Mysterious nodding disease debilitates children

[Aanker]

http://edition.cnn.com/2012/03/19/wo...se/index.html?

Quite an interesting article, my immediate first thought while reading the opening paragraphs was 'prions' but then the symptoms seemed to be quite off (and apparently the disease does not explicitly end in death?), and the experts gave the clue about parasites etc.

Any ideas? Comments?

[hellheaven1987]

Parasites may be, since prions generally caused quick death immediately. No matter what it is, it probably infect brain tissue, hence results all sore of abnormal behaviors.

[Sphere]

Awesome

[Aanker]

I just find it strange that a parasite species would suddenly start attacking the brain, though of course it could be the case of a sudden transmission from some other animal to humans, or a mutation. That the age group is rather limited I find even more perplexing, if this was in fact a parasite.

But would a parasite not also result in eventual death, especially if it indiscriminately attacked the brain?

[hellheaven1987]

I just find it strange that a parasite species would suddenly start attacking the brain

There are actually several parasites that specifically targeted human brain tissue, so it is not unheard about. For example, African sleeping sickness, which the parasite Trypanosome would invade human brain through circular system and caused all sore of symptoms.

But would a parasite not also result in eventual death, especially if it indiscriminately attacked the brain?

From my understanding nodding disease does cause death eventually.

[Aanker]

There are actually several parasites that specifically targeted human brain tissue, so it is not unheard about.

Yes, but I am rather referring to the fact that this seems to be a previously unobserved set of symptoms (or even a new disease completely), rather than something that has been encountered before.

PS. Oh, apparently it has been seen before, most prominently in South Sudan.

[Ludicus]

Principal suspect,Onchocerca volvulus.

1)

Spoiler Alert, click show to read: 

Epilepsia. 2008 Dec;49(12):2008-15. Epub 2008 May 21.
The head nodding syndrome--clinical classification and possible causes.
Winkler AS, Friedrich K, König R, Meindl M, Helbok R, Unterberger I, Gotwald T, Dharsee J, Velicheti S, Kidunda A, Jilek-Aall L, Matuja W, Schmutzhard E.
Source
Department of Neurology, University of Ulm, Ulm, Germany. drawinkler@yahoo.com.au
Abstract
PURPOSE:
In the 1960s in Tanzania, L. Jilek-Aall observed a seizure disorder characterized by head nodding (HN). Decades later, "nodding disease," reminiscent of what was seen in Tanzania, was reported from Sudan. To date this seizure disorder has not been classified and possible causes still remain obscure.
METHODS:
In a prospective study in southern Tanzania, we evaluated 62 patients with HN. Selected patients underwent blood (n = 51) and cerebrospinal fluid (CSF) (n = 48) analyses. Others were chosen for MRI (n = 12) and EEG (n = 10).
RESULTS:
Seizure type was classified as "head nodding only" and "head nodding plus," the latter being combined with other types of seizure (n =34). During HN, consciousness was impaired in 11 patients (17.7%) and supportive signs of epileptic seizures were described by 15 (24.2%) patients. Precipitating factors were confirmed by 11 (17.7%) patients. Fifty-six (90.3%) patients had at least one relative with epilepsy. EEG confirmed interictal epileptic activity in two patients and unspecific changes in four patients. MRI showed hippocampus pathologies (n = 5) and gliotic changes (n = 5). Skin polymerase chain reaction (PCR) positivity for Onchocerca volvulus was significantly associated with lesions on MRI. However, PCR of the CSF was negative in all cases.
CONCLUSIONS:
We present a comprehensive clinical description of the "HN syndrome," possibly a new epilepsy disorder in sub-Saharan Africa. MRI lesions and their association with positive skin PCR for O. volvulus despite negative PCR of the CSF is intriguing and deserves attention. Furthermore, the high prevalence of hippocampus sclerosis and familial clustering of epilepsy may point toward other potential pathogenetic mechanisms.

The head nodding syndrome—Clinical classification and possible causes.


------
2)

Spoiler Alert, click show to read: 

Winkler et al. (2008) give an excellent description of the “head nodding syndrome,” a disorder that has been found linked with epileptic seizures in four distinct geographic locations of sub-Saharan Africa (Jilek-Aall et al., 1979; Van der Waals et al., 1983; Kaiser et al., 2000; Lacey, 2003), all of which known as endemic for Onchocerca volvulus, the causative agent of river blindness. Over the last decade, O. volvulus has increasingly been implicated in the observation of clustering excess prevalence of epilepsy (Pion et al., 2009). With this background, the study of Winkler et al. is of great interest because, for the first time, it provides results of magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) analysis of patients with epilepsy living in an onchocerciasis endemic area.

A search for a pathologic substrate inducing epilepsy by O. volvulus should aim at the demonstration of the parasite in the central nervous system (CNS). Certainly, the macrofilarial stages of the parasite, because of their size (length 5–50 cm; width 0.1–0.45 mm), would be expected to produce clearly visible lesions and the absence of such findings argues against the involvement of the adult stage of O. volvulus in the CNS. However, the pattern of the pathologic MRI findings still leaves room for speculation about microfilariae (length 220–300 μm) producing more subtle changes in the brain. Even if no microfilariae are found in the CSF, one may consider changes due to degrading microfilariae, or to persisting immune reactions to these.

Winkler et al. do not provide information on antifilarial medication prior to their patients’ enrollment in the study, although this may have significantly influenced the results of their parasitologic examinations. Throughout most of the African endemic areas, patients with onchocerciasis are treated with the microfilaricidal drug ivermectin (Mectizan), which has been made available at no cost by its manufacturer (Merck & Co., Whitehouse Station, NJ, U.S.A.) since 1987. In Mahenge, the study area of Winkler et al., annual mass treatment has been carried out since 1998, with therapeutic coverage reaching up to 70% (WHO/APOC, 2007), and it appears likely that many of their patients already had received ivermectin. The very low microfilarial counts found in dermal biopsies also strongly indicate previous treatment with ivermectin. In view of the potent effect of ivermectin on O. volvulus microfilariae (Basáñez et al., 2008) it cannot be excluded that in the patients with head nodding examined by Winkler et al. microfilariae could have been present in the CSF before treatment, as they were previously demonstrated in the CSF of untreated patients (Duke et al., 1976).

Ultimately, the article of Winkler et al. leaves unsolved the question as to whether the phenomenon of head nodding constitutes a feature of an epileptic syndrome caused by O. volvulus. Future investigations should aim at studying patients without history of antiparasitic treatment and involve appropriate comparison groups of persons without epilepsy. We hope that this most interesting article will stimulate more researchers with neurologic and parasitologic background to get involved in this neglected subject.

Head nodding syndrome and river blindness: a parasitologic perspective.

[hellheaven1987]

The problem is that patients generally do not show the sign of river blindness; furthermore, it also does not explain why adults do not have same symptoms.

[Ludicus]

The problem is that patients generally do not show the sign of river blindness; furthermore, it also does not explain why adults do not have same symptoms.

...In Mahenge, the study area of Winkler et al., annual mass treatment has been carried out since 1998, with therapeutic coverage reaching up to 70% (WHO/APOC, 2007), and it appears likely that many of their patients already had received ivermectin. The very low microfilarial counts found in dermal biopsies also strongly indicate previous treatment with ivermectin. In view of the potent effect of ivermectin on O. volvulus microfilariae (Basáñez et al., 2008) it cannot be excluded that in the patients with head nodding examined by Winkler et al. microfilariae could have been present in the CSF before treatment, as they were previously demonstrated in the CSF of untreated patients (Duke et al., 1976).

---
(CSF :Cerebrospinal Fluid)

[Magicman2051]

The "nodding" symptoms, as described, initially struck me as similar to those experienced by heroin users.

[Col. Tartleton]

Africa sucks. I can't even get concerned about that. I didn't even see any nodding. I was expecting some kind of Quagmire Syndrome. River Blindness is not as fun.