Magnetic risonance imaging (mri) of olfactory bulbs and other brain structures in kallmann syndrome
G. Bellastella1, A. Elefante2, V. Palumbo1, A. DErrico2, M. Napoli2, L. Maione1, D. Visconti1, O. Vargas1, F. Briganti2, A. Brunetti2 & A. Sinisi1
Kallmann syndrome (KS) is characterized by hypogonadotropic hypogonadism and other non-reproductive disorders including smell deficiency due to olfactory bulb developmental abnormalities. The aim of our study was to evaluate retrospectively the role of MRI in patients with clinical diagnosis of KS, searching for any abnormalities of the brain structures involved.
Methods: We evaluated 25 KS pts (1432 years, 4F, 21 M). KS cases were classified as hyposmic (KSHO, n 9) or anosmic (KSAO, n 16) by using a modified smell test. Brain MRIs (SE T1 sagittal and coronal planes, TSE T2 axial and coronal planes 2 mm thick, volumetric MPRAGE) of olfactory bulbs and sulci, corpus callosum and pituitary were blind assessed by two radiologists.
Results: In KSAO group eight showed olfactory bulbs and sulci agenesis, four bulbs agenesis (3 normal, one hypoplastic sulci), 4 bulbs and sulci hypoplasia. In KSHO two showed bulbs and sulci agenesis, two bulbs agenesis, two bulb and sulci hypoplasia, 1 hypoplastic bulbs, one normal bulbs and sulci but turbinates abnormalities. three cases were not evaluated for technical reasons. The pituitary was abnormal in 8% of cases: three pituitary hypoplasia, 1 a mucinous cysts of the pars intermediate, three a sellar arachnoid diverticulum. Hypoplastic corpus callosum was done in 2 out 25 pts.
Conclusions: Clinical and MRI data are sometimes not correlated. 50% of KSAO presented agenesis of both sulci and bulbs, 25% only bulbs agenesis and 12% bulbs and sulci hypoplasia. KSHO showed a highly variable phenotypic framework. Associated abnormalities of sellar and suprasellar regions are less frequent. MRI is important to detect abnormalities of olfactory structures, especially in prepubertal patients, where clinical diagnosis is not always easy. Moreover, imaging study may reveal other possible causes of smell dysfunction, allowing to minimize any diagnostic bias.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This work was supported, however funding details unavailable.