Mathematical modelling for detection of brainstem lesions according abr changes
Abstract
The aim of this study was to elaborate an algorithm of the detection of brainstem lesion according BAEP changes. The following questions were raised for this purpose: 1) which interpretation strategy of BAEP changes selects the most patients with brainstem lesions? 2) which BAEP abnormalities differentiate between mass lesions of posterior fossa and demyelinating encephalomyelitis? 3) which BAEP changes differentiate among posterior fossa tumors?
The database for the elaboration of this mathematical model consisted of 459 patients: 245 with posterior fossa tumours (brainstem glioma, cerebellar glioma, CPA meningioma and acoustic neuroma) and 214 non- tumour patients with demyelinating encephalomyelitis. On the basis of the analyzed data an algorithm for the detection of brainstem affecting diseases was elaborated. The following procedure as a result of the study was proposed:
1) The shortest and the most optimal is the interpretation strategy which consisted of the evaluation of IPL I-V and interaural difference of the
IPL I-V).
2) The second step in the algorithm procedure is differentiation between mass lesions in posterior fossa and demyelinating encephalomyelitis. The following BAEP changes are significant for this purpose- increased latency of the wave III, increased IPL I-V, interaural difference of the IPL I-III.
3) After the high probability of posterior fossa tumour has been estimated the differential diagnosis among posterior fossa tumours is performed, using two BAEP changes which were identified as significant – increased latency of the wave III and interaural difference of IPL I-III.
