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Red Flags in Neurologic Examinations Point to MS


 

DENVER—Several “red flags” in neurologic examinations can provide valuable information that helps to accurately diagnose and direct the care of patients with multiple sclerosis (MS) who complain about certain symptoms, according to Stephen S. Kamin, MD. These red flags may “aid in diagnosis of disease, detect improvements or worsening of an already established disease, and discover unexpected deficits in the patient we may not even be aware of that require explanation, further investigation, or intervention,” he reported at the 22nd Annual Meeting of the Consortium of Multiple Sclerosis Centers.
Patients often complain of vague symptoms that may, at first, be difficult to interpret or treat. Patients’ descriptions of symptoms “don’t have necessarily very specific meanings, or they have rather personalized meanings,” said Dr. Kamin, Associate Medical Director of the Multiple Sclerosis Center at Holy Name Hospital in Teaneck, New Jersey, and Clinical Associate Professor in Neuroscience at the University of Medicine and Dentistry of New Jersey in Newark. “Not everybody uses the words in the same way,” he continued. “Some of these that you hear a lot are blurry vision, weakness, stiffness, tightness, stabbing, or unsteady gait. These are things that patients often complain about but that may mean a number of different things.” He recommended using a variety of tests as a way of distinguishing among the different possible explanations for these symptoms, including those that may be unrelated to MS.
Blurry Vision
Many patients older than 40 who complain of blurry vision, for example, simply need reading glasses; the cause is aging, not disease. In other cases, visual field defects can be interpreted as blurriness. Dr. Kamin suggested that in addition to Snellen cards, pinhole testing and computerized visual field testing are often useful. “In cases where you’re not sure exactly what’s going on,” he added, “you certainly shouldn’t hesitate to refer a person to an ophthalmologist or neuro-ophthalmologist for some more detailed formal testing.”
Many patients who complain of blurry vision have some form of diplopia. As a first approach, Dr. Kamin advised determining whether it occurs in one or both eyes, confirming that there is actual doubling and ascertaining its direction. “If [patients] see double with only one eye open, it’s not neurologic,” he explained. “It’s either ophthalmologic or psychiatric. You can help figure out exactly the nature of the diplopia by asking them, ‘Which direction of vision is the diplopia worse?’ and it will be in the direction of the weakness of the eye muscle involved. Often these are situations where you wind up sending people to a neuro-ophthalmologist for analysis.”
Dr. Kamin noted that the most common cause of diplopia in patients with MS is internuclear ophthalmoplegia caused by a lesion in the medial longitudinal fasciculus. Other causes, such as third or sixth nerve palsy, might be indicative of comorbidities such as diabetes or aneurysm. More rarely, blurry vision turns out to be oscillopsia, a subjective sense of visual field movement. This is produced by nystagmus and can sometimes be treated with topir­amate, baclofen, or clonazepam.
Weakness, Numbness, and Stiffness
Another common, vague complaint is weakness. “Weakness isn’t always weakness,” Dr. Kamin pointed out. “Sometimes it’s muscle weakness, fatigue, numbness, or incoordination. Numbness isn’t always numbness. Sometimes it’s weakness. So it’s really important, obviously, to get a good history and make sure you’re speaking the same language.
“But then you can use your neurologic examination to see, ‘Is this person really weak?’ or ‘Is what they have ataxia, and they’re calling that weakness?’ … ‘I can’t use my hand. It’s weak.’ Well, maybe it’s not weak; maybe it’s incoordinated, but the strength is actually fine,” he said. “And again, that’s going to be important. It reflects a disease in a different part of the nervous system, and your approach may be different.”
Likewise, stiffness may refer to contracture, spasticity, or sensations of swollenness or tightness in a limb. Dr. Kamin emphasized the importance of distinguishing between sensory problems and motor problems before attempting a course of treatment. True spasticity can be gauged using the Ashworth scale, and patients can be treated with stretching exercises and medications, such as baclofen and tizanidine. Contracture also responds well to stretching and may sometimes require tendon release or casting. Dr. Kamin noted that sensory problems are “much harder to treat” and named a variety of medications that may be helpful, from tricyclic antidepressants to anticonvulsants such as topiramate and gabapentin.
Unexpected and Unrelated Conditions
Neurologic examinations may also be especially helpful in identifying unexpected and unrelated conditions, said Dr. Kamin. One common difficulty is determining whether a sudden new neurologic problem is caused by MS or by a stroke. “Strokes are usually very rapid—minutes, hours, rarely longer than that,” Dr. Kamin explained. “MS attacks occur over hours, and they progress over days or even longer. So the tempo of the onset can be very helpful in swaying you one way or the other.” Other symptoms that are more common in stroke-related hemiparesis than in MS-related hemiparesis are flaccidity, complete plegia, visual field deficits, and aphasia or other language problems.
In the case of paraparesis, Dr. Kamin advised asking patients about back pain and fever, more common in spinal cord compression than MS. He added that for anyone with a history of cancer, metastatic cord compression is the most likely cause, even if physicians believed that the cancer had been cured. If a patient has language difficulties, a language examination can distinguish between dysarthria, which is common with MS, and dysphasia or aphasia, which are more likely to be caused by tumors or other neurologic problems. For ocular problems, pain and a swollen optic nerve head are often signs of optic neuritis, while ischemic optic neuropathy is painless. “None of these is an all-or-nothing situation,” he added. “It’s all a matter of probabilities and putting it all together. But these are some of the things that you can use.”

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