LE1 - NEURO 2023 Flashcards
Which of the following therapies is effective in treating Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)?
A. IVIG only
B. Corticosteroids, physical therapy, immune globulins
C. Corticosteroids, immune globulins, nerve growth factor
D. Corticosteroids, physical therapy, radiation therapy
E. Plasma exchange, surgery, immune globulins
B. Corticosteroids, physical therapy, immune globulins
Rationalization:
CIDP is an immune-mediated neuropathy that responds to immunomodulatory treatments. According to Harrison’s, corticosteroids, intravenous immunoglobulins (IVIG), and plasmapheresis are the mainstays of treatment. Physical therapy is also important for maintaining muscle strength and preventing atrophy. Nerve growth factors and radiation therapy are not effective treatments for CIDP.
True regarding the mechanism of seizure, EXCEPT:
A. Increase in extracellular K+ blunts hyperpolarization & depolarizes neighboring neurons
B. Accumulation of Ca2+ in presynaptic terminals, leading to enhanced neurotransmitter release
C. Depolarization-induced activation of the NMDA subtype of the excitatory amino acid receptor, which causes additional Ca2+ influx and neuronal activation
D. None, all statements are correct
D. None, all statements are correct
Rationalization:
Harrison’s details the mechanisms of seizure activity, which include increased extracellular potassium blunting hyperpolarization, calcium accumulation in presynaptic terminals enhancing neurotransmitter release, and depolarization-induced activation of NMDA receptors causing additional calcium influx. All these statements accurately describe mechanisms that contribute to seizure activity.
A 30 y/o female was admitted at the ER for sudden severe headache and neck stiffness. CT showed the following. What will be your primary working impression?
A. Subarachnoid hemorrhage
B. Brain tumor
C. Meningitis
D. Status migrainosus
A. Subarachnoid hemorrhage
Rationalization:
Harrison’s explains that a sudden severe headache, often described as the worst headache of one’s life, along with neck stiffness, is highly suggestive of subarachnoid hemorrhage. This is often confirmed by CT imaging showing bleeding.
The following statements are true regarding Subacute combined degeneration, EXCEPT:
A. Loss of vibration and position sense
B. Loss of reflexes without neuropathy
C. Predominant involvement of the posterior and lateral tracts, including Romberg’s sign
D. None, all are correct
B. Loss of reflexes without neuropathy
Rationalization:
Subacute combined degeneration, associated with vitamin B12 deficiency, affects the dorsal and lateral columns of the spinal cord, leading to loss of vibration and position sense, and positive Romberg’s sign. Loss of reflexes typically occurs with neuropathy, not without.
Drug of choice for Juvenile Myoclonic Epilepsy:
A. Phenytoin
B. Valproic acid
C. Oxcarbazepine
D. Ethosuximide
E. Carbamazepine
B. Valproic acid
Rationalization:
Valproic acid is considered the first-line treatment for Juvenile Myoclonic Epilepsy, as it effectively controls myoclonic jerks, generalized tonic-clonic seizures, and absence seizures. Harrison’s endorses this approach over other medications listed.
The normal EEG background activity in an awake adult is:
A. <4 Hz delta rhythm
B. >13 Hz beta rhythm
C. 8-13 Hz alpha rhythm
D. 4-7 Hz theta rhythm
C. 8-13 Hz alpha rhythm
Rationalization:
In an awake and relaxed adult, the normal EEG background rhythm is the alpha rhythm, typically ranging from 8 to 13 Hz, predominantly seen in the occipital regions. This is supported by electrophysiological data detailed in Harrison’s.
A 75-year-old woman presented to the clinic with a 2-year history of falling that had progressed over time. She reported she would just suddenly fall without a trigger. On examination, her neck was hyperextended and she had difficulty flexing. She had impaired vertical gaze, predominantly downward gaze. There was mild bilateral rigidity in the upper extremities. On pull test, she would fall if not caught by the examiner. MRI revealed atrophy of midbrain compared to pons. What is the most likely diagnosis?
A. Multiple-System Atrophy
B. Idiopathic Parkinson’s disease with early falling
C. Corticobasal ganglionic degeneration
D. Progressive Supranuclear Palsy
D. Progressive Supranuclear Palsy (PSP)
Rationale with keywords:
- History of Falling: PSP often presents with unexplained falls, which are typically backward falls. The patient’s 2-year history of sudden falls is consistent with PSP.
- Neck Hyperextension: A classic sign in PSP, neck hyperextension is a key clinical feature that helps distinguish it from other neurodegenerative diseases.
- Impaired Vertical Gaze: Difficulty with vertical gaze, especially downward gaze, is a hallmark of PSP. This symptom is a significant indicator as it is not commonly seen in other parkinsonian syndromes.
- Mild Bilateral Rigidity in Upper Extremities: PSP can present with rigidity, although it is often less pronounced than in Parkinson’s disease.
- Pull Test: The patient’s tendency to fall if not caught by the examiner during the pull test is indicative of postural instability, a common feature of PSP.
- MRI Findings: Atrophy of the midbrain compared to the pons, often described as the “hummingbird sign” or “penguin sign,” is a characteristic imaging finding in PSP.
These keywords and clinical features strongly suggest Progressive Supranuclear Palsy (PSP) as the most likely diagnosis.
A 14-year-old girl with history of muscle jerks in the early morning, or with sleep deprivation, presents with a generalized tonic clonic seizure after a late night playing video games. Which of the following is the most likely diagnosis?
A. Psychogenic seizure
B. Rolandic Epilepsy
C. Mesial Temporal Lobe Epilepsy
D. Juvenile Myoclonic Epilepsy
D. Juvenile Myoclonic Epilepsy
Rationalization:
Juvenile Myoclonic Epilepsy (JME) often presents with myoclonic jerks upon awakening and can be triggered by sleep deprivation. Harrison’s emphasizes the typical presentation and triggers for JME.
The following are true in TB meningitis, EXCEPT:
A. It usually presents as a subacute to chronic form of meningitis.
B. Hydrocephalus and arteritis are possible complications
C. Corticosteroids are contraindicated in TB meningitis as it has shown to increase morbidity and mortality
D. Acid-fast bacilli has a tendency to seed in the basal surface of the brain due to higher oxygen tension
C. Corticosteroids are contraindicated in TB meningitis as it has shown to increase morbidity and mortality
Rationale:
Harrison’s emphasizes that corticosteroids are actually recommended in TB meningitis as they have been shown to reduce mortality and improve outcomes by decreasing inflammatory responses and subsequent complications like hydrocephalus and arteritis. The statement in option C is incorrect.
A 72-year-old woman is brought to the clinic by her family for trouble walking. The patient reports that when she stands to walk, she feels her legs are very unsteady and she is scared of falling. Because of this fear, she prefers to get around on a wheelchair. However, if she is made to stand and finally walk, once she gets moving, her gait is fine and she has no difficulties. On examination, while seated, no tremor, rigidity, or bradykinesia are present. On standing, a high-frequency tremor in the thighs and “bobbing” of knees is seen, and the patient expresses a sense of unsteadiness and fear of falling. Which of the following is the most likely diagnosis?
A. Orthostatic tremor
B. Essential tremor
C. Psychogenic gait tremor
D. Normal-pressure hydrocephalus
A. Orthostatic tremor
Rationale:
- High-Frequency Tremor in the Thighs and Bobbing of Knees: These symptoms are characteristic of orthostatic tremor, which is a rare condition that presents with a high-frequency tremor (13-18 Hz) primarily affecting the legs when standing. This tremor is often described as a sensation of unsteadiness and may be visually observed as a rapid tremor in the thighs or knees.
- Sense of Unsteadiness and Fear of Falling: Patients with orthostatic tremor frequently experience a strong sense of unsteadiness and fear of falling when standing, which leads them to prefer sitting or using a wheelchair to avoid these sensations.
- Improvement with Movement: Unlike many other tremor disorders, patients with orthostatic tremor often find that their symptoms improve or resolve when they start walking or are seated, as the tremor is specifically associated with standing.
- Absence of Tremor, Rigidity, or Bradykinesia while Seated: The lack of tremor, rigidity, or bradykinesia when the patient is seated further supports orthostatic tremor, as these symptoms would be more suggestive of Parkinson’s disease or other parkinsonian syndromes if present.
Other options are less likely:
- B. Essential Tremor: Typically affects the hands and arms more prominently and is present with action, not specifically with standing.
- C. Psychogenic Gait Tremor: Often presents with inconsistency and variability, along with other psychological factors that are not indicated here.
- D. Normal-Pressure Hydrocephalus: Usually presents with a triad of gait disturbance, urinary incontinence, and cognitive impairment, none of which are specifically mentioned in this case.
Given the specific symptoms and clinical findings described, orthostatic tremor is the most likely diagnosis.
The most common clinical manifestation of muscle weakness with myasthenia gravis is:
A. Difficulty swallowing
B. Weakness of facial expression
C. Ocular muscle weakness
D. Dysarthria
C. Ocular muscle weakness
Rationale:
The most common clinical manifestation of muscle weakness in myasthenia gravis is ocular muscle weakness, which typically presents as ptosis (drooping of the eyelids) and diplopia (double vision). According to Harrison’s, these symptoms are often the initial and most prominent signs of myasthenia gravis, although generalized muscle weakness can also occur.
A nocturnal tonic-clonic seizure with focal onset is called:
A. Lennox-Gastaut Syndrome
B. Epilepsy with occipital spikes
C. Benign epilepsy of childhood with centrotemporal spikes
D. Juvenile Myoclonic Epilepsy
C. Benign epilepsy of childhood with centrotemporal spikes
Rationale:
Benign epilepsy of childhood with centrotemporal spikes, also known as Rolandic epilepsy, is characterized by nocturnal tonic-clonic seizures that can have a focal onset. Harrison’s describes this condition as the most common type of childhood epilepsy, with seizures often occurring during sleep and involving facial and oropharyngeal muscles.
The following is/are features of uncal herniation:
A. Tachycardia
B. Large pupil
C. None of the choices
D. Fully awake patient
B. Large pupil
Rationale:
Uncal herniation, a type of brain herniation, leads to compression of the oculomotor nerve, resulting in a dilated (large) pupil on the affected side. Harrison’s notes that this is a key clinical feature, along with other signs such as hemiparesis and decreased consciousness.
The following was noted on histopath. Which of the following is the most likely diagnosis?
A. Medulloblastoma
B. Ependymoma
C. Germinoma
D. Glioblastoma multiforme
A. Medulloblastoma
Rationale:
Medulloblastoma is a common pediatric brain tumor that often presents with characteristic histopathological findings, such as small, round blue cells. Harrison’s provides detailed descriptions of various brain tumors, noting that medulloblastomas are typically located in the cerebellum and are highly cellular with high mitotic activity.
EEG findings in a patient with Infantile spasm or West syndrome:
A. High-voltage spikes in the contralateral centrotemporal area
B. Continuous multifocal spikes and slow waves of large amplitude (hypsarrhythmia)
C. Slow 1-2 Hz spike and wave pattern
D. Generalized bursts of 4-6 Hz irregular polyspike activity
B. Continuous multifocal spikes and slow waves of large amplitude (hypsarrhythmia)
Rationale:
Infantile spasms, also known as West syndrome, are associated with a specific EEG pattern called hypsarrhythmia. This pattern consists of high-voltage, chaotic, asynchronous slow waves and spikes. Harrison’s emphasizes that hypsarrhythmia is a hallmark of this severe epilepsy syndrome, which typically presents in infancy and is often associated with developmental regression.
Where is the most common location of oligodendroglioma?
A. Parietal lobe
B. Temporal lobe
C. Frontal lobe
D. Occipital lobe
C. Frontal lobe
Rationale:
Oligodendrogliomas are primary brain tumors that most commonly arise in the frontal lobe. Harrison’s notes that the frontal lobes are the most frequent location for these tumors, accounting for a majority of cases. This localization can influence the clinical presentation, often causing personality changes, cognitive deficits, and other frontal lobe-related symptoms.
True of Charcot-Marie Tooth Disease, EXCEPT:
A. CMT3 is associated with deletion in PMP22 gene point mutation
B. CMT1 is the most common form of hereditary neuropathy
C. None, all are correct
D. Onion bulb formation seen on pathology
A. CMT3 is associated with deletion in PMP22 gene point mutation
Rationale:
Charcot-Marie-Tooth Disease (CMT) is a group of hereditary neuropathies. CMT1 is the most common form and is associated with a duplication of the PMP22 gene, not a deletion. CMT3, also known as Dejerine-Sottas disease, involves mutations in different genes (e.g., MPZ, PMP22, or EGR2), but it is not characterized by a deletion in PMP22. Onion bulb formations are seen in pathology for many forms of CMT due to repetitive demyelination and remyelination processes, as detailed in Harrison’s.
Most significant cause of cardioembolic stroke worldwide:
A. Cyocarditis
B. Non valvular atrial fibrillation
C. Cardiomyopathy
D. Rheumatic heart disease
B. Non valvular atrial fibrillation
Rationale:
Non-valvular atrial fibrillation is the most significant cause of cardioembolic stroke worldwide. This condition leads to the formation of thrombi in the atria, particularly the left atrial appendage, which can embolize to the cerebral circulation, causing stroke. Harrison’s highlights the prevalence and impact of atrial fibrillation as a leading risk factor for cardioembolic stroke.
Which of the following toxic neuropathy-causing drugs/agents may manifest as wrist drop?
A. Arsenic
B. Colchicine
C. Lead
D. Carbon
E. Mercury
C. Lead
Rationale:
Lead poisoning can result in a specific type of neuropathy that affects the radial nerve, leading to wrist drop. This occurs because the radial nerve is responsible for controlling the muscles that extend the wrist and fingers. Lead is known to cause peripheral neuropathy, and wrist drop is a classic symptom of lead-induced neuropathy.
Other options are less likely to specifically cause wrist drop:
- A. Arsenic: Arsenic poisoning typically causes a sensorimotor peripheral neuropathy but is not specifically associated with wrist drop.
- B. Colchicine: Colchicine toxicity primarily affects the gastrointestinal tract and bone marrow, and while it can cause myopathy and neuropathy, wrist drop is not a characteristic feature.
- D. Carbon: There is no well-known association between carbon exposure and wrist drop.
- E. Mercury: Mercury poisoning causes a range of neurological symptoms, but wrist drop is not a typical manifestation.
Therefore, lead is the correct answer due to its known effect on the radial nerve and the resulting clinical presentation of wrist drop.
A 35 y/o female, hypertensive, diabetic with rheumatic heart disease and atrial fibrillation presented with sudden onset left sided weakness. She has signs and symptoms of congestive heart failure (easy fatigability, bipedal edema, orthopnea). What is her CHADSVASc score?
A. 5
B. 6
C. 7
D. 3
C. 7
Rationale:
The CHADSVASc score is used to estimate the risk of stroke in patients with atrial fibrillation. The scoring system is as follows:
* Congestive heart failure (1 point)
* Hypertension (1 point)
* Age ≥ 75 years (2 points)
* Diabetes mellitus (1 point)
* Stroke/TIA/Thromboembolism history (2 points)
* Vascular disease (1 point)
* Age 65-74 years (1 point)
* Sex category (female) (1 point)
Which of the following statements is incorrect regarding Huntington Disease?
A. It is autosomal recessive in inheritance
B. It results from a mutation in chromosome 4
C. Mutation is due to excessive repeats of trinucleotide CAG
D. Atrophy of the caudate and putamen is the pathologic finding
A. It is autosomal recessive in inheritance (should be autosomal dominant)
Rationale:
Huntington Disease is an autosomal dominant disorder caused by a mutation in the HTT gene on chromosome 4, involving an excessive number of CAG repeats. The pathologic finding includes atrophy of the caudate and putamen. Harrison’s confirms that the inheritance pattern is autosomal dominant, not recessive.
The following may cause coma without lateralizing neurologic signs EXCEPT:
A. Anoxia
B. Hypoglycemia
C. Diabetic acidosis
D. Brain tumor
D. Brain tumor
Rationale:
Conditions like anoxia, hypoglycemia, and diabetic acidosis can cause coma without lateralizing neurologic signs because they affect the brain globally. A brain tumor, however, often produces focal neurological deficits or lateralizing signs. Harrison’s emphasizes that metabolic disturbances typically lead to diffuse encephalopathy, while structural lesions like tumors often cause localized deficits.
Most common site of hypertensive intraparenchymal hemorrhage:
A. Basal ganglia
B. Medulla
C. Midbrain
D. Cerebral cortex
A. Basal ganglia
Rationale:
The basal ganglia, particularly the putamen, is the most common site for hypertensive intraparenchymal hemorrhage. Harrison’s notes that chronic hypertension predisposes to hemorrhage in these deep brain structures due to the rupture of small penetrating arteries.
Pathophysiology of ischemic stroke:
A. Formation of atherosclerotic plaque in the large and medium sized blood vessels leading to weakness of blood vessel wall
B. Formation of charcot bouchard aneurysm
C. Lipohyalinosis
D. Hemorrhagic transformation + cerebral edema
A. Formation of atherosclerotic plaque in the large and medium-sized blood vessels leading to weakness of the blood vessel wall
Rationale:
- A. Formation of atherosclerotic plaque in the large and medium-sized blood vessels leading to weakness of the blood vessel wall: This option correctly describes a key mechanism in the pathophysiology of ischemic stroke. Atherosclerosis involves the buildup of plaques in the arteries, which can lead to narrowing or occlusion of these vessels, reducing blood flow to brain tissue and resulting in ischemic stroke. The plaques can also become unstable and lead to the formation of thrombi or emboli, which can travel to cerebral arteries and cause stroke.
Other options are less directly related to the pathophysiology of ischemic stroke:
- B. Formation of Charcot-Bouchard aneurysm: This is more relevant to hemorrhagic stroke, particularly in the context of hypertensive hemorrhages in small vessels.
- C. Lipohyalinosis: While this is a process affecting small vessels and can contribute to small vessel (lacunar) ischemic strokes, it is not the primary mechanism in most ischemic strokes, which commonly involve larger vessels.
- D. Hemorrhagic transformation + cerebral edema: These are potential complications of ischemic stroke, particularly after the initial event, but they do not describe the primary pathophysiological mechanism of ischemic stroke itself.
Therefore, the formation of atherosclerotic plaques in large and medium-sized blood vessels is the most accurate description of the pathophysiology of ischemic stroke.
True about neuroimaging for acute stroke:
A. Cranial MRI with contrast is the preferred method as it is the most sensitive in detecting acute blood
B. Cranial CT scan with contrast is the preferred neuroimaging method as it is more sensitive than routine MRI in detecting acute infarcts.
C. Cranial CT scan with contrast is the preferred method as it is more sensitive in detecting hematoma than plain CT scan
D. Plain cranial CT scan is the preferred neuroimaging method as it is readily available and can rule out presence of hematoma
E. Cranial MRI with DWI is the preferred method as it is readily available, may be done quickly and can detect hyperacute infarcts
D. Plain cranial CT scan is the preferred neuroimaging method as it is readily available and can rule out presence of hematoma
Rationale:
- D. Plain cranial CT scan is the preferred neuroimaging method as it is readily available and can rule out presence of hematoma: Plain cranial CT scan is commonly used as the initial imaging modality in the evaluation of acute stroke because it is widely available, can be performed quickly, and is effective in ruling out hemorrhagic stroke (presence of hematoma). This is crucial for determining the appropriate treatment strategy, particularly the use of thrombolytic therapy.
Other options explained:
- A. Cranial MRI with contrast is the preferred method as it is the most sensitive in detecting acute blood: MRI with contrast is not typically used in the acute setting for detecting hemorrhage. Non-contrast CT is faster and more accessible.
- B. Cranial CT scan with contrast is the preferred neuroimaging method as it is more sensitive than routine MRI in detecting acute infarcts: Non-contrast CT is usually preferred in the acute setting. MRI, particularly with DWI (Diffusion-Weighted Imaging), is more sensitive for detecting acute infarcts.
- C. Cranial CT scan with contrast is the preferred method as it is more sensitive in detecting hematoma than plain CT scan: Non-contrast CT is sufficient to detect hemorrhage in the acute setting. Contrast is not necessary and can sometimes obscure hemorrhage.
- E. Cranial MRI with DWI is the preferred method as it is readily available, may be done quickly and can detect hyperacute infarcts: While MRI with DWI is highly sensitive for detecting hyperacute infarcts, it is not as readily available and not as quick to perform as a non-contrast CT in many emergency settings.
Neuropathologic findings seen in Alzheimer’s Disease:
A. Lewy Bodies
B. Neuritic plaques & neurofibrillary tangles
C. Lysosomal aggregates
D. Negri bodies
B. Neuritic plaques & neurofibrillary tangles
Rationale:
The hallmark neuropathologic findings in Alzheimer’s Disease are neuritic plaques, composed of amyloid-beta, and neurofibrillary tangles, composed of hyperphosphorylated tau protein. Harrison’s highlights these features as key diagnostic criteria for Alzheimer’s Disease.
First line empiric treatment in a 30 year old patient presenting with acute bacterial meningitis:
A. Vancomycin + Ampicillin + Ceftazidime
B. 3rd generation cephalosporin + Vancomycin (+/- Ampicillin)
C. Cefotaxime + Ampicillin
D. 3rd generation cephalosporin + Metronidazole
B. 3rd generation cephalosporin + Vancomycin (+/- Ampicillin)
Rationale:
Empiric treatment for acute bacterial meningitis in adults typically includes a third-generation cephalosporin (e.g., ceftriaxone or cefotaxime) combined with vancomycin, and sometimes ampicillin if Listeria monocytogenes coverage is needed. Harrison’s recommends this regimen due to its broad coverage against common pathogens.
The following are subtle signs of an early infarct on CT scan except:
A. Dense MCA sign
B. Insular ribbon sign
C. Hyperdense lesion on the internal capsule
D. Obscuration of the lentiform nucleus
C. Hyperdense lesion on the internal capsule
Rationale:
Subtle signs of early infarction on a CT scan include the dense MCA sign, insular ribbon sign, and obscuration of the lentiform nucleus. A hyperdense lesion in the internal capsule is not typically an early sign of infarction. Harrison’s describes the early CT findings in acute ischemic stroke and emphasizes the importance of recognizing these subtle changes.
TRUE of Wilson’s disease:
A. It is an autosomal dominant in inheritance
B. Treatment includes low copper diet
C. Treatment includes copper supplementation
D. It results from a mutation in the gene encoding for the copper-binding protein ceruloplasmin
E. Treatment includes low zinc diet
B. Treatment includes low copper diet
Rationale:
Wilson’s Disease is an autosomal recessive disorder resulting from mutations in the ATP7B gene, which encodes a copper-transporting ATPase. Treatment includes a low copper diet and chelation therapy to reduce copper accumulation. Harrison’s outlines these therapeutic strategies and the genetic basis of the disease.
Which of the following statements pertain to epidural hematoma?
A. A lucid interval several minutes to hours prior to coma is more common in subdural hemorrhage
B. It is usually due to rupture of the bridging veins
C. Would present as concave or crescent shaped hypodensity on CT scan
D. Would present as concave shaped hyperdense lesion on CT scan
D. Would present as concave shaped hyperdense lesion on CT scan
Rationale:
An epidural hematoma typically presents as a biconvex (lens-shaped) hyperdense lesion on CT scan. This is due to bleeding between the dura mater and the skull, usually from a ruptured middle meningeal artery. Harrison’s discusses the classic imaging appearance and clinical features of epidural hematomas, including the potential for a lucid interval prior to neurological deterioration.
A 65 y/o female was admitted for decreased sensorium and left sided weakness which started 1 hour ago. BP at the ER was 180/100 mmHg. Cranial CT scan revealed massive intracranial hemorrhage on the right basal ganglia area. The following should be included in the management of this patient:
A. Thrombolysis using rTPA at a dose of 0.9 mg/kg body weight, 10% as bolus and 90% as drip or an hour
B. Routine use of steroid to decrease edema
C. None of the choices
D. Hydration of the patient using D5 containing intravenous fluid
E. Use of mannitol or hypertonic saline to decrease intracranial pressure
E. Use of mannitol or hypertonic saline to decrease intracranial pressure
Rationale:
In the management of massive intracranial hemorrhage, particularly in the basal ganglia, it is crucial to manage increased intracranial pressure (ICP). Mannitol or hypertonic saline is used to reduce ICP by osmotic diuresis and reducing brain swelling. Harrison’s outlines these treatment strategies as part of the acute management of intracerebral hemorrhage.
Regarding Essential tremor, which of the following statements is/are correct?
A. All are correct
B. The tremor is typically high frequency, in the range of 8-12 Hz
C. Alcohol intake worsens the tremor
D. There is typically a family history of tremor in patients with this disorder
E. The tremor seen in this disorder persists during sleep
D. There is typically a family history of tremor in patients with this disorder
Rationale:
Essential tremor often has a genetic component, with many patients reporting a family history of similar tremors. Harrison’s notes that the tremor in essential tremor is typically of high frequency (8-12 Hz) and can be improved with alcohol intake, not worsened. The tremor does not persist during sleep, distinguishing it from other tremor disorders.
How does botulinum toxin cause myasthenic syndrome?
A. Binds to Ach receptors
B. Causes massive release of acetylcholine, resulting in muscular contraction and paralysis from lack of acetylcholine
C. Binds irreversibly to acetylcholinesterase
D. Binds to cholinergic motor endings, blocking quantal release of acetylcholine
D. Binds to cholinergic motor endings, blocking quantal release of acetylcholine
Rationale:
Botulinum toxin causes paralysis by binding to cholinergic nerve endings and inhibiting the release of acetylcholine at the neuromuscular junction. This blockade prevents muscle contraction, leading to the characteristic flaccid paralysis seen in botulism. Harrison’s details the mechanism of action of botulinum toxin in causing myasthenic syndromes.
Drug of choice for Lewy Body Dementia:
A. Galantamine
B. Rivastigmine
C. Memantine
D. Donepezil
B. Rivastigmine
Rationale:
Rivastigmine, a cholinesterase inhibitor, is often used as the drug of choice for managing cognitive symptoms in Lewy Body Dementia (LBD). Harrison’s highlights that cholinesterase inhibitors, including rivastigmine, can help improve cognitive function and reduce neuropsychiatric symptoms in LBD patients.
A 23-year-old woman awakens with bilateral leg weakness and numbness, urinary retention, and impaired bowel control. She had several episodes of blurring of vision over the previous 2 years, but these had always been attributed to idiopathic papillitis. Which of the following is the most likely diagnosis?
A. Multiple Sclerosis
B. Neuromyelitis optica (Devic’s disease)
C. Neoplastic spinal cord compression
D. Idiopathic transverse myelitis
B. Neuromyelitis optica (Devic’s disease)
Rationale:
- Bilateral Leg Weakness and Numbness: This indicates a significant spinal cord involvement.
- Urinary Retention and Impaired Bowel Control: These symptoms suggest a substantial involvement of the spinal cord affecting autonomic functions.
- History of Blurring Vision: The repeated episodes of visual problems, previously attributed to idiopathic papillitis, suggest an optic neuritis component.
- Combination of Spinal Cord and Optic Nerve Involvement: Neuromyelitis optica (NMO) or Devic’s disease is characterized by the combination of optic neuritis and transverse myelitis. The presence of both these symptoms strongly suggests NMO.
Other options are less likely:
- A. Multiple Sclerosis: While MS can present with optic neuritis and spinal cord symptoms, the acute and severe presentation of bilateral leg weakness and autonomic dysfunction is more characteristic of NMO. MS typically has a more varied and relapsing course.
- C. Neoplastic Spinal Cord Compression: This would typically present with more localized symptoms and might not explain the history of visual disturbances.
- D. Idiopathic Transverse Myelitis: This condition could explain the spinal cord symptoms but not the repeated episodes of optic neuritis.
Given the combination of optic neuritis and transverse myelitis, Neuromyelitis optica (Devic’s disease) is the most likely diagnosis.
The following statements are true about Korsakoff amnestic syndrome EXCEPT:
A. Impaired consciousness and awareness
B. Associated sequelae with Wernicke’s encephalopathy and chronic alcoholism
C. May have confabulation or falsification of facts
D. Have retrograde and anterograde amnesia
A. Impaired consciousness and awareness
Rationale:
Korsakoff amnestic syndrome primarily affects memory and is characterized by severe deficits in forming new memories (anterograde amnesia) and retrieving old memories (retrograde amnesia). Other true characteristics include:
- B. Associated sequelae with Wernicke’s encephalopathy and chronic alcoholism: Korsakoff syndrome often follows Wernicke’s encephalopathy, which is related to thiamine deficiency, frequently seen in chronic alcoholism.
- C. May have confabulation or falsification of facts: Patients with Korsakoff syndrome may confabulate, creating fabricated memories to fill in gaps in their memory.
- D. Have retrograde and anterograde amnesia: Korsakoff syndrome involves both retrograde amnesia (difficulty recalling past events) and anterograde amnesia (difficulty forming new memories).
Impaired consciousness and awareness are not characteristic features of Korsakoff amnestic syndrome. Patients typically have clear consciousness and awareness but significant memory impairment. Therefore, option A is the exception and is not true about Korsakoff amnestic syndrome.
An 8-year-old boy presents with frequent staring episodes while in class. Electroencephalogram (EEG) showed generalized 3Hz spike and wave pattern. Which of the following is the most appropriate medication for this patient?
A. Phenytoin
B. Oxcarbazepine
C. Ethosuximide
D. Levetiracetam
C. Ethosuximide
Rationale:
Ethosuximide is the drug of choice for treating absence seizures, which are characterized by frequent staring episodes and a generalized 3Hz spike and wave pattern on EEG. Harrison’s supports the use of ethosuximide as the most effective treatment for this type of epilepsy in children.
Regarding Neoplastic spinal cord compression, which of the following statements is/are true?
A. All of the above
B. Most intradural mass lesions are slow-growing and benign
C. Most neoplasms in adults result from metastases to adjacent vertebral column
D. The thoracic spinal column is the most common involved
A. All of the above
Rationale:
Neoplastic spinal cord compression can result from metastases to the vertebral column, with the thoracic spine being the most commonly affected region. Intradural mass lesions tend to be slow-growing and benign. Harrison’s outlines these points and emphasizes the importance of early diagnosis and treatment to prevent irreversible spinal cord damage.
The following tests for cerebellar function EXCEPT:
A. Finger to nose test
B. Rombergs test
C. Heel to shin test
D. Alternate pronation supination
B. Rombergs test for proprioception
Rationale:
The Romberg test assesses proprioception, not cerebellar function. Tests for cerebellar function include the finger-to-nose test, heel-to-shin test, and alternate pronation-supination movements. Harrison’s discusses these tests as part of a neurological examination to evaluate cerebellar integrity.
Microorganism causing acute bacterial meningitis that has rapid onset, associated with rash and shock:
A. H. influenzae
B. N. meningitidis
C. S. pneumoniae
D. Pseudomonas aeruginosa
B. N. meningitidis
Rationale:
Neisseria meningitidis is known for causing acute bacterial meningitis with a rapid onset, often associated with a petechial or purpuric rash and shock. Harrison’s emphasizes the distinct presentation of meningococcal meningitis, including the rapid progression and characteristic rash.
MC, a 70 year old male was admitted at the emergency room for sudden onset right sided weakness and slurring of speech 2 hours ago. On examination, he was drowsy and had right hemiplegia, right central facial palsy and right homonymous hemianopia. His blood pressure was 180/110. Compute for the mean arterial pressure (MAP):
A. 136
B. 160
C. 126
D. 133
D. 133
MAP = SBP + 2 DBP / 3
Which of the following statements about Glasgow coma score is correct?
A. Decerebrate posturing is given a score of M3
B. Verbal response of incomprehensible sounds is given a score of V3
C. Eye opening to pain is given a score of E2
D. Spontaneous movement of extremities is given a score of M4
C. Eye opening to pain is given a score of E2
Rationale:
The Glasgow Coma Scale (GCS) is used to assess the level of consciousness in patients with acute brain injury. Eye opening to pain is scored as E2. Harrison’s outlines the GCS scoring, noting that:
E2: Eye opening to pain
V3: Inappropriate words (not incomprehensible sounds)
M3: Flexor response to pain (decorticate posturing)
M4: Withdrawal from pain
Which of the following statements is true
A. The lesion is most likely in the right facial nerve or nucleus
B. The lesion is most likely in the left corticobulbar tract
C. This is a right central facial palsy
D. This is a left peripheral facial palsy
D. This is a left peripheral facial palsy
Rationale:
A right central facial palsy indicates a lesion in the left corticobulbar tract, resulting in weakness of the lower face on the right side while sparing the forehead due to bilateral cortical innervation. Harrison’s explains that central facial palsy involves the contralateral lower face due to the pattern of corticobulbar innervation.
A 45 y/o F was rushed to the emergency room with decreased consciousness. On examination, she only had eye opening when a painful stimulus (nailbed pressure) was applied. How will you record her level of consciousness?
A. Awake
B. Stuporous
C. Obtunded
D. Lethargic
B. Stuporous
This is because stuporous patients require a painful repeated stimulus to sustain wakefulness. describes obtundation as a state where the patient has diminished interest in the environment and can be aroused only by vigorous stimuli.
A lesion in the shaded area will have the following spinal cord syndrome:
A. Contralateral weakness, Ipsilateral loss of pain and temperature, Contralateral loss of joint position and vibration sense
B. Ipsilateral weakness, Contralateral loss of pain and temperature, Contralateral loss of joint position and vibration sense
C. Ipsilateral weakness, Contralateral loss of pain and temperature, Ipsilateral loss of joint position and vibration sense
D. Ipsilateral weakness, Ipsilateral loss of pain and temperature, Contralateral loss of joint position and vibration sense
C. Ipsilateral weakness, Contralateral loss of pain and temperature, Ipsilateral loss of joint position and vibration sense
Rationale:
This describes Brown-Séquard syndrome, which occurs due to hemisection (one-sided damage) of the spinal cord. The key features are:
- Ipsilateral weakness: Due to damage to the corticospinal tract, which results in motor deficits on the same side as the lesion.
- Contralateral loss of pain and temperature: Because of damage to the spinothalamic tract, which crosses to the opposite side a few segments above the level of entry, leading to loss of pain and temperature sensation on the opposite side of the body below the level of the lesion.
- Ipsilateral loss of joint position and vibration sense: Due to damage to the dorsal columns, which carry proprioceptive and vibration sensations and ascend ipsilaterally in the spinal cord.
Thus, the combination of these deficits aligns with option C.
45 y/o male involved in a vehicular crash. How will you document the findings shown?
A. Hemotympanum
B. Raccoon sign
C. Lid lag
D. Battle sign
B. Raccoon sign
Rationale:
The “Raccoon sign,” also known as periorbital ecchymosis, is indicative of a basal skull fracture. It presents as bruising around the eyes resembling a raccoon’s mask. Harrison’s describes this as a clinical sign often seen in patients who have sustained significant head trauma.
