Deformational plagiocephaly

AKA positional plagiocephaly

CAUTION: must be differentiated from true suture synostosis

1. 
   

   Head has a parallelogram shape (contralateral occipital bossing)

   
   
2. 
   

   Ear may be anterior on symptomatic side

vs.

Unilateral coronal/lambdoid premature closure:

1. 
   

   Head has a trapezoid shape

   
   
2. 
   

   Ear may be normal or in posterior/inferior position on symptomatic side

1. 
   

   Imaging is rarely necessary.

   
   
2. 
   

   When needed perform:

   
   
   
   
   1. 
      

      Skull X-rays or

      
      
   2. 
      

      Ultrasound of the suspected suture

   
   
3. 
   

   When above is not diagnostic, consider CT scan ^{1 , 2}

• 
  

  Usually self-resolving starting by 6 mo of age, which is when the child starts sitting up

  
  
• 
  

  Six months of age is also an important milestone because skull growth slows down and thus skull plasticity to reform diminishes

  
  
• 
  

  Always rule out torticollis. If present, start physical therapy

  
  
• 
  

  Effectiveness of treatment options ¹ :

  
  
  
  
  1. 
     

     Repositioning <

     
     
  2. 
     

     Physical therapy <

     
     
  3. 
     

     Helmet

  
  
• 
  

  Treatment options:

  
  
  
  
  1. 
     

     Positioning pillow: equally effective as physical therapy but with significant compliance issues

     
     
  2. 
     

     Physical therapy: for children older than 7 wk

     
     
  3. 
     

     Helmet: preferred:

     
     
     
     
     1. 
        

        in cases of poor response to repositioning/physical therapy

        
        
     2. 
        

        in cases with severe deformity

Coronal suture synostosis

1. 
   

   Unilateral anterior plagiocephaly

   

   
   
   
   
   1. 
      

      Harlequin eye (elevation of superolateral corner of the orbit on pathological side)

      
      
   2. 
      

      Strabismus

      
      
   3. 
      

      Contralateral:

      
      
      
      
      • 
        

        i. Frontal bossing (secondary to open contralateral coronal suture and metopic suture)

        
        
      • 
        

        ii. Parietal bossing (secondary to open contralateral coronal and sagittal sutures)

      
      
   4. 
      

      Nose deviation

   
   
2. 
   

   Bilateral (turribrachycephaly)

   

   
   

   Consider genetic syndromes:

   
   
   
   
   1. 
      

      Crouzon = Cranial = bilateral closure of coronal suture + midface hypoplasia

      
      
   2. 
      

      Apert = All over = bilateral closure of coronal suture + cleft palate + syndactyly

      
      
   3. 
      

      Pfeiffer = craniosynostosis + broad/deviated thumbs and big toes + partial syndactyly + ocular proptosis/elbow ankylosis

1. 
   

   CT

   
   
2. 
   

   MRI

   
   
3. 
   

   Depending on presentation, consider genetic analysis

2nd most frequent synostosis in United States (accounts for ~25% of cases); metopic suture synostosis is a close 3rd

GOAL: make head longer

Craniotomy for repair + orbital rim based on need (fronto-orbital advancement)

Surgical technique

Basics for both unilateral and bilateral:

1. 
   

   Zigzag bicoronal skin incision centered over middle of anterior fontanelle

   
   
2. 
   

   Leave periosteum intact (less bleeding)

   
   
3. 
   

   Temporalis muscle stays with skin

   
   
4. 
   

   Dissect periorbita

   
   
5. 
   

   Release lateral but not medial canthal ligament

   
   
6. 
   

   Expose sphenoid from frontozygomatic to posterior root of zygoma

   
   
7. 
   

   Use fontanelle to strip dura from bone

1. 
   

   Unilateral

   
   
   
   
   1. 
      

      Patient supine

      
      
   2. 
      

      Bifrontal craniotomy positioned behind coronal suture

      
      
   3. 
      

      Biorbital rim ~1 inch wide + tenon extensions

      
      
   4. 
      

      Reshape by drilling inner cortex and bend out recessed orbital rim (reconstruct this by superimposing parietal bone graft)

      
      
   5. 
      

      Reposition rim by advancing ipsilateral tenon + recessing contralateral tenon

      
      
   6. 
      

      Drill part of hypertrophic ipsilateral sphenoid to level of superior orbital fissure

      
      
   7. 
      

      Barrel stave osteotomies to shape bifrontal bone, then replace it with absorbable plates or sutures

   
   
2. 
   

   Bilateral

   
   
   
   
   1. 
      

      Patient in supine or sphinx position: pre-op flexion/extension X-rays for stability

      
      
   2. 
      

      Bifrontal craniotomy to include both coronal sutures

      
      
   3. 
      

      Biorbital rim + tenon extensions

      
      
   4. 
      

      Bend out both rims and replace with tenons advanced (use absorbable mini plates)

      
      
   5. 
      

      Biparietal craniotomy with burr holes along sagittal sinus + transverse sinus → followed by sagittal strip craniotomy to include fontanelle (or the other way round: order is surgeon specific)

      
      
   6. 
      

      Dissect down to level of transverse sinus + barrel stave osteotomies on parietal and occipital bones

      
      
   7. 
      

      Drill down bilateral–sphenoid ridges to level of superior orbital fissure

      
      
   8. 
      

      Replace all craniotomies after barrel stave osteotomies (frontal bone may be rotated 180°, so previously bulging side is on previously recessed side)

± helmet for 4 wk postoperatively

Metopic suture synostosis

1. 
   

   Trigonocephaly: forehead is triangular with midline ridge

   
   
2. 
   

   ± hypertelorism

1. 
   

   CT

   
   
2. 
   

   MRI

• 
  

  19q chromosome is frequently involved

  
  
• 
  

  Metopic suture is the first suture to close physiologically at age 9 mo

GOALs:

1. 
   

   Make head less pointy

   
   
2. 
   

   Fix hypotelorism

1. 
   

   If no hypotelorism: craniotomy + fronto-orbital advancement similar to coronal synostosis

   
   
2. 
   

   In case of hypotelorism: craniotomy + address orbital rim similar to coronal synostosis, but first cut in half and place interposition graft in between the two pieces:

   
   
   
   
   1. 
      

      Harvest graft from temporal/parietal bone

      
      
   2. 
      

      Plate on the inside of rim to avoid cosmetic deformity

Except for the typical skull and face deformities there may be accompanying:

1. 
   

   Cognitive deficits

   
   
2. 
   

   Visual impairment

   
   
3. 
   

   Hearing impairment

   
   
4. 
   

   Increased ICP (more frequently in multiple suture involvement but possibly even in single-suture involvement) ^{6 , 7}

   
   

   ↑ ICP may present as:

   
   
   
   
   • 
     

     Papilledema

     
     
   • 
     

     Suture diastasis (rare in synostosis)

     
     
   • 
     

     Sellar erosion

     
     
   • 
     

     Digital markings on inner calvarium (Luckenschadel skull)

1. 
   

   Thin cut CT with reconstruction (diagnostic test of choice)

   
   

   Be cautious with the use of CT especially in young children. There is association with malignancies ⁸

   
   
2. 
   

   Technetium bone scan can clarify difficult cases:

   
   
   
   
   1. 
      

      The suture that prema turely tends to close will have abnormally increased uptake (compared to the others)

      
      
   2. 
      

      The closed suture will present with no uptake

• 
  

  Focal brain hypoperfusion may also coexist ⁹

  
  
• 
  

  Virchow’s law:

  
  
  
  
  1. 
     

     the skull normally grows perpendicular to the normal suture

     
     
  2. 
     

     Premature suture closure will cause growth parallel to the suture

• 
  

  Wait until 6 mo of age for surgery (more body weight and blood volume)

  
  
• 
  

  Be careful of blood loss during surgery; replace with 10 mL/kg matched blood

  
  
• 
  

  Consider absorbable plates (alternatives include nonabsorbable plates, sutures, wire)

  
  
• 
  

  Try to fill gaps with patient’s own bone after the completion of surgical remodeling

  
  
• 
  

  Head of bed > 30° postoperatively (reduces swelling).

  
  
• 
  

  Expect swollen eyes for 3–4 d

  
  
• 
  

  If bones don’t heal, redo surgery with rib grafts

  
  
• 
  

  Caution with air embolism during surgery (lower HOB and flood field with irrigation/wet sponges)

Cranial vault

Protruding mass in convexity

The most common in western world (~80%)

Use wedge osteotomies to expand the cranial cavity

Basal:

through cribriform plate or sphenoid bone

Presentation:

1. 
   

   Protrusion mass through skull base into nasopharynx → nonvisible

   
   
2. 
   

   Recurrent meningitis

   
   
3. 
   

   Obstructive airway

Differential diagnosis

1. 
   

   Encephalocele:

   
   
   
   
   1. 
      

      May be accompanied by hypertelorism

      
      
   2. 
      

      Mass medial to the middle turbinate

      
      
   3. 
      

      Positive Furstenberg sign: expansion/pulsation with compression of jugular vein or anterior fontanelle and Valsalva maneuver

   
   

   vs.

   
   
2. 
   

   Midline nasal masses:

   
   
   
   
   1. 
      

      Polyps: pedunculated and lateral to middle turbinate, usually in adults

      
      
   2. 
      

      Glioma: no pulsation and no stem connection to brain)

      
      
   3. 
      

      Mucocele

      
      
   4. 
      

      Granuloma

      
      
   5. 
      

      Dermoid

Rare (~1.5%)

0

Syrinx

No descent/no compression of neural structures

Regression of syrinx after posterior decompression has been described ¹⁴

2

1. 
   

   Vermis–pons/medulla–fourth ventricle: herniate below foramen magnum. Consequently:

   
   
   
   
   • 
     

     Apneic spells

     
     
   • 
     

     Lower cranial nerve issues

     
     
   • 
     

     Opisthotonos

     
     
   • 
     

     Downbeat nystagmus

   
   
2. 
   

   Spina bifida/myelomeningocele

   
   
3. 
   

   Hydrocephalus

Most frequently associated MRI brain findings:

1. 
   

   Beaking of tectum

   
   
2. 
   

   Large massa intermedia

   
   
3. 
   

   Polymicrogyria

   
   
4. 
   

   Dysgenesis of corpus callosum

   
   
5. 
   

   Medullary kinking

Infants

• 
  

  Development of symptoms dictates urgency of treatment ¹⁸ . Some recommend preventative intervention

  
  
• 
  

  Surgery:

  
  
  
  
  1. 
     

     Cranial surgery is similar to Chiari 1

     
     
  2. 
     

     Place shunt first!!

  
  

  CAUTION: Consider prophylactic or post-op tracheostomy for patients with cranial nerve issues

  
  
  
  
  • 
    

    Following closure of myelomeningocele: 80% will develop hydrocephalus and require shunt

    
    
  • 
    

    Post-op results: resolution of symptoms in 70% of patients

For all the above Chiari types

1. 
   

   Hydrocephalus ^{19 , 20}

   
   
2. 
   

   50% of patients have some degree of mental retardation

   
   
3. 
   

   Motor impairment

   
   
4. 
   

   Systemic anomalies may be present Always obtain preoperative cardiac evaluation

MRI brain

1. 
   

   Atresia of Magendie and Luschka

   
   
2. 
   

   Agenesis of cerebellar vermis

   
   
3. 
   

   Enlarged posterior fossa cyst that communicates with the 4th ventricle (tentorium and torcular herophili are usually elevated)

   
   
4. 
   

   Possible agenesis of corpus callosum

Various therapeutic choices ²¹ that may be combined.

1. 
   

   Shunt:

   
   
   
   
   1. 
      

      Ventriculoperitoneal shunt

      
      

      OR

      
      
   2. 
      

      Cystoperitoneal shunt

      
      

      OR

      
      
   3. 
      

      Both

   
   
2. 
   

   Endoscopic third ventriculostomy possibly combined with aqueductal stent placement or fenestration of the occluding membrane

   
   
3. 
   

   Posterior fossa craniotomy for membrane excision

What to shunt?

• 
  

  Because the 3rd and 4th ventricles may not communicate ^{22 , 23} , shunting one of them may not be enough and above all may cause upward or downward herniation → Best option: shunt lateral AND 4th ventricle and connect with “Y”

  
  
• 
  

  In infants, use low-pressure valve and in children use medium pressure OR just use programmable valve

Surgical technique:

1. 
   

   Plan trajectories carefully on MRI!!! → The large posterior fossa causes upward displacement of anatomic structures including sinuses.

   
   
2. 
   

   Curvilinear incision (of sufficient length)

   
   
3. 
   

   Supratentorial shunt:

   
   
   
   
   • 
     

     i. Burr hole 4–6 cm above inion and 2–4 cm lateral

     
     
   • 
     

     ii. Trajectory points to spot 1.5 cm above eyebrow along projection of the anterior fontanelle

   
   
4. 
   

   Infratentorial shunt:

   
   
   
   
   • 
     

     i. Dissect down suboccipital muscle and identify occipital squama

     
     
   • 
     

     ii. Burr hole: dura may be blue secondarily to cyst or venous lake

     
     
   • 
     

     iii. Aspirate with 22-gauge needle to make sure it is not vein.

     
     
   • 
     

     iv. Dural opening should be small because there is no brain mantle to seal CSF leak

     
     
   • 
     

     v. Beware of the catheter length (risk of brainstem injury)

Dandy–Walker variant: there is no enlargement of the posterior fossa ²⁴

Blake’s pouch cyst: a posterior fossa cyst (below and posterior to vermis) communicating with the 4th ventricle

Mega cisterna magna: vermis and 4th ventricle are normal