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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 36 year old woman presents to the neurology clinic complaining of a 1 week history of bilateral upper extremity weakness. Upon further questioning the patient reports that for the past 3 months, she has had multiple burns of both hands because she cannot seem to distinguish hot from cold objects. She also doesn't feel any pain in her hands which is why her burns are usually significant before she notices them. Physical exam reveals diminished upper extremity reflex bilaterally and lower extremity hyperreflexia. Which of the following images best depicts the location of the patient's lesion?
|Prompt=A 36-year-old woman presents to the neurology clinic with a complaint of a 1 week history of bilateral upper extremity weakness. Upon further questioning, the patient reports that for the past 3 months, she has had multiple burns in both hands because she cannot seem to distinguish hot objects. She also reports she has numbness over the shoulders and the arms that follow a cape-like pattern. Physical examination is remarkable for burn marks in both hands, loss of pain and temperature sensation in the shoulders and arms, and diminished upper extremity reflexes bilaterally. Which of the following images depicts the most likely location of the patient's lesion (lesion in red)?
|Explanation=Syringomyelia is a disease of the spinal cord related to the development of a fluid-filled cavity or syrinx within the central canal. As the central cavity expands, specific spinal tracts are affected. The syrinx first interrupts the spinothalamic tract fibers that decussate at the anterior white commissure in close proximity to the central canal. Stretching of the spinothalamic fibers that relay pain and temperature results in the loss of these sensations. Light touch, position sense and vibration senses are usually preserved. As the syrinx expands further it locally interrupts neurons of the anterior horn leading to LMN symptoms of the upper extremities. It also locally interrupts descending motor fibers leading to UMN symptoms of the lower extremities.  Patients present with a history of loss of temperature and pain sensation in the hands (most common location of syrinx formation is in the cervical spine), with a history of multiple burns. As the syrinx becomes more significant, symptoms of weakness arise. Syringomyelia can be associated with Arnold–Chiari malformation.  
|Explanation=Syringomyelia is a disease of the spinal cord caused by the the development of a fluid-filled cavity (syrinx) within the central canal. As the central cavity expands, nearby spinal tracts are affected. The syrinx first interrupts the spinothalamic tract fibers that decussate at the anterior white commissure in close proximity to the central canal. Stretching of the spinothalamic fibers that relay pain and temperature results in loss of pain and temperature. Most cases of syringomyelia affect the cervical spinal cord. As a result, patients often complain of a cape-like distribution of numbness over the shoulders and the arms. In contrast, light touch, position sense, and vibration senses are usually spared because they are carried by the relatively distant dorsal columns. As the syrinx expands further, it locally interrupts neurons of the anterior horn leading to lower motor neurons symptoms of the upper extremities, such as weakness, hyporeflexia, fasciculations, and muscle atrophy. It also locally interrupts descending motor fibers leading to upper motor neuron symptoms of the lower extremities, such as rigidity and hyperreflexia.  Patients typically present with a history of loss of temperature and pain sensation in the hands with a history of multiple burns. As the syrinx becomes more significant, symptoms of weakness arise. Syringomyelia can be associated with Arnold–Chiari malformation.
|AnswerA=[[Image:ALS.gif|300px]]
|AnswerA=[[Image:WBR0570E.gif|300px]]
|AnswerAExp=This image typically depicts spinal cord lesions of [[ALS]] that involve both descending corticospinal tracts, and the anterior horns. The involvement of both these structures is what leads to the combination of UMN and LMN symptoms seen in ALS.
|AnswerAExp=This image typically depicts spinal cord lesions of [[ALS]] that involve upper and lower motor neuron systems.
|AnswerB=[[Image:Anterior-horn.gif|300px]]
|AnswerB=[[Image:WBR0570D.gif|300px]]
|AnswerBExp=This image depicts isolated anterior horn injury usually seen in patients with [[poliomyelitis]] or [[Werdnig-Hoffman Syndrome]] (floppy baby syndrome). Both of these diseases only cause LMN signs due to the lack of involvement of descending motor tracts.
|AnswerBExp=This image depicts isolated anterior horn injury usually observed in patients with [[poliomyelitis]] or [[Werdnig-Hoffman Syndrome]] (floppy baby syndrome).
|AnswerC=[[Image:MS.gif|300px]]
|AnswerC=[[Image:WBR0570B.gif|300px]]
|AnswerCExp=This image depicts multiple, non-patterned white matter lesions usually seen in patients with multiple sclerosis.
|AnswerCExp=This image depicts multiple, non-patterned white matter lesions usually observed in patients with multiple sclerosis.
|AnswerD=[[Image:Syringomyelia spinal cord.gif|300px]]
|AnswerD=[[Image:WBR0570A.gif|300px]]
|AnswerDExp=This image is depicts an expanding central canal compressing adjacent tracts typically seen in syringomyelia. The anterior white commissure is the closest structure which leads to compression of the decussating spinothalamic tracts first.
|AnswerDExp=This image depicts an expanding central canal that compresses adjacent tracts typically observed in syringomyelia. Spinothalamic tracts are often affected first in syringomyelia due to the anatomic proximity of the anterior white commissure that carries these tracts.
|AnswerE=[[Image:Dorsal-Columns.gif|300px]]
|AnswerE=[[Image:WBR0570C.gif|300px]]
|AnswerEExp=Dorsal column lesions are not seen with syringomyelia. They are classical of tabes dorsalis in tertiary syphilis when isolated. Dorsal column lesions are also part of the subacute combined degeneration syndrome seen in [[vitamin B12]] and [[vitamin E]] deficiency.
|AnswerEExp=Isolated dorsal column lesions are classical of tabes dorsalis caused by tertiary syphilis.
|EducationalObjectives=[[Syringomyelia]] is a syndrome involving a fluid filled cavity of the central canal that interrupts the spinothalamic tracts leading to bilateral loss of temperature and pain sensation usually in the upper extremities.
|EducationalObjectives=[[Syringomyelia]] is caused by a fluid-filled cavity of the central canal that interrupts the spinothalamic tracts and results in bilateral loss of temperature and pain sensation in a cape-like distribution over the shoulders and the arms. Patients with syringomyelia often present with burns in their hands due to their inability to distinguish hot objects or the pain sensation normally associated with burns.
|References=Williams B. Progress in syringomyelia. Neurol Res. Sep 1986;8(3):130-45.
|References=Williams B. Progress in syringomyelia. Neurol Res. 1986;8(3):130-45.<br>
Kim J, Kim CH, Jahng TA, Chung CK. Clinical course of incidental syringomyelia without predisposing pathologies. J Clin Neurosci. Feb 29 2012
Kim J, Kim CH, Jahng TA, et al. Clinical course of incidental syringomyelia without predisposing pathologies. J Clin Neurosci. 2012.19(5):665-8.<br>
First Aid 2014 page 467
|RightAnswer=D
|RightAnswer=D
|WBRKeyword=Syringomyelia, Spinal cord, Spinothalamic tracts
|WBRKeyword=Syringomyelia, Spinal cord, Spinothalamic tracts, Spinothalamic tract, Pain, Temperature, Pain and temperature, Anterior white commissure, Cape-like, Cape-like distribution, Cape like distribution, Burn, Numbness, Burns, Syrinx, Fluid-filled cavity, Fluid filled cavity
|Approved=No
|Approved=No
}}
}}

Latest revision as of 01:00, 28 October 2020
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 36-year-old woman presents to the neurology clinic with a complaint of a 1 week history of bilateral upper extremity weakness. Upon further questioning, the patient reports that for the past 3 months, she has had multiple burns in both hands because she cannot seem to distinguish hot objects. She also reports she has numbness over the shoulders and the arms that follow a cape-like pattern. Physical examination is remarkable for burn marks in both hands, loss of pain and temperature sensation in the shoulders and arms, and diminished upper extremity reflexes bilaterally. Which of the following images depicts the most likely location of the patient's lesion (lesion in red)?]]
Answer A [[AnswerA::]]
Answer A Explanation [[AnswerAExp::This image typically depicts spinal cord lesions of ALS that involve upper and lower motor neuron systems.]]
Answer B [[AnswerB::]]
Answer B Explanation [[AnswerBExp::This image depicts isolated anterior horn injury usually observed in patients with poliomyelitis or Werdnig-Hoffman Syndrome (floppy baby syndrome).]]
Answer C [[AnswerC::]]
Answer C Explanation AnswerCExp::This image depicts multiple, non-patterned white matter lesions usually observed in patients with multiple sclerosis.
Answer D [[AnswerD::]]
Answer D Explanation [[AnswerDExp::This image depicts an expanding central canal that compresses adjacent tracts typically observed in syringomyelia. Spinothalamic tracts are often affected first in syringomyelia due to the anatomic proximity of the anterior white commissure that carries these tracts.]]
Answer E [[AnswerE::]]
Answer E Explanation AnswerEExp::Isolated dorsal column lesions are classical of tabes dorsalis caused by tertiary syphilis.
Right Answer RightAnswer::D
Explanation [[Explanation::Syringomyelia is a disease of the spinal cord caused by the the development of a fluid-filled cavity (syrinx) within the central canal. As the central cavity expands, nearby spinal tracts are affected. The syrinx first interrupts the spinothalamic tract fibers that decussate at the anterior white commissure in close proximity to the central canal. Stretching of the spinothalamic fibers that relay pain and temperature results in loss of pain and temperature. Most cases of syringomyelia affect the cervical spinal cord. As a result, patients often complain of a cape-like distribution of numbness over the shoulders and the arms. In contrast, light touch, position sense, and vibration senses are usually spared because they are carried by the relatively distant dorsal columns. As the syrinx expands further, it locally interrupts neurons of the anterior horn leading to lower motor neurons symptoms of the upper extremities, such as weakness, hyporeflexia, fasciculations, and muscle atrophy. It also locally interrupts descending motor fibers leading to upper motor neuron symptoms of the lower extremities, such as rigidity and hyperreflexia. Patients typically present with a history of loss of temperature and pain sensation in the hands with a history of multiple burns. As the syrinx becomes more significant, symptoms of weakness arise. Syringomyelia can be associated with Arnold–Chiari malformation.

Educational Objective: Syringomyelia is caused by a fluid-filled cavity of the central canal that interrupts the spinothalamic tracts and results in bilateral loss of temperature and pain sensation in a cape-like distribution over the shoulders and the arms. Patients with syringomyelia often present with burns in their hands due to their inability to distinguish hot objects or the pain sensation normally associated with burns.
References: Williams B. Progress in syringomyelia. Neurol Res. 1986;8(3):130-45.
Kim J, Kim CH, Jahng TA, et al. Clinical course of incidental syringomyelia without predisposing pathologies. J Clin Neurosci. 2012.19(5):665-8.
First Aid 2014 page 467]]

Approved Approved::No
Keyword WBRKeyword::Syringomyelia, WBRKeyword::Spinal cord, WBRKeyword::Spinothalamic tracts, WBRKeyword::Spinothalamic tract, WBRKeyword::Pain, WBRKeyword::Temperature, WBRKeyword::Pain and temperature, WBRKeyword::Anterior white commissure, WBRKeyword::Cape-like, WBRKeyword::Cape-like distribution, WBRKeyword::Cape like distribution, WBRKeyword::Burn, WBRKeyword::Numbness, WBRKeyword::Burns, WBRKeyword::Syrinx, WBRKeyword::Fluid-filled cavity, WBRKeyword::Fluid filled cavity
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