[Chiari II malformation. Supportive and predictive value of brainstem reflex and EAEP recordings].
BACKGROUND
In about 20% of patients with Chiari II malformation brainstem signs and symptoms occur. Ventilatory dysfunction is the main cause of death in these patients. The indication for craniocervical decompression is based on clinical examination because supporting electrophysiological or radiological methods were lacking.


METHODS
In a prospective study the clinical courses of 106 patients were documented during a 3-year period. In addition brainstem diagnostic procedures using the masseter reflex (MR), blink reflex (BR) and early auditory evoked potentials (EAEP) were done. Based on the model of binary logistic regression the odds ratio (OR) of progression over time was calculated.


RESULTS
The combination of MR and late BR components showed the highest correlation with clinical findings (OR: 23). The highest predictive value regarding clinical progression over a 3-year period was shown by the combined evaluation of MR, late BR components and EAEP interpeak latency I-V (OR: 17.6). Signs and symptoms had no predictive value.


CONCLUSIONS
Combined brainstem reflex recordings (MR and late BR components) support the clinical examination. To evaluate the long-term prognosis brainstem reflexes and EAEP recordings should be used.
Koehler
J
J
Abteilung für Neurologie, Asklepios Klinik Nord, Tangstedter Landstrasse 400, Hamburg, Germany. j.koehler@asklepios.com
Eggers
J
J
Schwarz
M
M
Faldum
A
A
D000293:Adolescent; D000328:Adult; D001139:Arnold-Chiari Malformation / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D001767:Blinking / Q000502:physiology; D001933:Brain Stem / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D019299:Decompression, Surgical; D004292:Dominance, Cerebral / Q000502:physiology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology; D008591:Meningomyelocele / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D009119:Muscle Contraction / Q000502:physiology; D009460:Neurologic Examination; D011237:Predictive Value of Tests; D011379:Prognosis; D011930:Reaction Time / Q000502:physiology*; D012021:Reflex, Abnormal / Q000502:physiology; D055815:Young Adult