Archive for the ‘Neuropsychiatric disorders’ Category

The PANDAS controversies

Thursday, December 22nd, 2011

We're not talking about this kind of Panda

The more I read about the relatively new syndrome PANDAS, Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus, the more I realize how complex the issues are that surround it. We appear to be entering a new field of medicine, one that holds enormous potential for unlocking the root causes of baffling problems in neurology and psychiatry

The story starts in the mid 1990s when Dr. Susan Swedo, now Chief of the National Institute of Mental Health's (NIMH)  Pediatrics & Developmental Neuroscience Branch , reported that childhood obsessive-compulsive disorder (OCD) may sometimes be triggered by a strep infection.  OCD may involve compulsive handwashing, twenty or thirty times a day; it can manifest itself as a need to have things "just so" in order to relieve anxiety, repeating and checking behavior, counting and arranging objects or clothing, hoarding, praying, reading a section of a story over and over again.

Some of these youngsters also have tics, involuntary movement disorders. Another subset just has tics, but no OCD.

A moving portrait of a child who fits this profile was published in the Los Angeles Times early this month. The boy involved wa a normal eleven-year-old sixth grader until he developed a strep throat. Then his behavior altered to the point where daily life seemed totally changed; he became obsessed with being clean  and afraid of germs to the point where he was unable to go back to school.

Increasingly these diseases and perhaps others are being linked by some eminent researchers to strep infections. A senior immunologist at the University of Oklahoma College of Medicine thinks the mechanism of PANDAS involves antibodies, released in response to a strep infection, that can bind to brain cells and cause the release of dopamine, a brain chemical which in excess, may be linked to OCD and tics. The diagnosis, at the moment, is strictly clinical; there is no lab test to confirm that a child has PANDAS.

One form of OCD involves repetitive handwashing

Many youngsters with OCD and/or tics don't appear to have this strep-related syndrome and some equally prominent academic physicians feel kids can have a mental health/neurological disorder first and just have it exacerbated by strep throat or other infections. Others want to treat the most severely affected of these children with antibiotics even if they don't have an active strep infection.

The NIMH makes the point that these children, as opposed to others with OCD and/or tics, have an abrupt worsening of their symptoms when they have a strep infection. They then will have a slowly improving course after a few weeks or months.

The guidelines are admittedly vague; NIMH says PANDAS can be "identified after two or three episodes of OCD or tics that occur in conjunction with strep infection."

A senior Harvard professor of psychiatry who is the head of the International OCD Foundation's scientific advisory board has been quoted as saying the portion of OCD linked to PANDAS is "exceedingly common."

Is this the tip of an iceberg of neuropsychiatric problems linked to infections? Only time and lots of research will tell.


Now we have PANDAS in the United States...unfortunately

Wednesday, December 14th, 2011

Those nodes are swollen

Until today I thought Pandas were black and white bears found in zoos or in small numbers in parts of China. Then I read a Wall Street Journal article titled "Does Strep Throat Trigger Serious Ills?" The concept being discussed was that of PANDAS or Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcus. I subsequently found a National Institutue of Mental Health (NIMH), article online about this unfamiliar, relatively new and bizarre condition in which children get neurological problems caused or flared by a streptococcal infection.

Let's begin this two-post discussion with an overview of strep throat, a bacterial infection most commonly seen in children between the ages of 5 and 15. Younger kids can certainly get this disease as can adults, but the typical kid in school has strep throat several times a year. It's important to realize that most (75-80%) sore throats in children aren't bacterial in origin, but if they are caused by streptococcal infection they can lead to severe consequences.

Among those are rheumatic fever with its attendant heart valve consequences and, less frequently, a significant kidney sequela, post-streptococcal glomerulonephritis (inflammation of the tiny filtering blood vessels in the kidneys). Both of these are seen worldwide with considerable frequency, but are much less common in the United States than in years past.

Why is that? Well, most of us who have healthcare (and I know that's far from all of us), would take our children to the pediatrician/family practice physician promptly if they had sudden onset of fever with a severe sore and red throat,  swollen lymph nodes in the neck and trouble swallowing (or even some of those). The doc would do a rapid strep test using a swab similar to that done for a throat culture and if that were positive prescribe antibiotics. If it was negative (it can be in about 5% of cases of strep throat, AKA strep pharyngitis), but the presentation and/or exam was suspicious, the physician would do a throat culture.

Those complications I mentioned are relatively rare. When they do occur they're due to an autoimmune reaction; that means the antibodies we produce to help fight the streptococcus can also, in some instances, attack our own tissues.. The theory behind that is called "molecular mimicry," a fancy way to say our heart valve, kidney, joint or brain tissue may have proteins that somehow resemble those of the bacterial cell wall.

after this you get a lollipop

There a PubMed Health review on treating strep throat, at least that caused by the bad kind of streptococcal bacteria. Their scientific name is group A beta-hemolytic strep sometimes termed GABHS. PubMed, by the way, comes from the National Institutes of Health's (NIH) National Library of Medicine and prints very solid material that I think you can rely on.

They looked at a series of articles on how best to treat strep throat, 17 trials with over 5,300 subjects, and concluded that good old-fashioned penicillin should be the first choice. It's cheap and no antibiotic resistance in GABHS has ever been documented. So unless you or your child have had an allergic reaction to penicillin, that's the drug your doc will likely use.

We'll get back to PANDAS next post.