Clinical Consult: Neuroimaging Decisions

brain mir neurological imaging scans

It’s natural for parents to worry: A headache. A seizure. A concussion. What if my child has a brain tumor? Brain scans are on the rise, and pediatricians may be tempted to turn to them as a diagnostic aid. That’s especially concerning for computed tomography (CT) scans, which expose children to ionizing radiation. A 2013 study in Pediatrics, for example, found that CT scans are widely used in children with headache, and that 67 percent of these pediatric brain scans were done outside the emergency department setting.

Sometimes brain scans can be misleading or even detrimental. “Most of the diagnosis of neurologic disease should be done at the bedside, through history and physical exam,” says Alan Cohen, MD, neurosurgeon-in-chief at Boston Children’s Hospital. “Imaging can then be used as a confirmatory measure.”

Since the child may be preverbal or non-verbal, the caregiver’s observations are key. “When the mom says there’s something wrong, we always take it seriously,” says Cohen.

These are some potential reasons to order a scan or refer a child to a neurologist or neurosurgeon:

  • New neurologic deficits: A change in the child’s level of consciousness, weakness, hearing or vision loss (especially one-sided loss), diplopia, balance or gait difficulty, loss of motor coordination, abnormalities in swallowing and new language difficulty all warrant further investigation and possible imaging.
  • Headache: Headaches are common in children and rarely cause for a scan, but several findings raise a red flag. Headaches that awaken the child in the morning could signal increased intracranial pressure, a possible indicator of a mass in the brain. Headaches associated with vomiting; severe, unexplained headaches that don’t remit; and headaches associated with neurological signs such as weakness, sensory changes or gait difficulty also warrant referral.Children with shunts commonly have headaches. These are usually not a concern, but if the headache is severe and unremitting and accompanied by a fever of unknown origin, this could mean a shunt infection or malfunction that would warrant imaging.
  • Concussion: Minor head trauma can cause headache, dizziness and difficulty concentrating. The decision to image should be guided by the severity of symptoms and your level of concern. Children with a bad headache that does not go away, accompanied by protracted vomiting, or neurologic deficits such as weakness or gait difficulties should be sent for a scan or referred to a specialist.

CT or MRI?

While CT is more readily available and less costly, radiation exposure is a significant concern in children and has been associated with secondary tumors. Though CT is a fast and reasonable option for patients with trauma, magnetic resonance imaging (MRI) is preferable in other settings, such as concern for a brain tumor or increased intracranial pressure. In the case of a possible malfunctioning shunt, fast MRI is an option that does not require the child to be sedated.

While it’s tempting to image, the neurologic history and examination findings are “where the truth is,” says Cohen. Because neuroimaging results are easy to misinterpret, any doubt about results of a brain scan should trigger a consult with a specialist, particularly if the radiologist flags a concern.

To discuss whether neurological imaging may be appropriate for one of your patients, or to refer a patient for neurological evaluation, contact Boston Children’s Hospital’s Department of Neurology.

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