmussen’s encephalitis
B. Febrile seizures
C. Temporal lobe epilepsy
D. Lennox-Gastaut syndrome
E. Childhood absence epilepsy

Answer 3

E. Childhood absence epilepsy

Primary (or idiopathic) generalized epilepsies (PGE) involve seizures that are generalized at seizure onset, with ictal EEG findings of generalized, synchronous, bilateral/symmetrical discharges. Interictal EEG shows generalized discharges such as spikes, polyspikes, spike and wave complexes. There are several PGE syndromes based on International League Against
Epilepsy (ILAE) criteria, including childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures on awakening. There is often clinical overlap between these conditions (e.g., a child with absence epilepsy may go on to develop juvenile myoclonic epilepsy). The other forms of epilepsy /seizures mentioned in the answer choices are not necessarily a form of epilepsy (febrile seizures), or they involve focal onset seizures that may secondarily generalize (e.g., temporal lobe epilepsy, Rasmussen’s encephalitis).

Question 4

A stereotactic frame has moved on a patient’s head after imaging. Which of the following is the most appropriate next step?

A. Continue with surgery and rely on anatomic landmarks
B. Re-secure the frame
C. Examine the patient
D. Continue with surgery and rely on microelectrode recordings
E. Re-image if possible and then continue surgery

Answer 4

C. Examine the patient

Stereotactic frame movement indicates the patient was not appropriately secured in the frame or the frame is faulty. The patient should be examined for lacerations and surgical team will need to understand why the frame has moved. A poorly secured frame on the patient is both in-accurate for surgery and may lead to injury for the patient, such as puncture to the eye with securing pins. A planned surgery may need to be canceled or at the very least, the patient will need to be re- secured in an appropriately positioned frame and undergo repeat imaging. During surgery, the patient needs to be examined and the anesthesia team should be notified. Surgery may or may not be able to be continued depending on the condition of the patient, the availability of a functioning stereotactic frame, and the availability of imaging.

Question 5

Which of the following types of seizure responds best to corpus callosotomy?

A. Focal onset seizures with sensory semiology
B. Infantile spasms
C. Complex partial seizures
D. Absence seizures
E. Atonic seizures (“drop attacks”)

Answer 5

E. Atonic seizures (“drop attacks”)

Corpus callosotomy is applied as a palliative treatment for patients with drug-resistant generalized seizures and focal onset seizures with rapid secondary generalization (where the focus cannot be identified). Typically generalized seizures that result in falls are most likely to respond favorably to callosotomy (such as tonic seizures, atonic seizures, myoclonic seizures). Callosotomy typically involves the anterior 2/3 of the corpus callosum, though complete callosotomy may also be performed (in some cases a completion callosotomy is performed, where the remaining posterior third of the callosum is later resected when seizures remain refractory to an initial anterior callosotomy). Callosotomy results in transient and permanent neurologic deficits, including hemiparesis, aphasia, mutism, akinesia, and disconnection syndrome.

Question 6

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) in a patient with Parkinson disease results in dysarthria at low thresholds of stimulation. Which of the following is the most likely position of the DBS electrode relative to the STN?

A. Lateral
B. Dorsal
C. Inferior
D. Anterior
E. Posterior

Answer 6

A. Lateral

Lateral is the correct answer. Subthalamic nucleus deep brain stimulation (STN-DBS) is a widely used treatment for Parkinson’s disease (PD) patients with motor complications, but can result in adverse effects (AEs) in a proportion of treated patients due to mispositioned leads. Common AEs seen at therapeutic levels of stimulation include dysarthria with facial pulling when leads are too lateral or dysarthria without facial pulling when too medial, muscle contractions when leads are too lateral, autonomic symptoms when anteromedial, paresthesias if posterior.

Question 7

Which of the following factors contraindicates the use of basal ganglia surgery to treat patients with parkinsonism?

A. History of falls
B. Levodopa-induced side effects
C. Significant cognitive impairment
D. Lack of tremor
E. History of stroke

Answer 7

C. Significant cognitive impairment

Contraindications to Deep Brain Stimulation (DBS) include significant cognitive impairment or dementia, failure of Unified Parkinson’s Disease Rating Scale (UPDRS) improvement with levodopa, non-parkinsonian movement disorder (e.g., progressive supranuclear palsy, frontotemporal dementia), or other surgical contraindication (e.g., unable to hold anticoagulation, poor pulmonary status, etc.). Lack of tremor is not a contraindication as other symptoms may be well-addressed with DBS, such as rigidity or bradykinesia. Levodopa-induced side effects are a common reason for referral to DBS, as DBS may reduce medication use. Risk of falls is generally not improved by DBS, but a history of falls is not a contraindication. While an infarct in the target structure may warrant consideration of a different target or trajectory, history of stroke is not a contraindication.

Question 8

Which of the following is the most common manifestation in patients with tuberous sclerosis?

A. Seizures
B. cardiac rhabdomyoma
C. subungual fibromas
D. lymphangioleiomyomatosis
E. shagreen patches

Answer 8

A. Seizures

Tuberous sclerosis (TS) is a phakomatosis/neurocutaneous disorder characterized by multiple forms of hamartomas and benign tumors. Brain lesions include cortical tubers, subependymal nodules and subependymal giant cell astrocytoma (SEGA). Cutaneous lesions include ash leaf spots (hypomelanic macules), adenoma sebaceum (facial angiofibromas), shagreen patches (thickened rough skin at nape of neck or lower back), periungual fibromas. Visceral tumors include cardiac rhabdomyoma, renal angiomyolipoma, and pulmonary lymphangioleiomyomatosis. The most common manifestation of tuberous sclerosis in the answer choices is seizures, as over 80% of patients with TS will experience seizures in their lifetime.

Question 9

A 65-year-old man who is receiving therapy for a brain abscess has a generalized seizure that does not abate in six minutes. Which of the following anticonvulsants is the most appropriate initial therapy?

A. fosphenytoin
B. lorazepam
C. valproate
D. levetiracetam
E. phenobarbital

Answer 9

B. lorazepam

Status epilepticus is defined as continuous seizure activity lasting over 5 minutes (though some organizations/publications only consider a longer duration, e.g., 10-60 minutes to be a criterium), or two or more seizures without full return to baseline between seizures. As with any medical emergency, the initial management of status epilepticus involves hemodynamic stabilization, followed by prompt seizure treatment. The algorithm for management of status epilepticus involves the administration of a benzodiazepine (lorazepam, midzolam, diazepam), brief observation (<3 minutes) for response, followed by administration of fosphenytoin, Phenobarbital, levetiracetam, or valproate sodium. Continued convulsive or non-convulsive status-epilepticus is managed with midazolam or propofol infusion, with refractory status then managed by pentobarbital or ketamine infusion. Additional therapies may include hypothermia, immnosuppression, and inhaled anesthetic agents.

Question 10

A patient with essential tremor undergoes deep brain stimulation of the thalamus and has paresthesias at low stimulation amplitudes. This finding suggests that the lead should be moved in which of the following directions?

A. Lateral
B. Posterior
C. Medial
D. Superficial
E. Anterior

Answer 10

E. Anterior

Persistent paresthesias indicate stimulation of Vc, which is posterior to VIM. Transient paresthesias can be seen with VIM stimulation. Anterior misplacement would not necessarily lead to stimulation related side effects. Medial misplacement may lead to dysarthria, due to the somatotopy of the nucleus, with face medial to hand. Lateral misplacement would lead to capsular side effects such as contractures of the face or hand and dysarthria. Pure ventral misplacement might also capture the area posterior and ventral to VIM, which is the medial lemniscus, also causing paresthesias.

Question 11

The wide dynamic range neurons are located within which of the following structures?

A. Nucleus gracilis
B. Rexed lamina V
C. Peri-aqeuductal gray
D. Post-synaptic dorsal column
E. Nucleus cuneatus

Answer 11

B. Rexed lamina V

The wide dynamic range neurons are located in Rexed lamina V. The posterior horn of the spinal gray matter comprises 6 layers, the laminae of Rexed I–VI. C-fibers of nociceptive neurons project to cells in the laminae of Rexed I (marginal zone) and II (substantia gelatinosa) and connect with the secondary afferent neurons of the contralateral spinothalamic tract. The A-fibers of the non- nociceptive neurons project to cells in the laminae of Rexed III–VI. Secondary neurons in the deeper lamina of Rexed V are called wide dynamic range (WDR) neurons because they receive synaptic inputs from A-fibers, connect with the contralateral spinothalamic tract, and are associated with pain conduction.

Question 12

Which of the following are the primary nociceptive-specific receptors?

A. Bare nerve endings
B. Ruffini’s corpuscles
C. Meissner’s corpuscles
D. Merkel’s receptors
E. Pacinian corpuscles

Answer 12

A. Bare nerve endings

Primary nociceptive-specific receptors are bare nerve endings. Dorsal root ganglion neurons are pseudo-unipolar neurons. A single axon emerges from the cell body and bifurcates into one peripheral axon that innervates the skin or other tissues and another axon directed centrally. The peripheral axon has one of several types of receptors that transduce signal energy (mechanical, thermal, etc.) into neural signals by membrane receptor-channel complexes.
Nociceptors respond to noxious stimuli, itch -sensitive neurons, or pruritic receptor, respond to histamine, and thermoceptors respond to temperature. The morphology of these three classes of receptor neurons is referred to as bare nerve endings.
Mechanoreceptors for limb position sense are sensitive to muscle or tendon stretch as well as mechanical changes in the tissues around muscles and joints. Mechanoreceptors have encapsulated axon terminals. Five major types of encapsulated sensory receptor neurons are in the skin and underlying deep tissue that mediate mechanosensations: Ruffini’s corpuscles, Merkel’s receptors, Meissner’s corpuscles, Pacinian corpuscles, and hair receptors.
Merkel’s receptors and Meissner’s corpuscles are located at the epidermis-dermis border and are sensitive to stimulation within a very small region of overlying skin (small receptive fields). These receptors are important for fine tactile discrimination, such as reading Braille.
Ruffini’s and Pacinian corpuscles are in the dermis. Ruffini’s corpuscles are sensitive to skin stretch and are important in discriminating the shape of grasped objects. Pacinian corpuscles are the most sensitive mechanoreceptor.
Merkel’s receptors and Pacinian corpuscles are rapidly adapting, responding to changes in the stimulus, such as when it comes on or shuts off. Meissner’s corpuscles and Ruffini’s receptors are slowly adapting, firing action potentials for the duration of the stimulus.
Hair receptors may be either slowly or rapidly adapting.
The principal receptor for proprioception is the muscle spindle receptor, which is located within the muscle belly. It measures muscle stretch. The muscle spindle is more complicated than the other encapsulated mechanoreceptors because it also contains tiny muscle fibers, controlled by the central nervous system, that regulate the receptor neuron’s sensitivity. There is another deep mechanoreceptor, the Golgi tendon receptor, which is entwined within the collagen fibers of tendon and is sensitive to the force generated by contracting muscle. It may have a role in an individual’s sense of how much effort it takes to produce a particular motor act. The muscle spindle and Golgi tendon receptors also play key roles in the reflex control of muscle. The joints are innervated by mechanoreceptors, but they play more of a role in sensing joint pressure and the extremes of joint motion than proprioception.

Question 13

A 58-year-old woman with hypertension has the sudden onset of acute ballistic and choreiform movements of the left arm. Physical examination shows normal motor strength and deep tendon reflexes. In which of the following regions of the right brain is an MR scan most likely to show a lacunar infarct?

A. Substantia Innominata
B. Globus Pallidus Internus
C. Field of forel
D. Substantia Nigra
E. Subthalamic Nucleus

Answer 13

E. Subthalamic Nucleus

The development of hemiballism after an injury to the subthalamic nucleus (STN) such as a hypertensive hemorrhage or stroke is rare but has been reported. Abnormal movements following a stroke can occur immediately or can be delayed and progressive. Hemichorea-hemiballism arising after stroke may improve with medical therapy but in certain circumstances, neurosurgical intervention may be appropriate particularly for refractory symptoms. Although definitive evidence is lacking, the relative safety and reversibility of GPi deep brain stimulation makes it a valuable proposition for those suffering from the disease.

Question 14

A 42-year-old woman with tremor is undergoing deep brain stimulation of the ventralis intermedius. During stereotactic placement of the electrode, the patient has uncomfortable low-threshold paresthesia in the contralateral hand. There is no evidence of movement or increased tone during test stimulation. The electrode is most likely displaced in what direction?

A. Posterior
B. Anterior
C. Medial
D. Lateral
E. Inferior

Answer 14

A. Posterior

A DBS lead too posterior will stimulate the sensory VC nucleus. Paresthesias that abate after several seconds (transient paresthesias) likely indicate adequate placement in VIM. Persistent paresthesias, which are typically uncomfortable, indicate the lead is too posterior and the patients do not tolerate chronic stimulation in this location. Muscle contractions indicate the lead is too lateral (corticospinal stimulation). A lead that is too inferior will cause ataxia due to stimulation of cerebellar pathways. A medial electrode may have speech side effects and an anterior electrode in Voa thalamus is not generally effective for tremor or requires very high voltages.

Question 15

Which of the following symptoms of Parkinson disease is most effectively treated with surgery?

A. Bradykinesia, Tremor, and Freezing
B. Tremor
C. Bradykinesia and Tremor
D. Freezing
E. Bradykinesia

Answer 15

C. Bradykinesia and Tremor

The cardinal symptoms of Parkinson’s disease are resting tremor, rigidity, and bradykinesia. These are typically responsive to both levodopa and deep brain stimulation, typically recommended once disease becomes refractory to levodopa. There are many other symptoms of Parkinson’s that do not respond to DBS, including freezing, falling, speech difficulty, cognitive decline, and bowel/bladder dysfunction.

Question 16

A 6-year-old girl who has epilepsy is evaluated because of intractable seizures, hemiparesis, and cognitive decline that have progressively worsened despite medication. No history of febrile illness is noted. Which of the following is the most likely diagnosis?

A. Rasmussen’s encephalitis
B. Moyamoya disease
C. Cerebral abscess
D. Primary generalized epilepsy
E. Juvenile pilocytic astrocytoma

Answer 16

A. Rasmussen’s encephalitis

Rasmussen’s encephalitis is an inflammatory process that affects children and young adults, most under the age of 10. It is characterized by unilateral inflammation of the cerebral cortex, drug- resistant epilepsy and progressive cognitive and neurological decline. Unilateral inflammation leads to symptoms such as hemiplegia, hemianopsia, language disturbance (if the dominant hemisphere is affected). Typical MRI findings include unilateral ventricular enlargement, unilateral atrophy of the caudate head, and unilateral T2/flair hyperintensity of the cerebral cortex. Seizure semiologies and EEG findings can be highly variable in Rasmussen’s encephalitis.
Immunosuppressive therapies may reduce inflammation and tissue loss, however they do not appear to reduce seizures. Hemispherectomy may be undertaken in younger patients to control severe seizures. Following functional hemispherectomy or hemispherotomy, younger patients less than 5 years of age are more likely to regain function than older patients, however for all groups these surgeries lead to significant permanent neurologic deficits, which must be carefully weighed against the patient’s disease symptomatology if left untreated.

Question 17

Which of the following nuclei is activated by new unexpected non-painful sensory stimuli, responsible for speeding information processing by the motor and sensory systems, and participates in the general arousal of the brain during interesting events in the outside world?

A. Substantia Nigra, pars compacta
B. Basal nucleus of Meynert
C. Locus ceruleus
D. Raphe nuclei
E. Substantia nigra, pars reticulata

Answer 17

C. Locus ceruleus

Locus ceruleus neurons have noradrenergic projections thought to play an important role in the response of the brain to stressful stimuli, particularly those that evoke fear.

Question 18

During resection of a hemangioblastoma, a patient with von Hippel-Lindau disease experiences an intraoperative hyperadrenergic crisis. Which of the following is the most likely cause?

A. Monoamine oxidase inhibitor use
B. Intravenous anesthetic
C. Inhalational Anesthetic
D. Subarachnoid hemorrhage
E. Pheochromocytoma

Answer 18

E. Pheochromocytoma

Pheochomocytomas occur in approximately 10-20% of patients who are diagnosed with von Hippel-Lindau disease with a mean age of onset of 30 years of age. In patients diagnosed with VHL, hyperadrenergic crisis has to be considered a manifestation of a pheochromocytoma until proven otherwise. VHL is an autosomal dominant disease with locus on chromosome 3. VHL is associated with hemangioblastoma, retinal angiomas, pheochromocytomas, pancreatic cyts, epididymal cysts, and renal cell carcinoma.

Question 19

In a patient who has just undergone lumbar fusion, administration of nonsteroidal anti-inflammatory medication is most likely to have which of the following effects?

A. Acute Radiculopathy
B. Adjacent Level Disease
C. Acute Kidney Injury
D. Decreased hospital opioid usage
E. Decreased fusion rate

Answer 19

D. Decreased hospital opioid usage

Use of non-steroidal medications after lumbar fusion has been previously associated with decreased fusion rates, generally given for longer durations at high doses. This seems to also correlate heavily to smoking status. In a meta-analysis, stratified by patients who are non-smokers, NSAID use does not seem to have a significant effect of fusion rates. However, in those who smoke, NSAID use does to seem to correlate with decreased fusion rates. While acute kidney injury is certainly possible with NSAID use, in previously healthy patients who are using the medication responsibly, this rate is fairly low. NSAID usage has been shown to decrease hospital opioid usage.

Question 20

Preganglionic sympathetic nerve fibers release which of the following neurotransmitters at their synapses?

A. Dopamine
B. Epinephrine
C. Acetycholine
D. Serotonin
E. Norepinephrine

Answer 20

C. Acetycholine

Preganglionic neurons of the sympathetic and parasympathetic divisions and postganglionic neurons of the parasympathetic nervous system utilize acetylcholine (ACh). Postganglionic neurons of the sympathetic nervous system use norepinephrine and epinephrine. Properties of the preganglionic neurons also differ with respect to the spinal cord exit points. The sympathetic division has thoracolumbar outflow, meaning that the neurons begin at the thoracic and lumbar (T1–L2) portions of the spinal cord. The parasympathetic division has craniosacral outflow, meaning that the neurons begin at the cranial nerves (CN3, CN7, CN9, CN10) and sacral (S2–S4) spinal cord.

Question 21

The nucleus accumbens is most associated with which of the following functions?

A. Facial recognition
B. Hunger
C. Reward processing, learning and motivation
D. Fear
E. Satiety

Answer 21

C. Reward processing, learning and motivation

The nucleus accumbens is thought to play a critical role in learning and motivation. It has rich connectivity with midbrain dopaminergic neurons and prefrontal and limbic areas that may help reinforce certain decisions. Many animal studies have implicated the ventral striatum (nucleus accumbens and olfactory tubercle) in the processing of reward information. In humans, fMRI studies have demonstrated that the ventral striatum is sensitive to a wide array of reward features. It exhibits signal changes in response to monetary reward and loss even if no physical money is given to an individual and only abstract remuneration occurs.

Question 22

Which of the following is a characteristic of oligodendrocytes?

A. Provide trophic support to neurons
B. Express ganglioside GD 3
C. Arise from neuroepithelium in the subventricular zone
D. Produce central myelin
E. All of the answers

Answer 22

E. All of the answers

Oligodendrocytes are a type of glial cell. Their main functions are to provide support and insulation to axons in the central nervous system equivalent to the function performed by Schwann cells in the peripheral nervous system. Oligodendrocytes do this by creating the myelin sheath. A single oligodendrocyte can extend its processes to 50 axons, wrapping approximately 1 μm of myelin sheath around each axon. They arise during development from oligodendrocyte precursor cells (OPCs), which can be identified by their expression of a number of antigens, including the ganglioside GD3. Most oligodendrocytes develop during embryogenesis and early postnatal life from restricted periventricular germinal regions.

Question 23

Ten years ago, a 54-year-old man had a favorable outcome from a left-sided thalamotomy for essential tremor. He now has a similar disabling tremor in his left arm and hand, and wishes to have his other side treated. Which of the following is the most appropriate surgical procedure for this patient’s contralateral side?

A. Propranolol
B. Right sided Thalamotomy
C. Right sided thalamic deep brain stimulator
D. Physical therapy
E. Primidone

Answer 23

C. Right sided thalamic deep brain stimulator

When considering a lesioning procedure, the ventralis intermedius nucleus (VIM) is the target of choice in most patients with medication-refractory tremor. However, bilateral thalamotomy carries an unacceptably high risk of dysarthria, dysphonia, aphasia and ataxia ranging from 30% to 50% of patients. As such, bilateral thalamotomy is contraindicated. Thalamotomy can be conducting via radiofrequency (RF) lesioning, focused ultrasound or stereotactic radiosurgery. During radiofrequency lesioning, before creating a permanent lesion, the effect on tremor reduction and presence of undesirable side effects can be evaluated by stimulation of the RF probe. In the awake patient, the effect is instantly visible after lesioning of the VIM. Surgical complications are similar to those seen with DBS such as dysarthria, gait disturbances, hemiparesis and intracerebral hemorrhage. These complications are often transient, but more prevalent compared to DBS. MRgFUS thalamotomy is based on a technique that delivers ultrasonic energy to a specific area in the brain. The lesion can be created with millimetric precision, due to MR guidance, as the local temperature can be accurately monitored with MR-thermometry in real-time. Comparable to RF thalamotomy, the effect is directly visible after creating a permanent thermal lesion. Similar to RF thalamotomy, MRgFUS is not indicated for bilateral treatment of tremor. However, the efficacy and safety of staged bilateral FUS treatment of ET is currently being studied (clinicaltrials.gov NCT03465761). Stereotactic radiosurgery uses radiation therapy to create a lesion in the VIM. In contrast to RF and MRgFUS thalamotomy, the effect of GK thalamotomy is not directly visible and can take several months until an effect is noticeable. For this patient, the non-lesional nature of DBS makes it the preferred neurosurgical treatment for this patient’s left sided tremor, by way of right sided VIM lead.

Question 24

An 11-year-old boy is evaluated for multiple daily episodes consisting of blank stares, rotating eyes, and rapid blinking. He is unresponsive to verbal commands during these episodes, but does not have generalized convulsions. Which of the following is the first-line drug of choice for this patient?

A. lamotrigine
B. levetiracetam
C. ethosuximide
D. phenytoin
E. oxcarbezepine

Answer 24

C. ethosuximide

Absence seizures are a form of generalized epilepsy and were re-classified by the International League Against Epilepsy (ILAE) in 2017 as “generalized non-motor seizures”, with sub- classifications of typical, atypical, myoclonic and eyelid myoclonia. These seizures are often seen in children between 4-12y of age. The classic EEG finding is 3Hz spike and wave discharges. This child is having absence/generalized non-motor seizures with eyelid myoclonia. Ethosuximide and valproate are first line medications for the treatment of absence seizures. Ethosuximide and valproate have equal efficacy in the treatment of absence seizures (45% and 44% seizure freedom at 12 months), moreso than lamotrigine (21% seizure freedom at 12 months).

Question 25

Which of the following disorders is most amenable to treatment by corpus callosotomy?

A. dacrystic seizures
B. generalized tonic-clonic seizures
C. epileptic spasms
D. atonic seizures
E. Lennox-gestaut syndrome

Answer 25

D. atonic seizures

Atonic seizures are now classified by the International League Against Epilepsy (ILAE) in 2017 as generalized motor seizures with the subtype atonic. These seizures are a form of generalized epilepsy characterized by rapid loss of muscular tone causing falls to the ground due to rapid seizure generalization, i.e. drop attacks. The rapid nature of the falls can cause severe injuries.
Atonic seizures aka drop attacks are treated with vagal nerve stimulation as first-line and corpus callosotomy for patients that do not respond to Vagal Nerve Stimulation (VNS). For atonic seizures specifically, VNS typically results in 57.6% of patients having at least 50% reduction in seizures, and corpus callosotomy 85.6%. Side-effects for VNS are typically mild with voice changes (22%), side-effects for corpus callosotomy include disconnection syndrome (13.2%).

Question 26

A 54-year-old man has a history of bilateral essential tremor. He underwent a successful left-sided thalamotomy 10 years ago. He now wants to have his other side treated. Which of the following is the most appropriate next step?

A. Right VIM deep brain stimulation
B. Right STN deep brain stimulation
C. Right thalamotomy
D. Right pallidotomy
E. He is not a candidate for surgical treatment.

Answer 26

A. Right VIM deep brain stimulation

In patients with previous thalamotomy and severe, medically refractory essential tremor on the untreated side, contralateral deep brain stimulation is a safe and effective therapy. However, the risk is increased of side effects is increased with bilateral procedures (e.g., dysarthria, gait ataxia) and stimulation may need to be titrated to avoid these. Bilateral thalamotomy is not recommended due to the significantly increased risk of these effects and the irreversibility of the procedure. The STN and globus pallidus are not targets of therapy for essential tremor.

Question 27

According to cortical stimulation mapping studies of the dominant hemisphere, which of the following cortical areas, when stimulated, is most likely to result in speech alteration?

A. Posterior inferior frontal gyrus
B. Orbitofrontal gyrus
C. Posterior middle frontal gyrus
D. Temporal pole
E. Posterior superior frontal gyrus

Answer 27

A. Posterior inferior frontal gyrus

The posterior inferior frontal gyrus (classically referred to as Broca’s area) is associated with speech arrest. The supramarginal gyrus and portions of the posterior temporal lobe (posterior superior and middle temporal gyri) are more commonly associated with alexia

Question 28

Which of the following anticonvulsant drugs is the safest to administer to a patient with hepatic failure?

A. Phenytoin (Dilantin)
B. Valproic acid (Depakote)
C. Felbamate (Onfi)
D. Phenobarbital (Luminal)
E. Levetiracetam (Keppra)

Answer 28

E. Levetiracetam (Keppra)

A number of anti-epileptic drugs are metabolized by the liver and should be avoided in patients with hepatic dysfunction and disease, including valproic acid, phenytoin, phenobarbital, and felbamate. Hepatic dysfunction requires careful dosing of these medications. A number of these medications can rarely be hepatotoxic as well. Renal function should also be considered when dosing anti-epileptic drugs, as protein-binding of medications such as phenytoin and valproic acid can be reduced, confounding measurement of serum concentrations.

Question 29

A 64-year-old woman is undergoing deep brain stimulation (DBS) of the thalamus for essential tremor. During intraoperative macrostimulation through the DBS electrode, she experiences contralateral arm contractions. The most appropriate strategy is to move the lead in which of the following directions?

A. Ventral
B. Anterior
C. Lateral
D. Posterior
E. Medial

Answer 29

E. Medial

The target for DBS for the treatment of essential tremor is the ventral intermediate nucleus of the thalamus. Contralateral arm contractions suggest stimulation of the internal capsule and the lead should be moved medially. Medial lead placement to the VIM may lead to orofacial paresthesia and dysarthria. Posterior lead placement may lead to persistent paresthesia suggests stimulation of Vc.

Question 30

While a patient with dystonia is undergoing deep brain stimulation, a microelectrode is passed through the bottom of the globus pallidus. Which of the following structures is encountered next?

A. Substantia nigra
B. Subthalamic nucleus
C. Optic tract
D. Thalamus
E. Zona incerta

Answer 30

C. Optic tract

The structure below the globus pallidus interna (GPi) is the optic tract. During awake testing, confirmation of visual obscurations indicates adequate lead placement, though slightly more shallow. The thalamus is medial and superior, the subthalamic nucleus (STN) is medial and inferior, and the substantia nigra is inferior to the STN. The zona incerta is between the thalamus and STN.

Question 31

A 24-year-old woman is evaluated for medically refractory complex partial seizures arising from the left mesial temporal structures. Intracarotid Wada test shows left hemispheric cerebral dominance for language. Which of the following neuropsychologic operations is most likely to be impaired?

A. Fine dexterity
B. Visual memory
C. Verbal memory
D. Speeded reaction time
E. Executive function

Answer 31

C. Verbal memory

Neuropsychologic testing is involved in the pre-surgical evaluation of patients with epilepsy. Testing is done to assess functional domains impacted by the patient’s epilepsy. As various
cognitive functions are somewhat localized in patients (e.g., dominant temporal lobe function is important for verbal memory, while frontal lobes serves executive functions, non-dominant temporal lobe functions in visual memory, etc), impaired performance in specific domains may indicate the brain area(s) in which seizures originate. Additionally, pre-surgical neuropsychological testing is used to predict the cognitive impacts of surgical epilepsy treatments, such as resection. Generally, if function of a brain area is not impaired in the epileptic patient, there is greater likelihood of neurocognitive impact with resection. This information surgical decision making and pre-surgical counseling of patients.

Question 32

Which of the following is the first-line drug of choice for simple partial and neonatal seizures?

A. phenobarbital
B. zonisamide
C. topiramate
D. clobazam
E. carbemazepine

Answer 32

E. carbemazepine

Epilepsy is defined as 2 or more unprovoked seizures at least 24 hours apart. Recurrence rate after the first unprovoked seizure is greatest within the first 2 years (20-45%). For adults presenting with a first unprovoked seizure, antiseizure medications (ASM) decreased recurrence by 35% in the first 2-years but had no effect compared to ASM deferral after 5 years. Therefore, initiation of ASM for first seizure in the absence of risk factors is not recommended. Initiation of ASM after the first unprovoked seizure may be considered for patients with identifiable risk factors such as brain tumor, traumatic brain injury, or central nervous system infection as seizure recurrence rate is much higher in this population (60%). First line anti-seizure medications for focal seizures include carbamazepine and lamotrigine. Levetiracetam can also be considered an alternative first-line medication. Lamotrigine and levetiracetam medications are best tolerated by patients (hazard ratio of stopping compared to carbamazepine: lamotrigine 0.75, levetiracetam 0.82).

Question 33

Which of the following medications is most effective in treating absence seizures?

A. phenytoin
B. levetiracetam
C. ethosuximide
D. lamotrigine
E. oxcarbezepine

Answer 33

C. ethosuximide

Absence seizures are a form of generalized epilepsy and were re-classified by the International League Against Epilepsy (ILAE) in 2017 as “generalized non-motor seizures”, with sub- classifications of typical, atypical, myoclonic and eyelid myoclonia. These seizures are often seen in children between 4-12 years of age. The classic EEG finding is 3Hz spike and wave discharges. Ethosuximide and valproate have equal efficacy in the treatment of absence seizures (45% and 44% seizure freedom at 12 months), more than lamotrigine (21% seizure freedom at 12 months).

Question 34

A 70-year-old woman has had the progressive development of head and arm tremors over the past 15 years. The arm tremor is most prominent with outstretched posture and intention. Which of the following is the most likely diagnosis?

A. Parkinson’s Disease
B. Essential Tremor
C. Dystonic tremor
D. Progressive supranuclear Palsy
E. Physiologic tremor

Answer 34

B. Essential Tremor

The correct answer is essential tremor. Essential tremor is a monosymptomatic, predominant postural or kinetic tremor which usually slowly progresses over the years. The topographic distribution in ET shows hand tremor in 94%, head tremor in 33%, voice tremor in 16% and leg tremor in 12% of the patients. ET may be hereditary and about 50–70% of the patients improve with intake of alcohol. The typical candidate for DBS has medication refractory symptoms affecting quality of life and the ability to work. In these patients, treatment with propranolol and primidone at maximum tolerated doses did not result in sufficient symptom alleviation. However, not every patient may be eligible for this procedure. Various other functional neurosurgical procedures are available, including radiofrequency thalamotomy, focused ultrasound and radiosurgery. Targets other than VIM, such as the posterior subthalamic area (PSA) or the dentato-rubro-thalamic tract (DRT), may be considered as well to target tremor, but are not considered first line treatment.

Question 35

Which of the following medications is most likely to cause tremor?

A. Levetiracetam
B. Risperidone
C. Salmeterol
D. Propranolol
E. Primidone

Answer 35

C. Salmeterol

Medication classes most likely to cause tremor include beta-agonists (e.g., bronchodilators such as salmeterol), selective serotonin reuptake inhibitors, and tricyclic antidepressants. Propranolol (a beta-blocker) and primidone (a barbiturate) are used to treat essential tremor.

Question 36

A patient with Parkinson disease undergoes implantation of a deep brain stimulation lead. The accompanying CT scan shows the location of the distal contact of the lead. Which of the following symptoms is best treated by a lead in this location?

A. Intention tremor
B. Postural tremor
C. Rest tremor
D. Dystonia
E. Freezing of gait

Answer 36

C. Rest tremor

The lead is shown in the left subthalamic nucleus, which is directly above the midbrain substantia nigra. Among the choices, resting tremor is most responsive to STN DBS. Other cardinal symptoms of Parkinson’s disease (rigidity, bradykinesia) are also responsive, but freezing is not. Dystonia may be primary, secondary, or associated with another movement disorder, but is generally best treated with GPI DBS. Postural tremor and intention tremor would be best treated with VIM thalamus DBS.

Question 37

Which of the following is most common in a 5-year-old child with Lennox-Gastaut syndrome?

A. Multiple seizure types, focal onset seizures, cortical heterotopias and tubers
B. Multiple seizure types, cognitive impairment, generalized slow spike-wave discharges
C. Absence seizures, developmental delay, hypsarrhythmia
D. Focal onset seizures with impaired awareness, oral automatisms, secondary generalization; mesial temporal atrophy
E. Drop attacks

Answer 37

B. Multiple seizure types, cognitive impairment, generalized slow spike-wave discharges

Lennox-Gastaut syndrome typically manifests during ages 3-5, and involves multiple seizure types. Medication management with valproic acid, as well as other agents such as cannabidiol,
lamotrigine, clobazam, topiramate, and rufinamide, is first-line therapy. A ketogenic diet may also be helpful. Vagus nerve stimulation has been used as a palliative treatment for Lennox-Gastaut syndrome. Centromedian thalamic deep brain stimulation has recently been used off-label as an alternative or adjunct treatment to Vagal Nerve Stimulation (VNS).

Question 38

A 60-year-old man has rigidity, bradykinesia, and tremor associated with Parkinson’s disease. Surgery on which of the following structures is most likely to improve the symptoms?

A. Globus pallidus interna (GPi) or Subthalamic nucleus (STN)
B. Globus pallidus interna (GPi)
C. Subthalamic nucleus (STN)
D. Ventralis intermedius (VIM) thalamus
E. Globus pallidus interna (GPi) , Subthalamic nucleus (STN), or Ventralis intermedius (VIM) thalamus

Answer 38

A. Globus pallidus interna (GPi) or Subthalamic nucleus (STN)

Medically refractory resting tremor, rigidity, and bradykinesia of Parkinson’s disease responds well to deep brain stimulation targeting either the subthalamic nucleus or globus pallidus interna. The VIM thalamus is the target for essential tremor.

Question 39

Which of the following is the most common EEG finding in Lennox-Gastaut syndrome?

A. Hypnagogic hypersynchrony
B. hypsarrhythmia
C. 1.5-2.5 Hz spike and wave discharges during interictal periods
D. Paracentral high amplitude ictal discharges
E. Ictal high amplitude 3 Hz spike and wave paroxysms

Answer 39

C. 1.5-2.5 Hz spike and wave discharges during interictal periods

Lennox-Gastaut is a severe form of epilepsy that strikes children during the first decade of life. It has multiple etiologies, including hypoxia-ischemia, infection, developmental, oncologic, and genetic. It involves multiple seizure types (typically tonic, atonic, and absence); interictal diffuse 1.5-2.5 Hz spike-and-wave discharges, and/or generalized paroxysmal fast activity; and intellectual disability and/or behavioral disorders. In drug-resistant cases (Lennox-Gastaut syndrome is typically medically refractory), surgical treatment involves resection of the seizure focus (if present/identifiable), corpus callostomy (for severe generalized seizures involving falls), vagus nerve stimulation, and, more recently, deep brain stimulation.

Question 40

Which of the following symptoms associated with Parkinson disease is most likely to persist after deep brain stimulation?

A. Cognitive dysfunction
B. Falls
C. All of the answers listed
D. Freezing
E. Imbalance

Answer 40

C. All of the answers listed

The cardinal symptoms of Parkinson’s disease are resting tremor, rigidity, and bradykinesia. These are typically responsive to both levodopa and deep brain stimulation (DBS), typically recommended once disease becomes refractory to levodopa. There are many other symptoms of Parkinson’s that do not respond to DBS, including freezing, falling, speech difficulty, cognitive decline, and bowel/bladder dysfunction.

Question 41

In patients who sustain moderate head injury (ie, with Glasgow Coma Scale score of 9 to 12), prophylactic phenytoin should be administered for:

A. 6 months
B. 24 hours
C. 3 days
D. 7 days
E. 30 days

Answer 41

D. 7 days

Early post-traumatic seizures may occur in as many as 12% of TBI patients. This is defined as seizure activity within the first 7 days of injury. Thus, 7 days of phenytoin administration has been shown to reduce the rate of early post-traumatic seizures in TBI patients. There is no evidence to support further duration of seizure prophylaxis in patients who have not previously had seizure activity.

Question 42

A 55-year-old woman with Parkinson disease and severe dyskinesias undergoes implantation of a deep brain stimulation electrode in the globus pallidus interna. Upon activation, which of the following adverse effects would indicate that the electrode has been placed too deep?

A. Perception of light flashes in the ipsilateral visual field
B. Paresthesias in the contralateral face
C. Adduction of the ipsilateral eye and elevation of the superior eyelid
D. Perception of light flashes in the contralateral visual field
E. Muscle contractions in the contralateral arm

Answer 42

D. Perception of light flashes in the contralateral visual field

A deep brain stimulation (DBS) electrode placed deep to the globus pallidus interna (GPi) will create a perception of light flashes (phosphenes) in the contralateral visual field. The most common basal ganglia nuclei targeted in DBS treatment of PD are the subthalamic nucleus (STN) and the GPi. Accurate placement of the DBS lead in these nuclei is important to avoid side effects of stimulation and maximize benefits. Side effects of electrical stimulation are caused by unintended stimulation of nearby anatomic structures. The GPi is located superior to the optic tract and lateral and anterior to the internal capsule (Figure 1). If a lead is placed too deep, the optic tract nerve fibers traveling below the GPi will be stimulated when the lead is turned on leading to perception of light in the contralateral visual field.
The optic tract contains fibers relaying visual information from the contralateral visual field and as such stimulation will not lead to ipsilateral visual field light perception. A lead placed medial or posterior to GPi, will result in stimulation of the internal capsule fibers and will lead to contralateral muscle contractions. Sensory fibers and oculomotor nerve fibers are not located near the GPi and as such a slightly misplaced lead will not lead to paresthesia or abnormal eye movements. The STN is located near those structures. An STN lead placed too medially will lead to stimulation of oculomotor nerve fibers leading to superior eyelid elevation and adduction of the ipsilateral eye. Similarly, a lead placed too posteriorly in the STN will activate contralateral sensory fibers in the medial lemniscus leading to contralateral paresthesia.

Question 43

Which of the following is the most common cause of a first-onset seizure in a patient who is over 65 years of age?

A. Brain metastasis
B. Stroke
C. Glioma
D. Alzheimer’s dementia
E. Amyloid angiopathy

Answer 43

B. Stroke

First seizure-of-life in patients over age 60 is most commonly (~30% of cases) associated with stroke. Brain tumors, while frequently associated with seizures, are a less common etiology of seizures in older patients (~15% of cases). Following a stroke, early seizures occur in around 2% of patients, while 11% of patients experience a seizure in the first five years following a stroke.
Hemorrhagic strokes and large stroke ischemic volumes, cortical involvement, and late seizures are associated with recurrent seizures following stroke.

Question 44

A 69-year-old man is undergoing lead placement into the subthalamic nucleus to perform deep brain stimulation for Parkinson disease. During intraoperative macrostimulation, he experiences persistent contralateral arm paresthesias without motor contractions. The most appropriate strategy is to move the lead in which of the following directions?

A. Posterior
B. Medial
C. Lateral
D. Ventral
E. Anterior

Answer 44

E. Anterior

Paresthesia without motor contractions suggest the patient is experiencing stimulation of the medical lemniscus and the lead should be moved anteriorly. Tonic muscle contractions suggest a lateral lead position, stimulating the internal capsule. Ipsilateral medial eye deviation and diplopia suggests medial lead position, stimulating the oculomotor nerve fibers. Medial lead position may also result in stimulation of the red nucleus, giving the patient feelings of warmth, dizziness, or nausea.

Question 45

The analgesic effects induced by electrical stimulation of the periaqueductal gray region are blocked by lesions in which of the following structures?

A. Dorsolateral funiculus
B. VPL of the thalamus
C. VPM of the thalamus
D. Commissural fibers of the anterolateral system
E. Anterolateral system

Answer 45

A. Dorsolateral funiculus

Electrical stimulation in the periaqueductal grey (PAG) matter can produce long-lasting analgesia. Lesions in the dorsolateral funiculus, which contain the efferent pathways responsible for the analgesic effects of PAG stimulation, can reduce or eliminate the analgesia produced by opiates or electrical stimulation of the PAG.

Question 46

Which of the following surgical interventions is most appropriate to treat essential tremor?

A. Stereotactic radiation targeting the ventral intermediate nucleus of the thalamus bilaterally
B. Deep brain stimulation targeting the ventral intermediate nucleus of the thalamus
C. Deep brain stimulation targeting subthalamic nucleus
D. Focused ultrasound targeting the subthalamic nucleus of the thalamus unilaterally
E. Deep brain stimulation targeting the anterior nucleus of the thalamus

Answer 46

B. Deep brain stimulation targeting the ventral intermediate nucleus of the thalamus

Generally, the more effective and most widely used target for treating essential tremor is the ventral intermediate nucleus of the thalamus. The posterior subthalamic nucleus (PSA) has also been a target of interest and research, but it is not as widely used. The subthalamic nucleus (STN) can also be effective for tremor, and is used in tremor-dominant Parkinson’s disease, but is not as effective for tremor as the VIM. This is true for both STN DBS and focused ultrasound of the STN. The anterior nucleus of the thalamus (ANT) is a target used for epilepsy. Bilateral ablative, rather than neuromodulatory techniques, are not widely used due to adverse and irreversible effects on axial functions such as gait, swallowing, speech, and cognition.

Question 47

A lesion of the subthalamic nucleus is most likely to produce contralateral

A. Essential tremor
B. Ataxia
C. Dystonia
D. Parkinsonism
E. Hemiballismus

Answer 47

E. Hemiballismus

A lesion of the subthalamic nucleus (STN) is most likely to produce contralateral hemiballismus. In the indirect pathway, the STN excites the globus pallidus interna (GPi) to inhibit the ventrolateral (VL) thalamus and, therefore, provide less excitation of the cerebral cortex. Decreased STN output due to a lesion would lead to increased excitation of the cerebral cortex causing contralateral wild flinging movements of the extremities (hemiballismus). The above is well illustrated in Figure 1 of Reference 1.
Parkinsonism is typically caused by decreased output of the substantia nigra. Ataxia is typically caused by a cerebellar lesion. The cause of essential tremor is typically unknown. It can be surgically treated with deep brain stimulation of the ventralis intermedius nucleus (VIM) thalamus. Dystonia can have multiple causes, including heredity.

Question 48

A 56-year-old man with a 5-cm right temporal glioma presents with a generalized tonic-clonic seizure, that did not cease after two doses of intravenous benzodiazepine administration. Which of the following is the most appropriate acute management of this patient’s seizure?

A. third dose of benzodiazepine
B. fosphenytoin
C. sodium valproate
D. keppra
E. isoflurane

Answer 48

B. fosphenytoin

Status epilepticus (SE) is defined as 2 or more consecutive seizures without return to baseline or more than 30 minutes of continuous seizure activity. SE constitutes a medical emergency and is managed by ABC evaluation. Benzodiazepines are the mainstay of medical management, lorazepam 4-8mg IV bolus is often first-line therapy, SE refractory to IV bolus of benzodiazepine should be treated with fosphenytoin 15-20mg/kg IV load. Reversible causes of SE should be sought and rapidly treated, including hypoglycemia, hyponatremia, toxic substance screen etc.

Question 49

A 69-year-old man with Parkinson disease undergoes placement of a deep brain stimulator in the globus pallidus interna. After passing through the bottom of the globus pallidus interna, which of the following structures is the microelectrode most likely to encounter next?

A. Subthalamic nucleus
B. Optic tract
C. Internal capsule
D. Thalamus
E. Substantia nigra

Answer 49

B. Optic tract

The structure below the globus pallidus interna (GPi) is the optic tract. During awake testing, confirmation of visual obscurations indicate adequate lead placement, though slightly more
shallow. The thalamus is medial and superior, the internal capsule is immediately medial to the GPI. The subthalamic nucleus (STN) is medial and inferior, and the substantia nigra is inferior to the STN.

Question 50

A 59-year-old man has an essential tremor and a proximal action tremor primarily involving the arms. The tremor has not responded to treatment with propranolol and primidone. Therapeutic neural stimulation at which of the following target sites is most likely to be effective in this patient?

A. Globus pallidus interna
B. Globus pallidus externa
C. Substantia nigra
D. VIM thalamus
E. Subthalamic nucleus

Answer 50

D. VIM thalamus

Deep brain stimulation of the ventral intermediate (VIM) nucleus of the thalamus is most effective for essential tremor. The subthalamic nucleus and globus pallidus interna (GPi) are targets for Parkinson’s disease. The substantia nigra and globus pallidus externa are not DBS targets.

Question 51

A 30-year-old man is brought to the emergency department after a motor vehicle collision. His Glasgow Coma Scale score is 13. During evaluation, he has four seizures without returning to full wakefulness. Which of the following drugs is most appropriate to administer?

A. Lorazepam, followed by fosphenytoin B. Valproic acid
C. Ethosuxamide
D. Phenobarbital
E. Phenytoin

Answer 51

A. Lorazepam, followed by fosphenytoin

In this scenario it is important to distinguish between prophylactic treatment of post-traumatic seizures, and the management of status epilepticus. While rare, status epilepticus can occur in the acute period following TBI. This patient is exhibiting status epilepticus, which defined as a continuous seizure lasting more than 5 minutes (though definitions have varied, with some organizations/publications considering durations of 10-60 minutes to be a criterium), or two or more seizures without full recovery of consciousness between any of them. Management of status epilepticus involves benzodiazepine administration, and if seizures remain refractory, subsequent loading of intravenous anti-epileptic drug (e.g., fosphenytoin, levitiracetam, Phenobarbital, valproic acid). The prophylactic administration of phenytoin has been shown to reduce post-traumatic seizures during the first week following injury, but not during late periods (up to 1 year).

Question 52

Infantile spasms are most often characterized by which seizure semiology and EEG findings?

A. Brief flexor, extensor, and mixed flexor-extensor activity; hypsarrhythmia B. Brief tonic-clonic activity; generalized spike-wave discharges
C. Brief head-nodding episodes; hypsarrhythmia
D. Atonic events with falls; generalized spike-wave discharges
E. Mixed unilateral jerking; localized high amplitude discharges with evolution

Answer 52

A. Brief flexor, extensor, and mixed flexor-extensor activity; hypsarrhythmia

Infantile spasms occur during early infancy and manifest as a unique seizure type involving brief (typically <5s, and often in clusters) events characterized by flexor, extensor and mixed flexor- extensor movements. The characteristic EEG feature is hypsarrhythmia, which involves varying diffuse random, high-voltage, slow waves and spikes.

Question 53

A 69-year-old man with essential tremor undergoes placement of a deep brain stimulator in the ventralis intermedius thalamic nucleus. Test stimulation causes strong contraction of the contralateral face and arm. This finding indicates that the electrode is located too far in which of the following directions in relation to the nucleus?

A. Anterior
B. Posterior
C. Medial
D. Inferior
E. Lateral

Answer 53

E. Lateral

A lateral DBS will stimulate adjacent corticospinal fibers and cause muscle contractions. A medial electrode may have speech side effects. An anterior lead in Voa is not generally effective for tremor or requires very high voltages. A lead that is too posterior with cause persistent paresthesias that are typically uncomfortable. A lead that is too inferior will cause ataxia due to stimulation of cerebellar pathways.

Question 54

The mu-opioid receptors are located within which of the following structures?

A. Periaqueductal grey
B. Amygdala
C. Pedunculopontine nucleus
D. Dorsal root ganglion
E. Dentate nucleus

Answer 54

A. Periaqueductal grey

The opioid system consists of mu, kappa, and delta receptors. Mu receptors respond to mechanical, chemical, and thermal nociception at a supraspinal level. Mu receptors are found in the midbrain periaqueductal gray, the nucleus raphe magnus, and the rostral ventral medulla. They form the descending inhibitory system modulating pain transmission. Opioid receptors bind to three major groups of endogenous opioid peptides including enkephalins, endorphins, and dynorphins. They are activated by exogenous opiates (such as morphine), endogenous peptides (such as beta-endorphin), and modulate nociception.

Question 55

The quick phase of pain sensation in the peripheral nerve is mediated by?

A. A-β fibers
B. A-α fibers
C. A-δ fibers
D. C-fibers

Answer 55

C. A-δ fibers

Nociceptors are both thinly myelinated (A-δ) and unmyelinated (C fibers). A brief noxious stimulus evokes initially a sharp, pricking pain, sometimes termed “fast” pain, mediated by A-δ nociceptors, followed by a dull burning pain sometimes termed “slow” pain, mediated by C-fiber nociceptors. Thermoreceptor axons also conduct action potentials in the A-δ and C-fiber ranges. Pruriceptors are C-fibers only. Mechanoreceptors have large, heavily myelinated axons (A-α and A-β).

Question 56

A right-handed patient is scheduled to undergo a left frontotemporal awake craniotomy for the purposes of speech localization. The patient has a left frontotemporal brain tumor. Which of the following brain regions is most likely to result in speech arrest when stimulated?

A. The anterior superior temporal gyrus
B. The motor strip medial to the hand knob
C. The posterior inferior frontal gyrus
D. The lateral postcentral gyrus
E. The anterior inferior frontal gyrus

Answer 56

C. The posterior inferior frontal gyrus

The posterior third of the inferior frontal gyrus contains the area classically referred to as “Broca’s area.” This area (and the underling white matter tracts) is essential for the production of fluent speech. Broca’s area has been referred to by some authors as the pars triangularis and others as the pars opercularis, but it is generally accepted to overlap with the posterior inferior frontal gyrus. Quinones-Hinojosa and colleagues found that the majority of speech arrest occurring during intraoperative direct electrical cortical stimulation was seen with stimulation over or near the posterior inferior frontal gyrus

Question 57

Which of the following neurotransmitters is released within the dorsal horn of the spinal cord by central sensory nerve endings of nociceptive afferents?

A. Serotonin
B. Norepinephrine
C. Glutamate
D. Dopamine
E. GABA
F. Acetylcoline

Answer 57

C. Glutamate

Small diameter primary afferents terminate superficially in lamina I and II of the dorsal horn of the spinal cord and exert frequency-dependent depolarizing effects upon second order neurons. This effect is mediated in part through the release of excitatory transmitters such as glutamate and peptides such as substance P.

Question 58

Complex regional pain syndrome most commonly results from injury to which of the following?

A. Nociceptive afferent fibers
B. Periaqueductal gray
C. Nucleus gracilis
D. Nucleus cuneatus
E. Zygapophyseal joint

Answer 58

A. Nociceptive afferent fibers

Nociceptive afferents may become sensitive to sympathetic modulation following injury, and this is thought to be a factor contributing to some pain conditions such as certain types of complex regional pain syndrome. In CRPS Type 1, formerly known as reflex sympathetic dystrophy (RSD), dysregulation of sympathetic activity has been traditionally thought to play a fundamental role in the syndrome’s pathogenesis. Inflammation is also thought to play a role in the syndrome, and the clinical presentation often has characteristics of an acute inflammatory process (erythema, edema, warmth, and pain). Finally, peripheral sensitization from inflammatory and immunologic responses may ultimately lead to central sensitization and play a role in the pathophysiology.

Question 59

The loss of cell bodies in a projection system from the substantia nigra in Parkinson disease results in loss of:

A. Acetylcholine
B. Norepinephrine
C. Serotonin
D. Dopamine
E. Glutamate

Answer 59

D. Dopamine

The correct answer is dopamine. The basal ganglia are subcortical nuclei controlling voluntary actions and have been implicated in Parkinson’s disease (PD). The prevailing model of basal ganglia function states that two circuits, the direct and indirect pathways, originate from distinct populations of striatal medium spiny neurons (MSNs) and project to different output structures. These circuits are believed to have opposite effects on movement. Specifically, the activity of direct pathway MSNs is postulated to promote movement, whereas the activation of indirect pathway MSNs is hypothesized to inhibit it. Their activity is modulated by D1 and D2 dopamine receptors contained in the substantia nigra, pars compacta.
Direct pathway
Type: Excitatory
Pathway: cortex -> striatum -> globus pallidus, pars interna -> thalamus -> motor cortex -> spinal cord / brainstem
Function: movement initiation

Indirect pathway
Type: Inhibitory
Pathway: cortex -> striatum -> globus pallidus, pars externa -> subthalamic nucleus -> globus pallidus, pars externa -> thalamus -> motor cortex -> spinal cord / brainstem
Function: movement termination
The nigrostriatal pathway projects from the substantia nigra pars compacta to the striatum, and it utilizes the neurotransmitter dopamine. This pathway has a modulatory effect on the basal ganglia, with dopamine facilitating the motor loop in these two ways: It excites the direct pathway, and it inhibits the indirect pathways
The different effect on the direct and indirect pathway is explained by the activation of the different dopamine receptors that are located within the neurons of the striatum. Stimulation of D1 results with the excitation of the neuron, while the stimulation D2 results with inhibition. The final effect of the nigrostriatal pathway is the promotion of the direct pathway and at the same time the inhibition of the indirect pathway

Question 60

Deep brain stimulation of which of the following is the most appropriate surgical treatment for essential tremor?

A. VIM thalamus
B. Subthalamic nucleus
C. Globus pallidus interna
D. Globus pallidus externa
E. Substantia nigra

Answer 60

A. VIM thalamus

Deep brain stimulation of the ventral intermediate (VIM) nucleus of the thalamus is most effective for essential tremor. The subthalamic nucleus and globus pallidus interna (GPi) are targets for Parkinson’s disease. The substantia nigra and globus pallidus externa are not DBS targets.

Question 61

Which of the following is most likely to be effective in the treatment of palmar hyperhidrosis?

A. Botulinum toxin injections
B. Astringent solutions
C. Anticholinergic medications
D. Radiofrequency sympathectomy
E. Video-assisted thorascopic sympathectomy

Answer 61

E. Video-assisted thorascopic sympathectomy

Video-assisted thorascopic sympathectomy has become the procedure of choice in the treatment of palmar hyperhidrosis. While RF sympathectatomy is possible, this has not achieved the level of success that has been achieved with direct sympathetctomy. Botulinum toxin, anticholinergic medications and astringent solution are reasonable conservative measures but also have not achieved the same level of success as that seen in thorascopic sympathectomy. T2 and T3 thoracic ganglia are the targets for palmar hyperhidrosis. The T4 thoracic ganglia is the target for axillary hyperhidrosis. Horner’s syndrome can result from injury to the T1 ganglion.

Question 62

Which of the following tests directly measures changes in regional cerebral blood flow?

A. Intracarotid amobarbital injection
B. PET
C. SPECT
D. Transcranial Doppler ultrasound

Answer 62

C. SPECT

During a seizure there is an acute elevation of perfusion to involved brain areas. SPECT evaluates dynamic changes in cerebral perfusion that occur during a seizure. It is a technique in which an isotope (Technetium-99) is intravenously administered during two phases (during interictal periods and during seizures), and then imaged using a CT scanner and gamma camera.
EEG studies are performed in parallel to assess seizure activity. A subtraction analysis of radioisotope signal (ictal pattern minus interictal pattern) is performed to identify areas of increased radiotracer signal during seizures. This information can provide localizing information as to the onset/involvement of seizures. SPECT is limited in part by the requirement that the tracer should be injected within 30 seconds of seizure onset in order to achieve reliable results. Radiotracer uptake is a delayed process (taking ~40s), meaning that short seizures may terminate before perfusion can be assessed.

Question 63

Macrostimulation within the globus pallidus interna (GPi) for treatment of Parkinson disease is most likely to result in which of the following?

A. Muscle contractions
B. Paresthesia
C. No effect
D. Reduction of tremor
E. Visualization of phosphenes

Answer 63

D. Reduction of tremor

Macrostimulation in the posterioventral GPi should result in a decrease in Parkinsonian symptoms, particularly bradykinesia, tremor, rigidity. Muscle contractions at low stimulation levels signifies that the lead position is either posterior or medial, leading to stimulation of the internal capsule. Stimulation of the optic tract deep to the GPi will result in the visualization of phosphenes in the contralateral hemifield.

Question 64

A 65-year-old man is brought to the emergency department after being found unconscious at home. He has had tonic-clonic convulsive movements of all extremities for the past 15 minutes. He had a right hemisphere stroke six months ago. His airway is unobstructed; his oxygen saturation is 92%. Which of the following is the most appropriate initial step in management?

A. STAT CT brain with perfusion studies
B. Metabolic panel and toxicology studies
C. Administration of intravenous anti-epileptic
D. Administer Thiamine
E. Emergent intubation

Answer 64

C. Administration of intravenous anti-epileptic

The initial assessment of any critical ill patient should involve evaluation and management of ABCs: Airway, Breathing, Circulation. This patient presents with an unobstructed airway and appropriate oxygen saturation. Provided the patient exhibits sufficient cardiac and autonomic function to maintain a pulse and adequate perfusion (e.g., normotension), then the next step in his management is to address seizure activity, which, if not properly managed, could contribute to decline of ABCs and other critical systems/functions. Thus, administration of anti-epileptic agents (e.g., a benzodiazepine, followed by loading of longer-acting agents such as fosphenytoin, valproic acid, keppra), is the next step in the patient’s management. While brain imaging and blood studies should be obtained, management of the patient’s seizures should be prioritized.

Question 65

Which of the following is the most appropriate anatomic target for deep brain stimulation to treat rigidity and bradykinesia in a patient with Parkinson disease?

A. Substantia nigra
B. None of the above
C. VIM thalamus
D. Globus pallidus externa
E. Globus pallidus interna

Answer 65

E. Globus pallidus interna

The two targets of Parkinson’s disease are the globus pallidus interna (GPi) and subthalamic nucleus (STN). Both targets have similar motor outcomes and the decision of which target to recommend is typically based on individual patient needs. However, GPI DBS may be more effective in cases with significant dystonia or lower baseline cognitive status. DBS targeting the STN typically results in greater medication reduction than GPI. The globus pallidus externa, substantia nigra, and VIM thalamus are not targets for Parkinson’s disease.

Question 66

Cholinergic nerve impulses cause which of the following?

A. Pupil dilation
B. Constipation
C. Vasodilation
D. Piloerection
E. Tachycardia

Answer 66

C. Vasodilation

Acetylcholine is the chief neurotransmitter of the parasympathetic nervous system. There are two main classes of acetylcholine receptors, nicotinic and muscarinic. Nicotinic receptors are inotropic whereas muscarinic receptors are g-protein coupled. In cardiovascular system, acetylcholine acts as a vasodilator, decreases heart rate, and decreases heart muscle contraction. In the gastrointestinal system, acetylcholine acts to increase peristalsis in the stomach and the amplitude of digestive contractions. In the urinary tract, its activity decreases the capacity of the bladder and increases voluntary voiding pressure. Acetylcholine also affects the respiratory system and stimulates secretion by all glands that receive parasympathetic nerve impulses.

Question 67

A patient who is comatose because of which of the following disorders is most likely to demonstrate non-convulsive status epilepticus when monitored by EEG?

A. raised intracranial pressure
B. cerebrospinal fluid leak
C. ethanol withdrawal
D. depressed skull fracture
E. hypoxic brain injury

Answer 67

E. hypoxic brain injury

Hypoxic brain injury can result in the development of non-convulsive status epilepticus (NCSE). Given that these patients often present with coma, a low threshold must be maintained for EEG evaluation in these patients to ensure that NCSE is identified and treated. Non-convulsive status epilepticus occurs in 22% of patients that are comatose after cardiac arrest due to hypoxic brain injury. In post-traumatic patients, hypoxemic brain injury has the highest relative risk of non- convulsive status epilepticus with a relative risk of 0.77.

Question 68

Which of the following antiepileptic drugs demonstrate the highest incidence of cross-sensitivity in the production of a rash?

A. Phenobarbital and Carbamazepine
B. Topiramate and Keppra
C. Carbamazepine and Phenytoin
D. Lamotrigine and Oxcarbazepine
E. Oxcarbazepine and Lamictal

Answer 68

C. Carbamazepine and Phenytoin

Administration of anti-epileptic drug therapy can result in skin rashes in nearly 10-15% of patients. There is a high degree of cross-sensitivity to anti-epileptic drugs, where sensitivity to one agent is
associated to sensitivity to other agents (rates of cross-sensitivity can be as high as 30-60%). In this regard, there is a high degree of cross-sensitivity to carbamazepine, oxcarbazepine, and phenytoin.

Question 69

A 22-year-old woman who has acute viral myocarditis suffers a left frontal stroke. She develops unremitting rhythmic jerking of her right lip and thumb that persists for three weeks and does not respond to therapy. She is able to follow commands but cannot stop the twitching. This seizure type is most consistent with which of the following?

A. hemiballismus
B. epilepsia partialis continua
C. chorea
D. oromandibular dystonia
E. functional disorder

Answer 69

B. epilepsia partialis continua

Post-stroke seizures can occur in up to 11.5% of patients after 5 years. This risk is higher with hemorrhagic stroke (up to 15.4%) and lower with ischemic stroke (8.5%). Approximately 7% of patients develop epilepsy after stroke. In this patient, unremitting continuous motor movements may represent focal motor epilepsia partialis continua, she is able to follow commands as this form of status epilepticus is not generalized. Epilepsia partialis continua is also known as Kozhevnikov’s epilepsia.

Question 70

A 50-year-old man has a progressive unilateral familial intention tremor that is refractory to medical therapy. Which of the following is the most appropriate treatment?

A. Bilateral VIM deep brain stimulation
B. Unilateral thalamotomy
C. Unilateral VIM deep brain stimulation
D. Unilateral GPi deep brain stimulation
E. Unilateral dentate nucleus deep brain stimulation

Answer 70

C. Unilateral VIM deep brain stimulation

In patients without contraindication to open surgery, deep brain stimulation of the VIM thalamus is the most appropriate treatment for medically refractory tremor. As the patient’s symptoms are unilateral, a unilateral target would be chosen. Tremor is characterized by its frequency and characteristic postural features. An intention tremor is a type of kinetic tremor that is <5 Hz and brought out with finger to nose movements. It is considered a cerebellar outflow tremor and may be due to a familial genetic abnormality or multiple sclerosis. A Holmes tremor is another type of kinetic tremor, 2-4 Hz, and is frequently caused by stroke. Postural tremor is characterized by an 8-12 Hz movement brought out when the limb is outstretched against gravity. Essential tremor is the most common type. A dystonic tremor is typically 4-7 Hz and associated with rigidity. GPi is not considered the first choice for these tremors, though it may be an option for VIM-refractory cases. Dentate nucleus DBS has not been extensively studied for tremor and would not be a first- line therapy. Thalamotomy is generally not a first choice due to irreversibility, though if patients are averse to open surgery, have medical comorbidities, or do not wish to have hardware implanted, unilateral thalamotomy could be considered. In complex tremors not responding to conventional targets, other targets may be considered, such as the subthalamic area, prelemniscal radiation, zona incerta, and others.

Question 71

Which of the following lesions is most likely to be associated with gelastic seizures?

A. DNET
B. subependymal giant cell astrocytoma C. focal cortical dysplasia
D. periventricular nodular heterotopia
E. hypothalamic hamartoma

Answer 71

E. hypothalamic hamartoma

Hypothalamic hamartomas (HH) are benign hamartomatous growths in the hypothalamus that are associated with central precocious puberty and seizures (approximately 40% of HH patients with epilepsy also have precocious puberty). Seizure semiologies associated with hypothalamic hamartomas include gelastic and dacrystic seizures, which are characterized by laughing or crying spells respectively. These are believed to be due to spread of seizure activity into the limbic portions of the cingulate cortex. Mean age of gelastic seizures is 11 months of age. Associated symptoms include developmental delay, cognitive deterioration, and behavioral symptoms (especially rage-attacks/explosive anger). Over 95% of HH are idiopathic, it is also associated with Pallister-Hall syndrome, associated with a gene mutation in GLI3, a transcription factor in the sonic hedgehog (SHH) pathway.

Question 72

During seizure activity, which of the following changes in cerebral blood flow (CBF) and cerebral oxygen utilization (CMRO2) occur?

A. Decrease CBF, Increase CMRO2
B. Increase CBF, Increase CMRO2
C. Increase CBF, Increase CMRO2
D. No change CBF, Increase CMRO2
E. Decrease CBF, Decrease CMRO2

Answer 72

B. Increase CBF, Increase CMRO2

Human studies of focal seizures have shown hyperperfusion and hypermetabolism at the site of the focus often with widespread depression of both parameters in the ipsilateral neocortex. Thus, seizures increase cerebral blood flow and cerebral oxygen utilization. The high metabolic rate during sustained seizure activity will increase the susceptibility of the brain to ‘ischemic’ damage during prolonged seizures. Additional metabolic stress may also be imposed by cerebral hypoxia, arterial hypotension, hyperpyrexia or hypoglycemia.