Lambdoid craniosynostosis is a congenital condition where specific joints in a baby’s skull close earlier than they should. An infant’s skull is composed of multiple bony plates separated by flexible seams known as sutures. These sutures allow the skull to expand as the brain undergoes rapid growth in the first few years of life. In cases of lambdoid craniosynostosis, one or both of the lambdoid sutures, located along the back of the head, fuse prematurely. This early fusion can restrict the brain’s normal development and alter the head’s shape. It is considered one of the rarest forms of craniosynostosis.
Identifying Lambdoid Craniosynostosis
The most apparent sign of lambdoid craniosynostosis is an abnormal head shape. The premature fusion of a lambdoid suture causes a characteristic flattening on one side of the back of the head. This unilateral flattening can lead to a trapezoidal appearance when the baby’s head is viewed from above. A palpable, hard ridge may be felt over the affected suture line.
Other physical indicators accompany the skull’s asymmetry. The ear on the flattened side is positioned lower and further back than the other ear. There may also be a noticeable bulging or bossing of the forehead on the opposite side as the brain grows in the direction of least resistance.
It is important to distinguish this condition from positional plagiocephaly. Positional plagiocephaly also involves flattening at the back of the head but is caused by external pressure, such as a baby consistently lying in the same position. Unlike craniosynostosis, the skull plates in positional plagiocephaly are not fused, and the condition does not require surgery.
Diagnostic Process and Causes
The diagnostic journey begins with a thorough physical examination by a specialist, often a pediatric craniofacial surgeon or neurosurgeon. The specialist will assess the baby’s head shape, feel for ridges along the suture lines, and take precise measurements of the head’s circumference.
To confirm a diagnosis of lambdoid craniosynostosis, medical imaging is necessary. A computed tomography (CT) scan is the most common imaging test used, as it provides detailed, three-dimensional images of the skull bones. This allows the medical team to see the fused lambdoid suture and rule out other possibilities. These scans also help surgeons plan the most appropriate treatment.
The exact cause of lambdoid craniosynostosis is often unknown and is considered sporadic, meaning it occurs by chance. It is not linked to any specific actions taken or avoided by the parents during pregnancy. In a small number of cases, the condition may have a genetic basis and can be associated with certain syndromes that affect skeletal development.
Surgical Treatment Options
Surgery is the primary treatment for lambdoid craniosynostosis, performed to correct the skull’s shape and, more importantly, to allow adequate space for the growing brain. Without intervention, the restricted skull volume could lead to increased pressure on the brain, which can have developmental consequences. The surgical approach is tailored to the individual child, depending largely on their age at the time of diagnosis and the specifics of their condition.
For infants older than six months, the standard procedure is open cranial vault remodeling. This extensive surgery involves a scalp incision that allows surgeons to access the skull bones. The surgical team, comprising a craniofacial plastic surgeon and a neurosurgeon, then reshapes and repositions the affected bones to create a more typical head shape and size. This comprehensive reconstruction provides immediate correction and space for brain growth.
A different approach, known as minimally invasive endoscopic surgery, is an option for infants younger than three to four months. This technique involves one or two small incisions, through which an endoscope (a tiny camera) and specialized instruments are inserted to release the fused suture. This procedure is less invasive, with reduced blood loss and a shorter hospital stay. Following endoscopic surgery, the infant is required to wear a custom-molded helmet for several months to help guide the skull’s growth into a more rounded shape.
Recovery and Long-Term Outlook
Following surgery, the child’s recovery begins with a hospital stay, which may include monitoring in a pediatric intensive care unit for a short period. The length of the hospital stay varies depending on the type of surgery performed, with open procedures requiring a longer stay than endoscopic ones.
The long-term prognosis for children who undergo timely surgical correction for lambdoid craniosynostosis is very positive. The vast majority of children experience normal brain development and lead healthy, active lives. The cosmetic appearance of the head is also significantly improved, which can be important for a child’s self-esteem later in life.
Regular follow-up appointments with the craniofacial and neurosurgical team are an important part of post-operative care. These visits allow the medical team to monitor the child’s head growth and overall development to ensure a successful outcome. Imaging scans may be used during these follow-ups to check that the skull continues to grow correctly.