Surgical Indications and Treatment for Cranial Occipital Anomalies

Fig. 8.1
(a, b) Vertex views of the infant for differentiating posterior plagiocephaly. (a) Positional nonsynostotic plagiocephaly (PP): the superior aspect of the head resembles a parallelogram due to anterior displacement of the ipsilateral ear, accentuation of the ipsilateral frontal bossing, and compensatory flattening of the contralateral frontal bone. (b) Synostotic lambdoid plagiocephaly (SP): the superior aspect of the head resembles a trapezoid due to ipsilateral frontal bone flattening and contralateral compensatory frontal and parietal bossing; the ipsilateral ear remains in the same line of the contralateral one or even posteriorly displaced. The arrows point out the different ear positions in PP and SP

Conversely, in case of SP, the premature closure of the hemi-lambdoid suture will prevent the growth of affected hemi-skull, such that the ipsilateral ear will remain in the same line of the contralateral one (or even posteriorly displaced) and there will be some degree of mastoid bossing and frontal bone flattening; contralaterally, a compensatory frontal and parietal bossing will result. In other words, the superior aspect of the synostotic form resembles a trapezoid [57].

Associated contralateral muscular torticollis may be seen in children with PP, being the stiffness of contralateral sternocleidomastoid (SCM) muscle the primum movens with contralateral head tilt and ipsilateral head twist [1].

Proposed measures to document and then follow up the severity of the cranial deformity include anthropomorphic measurements and grading scales based on visual inspection (e.g., Argenta classification) [8]. The formers are obtained by using calipers to measure standard cranial diameters: cranial vault asymmetry, diagonal difference, and transcranial diameter [4].

8.2.2 Diagnostic Workup

Differential diagnosis of PP and SP is clinical based and often necessitates observation of the growth pattern. Radiographic evaluation is rarely indicated, particularly when the clinical examination is equivocal. CT scan is best used to ascertain sutural patency and thus for ruling out craniosynostosis.

In our practice, CT scan (with 3D reconstructions) is usually reserved to such doubtful cases and as a preliminary tool for surgery in order to plan the osteotomies when the operation has been already decided.

In equivocal cases, the decision for imaging assessments depends on the patient’s age as well. Since the possible operation is rarely urgent and is usually postponed till the patient is at least 6 months old, a “wait and see” policy may represent a valid option in newborns and small infants, even for radiological assessments. Conversely, a true plagiocephalic patient with more than 6 months of age usually demands timely diagnosis and, if needed, prompt surgical correction. In such cases, CT scan may be helpful addressing the diagnosis readily.

Plain skull X-rays are more useful in detecting signs of intracranial pressure (“copper beating”) and temporomandibular joint/mandibular ramus alignments [9, 10].

However, at times, it may be adequate for showing unclosed suture as well.

However, the 3D CT represents the gold standard for assessing the lambdoid sutures, and it provides information about the vault and skull base as well. The typical sutural pattern in SP is that of complete obliteration of the suture, associated with ectocranial and endocranial ridging, ipsilateral mastoid bossing, and contralateral parietal bossing. Conversely, in PP, lambdoid sutures have the typical aspect of “spot welding,” alternating areas of focal fusion with endocranial ridging, narrowing, and sclerosis to areas of patency and perisutural thinning. Burke et al. demonstrated some pathological findings mirroring the CT images: bony bridging or microspicule formation in the lambdoids of affected children [11].

Further radiological hints are “thumbprinting” and erosion of the bone over the posterior bone plates in case of local increased intracranial pressure, thickened asterion on the affected side, enlarged subarachnoid space over the frontal regions (frequently associated with craniosynostosis), and shift of the petrous ridge [1, 9, 12].

Magnetic resonance imaging is reserved for the rare patients who demonstrate intracranial abnormalities on CT scan.

Ultimately, we need to stress the concept that the diagnosis of PP versus SP is primarily made by clinical examination.

8.2.3 Clinical Sequelae

Some authors have advocated potential clinical sequelae of PP that is left untreated, but controversies exist.

Conflicting data on the ocular sequelae of PP have been reported in terms of visual field constriction [1].

Auditory processing showed smaller response amplitudes, a result consistent with compromised brain function, in both types of plagiocephaly [13].

Several studies have reported on the potential neurodevelopmental sequelae of plagiocephaly, identifying minor learning disorders in single-suture craniosynostosis and cognitive and psychomotor developmental delays in PP [1416]. Other studies documented the need for special education in 40 % of patients with PP [17].

In multiple studies, a subset of infants was classified as delayed, although the classification rarely was made using rigorous testing regimens nor the extent and type of delay were classified. Additionally, following the anti-SIDS campaign, infants placed supine for sleep with minimal prone time while awake are likely to have a period of relatively delayed motor development that then resolves by 18 months. The early motor skill achievement tests focus on activities related to prone position. Infants placed prone achieved motor milestones earlier than those placed supine [4, 18]. These studies suggest that any reports evaluating development in infants with PP need to account for sleep position to obtain an accurate comparison.

Accordingly, overall studies on early infant development failed to demonstrate that PP by itself is a risk factor for delayed development in infants [4].

Furthermore, dealing with plagiocephaly and developmental delays, the question is raised on which causes which. Does the plagiocephaly place children at higher risk for delays, or rather are children with preexisting delays and risk factors more prone to plagiocephaly because they are not moving as quickly and are spending more time on their backs? [19].

8.3 Conservative Treatment

Treatment strategies of PP begin with prevention via behavioral modifications. Parents have to be educated on methods of reducing the risk of deformational plagiocephaly. The infant’s head position during sleep should be alternated from left to right sides. The goal is to prevent the establishment of a persistent sleep position, precursor to deformational plagiocephaly. Infants should spend minimal time in car seats or other seating mechanisms that maintain supine positioning. A considerable amount of prone positioning or “tummy time” for the awake infant is recommended to prevent deformation [1].

Conversely, when PP is present, two factors affect the treatment plan and outcome: the age of presentation and severity of the deformity.

At less than 5–6 months of age, when the deformity is mild to moderate, behavioral modifications and mechanical adjustments are indicated. They consist of repositioning the infant’s head during sleep, off-loading the affected side of the occiput. If torticollis is diagnosed, neck exercises and physical therapy have to be performed. The goal is releasing the stiffness of SCM muscle and implementing the range of motion in the cervical region. The child is followed up for 1–2 months: if significant progress is not observed, radiological assessments of the cervical spine are obtained for ruling out skeletal anomalies. The vast majority of children with muscular torticollis associated with PP are successfully treated with physical therapy. When needed, a simple muscle-release procedure is performed, but surgery is usually necessary in less than 5 % of cases [1, 20].

Aggressive repositioning and behavioral modifications by the parents correct the occipital abnormality in almost 85–93 % of cases [9, 12].

However, those cases who at 5–6 months of life (1) fail conservative management, (2) present with initial moderate to severe deformities, or (3) have concomitant anterior craniofacial deformities are candidates for orthotic treatment with an external device. Orthosis is most effective for children 4–8 months of age, and the usual length of treatment is 2–3 months [1, 20, 21]. These devices are custom-fitted molding helmets that facilitate skull reshaping. Helmet therapy has to be started as soon as it becomes evident that conservative methods have failed or will not be an option because of the severity of deformation or advanced age.

Time is of essence, because the goal is capitalizing on the still-malleable cranial bones. Children need to be compliant, since they are encouraged to spend at least 23 h a day in the helmet.

There still remain a small group of patients in whom the deformation continues to progress, with developing severe deformation of the posterior occipital region. These cases with failure of helmet therapy, severe deformations, or older age of presentation are evaluated for surgery.

8.4 Surgical Indications

Indications for surgery are mainly based on the severity/course of the deformity and the age of presentation.

The goals of surgery are to prevent brain damage and to reduce cosmetic deformity.

The need for operative intervention in PP is rare. However, some studies support the concept that the severity of the posterior deformity dictates the surgical indication, especially when associated with compensatory frontal bossing and facial scoliosis, instead of the specific etiology of the flattening [5, 7].

There is a subset of infants who suffer from severe and aesthetically unacceptable deformational posterior plagiocephaly or who are too old to be treated successfully by using conservative measures. Surgical intervention is evaluated in these patients if at least 6 months of conservative treatment elapse without evidence of improvement.

The surgical procedure is the same as used for the correction of synostotic posterior plagiocephaly [7].

Additionally, age and timing are of essence for the outcome and treatment strategy: the efficacy of conservative treatment drastically diminishes after the age of 12–15 months, when the calvaria thickens and loses its molding attitude. If a patient presents at that age with severe deformity or by that age has shown failure of conservative options, then surgical treatment has to be considered.

Conversely, in case of SP, the accepted method is surgical intervention.

Craniosynostosis is a congenital deformity in which one or more sutures between the bones of the cranial vault fuse prematurely. With this condition the skull becomes deformed and brain growth and development may be impaired. The deformity of the skull is usually evident at birth.

Increased intracranial pressure, seizures, and developmental delays can occur if the craniosynostosis is not corrected. Patients with single-suture craniosynostosis have distinct head shapes that correlate with the specific suture that has closed. A palpable ridge along the suture is typically present and addresses the diagnosis. Craniosynostosis is more severe when more than one suture is involved. Multiple-suture craniosynostosis is associated with as many as 70 syndromes. Apert, Crouzon, Pfeiffer, Saethre-Chotzen, and Muenke are the most common. Multiple-suture craniosynostosis significantly restricts the skull’s ability to expand as the brain grows. As pressure builds on the brain, infants might develop bulging fontanelle, prominent scalp veins, proptosis, increasing head circumference, apnea, seizures, and developmental delays. If left untreated, severe intracranial hypertension may cause blindness and death [20].

There are basically three types of craniosynostosis: (1) single-suture lambdoid nonsyndromic, which is very rare; (2) multiple-suture (coronal + lambdoid or sagittal + lambdoid, the so-called Mercedes-Benz syndrome) nonsyndromic; and (3) syndromic (the deformation is included in one syndrome, like Apert, Crouzon, or cloverleaf).

Almost every case of diagnosed craniosynostosis has to undergo surgical correction.

Timing of surgical operation is variable and basically depends on the severity of deformity and potential signs of increased intracranial pressure. Surgical intervention in the first few months of life are recommended when associated craniofacial deformities limit vital functions, including visual and oral tasks, or when signs of increased intracranial pressure are evident. In these cases long-term results are less satisfactory.

The remaining cases of synostotic deformations are better treated via cranial vault reconstruction and cranial reshaping with rigid osteosynthesis at around 6–10 months of age. Performing surgery at this age guarantees better long-term results.

In conclusion, all patients are initially evaluated for the degree of severity of the involved posterior deformity. These children are then monitored over 3–6 months, unless they have evidence of increased intracranial pressure or severe secondary calvarial/facial changes necessitating earlier surgical correction. We consider the ideal surgical window being between the ages of 6 and 12 months.

By this age, the child has been given the opportunity to improve with conservative therapy and his/her blood volume has naturally increased.

The majority of patients, because of their early referral and mild plagiocephaly, improve with simple positional modifications and behaviors. For children who continue to worsen or who have significant cosmetic defects despite conservative strategies, earlier surgical intervention leads to better results.

This treatment strategy will reduce the risk of unnecessary surgery, and the operation, if still indicated, will be facilitated by firmer bone.

We operate by 8–10 months of age in the majority of our patients. However, when infants present with severe deformities since birth and show progressive facial deformities before the age of 3 months, these cases are offered surgical correction at 3–4 months, preventing severe facial scoliosis and providing better long-term cosmetic results (Table 8.1).

Table 8.1
Indications for surgery in posterior plagiocephaly

Failure of conservative options (behavioral, positional, helmets) after 6 months

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Mar 29, 2017 | Posted by in ORTHOPEDIC | Comments Off on Surgical Indications and Treatment for Cranial Occipital Anomalies

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