# 4324
Once again we have additional evidence of neurological problems being induced by the novel H1N1 virus. This time from an expedited letter appearing in the CDC’s Journal of Emerging Infectious Diseases .
DOI: 10.3201/eid1603.091699
Suggested citation for this article: Kitcharoen S, Pattapongsin M, Sawanyawisuth K, Angela V, Tiamkao S. Neurologic manifestations of pandemic (H1N1) 2009 virus infection [letter]. Emerg Infect Dis. 2010 Mar; [Epub ahead of print]
Neurologic Manifestations of Pandemic (H1N1) 2009 Virus Infection
This four page letter describes the presentation, testing, and course of illness of a 34-year-old man, previously healthy, who was admitted to Chaiyaphum Hospital in Chaiyaphum, Thailand, back in August with flu-like symptoms.
By day 2 post admission, the patient’s condition had deteriorated, with significant neurological symptomology.
Some excerpts from the report follow:
. . . progressive quadriparesis with bilateral, symmetric paresthesia (glove-and-stocking pattern), and areflexia developed. His motor weakness (grades III/V) began in both legs and then involved both arms and hands. Other neurologic examinations showed limitation of extraocular movement in all directions, normal pupil size and light reflex, and facial diplegia.
On Day 3, acute respiratory failure occurred.
From there, the patient’s neurological deficits increased, and testing pretty much ruled out the `usual suspects’ for those types of symptoms.
. . . . negative results for syphilis testing and for serologic tests for HIV, hepatitis B virus, hepatitis C virus, Japanese encephalitis virus, herpes simplex virus, and Mycoplasma pneumoniae. A CSF antigen test was negative, and CSF culture was negative for bacteria.
Although a diagnosis of GBS (Guillain Barre Syndrome) was considered, testing and some clinical signs did not support that diagnosis. The authors conclude:
Our report shows neurologic manifestations associated with pandemic (H1N1) 2009 virus infection in an adult. The manifestation of progressive quadriplegia with diffuse sensory loss is compatible with a polyneuropathy. The neurologic signs developed 2 days after the respiratory tract signs.
You can read the whole paper here.
This, of course, isn’t our first hint of neurological problems stemming from the H1N1 virus. And in truth, on rare occasions, even seasonal flu can induce neurological problems.
But pandemic strains, like novel H1N1 and the H5N1 bird flu virus, seem more adept at producing neurological manifestations.
In November, in a blog entitled Japan: Influenza Related Encephalopathy we looked at this report in the Yomiuri Shimbun.
132 flu patients hit with brain disorders since July
The Yomiuri Shimbun
A total of 132 influenza patients in Tokyo and 27 prefectures have developed encephalopathy, or swelling of the brain, since July, according to the National Institute of Infectious Diseases.
Normally, only about 40 to 50 seasonal flu sufferers develop encephalopathy each year, meaning the latest figure has already more than doubled in four months since the new strain of flu began spreading.
Earlier in November, Children’s Hospital in Pittsburgh, PA reported several children with H1N1 related encephalitis.
And last summer, CDC’s MMWR (July 23rd issue) reported on 4 pediatric patients with the novel H1N1 virus who presented with neurological symptoms including unexplained seizures and altered mental status.
Neurologic Complications Associated with Novel Influenza A (H1N1) Virus Infection in Children --- Dallas, Texas, May 2009
Neurologic complications, including seizures, encephalitis, encephalopathy, Reye syndrome, and other neurologic disorders, have been described previously in association with respiratory tract infection with seasonal influenza A or B viruses (1--2), but not with novel influenza A (H1N1) virus.
On May 28, 2009, the Dallas County Department of Health and Human Services (DCHHS) notified CDC of four children with neurologic complications associated with novel influenza A (H1N1) virus infection admitted to hospitals in Dallas County, Texas, during May 18--28.
As more reports, studies, and investigations into the impact and sequelae of this pandemic come in, we will get a better idea of how to regard this H1N1 virus.
While not the killer pathogen some feared, it quite obviously differs from seasonal flu on several fronts.
The next few years are going to be a time of much study, and hopefully discovery, as we sift through the reams of data accumulated over the past nine months.
