title: The head nodding syndrome--clinical classification and possible causes.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Neurology, University of Ulm, Ulm, Germany. drawinkler@yahoo.com.au
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Winkler
authors.forename: Katrin
authors.initials: K
authors.lastname: Friedrich
authors.forename: Rebekka
authors.initials: R
authors.lastname: König
authors.forename: Michael
authors.initials: M
authors.lastname: Meindl
authors.forename: Raimund
authors.initials: R
authors.lastname: Helbok
authors.forename: Iris
authors.initials: I
authors.lastname: Unterberger
authors.forename: Thaddaeus
authors.initials: T
authors.lastname: Gotwald
authors.forename: Jaffer
authors.initials: J
authors.lastname: Dharsee
authors.forename: Sandeep
authors.initials: S
authors.lastname: Velicheti
authors.forename: Aslam
authors.initials: A
authors.lastname: Kidunda
authors.forename: Louise
authors.initials: L
authors.lastname: Jilek-Aall
authors.forename: William
authors.initials: W
authors.lastname: Matuja
authors.forename: Erich
authors.initials: E
authors.lastname: Schmutzhard
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002648:Child; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006257:Head / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D017181:Onchocerca volvulus / Q000276:immunology; D009855:Onchocerciasis / Q000150:complications; D011446:Prospective Studies; D012640:Seizures / Q000145:classification* / Q000175:diagnosis* / Q000209:etiology* / Q000382:microbiology; D012867:Skin / Q000382:microbiology / Q000473:pathology; D013577:Syndrome; D013636:Tanzania / Q000453:epidemiology; D055815:Young Adult