An infant is brought to the clinic by his mother, who has noticed that he holds his head in an unusual position and always faces to one side. Which of the following is the most likely explanation?
A. Torticollis, with shortening of the sternocleidomastoid muscle.
B. Craniosynostosis, with premature closure of the cranial sutures.
C. Plagiocephaly, with flattening of one side of the head.
D. Hydrocephalus, with increased head size.
Correct Answer: A. Torticollis, with shortening of the sternocleidomastoid muscle.
In torticollis, the sternocleidomastoid muscle is contracted, limiting range of motion of the neck and causing the chin to point to the opposing side. Torticollis or twisted neck (tortum collum) of Italian origin “torti colli” is a vicious attitude of the head and neck, typically presenting with abnormal slope and rotation. There may be several presenting positions, including flexion, extension, right or left tilt. These have names such as horizontal torticollis, vertical, oblique, or torsion.
Option B: In craniosynostosis one of the cranial sutures, often the sagittal, closes prematurely, causing the head to grow in an abnormal shape. Craniosynostosis is the result of the early fusion of cranial sutures. These sutures exist to facilitate the passage of the baby through the birth canal and later on allow the expansion and growth of the brain. When one or more sutures close prematurely, the structure of the skull becomes altered, growing on the path of least resistance (perpendicularly to the closed suture) and resulting in an atypically shaped skull leading to increased intracranial pressure (ICP) and having an effect on the respiratory and neurologic systems, as well as the development of the child.
Option C: Plagiocephaly refers to the flattening of one side of the head, caused by the infant being placed supine in the same position over time. Plagiocephaly is defined as an asymmetric shape of the head due to unilateral flattening. The term flathead can be used as a synonym. Plagiocephaly can be categorized into synostotic or deformational types.
Option D: Hydrocephalus is caused by a build-up of cerebrospinal fluid in the brain resulting in large head size. Hydrocephalus is the symptomatic accumulation of cerebrospinal fluid (CSF) inside the cerebral ventricles. This accumulation may be due to obstruction in the normal flow of the CSF, or to problems with absorption into the venous system by the Pacchionian arachnoid granulations, or due to excessive production of CSF.