Growth hormone deficiency: a window to CNS malformations

Chiari malformation denotes a pathological caudal ectopy of the cerebellar tonsils below the level of the foramen magnum. Several types of the condition exist, of which Type 1 is the most common. It often results in few symptoms, and in many cases is detected as an incidental finding when an MRI is performed. Chiari type 1 has been hypothesized to be associated with Growth Hormone deficiency. A 6-year-old female child, 2nd by birth order born of non- Consanguineous marriage presented with short stature (83cm, below 3rd SD) with normal head size, normal US:LS ratio with no motor developmental delay and the child's height was below the mid parental height percentile. Work up for proportional short stature was done and child's basal Growth Hormone levels were low -0.153ng/ml (2-5 ng/ml) and IGF-1 levels were low 1736 ng/ml (2188-4996 ng/ml). The thyroid function test, cortisol levels, calcium, phosphorus, ALP were normal. Growth Hormone stimulation with clonidine revealed low post stimulation GH levels being 0.177, 0.86, 1.1, 0.6, 0.66 respectively at 0, 30, 60, 90 mins and GH stimulation with Glucagon revealed low post stimulation GH levels being 0.19, 0.27, 0.18, 0.74, 0.32, 0.32 respectively at 0, 30, 60 ,90, 120 mins. Work up for other pituitary hormones were normal. MRI brain of the child was done which showed cerebellar tonsillar herniation with likely syrinx in visualized section of cervical spinal canal cord suggestive of Chiari malformation type 1.