Kallmann syndrome is a genetical disorder that prevents a person from starting or fully completing adolescence. It is a form of a group of conditions known as hypogonadotropic hypogonadism.

To distinguish it from other forms of hypogonadotropic hypogonadism, Kallmann syndrome has the additional symptom of a total lack of sense of smell or a reduced sense of smell

The mnemonic to master Kallman syndrome features is : KALMAN

   Color blindness (K sounds like C)
   Anosmia
   Low LH, FSH, Sex hormones → delayed puberty
   Midline defects (cleft palate, cleft lip)
   Ataxia (cerebellar ataxia)
   Nerve deafness

Imaging of Kallman Syndrome

 It is easiest to appreciate the anatomical anomalies present in Kallman syndrome by comparing it to a normal patient.

The normal anatomy of the region consists of the olfactory bulbs (blue arrows) located in the olfactory grooves of the anterior cranial fossa.

The inferior surface of the frontal lobes usually consists gyrus rectus (aka straight gyrus) (R) separated from the medial orbital gyrus (M) by the olfactory sulcus (yellow arrow). These are absent in Kallman syndrome.