Shingles may be rare trigger for developing NMOSD: Case report
Researchers found 11 cases in the scientific literature since 2008
Shingles is caused by an infection of the varicella-zoster virus (VZV), but in rare cases, it may trigger neuromyelitis optica spectrum disorder (NMOSD), a new study reports.
The study’s researchers said clinicians should look for possible signs of NMOSD in patients being treated for shingles, even though developing NMOSD after the condition is rare. The study, “Aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder triggered by herpes zoster: a case report and literature review,” was published in the Journal of International Medical Research.
NMOSD is an autoimmune disease wherein the immune system erroneously attacks healthy nervous system cells, causing damaging inflammation in the spinal cord and optic nerve, which relays signals between the eyes and brain. In most NMOSD patients, self-reactive antibodies target aquaporin-4 (AQP4), a protein in nervous system support cells.
What causes NMOSD isn’t known, but data suggest viral infections may trigger it in some cases. It’s thought when the immune system ramps up to go after the virus, healthy cells may get caught in the crossfire, causing the autoimmune disease to develop.
The varicella-zoster virus, which causes chickenpox in childhood, remains in the body after a first infection and stays dormant in nerves around the spinal cord. The virus can reactivate later in life and cause shingles, which results in a painful rash.
“Currently, literature on [AQP4-related] NMOSD following [shingles] mainly consists of case reports, which do not provide a comprehensive understanding of its clinical characteristics and prognosis,” the researchers wrote.
Shingles leads to NMOSD
Here, scientists in China described the case of a 45-year-old woman who developed NMOSD following a bout of shingles and reviewed data of similar cases in the literature.
The woman developed shingles with stabbing and burning pain on her right arm and hand. She had begun taking antiviral medications and traditional Chinese medicine, and developed nausea and vomiting a week later. She received medicine for her symptoms after being admitted to the researchers’ hospital. A brain MRI showed no abnormalities.
She was not improving, so she was transferred to the pain management department and received more anti-pain medications, including opioids, which were only temporarily effective.
A few days later, she developed new pain in the left neck and shoulder, “which was initially misdiagnosed as new onset … herpes zoster infection,” the researchers wrote. The woman was started on into-the-vein antiviral treatment for shingles, but continued to have significant pain along with worsening nausea, vomiting, and hiccups.
Long-standing attacks of uncontrollable nausea, vomiting, or hiccups is known as area postrema syndrome (APS) and may occur as the first symptom of NMOSD. However, at the time, these symptoms, along with a new inability to completely empty her bladder, “were considered adverse reactions to the opioids,” the researchers wrote.
About a month after the first symptoms, her pain and nausea lessened, and the woman asked to be discharged. But two weeks later, she started having spasms in her right upper limb that caused her hand to clench uncontrollably into a fist. This prompted a neurological examination that revealed damage in her spinal cord and a positive test for anti-AQP4 antibodies, leading to a diagnosis of NMOSD. She received immunosuppressive medications, including corticosteroids and mycophenolate mofetil, along with intravenous immunoglobulin, which is intended to neutralize self-reactive antibodies in the blood.
Several months later, her spasms had significantly reduced and she continued taking the immunosuppressive medications. A spine MRI showed no abnormalities.
A rare event
“This case further reinforces the notion that infections can trigger attacks of [AQP4-related] NMOSD,” wrote the researchers, who said the woman’s case was the first shingles-induced AQP4-related NMOSD “presenting initially with persistent nausea and vomiting, and experiencing fluctuating relapses throughout the disease course.”
They found the woman’s case was the 11th of AQP4-related NMOSD developing after shingles since 2008. All concerned females, seven Asian and four European. The average age at onset was 47, with NMOSD developing a median of about three weeks after shingles.
“All patients exhibited motor, sensory, or sphincter dysfunctions,” as well as spinal cord inflammation, the researchers wrote, while optic nerve inflammation was less common. “Our findings suggest that [AQP4-related] NMOSD following VZV infection tends to spare the optic nerves.”
All 11 cases were treated with corticosteroids and most patients still “had residual motor or sensory impairments” at the last follow-up, the researchers wrote, adding the woman’s case shows clinicians shouldn’t overlook potential symptoms of NMOSD in people with shingles. “During the course of the disease, some patients with [shingles] may develop or have concurrent conditions such as … NMOSD, and clinical symptoms not directly associated with VZV infection may be overlooked by physicians. Although NMOSD following herpes zoster is rare, it remains a critical consideration for clinicians.”
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