A 33-year-old man with a history of multiple sclerosis is brought to the emergency department due to new-onset leg weakness, numbness, and urinary incontinence. In the past, he has had several acute exacerbations of multiple sclerosis, causing vertigo, vision impairment, and upper extremity weakness, all of which improved after glucocorticoid treatments. A year ago he stopped taking disease-modifying therapy due to severe adverse effects. His vital signs are within normal limits. Mental status and cranial nerve examination are normal. Muscle strength in the upper extremities is 5/5 and in the lower extremities is 3/5. Pinprick sensation is decreased below the nipple. Proprioception is decreased over both lower extremities. Babinski reflex is present bilaterally. MRI of this patient is most likely to reveal new plaques in which of the following locations?

Question

A 33-year-old man with a history of multiple sclerosis is brought to the emergency department due to new-onset leg weakness, numbness, and urinary incontinence.  In the past, he has had several acute exacerbations of multiple sclerosis, causing vertigo, vision impairment, and upper extremity weakness, all of which improved after glucocorticoid treatments.  A year ago he stopped taking disease-modifying therapy due to severe adverse effects.  His vital signs are within normal limits.  Mental status and cranial nerve examination are normal.  Muscle strength in the upper extremities is 5/5 and in the lower extremities is 3/5.  Pinprick sensation is decreased below the nipple.  Proprioception is decreased over both lower extremities.  Babinski reflex is present bilaterally.  MRI of this patient is most likely to reveal new plaques in which of the following locations?

Quizplus · Accepted Answer

11ec25c8_d5b4_42cb_bc81_f512ca78f863_MD0003_00 Multiple sclerosis is an autoimmune inflammatory demyelinating disorder of the central nervous system that typically affects women age 15-50 and presents with neurologic deficits disseminated in space and time. This patient's previous episodes of vertigo, vision impairment, and upper extremity weakness were likely related to prior lesions at different levels of the spinal cord and brain. His new findings, including decreased pinprick sensation below the nipple, likely reflect a new plaque in the upper thoracic spinal cord based on the dermatomal distribution (as the nipples are innervated at the T4 level). This plaque has likely damaged the lateral corticospinal tract (leg weakness), the lateral spinothalamic tract (decreased pinprick sensation), and the dorsal columns (decreased proprioception). The patient's urinary incontinence is likely from injury to the descending motor (voluntary bladder control) and the parasympathetic autonomic fibers. (Choice A) A lesion in the brainstem can lead to cranial nerve dysfunction ipsilateral to the lesion with contralateral motor weakness and sensory changes of the body. (Choices B and C) A lesion in the cerebellar hemispheres can cause dysdiadochokinesia (difficulty with rapid-alternating movements), dysmetria (past-pointing on finger-to-nose testing), limb ataxia, and an intention tremor. A lesion in the cerebellar vermis can cause ataxic gait and trunk, dysmetria, saccadic movements of the eye (episodes of the eye darting quickly), and horizontal nystagmus. (Choices D and E) A lesion in the cervical spinal cord can cause motor weakness and decreased sensation involving the upper extremities and upper chest as well as potentially below that level. Depending on the location of the lesion, the diaphragm can be involved (C3-C5, which form the phrenic nerve), leading to respiratory failure. A lesion in the lumbosacral spinal cord can cause motor weakness and sensory changes below that level (in the lower abdomen and extremities) but would not lead to decreased sensation in the upper torso. (Choice F) A lesion in the supratentorial white matter usually leads to partial or complete hemiparesis and possible sensation changes, generally contralateral to the lesion, similar to what can be seen in a patient with stroke. Educational objective: A multiple sclerosis plaque in the upper thoracic spinal cord can result in paraplegia, bladder incontinence, and absent sensation below the level of the lesion. References: Prospective study of patients presenting with acute partial transverse myelopathy. (http://www.ncbi.nlm.nih.gov/pubmed/14673577) The onset location of multiple sclerosis predicts the location of subsequent relapses. (http://www.ncbi.nlm.nih.gov/pubmed/19066192)

A 33-Year-Old Man with a History of Multiple Sclerosis Is