Name:
A 31-Year-Old with Blurry Vision
Description:
A 31-Year-Old with Blurry Vision
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Duration:
T00H10M39S
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Upload Date:
2022-02-28T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[intro music]
DR. HANDY: Hi, welcome to Harrison's Podclass where we discuss important concepts in internal medicine. I'm Cathy Handy.
DR. WIENER: And I'm Charlie Wiener and we're coming to you from the Johns Hopkins School of Medicine.
DR. HANDY: Welcome to episode 57, a 31-year-old with blurry vision.
DR. WIENER: Okay Cathy, so a 31-year-old white woman comes to you complaining of symptoms of blurred vision for a few months and recent leg weakness.
DR. HANDY: What kind of weakness?
DR. WIENER: She feels as though her left leg is weak, but it's not sore, and this has been present for the past weeks.
DR. HANDY: Okay, so unilateral weakness in the lower extremity with blurry vision. Tell me more.
DR. WIENER: Okay, well, on further questioning, she reports that she's had intermittent blurring of her vision for the past two months, although it's been more persistent in the past two weeks. She states that she also notes that colors seem less vivid to her and that her symptoms are worse in the right eye than in the left eye. Three months ago, she had a few episodes of sharp pains in the right eye that were worse when she looked around.
DR. WIENER: These lasted for about two to three days, then went away spontaneously. She thought it was eyestrain, so she didn't seek attention.
DR. HANDY: Okay, so I'm trying to put together one lesion that would cause blurry vision, unilateral eye pain, and left lower extremity weakness. I can't think of one lesion that would be causing this, so now I'm starting to think of systemic processes that would be contributing to these symptoms, mostly inflammatory or infectious causes. But tell me more about what's going on with her.
DR. WIENER: Okay, well, as I mentioned the pain in her right eye three months ago subsided after a few days and since then her vision changes have worsened. With regards to the weakness, she sometimes feels as if her left leg will give out on her if she stands on it for a prolonged period of time, there is no soreness, there's no redness and there's no pain. And she really has trouble telling me more symptoms than that.
DR. HANDY: What about our past medical history and her physical examination?
DR. WIENER: So her past medical history is significant for type 1 diabetes mellitus for which she uses an insulin pump, her hemoglobin A1c is consistently around 5.5%. Despite your best guidance, she has smoked one pack of cigarettes daily since the age of 18. On physical examination, she's fully alert and fully oriented with no cognitive issues.
DR. WIENER: However, there's spasticity in both of her lower extremities with passive motion. Deep tendon reflexes are 3+ bilaterally and strength in the quadriceps on her left side is markedly diminished at three to four, over five. All of the strength in the lower extremities is normal bilaterally and is otherwise symmetric.
DR. HANDY: So a note about that neuro exam, the unilateral weakness with hyperreflexia and spasticity that you described in the lower extremity is consistent with an upper motor neuron lesion. What about the rest of her neurologic examination?
DR. WIENER: Okay, well, her sensation to light touch and pinprick is decreased on the lower extremities and you're able to perform a dilated funduscopic examination, which shows swelling of her optic disc. Her cardiac, pulmonary and abdominal examinations are normal, and she has no skin rashes. I didn't mention it earlier but her vital signs were normal.
DR. HANDY: So based on this physical exam, along with what sounds like optic neuritis with diminished visual acuity, periorbital pain, that's aggravated by eye movement that preceded the visual loss and weakness of the limbs that is of the upper motor neuron type, I'm actually leaning towards multiple sclerosis as the cause of the symptoms in this 31-year-old woman. She has controlled her glucoses with an impressive A1c of 5.5, so I doubt she has significant peripheral neuropathy but that would not explain the other physical exam findings anyways.
DR. WIENER: Okay, so the question asks, based on the history and physical examination, which of the following findings is most likely to be demonstrated on further evaluation? Option A is an elevated protein levels in the CSF to more than 100 mg/dL. Option B is hyperintensity on a T1-weighted MRI image consistent with a mass lesion in the occipital lobe and surrounding hydrocephalus. Option C is hyperintensity on a T2-weighted MRI image in multiple areas of the brain, brainstem and spinal cord.
DR. WIENER: Option D is marked increase in transmission of somatosensory evoked potentials of the lower limbs. Option E is presence of 15 polys in the cerebral spinal fluid.
DR. HANDY: Well as I mentioned, I think this is multiple sclerosis or MS, so the answer is C, you would expect to see hyperintensity on T2-weighted MRI images in multiple areas of the brain, brainstem and spinal cord.
DR. WIENER: Okay, well, tell me more about MS and how you came to that conclusion.
DR. HANDY: It's an autoimmune demyelinating disorder of the central nervous system which can present in many ways. It can present with an abrupt onset of symptoms, or it can also develop gradually. The most common initial presenting symptoms include sensory loss, optic neuritis, weakness, paresthesias and diplopia. She had a few of these, as you mentioned before. Weakness of the limbs may be asymmetric and manifest as loss of strength, speed, dexterity or endurance.
DR. HANDY: Symptoms are upper motor neuron in origin and have associated spasticity, hyperreflexia and Babinski sign most commonly. However if there's a spinal cord lesion, lower motor neuron signs and loss of reflexes may also be seen. A diagnosis of MS can be difficult to confirm in some individuals, there is no definitive test for MS, but the diagnostic criteria require two or more episodes of symptoms and two or more signs of dysfunction in non-contiguous white matter tracts.
DR. WIENER: So this patient seems to meet that criteria.
DR. HANDY: Yes, she had the optic neuritis about three months ago and then the more recent leg weakness.
DR. WIENER: What other diagnostic findings can help make this diagnosis? You mentioned the MRI findings.
DR. HANDY: MRI can help confirm the diagnosis in patients with diagnostic clinical findings. MRI characteristically shows multiple hyperintense T2-weighted lesions that can be present in the brain, brainstem and the spinal cord. More than 90% of lesions that are seen on MRI, however, are asymptomatic. Approximately one third of lesions that appear hyperintense on T2-weighted images will be hypointense on T1-weighted images.
DR. HANDY: These "black holes" may be a marker of irreversible demyelinated axonal loss.
DR. WIENER: What about the other choices? CSF was mentioned and also evoked potentials?
DR. HANDY: Evoked potentials are no longer commonly used in MS and are most useful in studying pathways that are not exhibiting clinical symptoms. Evoked potentials are not specific to MS although a marked delay in latency of transmissions does suggest demyelination. In patients with MS, the CSF may show an increased number of mononuclear cells, although CSF protein is typically normal.
DR. HANDY: Oligoclonal bands help to assess the intrathecal production of immunoglobulin for IgG. The presence of two or more discrete oligoclonal bands in the CSF that are not present in the serum is found in more than 75% of MS patients. If a patient in the CSF has a pleocytosis of over 75 cells, presence of any polys or protein concentration over a 100 mg/dL, again, this is all within the CSF, an alternative diagnosis should be sought because MS is not the most likely cause.
DR. WIENER: So any other tests you would order to rule out other potential possibilities?
DR. HANDY: Well, disorders possibly mistaken for MS would include neuromyelitis optica, sarcoidosis, vascular disorders, like antiphospholipid syndrome and vasculitis, rarely a CNS lymphoma and still more rarely infections, such as syphilis or Lyme disease. But the specific tests required to exclude alternative diagnosis will vary with each clinical situation.
DR. HANDY: However, an erythrocyte sedimentation rate, or ESR level, serum B12 level, anti-nuclear antibodies and a Treponema antibody should probably be obtained in all patients with suspected MS.
DR. WIENER: Okay, well, so this is a two part question. And the second part of the question asks, in this patient, the expected finding is demonstrated on testing, and we'll assume that's the MRI that you mentioned, on further historical review, the patient reports that she had one prior episode of blurred vision that resolved spontaneously about eight months ago.
DR. WIENER: She never sought treatment for it, although it did last for two weeks. You make the correct diagnosis of MS. All of the following are epidemiologic risk factors for multiple sclerosis, except? Option A is age between 20 and 40; B. cigarette smoking; C. female sex; D. history of an autoimmune disorder, such as type 1 diabetes in this case; or E. white race.
DR. HANDY: So the question is asking about the epidemiology of multiple sclerosis, so let's go through that. It affects about 350,000 individuals in the United States and has a variable clinical course with some individuals experiencing very limited symptoms and others becoming very incapacitated due to the disease. MS is three times more common in women than men and the typical age of onset is between 20 and 40 years. So she's right in the middle of that age range.
DR. HANDY: MS is more common in white individuals than those of African or Asian descent. In addition, geographic variations in disease prevalence have also been demonstrated, with higher prevalence in the temperate zone areas of Northern North America and Northern Europe, Southern Australia and New Zealand. In contrast, the tropics have a prevalence that is 10 to 20 times less.
DR. HANDY: Other well-established risk factors for the development of MS include vitamin D deficiency, exposure to Epstein-Barr Virus after early childhood and cigarette smoking. Now, despite the fact that this is an autoimmune disorder there actually has not been an association between MS and other autoimmune disorders.
DR. WIENER: So in this case, the type 1 diabetes is the one that is not related to her situation.
DR. HANDY: That's correct.
DR. WIENER: Okay, great. So the teaching point in this case is that multiple sclerosis is largely still a clinical diagnosis involving multiple neurologic abnormalities spread over time. There are characteristic findings on MRI that can support the diagnosis. While it is an autoimmune disease, it is not associated with other diseases of autoimmunity.
DR. HANDY: And to learn more, you can read in Harrison's chapter on multiple sclerosis. [outro music] [Mr. Shanahan] This is Jim Shanahan, publisher at McGraw Hill. Harrison's Podclass is brought to you by McGraw Hill's Access Medicine, the online medical resource that delivers the latest trusted content from the best minds in medicine. Go to accessmedicine.com to learn more.