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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{Rim}}
|QuestionAuthor={{Rim}} (Reviewed by {{YD}})
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Pathophysiology
|MainCategory=Pathophysiology
Line 21: Line 21:
|MainCategory=Pathophysiology
|MainCategory=Pathophysiology
|SubCategory=Neurology
|SubCategory=Neurology
|Prompt=A 35-year-old male patient presents with one-month history of progressive upper extremities weakness. The patient initially started to note difficulty moving his right arm and then the weakness involved both his arms. He also reports that he has been noting some twitching in his arms from time to time. The patient works as a lawyer and has been lately frustrated because he has been stuttering which is impeding his work. Physical exam of the upper extremities reveals bilateral fasciculation, proximal muscle atrophy, weakness more pronounced on the right side than on the left and intact sensation bilaterally. Rigidity is noted upon attempting to passively extend the patient’s arms. Motor strength and sensation are intact in the lower extremities. Reflexes are increased throughout the body and Babinski sign is positive bilaterally. Based on the clinical history and physical exam findings, which of the following images depicting spinal cord lesions in red correlates with the site of the neurological lesion of the patient?
|Prompt=A 35-year-old man presents with a one-month history of progressive weakness in his upper extremities. The patient initially had difficulty moving his right arm but was then complaining of inability to move both arms. He also reports stuttered speech and some occasional twitching in his arms. The patient works as a lawyer and has been lately frustrated because of his symptoms. Physical examination of the upper extremities reveals bilateral fasciculation, proximal muscle atrophy, and weakness that is more pronounced in the right upper extremity than in the left. Rigidity is noted upon attempting to passively extend the patient’s arms. Sensory neurological examination is unremarkable in both upper and lower extremities. Babinski sign is positive bilaterally. Based on the clinical history and physical examination findings, which of the following images correlates with the site of the neurological lesion in the patient (lesion in red)?
|Explanation=[[ALS]] is a rapidly progressive neurodegenerative disease involving the upper and lower motor neurons in the absence of any sensory involvement.  The patient presents with findings of upper motor neurons (UMN) and lower motor neurons (LMN) involvement suggestive of a diagnosis of ALS. UMN findings include hyperreflexia, increased muscle spasm and positive [[Babinski sign]], whereas LMN findings include fasciculation and muscle atrophy. Bulbar involvement occurs in ALS and can present as [[dysarthria]] or [[dysphagia]].
|Explanation=Amyotrophic lateral sclerosis (ALS or Lou Gehrig disease) is a progressive neurodegenerative disorder of the central and peripheral motor systems. The hallmark of ALS is the presence of signs and symptoms that suggest the simultaneous involvement of upper motor and lower motor neuron disease. Notably, ALS does not affect the sensory, cognitive, or oculomotor nervous systems. Manifestations of ALS vary, and symptoms may suggest prognosis and progression. Presentations may have a limb-onset, bulbar-onset, or less commonly pure upper/lower motor neuron involvement. Patients may develop of limb spasticity, weakness, fasciculations, wasting, and hyperreflexia. In addition, bulbar symptoms may include spastic dysarthria that causes distorted nasal speech, flaccid dysarthria, brisk gag/jaw jerks, or dysphagia. This patient has signs and symptoms consistent with ALS. Fasciculations and muscle atrophy are signs of lower motor neuron involvement, whereas rigidity, hyperreflexia marked by a positive Babinski test, and stuttered speech are signs of upper motor neuron involvement. Weakness in his extremities may be signs of either upper or lower motor neuron involvement. The cause of ALS is unknown, but some have speculated a role of superoxide dismutase 1 defects in the pathogenesis of the disease. The majority of patients with ALS die within 30 months of onset of symptoms, and less than 20% survive beyond 5 years. The management of ALS is very limited, riluzole has demonstrated modest improvement in survival among ALS patients.
|AnswerA=[[Image:Syringomyelia spinal cord.gif|300px]]
|AnswerA=[[Image:WBR0570A.gif|300px]]
|AnswerAExp=This image illustrates a lesion in the central cord depicting [[syringomyelia]]. ALS is not associated with lesions in the central cord.
|AnswerAExp=This image illustrates a lesion in the central cord depicting [[syringomyelia]].  
|AnswerB=[[Image:MS.gif|300px]]
|AnswerB=[[Image:WBR0570B.gif|300px]]
|AnswerBExp=This image depicts asymmetric lesions in the white matter, which is characteristic of [[multiple sclerosis]]. ALS involves lesions in the white matter and grey matter.
|AnswerBExp=This image depicts asymmetric lesions in the white matter, which are characteristic of [[multiple sclerosis]].  
|AnswerC=[[Image:Dorsal-Columns.gif|300px]]
|AnswerC=[[Image:WBR0570C.gif|300px]]
|AnswerCExp=This image depicts lesions in the dorsal columns which may be found in vitamin B12 deficiency.  ALS involves lesions in the white matter and grey matter.
|AnswerCExp=This image depicts lesions in the dorsal columns consistent with tabes dorsalis due to tertiary syphilis.  
|AnswerD=[[Image:Anterior-horn.gif|300px]]
|AnswerD=[[Image:WBR0570D.gif|300px]]
|AnswerDExp=This image depicts lesions in the anterior horn of the [[spinal cord]] which is not characteristic of [[ALS]].
|AnswerDExp=This image depicts lesions in the anterior horn of the [[spinal cord]] characteristic of poliomyelitis.
|AnswerE=[[Image:ALS.gif|300px]]
|AnswerE=[[Image:WBR0570E.gif|300px]]
|AnswerEExp=This image depicts lesions in the white matter and grey matter. This pattern of lesions is found in [[ALS]] which presents with upper motor neurons and lower motor neurons symptoms.
|AnswerEExp=This image depicts lesions in the white matter and grey matter. This pattern of lesions is typical of [[ALS]], where patients present with symptoms of upper and lower motor neuron involvement.  
|EducationalObjectives=ALS is a progressive disease involving lesions in the white and grey matter which leads to symptoms of UMN and LMN involvement.
|EducationalObjectives=ALS is a progressive neurodegenerative disorder characterized by involvement of upper and lower motor neuron systems. In the spinal cord, ALS is caused by lesions that typically involve the white and grey matters.
|References=First Aid 2014 page 467
|References=Kiernan MC, Vucic S, Cheah BC, et al. Amyotrophic lateral sclerosis. Lancet. 2011;377:942-55.<br>
First Aid 2014 page 467
|RightAnswer=E
|RightAnswer=E
|WBRKeyword=Spinal cord, ALS
|WBRKeyword=Spinal cord, ALS, Upper motor neuron, Lower motor neuron, Motor, Neurodegenerative, Neurodegenerative disease, Neurodegenerative disorder, Idiopathic, Riluzole
|Approved=No
|Approved=Yes
}}
}}

Revision as of 17:09, 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 35-year-old man presents with a one-month history of progressive weakness in his upper extremities. The patient initially had difficulty moving his right arm but was then complaining of inability to move both arms. He also reports stuttered speech and some occasional twitching in his arms. The patient works as a lawyer and has been lately frustrated because of his symptoms. Physical examination of the upper extremities reveals bilateral fasciculation, proximal muscle atrophy, and weakness that is more pronounced in the right upper extremity than in the left. Rigidity is noted upon attempting to passively extend the patient’s arms. Sensory neurological examination is unremarkable in both upper and lower extremities. Babinski sign is positive bilaterally. Based on the clinical history and physical examination findings, which of the following images correlates with the site of the neurological lesion in the patient (lesion in red)?]]
Answer A [[AnswerA::]]
Answer A Explanation [[AnswerAExp::This image illustrates a lesion in the central cord depicting syringomyelia.]]
Answer B [[AnswerB::]]
Answer B Explanation [[AnswerBExp::This image depicts asymmetric lesions in the white matter, which are characteristic of multiple sclerosis.]]
Answer C [[AnswerC::]]
Answer C Explanation AnswerCExp::This image depicts lesions in the dorsal columns consistent with tabes dorsalis due to tertiary syphilis.
Answer D [[AnswerD::]]
Answer D Explanation [[AnswerDExp::This image depicts lesions in the anterior horn of the spinal cord characteristic of poliomyelitis.]]
Answer E [[AnswerE::]]
Answer E Explanation [[AnswerEExp::This image depicts lesions in the white matter and grey matter. This pattern of lesions is typical of ALS, where patients present with symptoms of upper and lower motor neuron involvement.]]
Right Answer RightAnswer::E
Explanation [[Explanation::Amyotrophic lateral sclerosis (ALS or Lou Gehrig disease) is a progressive neurodegenerative disorder of the central and peripheral motor systems. The hallmark of ALS is the presence of signs and symptoms that suggest the simultaneous involvement of upper motor and lower motor neuron disease. Notably, ALS does not affect the sensory, cognitive, or oculomotor nervous systems. Manifestations of ALS vary, and symptoms may suggest prognosis and progression. Presentations may have a limb-onset, bulbar-onset, or less commonly pure upper/lower motor neuron involvement. Patients may develop of limb spasticity, weakness, fasciculations, wasting, and hyperreflexia. In addition, bulbar symptoms may include spastic dysarthria that causes distorted nasal speech, flaccid dysarthria, brisk gag/jaw jerks, or dysphagia. This patient has signs and symptoms consistent with ALS. Fasciculations and muscle atrophy are signs of lower motor neuron involvement, whereas rigidity, hyperreflexia marked by a positive Babinski test, and stuttered speech are signs of upper motor neuron involvement. Weakness in his extremities may be signs of either upper or lower motor neuron involvement. The cause of ALS is unknown, but some have speculated a role of superoxide dismutase 1 defects in the pathogenesis of the disease. The majority of patients with ALS die within 30 months of onset of symptoms, and less than 20% survive beyond 5 years. The management of ALS is very limited, riluzole has demonstrated modest improvement in survival among ALS patients.

Educational Objective: ALS is a progressive neurodegenerative disorder characterized by involvement of upper and lower motor neuron systems. In the spinal cord, ALS is caused by lesions that typically involve the white and grey matters.
References: Kiernan MC, Vucic S, Cheah BC, et al. Amyotrophic lateral sclerosis. Lancet. 2011;377:942-55.
First Aid 2014 page 467]]

Approved Approved::Yes
Keyword WBRKeyword::Spinal cord, WBRKeyword::ALS, WBRKeyword::Upper motor neuron, WBRKeyword::Lower motor neuron, WBRKeyword::Motor, WBRKeyword::Neurodegenerative, WBRKeyword::Neurodegenerative disease, WBRKeyword::Neurodegenerative disorder, WBRKeyword::Idiopathic, WBRKeyword::Riluzole
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