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MRI Links COVID-19 to Rare Form of Encephalitis

In a case report recently published online in Radiology, a team of doctors from Henry Ford Health System in Michigan describe a case of acute necrotizing encephalitis (ANE), a central nervous infection that mostly afflicts young children, that developed in a 58-year-old female patient who tested positive for COVID-19. The patient was hospitalized in serious condition. The case report is believed to be the first published case highlighting the association between encephalitis and COVID-19.

“This is significant for all providers to be aware of and looking out for in patients who present with an altered level of consciousness. We need to be thinking of how we’re going to incorporate patients with severe neurological disease into our treatment paradigm,” says Elissa Fory, MD, a neurologist at Henry Ford who was part of the team of medical experts involved in making the diagnosis. “This complication is as devastating as severe lung disease.”

The team included neuroradiologist Brent Griffith, MD; infectious disease specialist Pallavi Bhargava, MD; neurologist Shaneela Malik, MD; and neurologist Poonam Bansal, MD. Griffith, senior author of the published case report, says the paper shows “the important role that imaging can play in COVID-19 cases.”

ANE is a rare condition, particularly in the adult population, and is associated with poor clinical outcomes. It develops in response to other infections such as influenza, chickenpox, and enterovirus.

The patient had several days of fever, cough, and muscle aches—symptoms consistent with COVID-19. On March 19, she was transported by ambulance to the emergency department and showed signs of confusion, lethargy, and disorientation, Fory says. A flu test was negative, but a rapid COVID-19 test, developed in house by Henry Ford’s clinical microbiology lab, confirmed positive coronavirus.

When the patient remained lethargic, doctors ordered repeat CT and MRI scans. The MRI scan identified abnormal lesions in both thalami and temporal lobes, parts of the brain that control consciousness, sensation, and memory function. These scans confirmed doctors’ early suspicions.

“The team had suspected encephalitis at the outset, but then back-to-back CT and MRI scans made the diagnosis,” Fory says.

Update: Patient Discharged, Medical Team ‘Very Cautiously Optimistic’

The patient who developed a rare form of encephalitis after testing positive for the coronavirus has been discharged from the hospital. The 58-year-old female patient was discharged April 9 to a rehabilitation facility. Fory says the patient’s improvement is a hopeful sign. “I’m very cautiously optimistic that she will continue to recover,” Fory says.

Henry Ford doctors say the case highlights that patients with COVID-19 and an altered level of consciousness should be monitored for focal neurologic signs, suggestive of more severe neurologic complications such as encephalitis or stroke.

— Source: Henry Ford Health System

ACR Offers Guidance on COVID-19 and MR Use

For patients known to have tested positive for, or are under investigation for, COVID-19, the ACR recommends that practitioners minimize the use of MR except where absolutely necessary and postpone all nonurgent or nonemergent exams. In some cases, the use of alternative imaging methods, eg, point-of-care or portable imaging, may be appropriate. As with all imaging, the impact of the results of the imaging must potentially affect imminent clinical management.

Regarding other ACR recommendations, MR room cleaning and disinfecting protocols are quite varied and subject to change with the unique clinical circumstances of particular sites (eg, availability of personal protective equipment [PPE], emergent need for truly immediate access to the only available but not yet disinfected MR scanner for a non-COVID patient). General guidelines exist, such as 60-minute downtime followed by cleaning protocol with approved cleaning agents following a clockwise, linear, top-to-bottom pattern of cleaning all visible surfaces. However, these will be tempered by local guidelines and policies, especially the specific clinical needs of the patients and site, and are likely to change over time.

Regarding MR exams for patients utilizing standard surgical face masks (non-N95 respirators), if there is a metal strip in the surgical mask, inpatients should be fit with known MR Safe masks or respirators prior to entering the radiology department.

Alternatively, when this is not possible, metallic components from a face mask should be removed prior to, or when necessary, upon, the patient’s arrival at the MR suite. Tape may be applied across the bridge of the nose section of the mask after removing the metal strip if the site feels that this would be sufficient for adequate fomite control and to maintain the intended function of the mask. If the patient has a tracheostomy, a face mask without metallic component should also be placed over the tracheostomy.

MRI examinations with non-MR Conditional masks is strongly discouraged. If absolutely necessary for unanticipated reasons, lowering specific absorption rate values and/or shortening radio frequency (RF) transmission durations and/or introducing cool-down periods between scans may help minimize the risks of patient injury. These will result in longer study times for that patient.

Powered air-purifying respirators (PAPR) should not be brought into Zone IV due to the potential risks of adverse interactions with ferromagnetic components of the PAPR system.

As PPE worn by health care personnel is not expected to be exposed to the time-varying RF or gradient magnetic fields of the MR imaging environment, the only MR-related safety concern is that of potentially ferromagnetic components of the PPE (eg, staples, metallic band inserts) and possible translational and rotational forces that the static magnetic field and the static magnetic field gradient may exert upon it. For such equipment, potential risks can be mitigated by ensuring that no ferromagnetic components are present in the PPE or by removing such components and replacing them with tape—if possible, without adversely affecting their intended isolation functionality.