WBR0574: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{Rim}}
|QuestionAuthor={{Rim}} (Reviewed by {{YD}})
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|MainCategory=Pathology, Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|Prompt=A 66 year old woman with recent hip fracture after a fall presents to the neurology clinic with complaints of hand tremor. She noticed the tremor a few months ago, and although it has not increased significantly since then, she explains that it is very bothersome and interferes with her daily activities. The patient notices the tremor only when conducting activities that require the use of her arms. On exam, you notice no baseline tremor, but when the patient is asked to reach for a pen she exhibits a slow, coarse, zigzag motion of her hand as she extends for it. The tremor increases in intensity as the patient’s hand gets closer to the object. You also notice that the patient requires a few attempts before grabbing the pen often overshooting the actual location. What is the most likely cause of her tremor?
|Prompt=A 66-year-old woman, who had a recent hip fracture after a fall, presents to the neurology clinic with complaints of hand tremor for the past few months. Although the tremor has not significantly worsened over time, the patient explains that it is very bothersome and interferes with her daily activities. The patient notices the tremor only when she performs activities that require use of her arms. On physical examination, the physician notes an absence of a baseline tremor; but when the patient is asked to reach for a pen, she exhibits a slow, coarse, zigzag motion of her hand as she extends for it. The tremor increases in intensity as the patient’s hand gets closer to the object. Also, the patient often overshoots and often requires a few attempts before grabbing the pen. What is the most likely cause of this patient's tremor?
|Explanation=Kinetic tremor (intention tremor) is a tremor that occurs during voluntary movement. The above presentation closely represents the classical findings of intention tremor associated with cerebellar dysfunction. The [[tremor]] is characterized by a low frequency, coarse motion that is accentuated as the patient gets closer to a desired target. Dysmetria is also often associated referring to a lack of coordination leading to an overshoot or undershoot phenomenon that causes the patient to miss the intended target. Typically, finger-to-nose testing will reveal the tremor. Intention tremors can be isolated or associated with [[ataxia]] or other cerebellar symptoms. This patient has a history of fall and hip fracture which may be related. Other causes of intention tremor include [[multiple sclerosis]] and [[Wilson’s disease]].
|Explanation=Intention tremor (kinetic tremor) is a tremor that only occurs during voluntary movement. The above presentation closely represents the classical findings of intention tremor associated with cerebellar dysfunction. Intention [[tremor]] is characterized by a low frequency, coarse motion that is accentuated as the patient gets closer to a desired target. Dysmetria, defined as a lack of coordination that results in an overshoot or undershoot phenomenon that causes the patient to miss the intended target, is also often associated with intention tremor. Typically, finger-to-nose testing will reveal the tremor. Although intention tremors may be isolated events, they may be associated with [[ataxia]] or other cerebellar symptoms. This patient has a history of fall and hip fracture which may be related to her tremor. Other causes of intention tremor include [[multiple sclerosis]] and [[Wilson’s disease]].
|AnswerA=Genetic predisposition
|AnswerA=Genetic predisposition
|AnswerAExp=[[Essential tremor|Essential or postural tremor]] is usually due to genetic predisposition. It is typically a tremor associated with maintenance of a certain posture (ex. outstretched arms, pouring water, drinking from a cup). The tremor can involve the hands, the head, and even the voice. Many risk factors have been linked to essential tremor including age, Caucasian race, and family history. The tremor is usually exacerbated by stress, fever, caffeine, and β-adrenergic agonists among others. Patients classically self-medicate with alcohol that decreases the intensity of the tremor. Treatment is usually with β-blockers.
|AnswerAExp=[[Essential tremor|Essential or postural tremor]] is usually due to genetic predisposition. It is typically a tremor associated with maintenance of a certain posture (eg outstretched arms, pouring water, drinking from a cup). Essential tremor can involve the hands, the head, and even the voice. Many risk factors have been linked to essential tremor, including age, Caucasian race, and family history. Essential tremor is usually exacerbated by stress, fever, caffeine, and β-adrenergic agonists. Patients classically self-medicate with alcohol that decreases the intensity of the tremor. Treatment is usually with β-blockers.
|AnswerB=Excessive caffeine consumption
|AnswerB=Excessive caffeine consumption
|AnswerBExp=Stress, fever, caffeine, and β-adrenergic agonists usually exacerbate a pre-existing tremor in patients with essential (postural) tremor or [[Parkinson's disease]]. Excessive caffeine consumption can lead to a low amplitude tremor in a small minority of patients with no underlying disease.
|AnswerBExp=Stress, fever, caffeine, and β-adrenergic agonists usually exacerbate a pre-existing tremor among patients with essential (postural) tremor or [[Parkinson's disease]]. Excessive caffeine consumption maylead to a low amplitude tremor among a small minority of patients with no underlying disease.
|AnswerC=Cerebellar lesion
|AnswerC=Cerebellar lesion
|AnswerCExp=Intention tremor secondary to a cerebellar lesion is characterized by a slow, coarse, and zigzag motion that is observed when the patient is reaching for a target ex. finger-to-nose testing. It becomes more prominent as the patient approaches the desired object, often missing the actual location. It can be either bilateral or unilateral depending of the location of the cerebellar lesion
|AnswerCExp=Intention tremor secondary to a cerebellar lesion is characterized by a slow, coarse, and zigzag motion that is observed when the patient is reaching for a target (eg finger-to-nose testing). Intention tremor becomes more prominent as the patient approaches the desired object, often missing the actual location. Intention tremor may be either bilateral or unilateral depending of the location of the cerebellar lesion.
|AnswerD=Dopamine depletion in the substantia nigra
|AnswerD=Dopamine depletion from the substantia nigra
|AnswerDExp=[[Parkinson’s disease]] involves [[dopamine]] depletion from the [[substantia nigra]] leading to resting tremor, bradykinesia and cogwheel rigidity. Resting tremor is the presenting complaint of 70% of patients with Parkinson’s disease. In most cases the tremor is present at rest and abates if the patient is asked hold his hands outstretched for a period of time.
|AnswerDExp=[[Parkinson’s disease]] involves [[dopamine]] depletion from the [[substantia nigra]], leading to resting tremor, bradykinesia, and cogwheel rigidity. Resting tremor is the presenting complaint of the majority of patients with Parkinson’s disease. Classically, the tremor is present at rest and abates if the patient is asked to hold his hands outstretched for a period of time.
|AnswerE=Caudate atrophy
|AnswerE=Caudate atrophy
|AnswerEExp=[[Caudate]] atrophy is seen in [[Huntington’s disease]] and usually does not cause tremor. Huntington’s disease typically causes chorea and athetosis. Chorea refers to sudden, jerky involuntary movements while athetosis describes slow, convoluted, writhing movements classically seen in the fingers
|AnswerEExp=[[Caudate]] atrophy is observed among patients with [[Huntington’s disease]]. Caudate atrophy does not usually cause tremor. Huntington’s disease typically manifests as chorea and athetosis. Chorea refers to sudden, jerky involuntary movements; while athetosis describes slow, convoluted, writhing movements usually observed in the fingers.
|EducationalObjectives=Intention tremor or kinetic tremor is a slow, low-amplitude motion seen when a ptient is reaching for a target. It is associated with cerebellar lesions or atrophy.
|EducationalObjectives=Intention tremor (kinetic tremor) is a slow, low-amplitude motion observed when a patient is voluntarily reaching for a target. It is associated with cerebellar lesions or atrophy.
|References=Elble RJ. Tremor: clinical features, pathophysiology, and treatment. Neurol Clin. 2009;27(3):679-95, v-vi.
|References=Elble RJ. Tremor: clinical features, pathophysiology, and treatment. Neurol Clin. 2009;27(3):679-95, v-vi.<br>
Louis ED. Essential tremor. Lancet Neurol. 2005;4(2):100-10.
Louis ED. Essential tremor. Lancet Neurol. 2005;4(2):100-10.<br>
First Aid 2014 page 454
|RightAnswer=C
|RightAnswer=C
|WBRKeyword=Tremor, Cerebellum, Intentional tremor, Essential tremor
|WBRKeyword=Cerebellum, Intentional tremor, Essential tremor, Kinetic tremor, Cerebellar lesion, Voluntary, Movement, Intention, Tremor, Intention tremor
|Approved=No
|Approved=Yes
}}
}}

Revision as of 21:40, 15 October 2014

 
Author [[PageAuthor::Rim Halaby, M.D. [1] (Reviewed by Yazan Daaboul, M.D.)]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Pathophysiology
Sub Category SubCategory::Neurology
Prompt [[Prompt::A 66-year-old woman, who had a recent hip fracture after a fall, presents to the neurology clinic with complaints of hand tremor for the past few months. Although the tremor has not significantly worsened over time, the patient explains that it is very bothersome and interferes with her daily activities. The patient notices the tremor only when she performs activities that require use of her arms. On physical examination, the physician notes an absence of a baseline tremor; but when the patient is asked to reach for a pen, she exhibits a slow, coarse, zigzag motion of her hand as she extends for it. The tremor increases in intensity as the patient’s hand gets closer to the object. Also, the patient often overshoots and often requires a few attempts before grabbing the pen. What is the most likely cause of this patient's tremor?]]
Answer A AnswerA::Genetic predisposition
Answer A Explanation [[AnswerAExp::Essential or postural tremor is usually due to genetic predisposition. It is typically a tremor associated with maintenance of a certain posture (eg outstretched arms, pouring water, drinking from a cup). Essential tremor can involve the hands, the head, and even the voice. Many risk factors have been linked to essential tremor, including age, Caucasian race, and family history. Essential tremor is usually exacerbated by stress, fever, caffeine, and β-adrenergic agonists. Patients classically self-medicate with alcohol that decreases the intensity of the tremor. Treatment is usually with β-blockers.]]
Answer B AnswerB::Excessive caffeine consumption
Answer B Explanation [[AnswerBExp::Stress, fever, caffeine, and β-adrenergic agonists usually exacerbate a pre-existing tremor among patients with essential (postural) tremor or Parkinson's disease. Excessive caffeine consumption maylead to a low amplitude tremor among a small minority of patients with no underlying disease.]]
Answer C AnswerC::Cerebellar lesion
Answer C Explanation [[AnswerCExp::Intention tremor secondary to a cerebellar lesion is characterized by a slow, coarse, and zigzag motion that is observed when the patient is reaching for a target (eg finger-to-nose testing). Intention tremor becomes more prominent as the patient approaches the desired object, often missing the actual location. Intention tremor may be either bilateral or unilateral depending of the location of the cerebellar lesion.]]
Answer D AnswerD::Dopamine depletion from the substantia nigra
Answer D Explanation [[AnswerDExp::Parkinson’s disease involves dopamine depletion from the substantia nigra, leading to resting tremor, bradykinesia, and cogwheel rigidity. Resting tremor is the presenting complaint of the majority of patients with Parkinson’s disease. Classically, the tremor is present at rest and abates if the patient is asked to hold his hands outstretched for a period of time.]]
Answer E AnswerE::Caudate atrophy
Answer E Explanation [[AnswerEExp::Caudate atrophy is observed among patients with Huntington’s disease. Caudate atrophy does not usually cause tremor. Huntington’s disease typically manifests as chorea and athetosis. Chorea refers to sudden, jerky involuntary movements; while athetosis describes slow, convoluted, writhing movements usually observed in the fingers.]]
Right Answer RightAnswer::C
Explanation [[Explanation::Intention tremor (kinetic tremor) is a tremor that only occurs during voluntary movement. The above presentation closely represents the classical findings of intention tremor associated with cerebellar dysfunction. Intention tremor is characterized by a low frequency, coarse motion that is accentuated as the patient gets closer to a desired target. Dysmetria, defined as a lack of coordination that results in an overshoot or undershoot phenomenon that causes the patient to miss the intended target, is also often associated with intention tremor. Typically, finger-to-nose testing will reveal the tremor. Although intention tremors may be isolated events, they may be associated with ataxia or other cerebellar symptoms. This patient has a history of fall and hip fracture which may be related to her tremor. Other causes of intention tremor include multiple sclerosis and Wilson’s disease.

Educational Objective: Intention tremor (kinetic tremor) is a slow, low-amplitude motion observed when a patient is voluntarily reaching for a target. It is associated with cerebellar lesions or atrophy.
References: Elble RJ. Tremor: clinical features, pathophysiology, and treatment. Neurol Clin. 2009;27(3):679-95, v-vi.
Louis ED. Essential tremor. Lancet Neurol. 2005;4(2):100-10.
First Aid 2014 page 454]]

Approved Approved::Yes
Keyword WBRKeyword::Cerebellum, WBRKeyword::Intentional tremor, WBRKeyword::Essential tremor, WBRKeyword::Kinetic tremor, WBRKeyword::Cerebellar lesion, WBRKeyword::Voluntary, WBRKeyword::Movement, WBRKeyword::Intention, WBRKeyword::Tremor, WBRKeyword::Intention tremor
Linked Question Linked::
Order in Linked Questions LinkedOrder::