SURGERY FOR - PDF document

1 SURGERY FOR Humans produce cerebrospina
SURGERY FOR Humans produce cerebrospinal fluid at a rate flows from the lateral ventricles to the third the third ventricle to the the aqueduct and out the fourth ventricle either through the the ventricular into the spinal and into the venous absorption into the venous system along the superior sagittal sinus is absorbed at the same rate as it is produced. Hydrocephalus represents an imbalance between the rate and the rate (usually caused choroid plexus tumors) is very rare. Much more frequently, impaired. Impairment can be mechanical obstruc- tion within (i.e., blockage from one ventricle to or obstruction distally at the arachnoid granulations, where into the former is known as the latter is referred to as communicating can result from obstruction within the ventricular usually occurs at the Sylvius, or the fourth and its outlet hydrocephalus include inflammatory scarring; iritraventricular hemorrhage; at the Monro can be astrocytomas (in sclerosis), choroid plexus papillomas and mas. Obstruction at the aqueduct a mass be caused the midbrain an

2 d posterior can be medulloblastomas, epe
d posterior can be medulloblastomas, ependymomas, cerebellar astrocytomas, brainstem gliomas. and are around the third ventricle ventricle. Inflammatory responses lead to can be with aqueductal been identified.7, includes mental and spasticity with other central nervous system anomalies, the corpus and atrophy the pons corticospinal tracts. hydrocephalus include trauma, and these processes is thought to that impedes the the subarachnoid the venous some cases is present. signs and symptoms hydrocephalus depend on the course for age is relatively benign because cranial vault, Head growth is abnormally fast, PEDIATRIC NEUROSURGICAL the head fontanelle is full, the sutures are scalp veins be prominent. vomiting may Developmental milestones may developmental milestones may be present. Increased tone or hyperreflexia may apparent, particularly in the legs. Late signs include sixth nerve upgaze with a downward deviation the cranium is less able to expand mounting volume the signs are, therefore, more intracranial pressure. Headaches, especially those chi

3 ld from sleep or are present strongly su
ld from sleep or are present strongly suggestive Other symptoms include nausea, vomiting, school performance, loss mental milestones, behavioral change. are particularly telling signs. can be confirmed radiographically by cranial anterior fontanelle is computed tomographic scans, or options, especially provide the best visualization the brain, underlying structural cause for the hydrocephalus cardiac gated imaging, can dynamically measure the through the aqueduct during the in diagnosing aqueductal decision to treat children with signs and symptoms pressure is straightforward. A much more difficult deciding whether asymptomatic children with normal development but who have ventricular enlargement. these patients, with or without treatment, is largely authors advocate using the mantle as a guide whether the hydrocephalus should suggest that children with a mantle thickness or more after treatment with a with a postshunt cortical mantle are developmentally delayed. authors suggested that children with untreated shunting. Children with decision to tre

4 at child based on the cortical mantle is
at child based on the cortical mantle is not universally accepted. Others have suggested that children with moderate is not known with currently no are that children are likely to benefit from treatment options hydrocephalus are production, such as acetazolamide or furosemide, provide a options are dictated the type shunting has and is the only available children with infants with older children with an alternative treatment op- patients with communicating hydrocephalus, shunt system inserted into most commonly the lateral the lumbar subarachnoid connected to a valve that serves about the valve is connected to a distal catheter that passed subcutaneously to a distal site currently the the distal insertion with minimal risk. older than the pleural is another alternative site; however, the pleura may develop symp- Other sites the distal catheter include the venous vena cava) relatively new surgical technique that offered as an alternative to patients with is endoscopic third ventriculostomy. This is performed with the aid is passed into the ventricu

5 lar system and, under direct vision, cre
lar system and, under direct vision, create a small hole fenestration) between the third spaces, bypassing the ventricular obstruction. Endoscopic third ventriculostomy effective in Patient selection is crucial; with noncommunicating hydrocephalus are series report a higher success rate in children although this is not recognized by respond less readily to endoscopic third ventriculostomy because they granulations with these patients therefore, simply convert a noncommunicating a communicating for endoscopic third ventriculostomy older than hydrocephalus but decreases to children younger than fore offers patients older than children, we perform a at the with several complications, several large years following insertion.8* signs and similar to those untreated hydrocephalus a flulike illness listen carefully to because they often can tell from experience when the shunt has a child may rarely lethargy, coma, more commonly several days, weeks, or even months. PEDIATRIC NEUROSURGICAL Symptoms may or may intermittently. Examination signs or symptoms. P

6 umping the little useful may actually su
umping the little useful may actually suck or choroid plexus into the shunt; the authors, mend routinely to make a diagnosis. diagnostic studies scan usually always) shows ventricular changes in ventricular a comparison should be made with prior baseline scans available. Unfortunately, some patients have no malfunction. Radionuclide studies are abnormal in with obvious shunt unfortunately are little benefit shunt tap can be gauge needle into the show poor the ventricular pressure, or consistent in symptoms after removal tests is one must in the a strong history. When pediatric neurosurgeons polled, the history was frequently identified as the important determinant in diagnosing shunt followed by change in ventricular elevated pressure a shunt tap? reason for malfunction is catheter by choroid plexus, glial or tissue, or the distal catheter is the next most common Other rare include fracture the catheter system with either the proximal or distal end, and the distal end the appropriate location. In malfunction cannot determined. Shunt treated by or r

7 eplacing entire system. rates vary Seven
eplacing entire system. rates vary Seventy percent months, and infection rates; months old risk for whereas the rate is only the patients with Other symptoms include tenderness, and erythema along the shunt established by aspirating fluid for culture, with a low glucose, a high protein. lumbar puncture not adequate diagnose a shunt infection because cultures are proven shunt tap is not to exclude a diagnosis bacterial meningitis).6 Shunt infections are most frequently Staphylococcus epidermidis, in neonates), are treated with intravenous Although some advocate usually inserted provide temporary also serves as only after has been adequately eradicated, several negative by James.+' can be situ, subsequently at the immediately with new shunt; is less successful, eradicating the in 90% the shunt is successful are unique in that may often shunts include insertion and into the the distal catheter over time. Ventriculoatrial obstruction, pulmonary and arrhythmias. Shunt overdrainage pressure (headaches brought on sitting or standing recumbency) or subdur

8 al hematomas is too A complication is th
al hematomas is too A complication is the development a Chiari I malformation. the spinal disturbs the cerebellar tonsils downward through the foramen magnum and into the are used frequently than are Potential complications branches (extremely with devasta- Other potential include transient nent hormonal diabetes insipidus) incurred the hypothalamus memory loss from surrounding structures. are the most common cause setting. Head the 95th percentile age begin to accelerate cross percentiles. accelerated growth point the curve begins to parallel, does not toward the normal curve (unpub- lished observations, There is a without treatment The cause children have may result from a transient imbalance or delayed development these parasagittal a mild self-limiting form Clinical Presentation and Diagnostic Studies children with are otherwise asymptomatic head growth. fontanelle is flat or minimally sutural diastasis Developmental milestones although some transient delays in 1997). The diagnosis is cranial sonog- being the most logical choice because shows t

9 he prominent identify other in the brain
he prominent identify other in the brain better than characteristic radio- bilaterally symmetric containing spaces the brain and frontal regions enlarged in must be distinguished the subdural collections or child abuse. Whereas has the signal seems to be in the subarachnoid is associated with widened cerebral sulci? the subdural abuse are density or are slightly more adjacent sulci or produce mass on the or cerebral hemispheres. is extremely useful in questionable whenever any doubt about the radiographic features cases because when adequate capacity develops, usually infants with months with frequent head measurements and develop- is reserved head growth does not or for those more significant developmental delays potentially attributable CRANIOSYNOSTOSIS AND normally allow the calvarium Craniosynostosis represents these cranial restricted bone growth perpendicu- lar to the fused suture. with compensated growth at other sutures, results a misshapen head.I7 craniosynostosis is Sagittal synostosis is most common, lambdoid synosto- multiple sutures i

10 s more often Single-suture synostosis mo
s more often Single-suture synostosis most often brain growth or particularly when or more may restrict calvarial degree that intracranial hyperten- developmental delays may final analysis, all misshapen simply divided into particular suture: the short head (brachycephaly, usually caused by bilateral coronal synostosis); (dolichocephaly or scaphocephaly, sagittal synostosis); the triangular-shaped head, to a anteriorly (trigonocephaly, caused by metopic synostosis), and the side is different from the other plagiocephaly generally involves both the occipital regions some degree, most frontal asymmetry caused by synostosis) or Head circumference growth chart for girls. The curve crosses above the norm at about months, and continues away from the curve until about which time the curve parallels, but does deviate back toward, the normal curve. Partington, Dias, Li, Winston (in Illustration continued PEDIATRlC NEUROSURGICAL scan characteristics extra-axial cerebrospinal are generous, particularly over asymmetry (occipital often caused very rarely cau

11 sed by lambdoid synostosis). one keeps i
sed by lambdoid synostosis). one keeps in mind, it usually quite easy to categorize misshapen pinpoint the problem. these conditions is discussed in microcephaly as craniosynostosis is discussed because it a pediatric neurosurgeon by far the more common. Most cases occipital brachycephaly are caused positional molding caused life. This is discussed together with Frontal brachycephaly is caused bilateral coronal synostosis. On tion (Fig. the forehead is flattened bilaterally (more than the occiput), and the anterior fontanelle is more anteriorly positioned. palpably (and, in some visibly) ridged, are more anteriorly positioned, whereas the lateral portion the coronal a little more than breadth anterior to the The lateral margin the fused further forward just behind the lateral rim producing a small anterior fossa. superior orbital rims, particularly their lateral aspects, are bilaterally flattened (retruded) and deviated slightly other sutures, particularly the genetic syndromes, produce additional deformities. associated midface hypoplasia is PEDI

12 ATRIC NEUROSURGICAL inferior orbits are
ATRIC NEUROSURGICAL inferior orbits are severely flattened (Fig. orbits are globes is present bilaterally. nose may short, stubby, and upturned a ”parrot’s coronal synostosis often occurs in the setting one or another Some common associated anomalies suggest a include syndactyly (which, severe suggests or less severe+specially limited to portions and third drome), broad thumbs or great toes (suggesting ing only the less commonly ptosis (suggesting Saethre-Chotzen syndrome), with nasal (suggesting craniofrontonasal dysplasia). more common their associated anomalies listed in Although bilateral coronal synostosis is usually obvious radiographic features confirm as many with bilateral coronal other sutures cardinal features are marked Infant with Crouzon’s disease and brachycephaly owing bilateral coronal and midface hypoplasia. GENETIC SYNDROMES WITH ASSOCIATED CRANIOSYNOSTOSIS Inheritance Craniosynostosis Clinical Characteristics Saethre-C hotzen Craniofrontonasal dysplasia Coronal Midface hypoplasia, shallow proptosis, strabismus Co

13 ronal Midface hypoplasia, shallow orbits
ronal Midface hypoplasia, shallow orbits, downslanting strabismus, hypertelorism, arched palate, complete hands and feet minimally involving digits frontal hairline, ptosis, variable brachydactyly and cutaneous syndactyly especially fingers great toes Proptosis, strabismus, hypertelorism, downslanting palpebral fissures, midface hypoplasia, thumbs and great hands and feet Broad first metatarsals bones, occasionally broad toes, normal May have Pfeiffer-like, Saethre-Chotzen-like, or feet, variable displacement, genu valga, short stature, congenital heart defects, radiohumeral synostosis, contractures, arachnodactyly, femoral hypertelorism, broad tip, various proptosis, midface hypoplasia, dysplastic ears, autosomal dominant; autosomal recessive; Diagnosis, Evaluation, Raven Press, with permission. PEDIATRIC NEUROSURGICAL DISEASE bilateral coronal eye deformities. the lateral orbits compensatoty expansion Evaluation and or obliteration the coronal sutures; anterior bowing both coronal sutures, with shallow anterior cranial shallow orbits the lateral

14 bilateral harlequin eye deformities the
bilateral harlequin eye deformities the anteroposterior the coronal or impossible to visualize, the sphe- wings are anteriorly displaced, the orbits anterior cranial deep and wide growth along the squamosal suture.54 coronal synostosis is ideally repaired involves a bilateral fronto-orbital reconstruction. to a (also commonly called describes a head that is both in the anteroposterior dimension and usually abnormally narrow some cases in premature infants who are laid heads turned the side in the neonatal intensive care most cases caused by isolated synostosis. Sagittal boys three times more frequently than girls. Associated lacking, clinical elevated intracranial is extremely is normal. synostosis is although sagittal also be other sutures as a genetic Clinical Presentation head shape in sagittal further within a few is both narrow. There occipital prominence, the head may like a saddle, with peanut shape the head. is almost always prominently ridged long. A sagittal suture length is to measure the distance between the anterior and posterior fon

15 tanelles; this distance is the nasion (a
tanelles; this distance is the nasion (at the the nose) the anterior infants with sagittal distance between usually confirm head is elongated occipital prominence may the sagittal suture may contain ponding to the saddle deformity seen clinically. Most prominent perisu- is present along either side the sagittal suture edges may produce involving only a the suture, tangential views. any abnormality should associated coronal usually undertaken at approximately to capitalize the rapid brain growth Sagittal synostosis corrected by first removing a bone between the anterior and posterior bone behind the posterior several modifications which result both immediate narrow midline all procedures work best when performed early. Longer delays (beyond approximately mo) result operative results and, PEDIATRIC NEUROSURGICAL DISEASE Dolichocephaly owing sagittal synostosis. from above an infant sagittal synostosis shows elongated head shape. Radiographic features The elongated head is evident the lateral radiograph normal coronal sutures). Naidich TP: Radiologic

16 al evaluation Craniosynostosis: Diagnosi
al evaluation Craniosynostosis: Diagnosis, Evaluation and Management. Press, New Michael Cohen, MD; with permission.) months, require a more extensive potentially more cranial reconstruction. is therefore the diagnosis is birth and Triangular Shaped metopic synostosis accounts for approximately probably exist. more common form isolated palpable visible) midline bony ridge change in head shape or hypotelorism. In most nothing further be done these individuals; the midline ridge needs burred down, second form is with secondary in skull shape producing forehead is triangularly shaped a boat. with the midparietal width gives a teardrop shape to the head when viewed from above. the lateral the teardrop shape often visible present along part or all may result from a midline embryonic metopic synostosis midline brain development, as holoprosencephaly or septo-optic dysplasia disordered midline development producing scans in all children with because they may predict future developmental delays. radiographs and in patients with demonstrate the prominent m

17 idline bitemporal narrowing narrow anter
idline bitemporal narrowing narrow anterior lateral orbital surgical repair for metopic synostosis coronal synostosis, with repairs ideally coronal synostosis, a bilateral procedure is recommended, advanc- ing the lateral portions the orbits forward, the midline frontal bone to the triangular shape Orbital hypotelorism by moving the two and plating bone between them. superiorly and required in older Children with almost always have one less common the two is frontal NEUROSURGICAL DISEASE pronounced perisutural the lateral children have flattening flattening, lateral canthal retrusion, slight superior displace- brow (giving ”raised eyebrow” appearance). forehead is often slightly prominent compared addition, several secondary findings shore the diagnosis. side is also flattened, giving to the deviates toward, and the nasal tip away canting the nose. midface is often mildy asymmetric as well (because in the skull rather than midface hypoplasia), the orbits may present in the vertical plane (vertical dystopia). on the side often has promine

18 nt ridge is anteriorly displaced compare
nt ridge is anteriorly displaced compared the opposite side. far more common cause one that currently accounts outpatient referrals the pediatric neurosurgeon, plagiocephaly (also known as plagiocephaly (OP) is caused by the child persistently lying the head toward the are associated with The incidence this disorder has risen dramatically following the American Academy Pediatrics recommendations urg- parents to sleep their infants position to reduce the risk for have witnessed as much increase in referrals the past several these infants have been erroneously lambdoid synostosis. plagiocephaly is onto the top The clinical features are ipsilateral frontal bossing a parallelogram to the head, the entire side the head contrast, both coronal lambdoid synostosis produce both the same (affected) side, yielding a trapezoi- to avoid misdiagnosis. The sever- flattening is nearly always greater than the are often present include anterior sometimes inferior) deviation ipsilateral ear (best assessed the fingers in both external from above), and the ipsilateral

19 malar eminence. The vertex may also slo
malar eminence. The vertex may also slope toward the side when viewed from the front, inverse relationship between the degree occipital flattening and unilateral coronal the ipsilateral contralateral forehead root is tilted toward the affected (crossed arrow), orbital deformity ipsilateral deviation the nasal (crossed arrow). Craniosynostosis: Diagnosis, Evaluation and Illustration continued PEDIATRIC NEUROSURGICAL DISEASE 1558 DIAS&LI Figure 8. See legend on opposite page PEDIATRIC NEUROSURGICAL DISEASE positional molding. flattening, anterior and malar 5:150, 1994; along the parallelogram head Craniosynostosis: Diagnosis, vertex sloping.85 often present the occiput where the child has lain on the head may seem very viewed from the front, the ipsilateral orbit may appear slightly The lambdoid is more some infants may have bilateral occipital type brachycephaly in which the calvar- ium gradually slopes back to a more posteriorly displaced vertex a flattened although bilateral, usually one side is flatter the other. in whom the deformity is usua

20 lly birth, three infants with have norma
lly birth, three infants with have normal head shapes at slowly over the infants lay with the head toward the side the first months Eighty percent cases involve right-sided flattening.19* The right-sided represents a marked predilection for normal infants to lie with their heads turned toward the rightloo; infants with authors found a perfect concordance between the positional preference and the side male preponderance may the common (see the previous discussion infants with also arises more frequently in girls (by a ratio and among a greater OP (Partington, othersq4 have proposed that relative increase intracranial water content may allow greater cranial some have suggested the interfering with predispose infants benign extra-axial Diagnostic Studies with frontal radiographic features unilateral coronal synostosis are almost is indistinct, common. The anteriorly compared with the that both sutures are different positions on true lateral most importantly, the sphenoid wing the skull base is elevated on the side, giving the unilateral harlequin eye

21 the anteroposterior scans show the indi
the anteroposterior scans show the indistinct suture, perisutural elevated sphenoid wing, flattened shallow anterior both the contralateral and the ipsilateral temporal views show the harlequin eye deformity and deviation the nasal radiographic features indistinct portion suture or perisutural plain radiographs and may suggest lambdoid synostosis; however, rather than head shape should suggest rather than tures has shown histologic evidence proposed that infants with OP initially deform their skulls in a plastic way their positioning changed sufficiently skull shape reversible; however, changes in the like a reactive may produce radiographic that simulate coronal synostosis, with the bilateral form, is ideally performed coronal synostosis over the past treatments using unilateral approach (advancing the lateral portion craniofacial deformities, such frontal prominence many authors now agree are a more extensive bifrontal craniotomy bilateral orbitofron- tal reconstruction that proposed for bilateral coronal treatment options are available for infa

22 nts with outset, the treatment must kept
nts with outset, the treatment must kept in mind. most importantly, to be simply problem; there evidence that OP produces pressure, interferes with brain growth developmental delays (although delayed infants who spend time in one position may be predisposed develop OP). treatments must be OP is occipital deformity, covered by child grows. PEDIATRIC NEUROSURGICAL DISEASE most common to change the position. A towel or blanket under the infant to encourage the infant on the contralateral side the head. During the day (and supervision), the infant turned into a side-lying position (this is not at night side lying may risk for parents are with the A recent morphometric analysis infants with occipital deformities showed a asymmetries with positional second treatment is to use cranial orthosis, or "molding which restricts calvarial growth at prominent areas growth at the points of flattening. one step further molding prominent flattened areas. Anthropometric measurements pretreatment post-treatment with demonstrate approximately and currently the least c

23 ommon was caused led to several surgical
ommon was caused led to several surgical procedures designed the lambdoid suture (strip craniectomy) or reconstructing (unilaterally or even bilaterally).% Surgery a much less treatment for (although it is still effective for the rare true lambdoid synosto- is now generally used in only severe or recalcitrant One proce- was evaluated using calvarial asymmetries by only one third, less obtained with or simple on the information available, the authors cannot for severe that have failed more conservative (defined as than the caused by genetic brain development, postnatal brain craniosynostosis. Craniosynostosis as a microcephaly is involve fusion cranial sutures, and the head shape is obvious. The most deformity, kleeblatschadel, characterized by a trilobed head with sometimes even monstrous, deformities. Others have turricephaly (tower skull), or oxycephaly (pointed skull). extraordinarily rare subgroup presents with head shapes and facies, clinical of intracranial hypertension, radiographic evidence of delayed all cranial series, only four (presenti

24 ng between had delayed of the four had a
ng between had delayed of the four had a family and another a family hypophosphatasia (a condition known to craniosynostosis). these three patients, then only patients with novo with normal head in the an abnor- head shape or intracranial hypertension vomiting, or papilledema), craniosynostosis to be the divide dysraphic into those that are open occult (e.g., lipoma, diastematomyelia, dermal sinus thickened filum terminale, and caudal attractive, this scheme is confusing in that many malformations have apparent cutaneous markers appendages, or tufts hair), which, for the astute serve as the underlying spinal cord anomaly. begun to on reputed malformation compatible a frequency represents a failed to and the neural tissue (or therefore remains by definition, exposed the infant such thing briefly review some interested reader referred to several recent for a complete discussion. important to give accurate reliable information parents who are carrying fetus with a myelomeningocele. isolated myelomeningoceles other organs) survive adulthood, and the h

25 ave normal learning disability (verbal a
ave normal learning disability (verbal are better than solving are particularly peculiar form Reputed Embryogenetic Mechanism Split cord Incomplete dysjunction Disordered development PEDIATRIC NEUROSURGICAL DISEASE bifida. The the surrounding been recognized in these may respond methylphenidate (Ritalin). Hydrocephalus is pres- ent in bears little relationship to preadolescents are community ambulators (although this during adolescence), continent" (meaning they are although many perform intermittent catheterization)?'j a static disease, deterioration in children with should prompt a search for underlying cause. Unfortu- most children myelomeningocele experience one or more episodes deterioration sometime their lives. the most common deterioration is a malfunction, which can present a bewildering ways. Nowhere pediatric neurosurgery is in the a child with malfunction. In to the usual headache, nausea, vomiting, these children may present with pain (especially at the myelomeningocele closure seizures (either onset or a change a preexisting pattern

26 seizures); significant changes behavior
seizures); significant changes behavior or performance; swallowing or other evidence dysfunction; changes or lower extremity strength, coordination, bal- in urinary or bowel or other orthope- as discussed have papilledema without any malfunction in population can should always other treatment options. function, the explored opera- undertaking any other procedures. Other causes deterioration in children myelomeningoceles include spinal cord tethering (occurring in approximately one third children with and hindbrain and spinal cord dysfunction caused by the malformation or syringomyelia (occurring children with myelomeningoceles). Spinal cord tethering identified radiographically abnormally low position the caudal some children because down in cannot move with the Chiari malformation refers to the cerebellar tonsils brainstem through the foramen skull base canal, which by compressing Syringomyelia (Fig. cystic collection cord, which produces by stretching ing the adjacent cord tissue. Tethered cord Chiari malformations are present radiographically n

27 early every child syringomyelia is prese
early every child syringomyelia is present in mere presence these malformations vermis and caudal brainstem are descended (large arrows). cervical and larger thoracic also present (small arrows). suggest the need for treatment is reserved for Spinal cord pain, deterioration in lower extremity function, scoliosis or other orthopedic produce headache pain, lower cranial nerve dysfunction vocal cord palsies, recurrent apnea), upper or gait distur- Syringomyelia may produce segmental motor weakness, extremity hyperreflexia a dissociated bladder dysfunction is rare.& A complete discussion and the interested referred to recent monographs for a more complete Although recognizing myelomeningoceles, more problematic is identifying craniospinal dysraphism, including spinal malformations (diastematomyelia cranial or spinal dermal dermoid tumors, neurenteric cysts, myelocystoceles, fat infiltrated filum terminale, agenesis. Although these malformations are truly occult, most marker that, appreciated, direct the underlying spinal cutaneous markers as signs und

28 erlying spinal malformations is critical
erlying spinal malformations is critical because tions can cord injury from tethering and deterioration, and, although stabilized by are often these reasons, most the spinal malformation pro- phylactically in infancy, before the onset malformations bind, or the spinal abnormally low position tethering is generally defined the mid-body prohibits the conus rising with continued growth and patients eventually results in dysfunction as a result stretching, ischemia, decreased mitochondria1 Tethering from cause may leg, or pain; progressive lower extremity sensorimotor dysfunction sensory abnormalities tion from a neurogenic bowel incontinence or constipation; lower as pes varus deformities; Lipomas (Lipomyelomeningocele) Clinical Presentation. lipomas are the most common subcutaneous fatty mass Other cutaneous markers spinal lipomas dimples, skin are thought arise through premature separation (dysjunction) neural tube from the cutaneous ectoderm (skin); this allows mesenchymal the inside the neural tube, where they are induced form fat. Diagnostic Stu

29 dies. image shows the lipoma a hyperinte
dies. image shows the lipoma a hyperintense workup should also in- clude a formal assessment lower extremity muscle function (a test, or evaluation including urodynamic studies, orthopedic assessment lower extremity deformities. Surgery involves debulking the lipoma, removing with the spinal untethering the spinal cord. cosmetic excision subcutaneous lipoma addressing the underlying spinal cord anomaly not adequate. subcutaneous component the lipoma always extends through a dorsal the spine (often, not always, between dysplastic PEDIATRIC NEUROSURGICAL DISEASE underlies the lumbosacral region. mass attached the dorsal the dorsal the spinal and ends within the intramedullary portion the spinal the lipoma may purely intradural, having still tethers the spinal cord. tracts are represent incomplete dysjunction the neural tube cutaneous ectoderm) cutaneous tissue remains attached the lumbosacral dermal sinus tract overlies lumbosacral spine, and the stalk penetrates the underlying spinal canal to end on the spinal cord just above the tip the conus medu

30 llaris. spinal cord, dermal sinus tracts
llaris. spinal cord, dermal sinus tracts can cause symptoms signs through three other mechanisms. they can serve as leading to recurrent infections (bacterial meningitis or spinal abscess). dermoid tumors can develop within the spinal cord or canal the spinal cord. Third, desquamation can produce intense inflammatory response, resulting in tracts almost always have some usually the tract which produces dimple. Dermal tracts should differentiated from the benign dimple, which present in approximately its name the benign dimple is located just above within the gluteal cleft. The is readily palpated the dimple. contrast, the dermal sinus tract is located in the the lumbosacral almost always cranial to the the gluteal tracts may skin or small associated with cutaneous hemangiomas, skin tags, or tufts hair within the ostium. Abnormal or asymmetric forking the gluteal is common; the tract may one fork. tracts may associated with neurogenic bladder, orthopedic deformities. dimples are never associated sinus malformations are most commonly located either

31 anteriorly (frontonasal tracts) or in th
anteriorly (frontonasal tracts) or in the they may parietal in location. Frontonasal dermal tracts typically along the anywhere between the tip the nasion travel between the skin nasal cartilage to or near the anterior skull base. Although they often in the extracranial space, some sinuses extend intracranially through a tiny defect in the anterior skull base near the foramen brain abscess) or intracranial dermoid the occipital tract can also have intracranial extension into the supratentorial compartment, the posterior or both the lumbar spine the spinal tethered. Dermoid tumors, present, may seen within the sac or spinal cord parenchyma isointense to therefore, difficult to visualize. Unfortunately, dermal sinus tracts are sinus tract. PEDIATRIC NEUROSURGICAL sinus tract. small dimple the absence tract does exclude a the lesion seems suspicious, especially the conus is the malformation explored regardless whether a cranial dermal tracts should include both associated dermoid tumors may best scans with gadolinium enhanced sagittal and coronal vie

32 ws, a small bony defect may be visible o
ws, a small bony defect may be visible only on coronal bone windows, even though intracranial abnormality imaging cannot the lumbosacral dermal tracts, all suspicious explored even are negative. there is known intracranial extension, entire tract removed, either in intracranial procedure or in intracranial extension is present, the extracranial tract excised locally the tract followed toward the skull exploration is performed intracranial extension is found the time Cord Malformations Split cord malformations are anomalies in which the cord is split or over a portion its length. were used in the past have generated a great deal these terms have been by the common term malformations seem a disorder gastrulation to produce a split are recognized. lesions are double the spinal cord are split, bony or fibrocartilaginous interposed between the thecal sacs (Fig. malformations are single which the not the Split cord malformations (SCM). CT myelogram in a child with a type shows two hemicords each within its own dural and separated by a Split cord malform

33 ation: A unified theory embryogenesis fo
ation: A unified theory embryogenesis for double spinal cord malformations. Neurosurgery myelogram in a child with a type contains two hemicords within a common dural sac. No intervening septum apparent, but a septum was encountered at Pang, MD.) hypertrichosis (fawn's tail) in a child with a type hemicords are contained within sac (Fig. Although the earlier literature suggested the type not contain tethering element, tissue (analogous to the type malformations) is usually found between the two hemicords. both types malformations contain tethering element in neurologic Clinical Presentation. Cutaneous stigmata are present Although the most common patients) and hypertrichosis (the tail"; Fig. cutaneous stigmata include cutaneous hemangiomata, dimples, lipomas, bony abnormalities?l particularly with the type (butterfly) vertebrae, missing or duplicated vertebrae have all the spinal column is completely split (the Associated enteric malformations or neurenteric cysts) duplication, horseshoe kidneys, or pelvic also be scan with intrathecal contrast my

34 elogram). Although the more sensitive ev
elogram). Although the more sensitive evaluating the details malformations for surgical myelography is particularly identifying thin intradural tethering bands in the malformations, which may be visible have tandem Treatment. Surgical treatment is usually recommended prophylactically, children develop signs the tethering bands (type the type the two hemicords is a single sac reconstituted (described to a terminale is usually is sectioned Thickened Filum Terminale filum terminale a nonfunctional tissue that projects from the conus sac. A thickened filum terminale that is (either on scans or have fat within the filum terminale “fatty filum”), a low-lying Although as many as normal individuals have some a thickened, fat a low- patients have cutaneous markers, many patients first present with a neurogenic a defect one or more demonstrates the a filum terminale, which is hyperintense strand the conus and the distal thecal sac T1-weighted images). involves sectioning near its caudal end. rare caudal spinal cord malformation which a the caudal e

35 nd the spinal is present, with the cauda
nd the spinal is present, with the caudal giving a “double-bubble” appearance associated lipoma is can reach monstrous size (Fig. 16). Clinically, the lesions appear as closed, skin-covered, lumbosacral masses spinal lipoma. Many these have misnomer because, a myelomeningocele Thickened fatty terminale. Sagittal tissue (the extending between the the thecal cannot, by definition, be closed). embryogenesis is unknown but involves abnormal (the multipotent under the after primary neurulation is completed to the caudal neural tube Surgical treatment involves repairing and untethering the spinal cord from agenesis is usually included in the spectrum dysraphic malformations, or other neurosurgical lesions common in these patients. or all the sacrum usually missing; agenesis can extend rostrally to involve or even lower thoracic segments.38 is more common offspring born sacral agenesis, sacral agenesis are offspring ketones have been implicated child is born with varying leg musculature buttocks are flattened is almost universal. Sensory functi

36 on is curiously preserved.70 spine radio
on is curiously preserved.70 spine radiographs reveal absence PEDIATRIC NEUROSURGICAL DISEASE a huge skin-covered lumbosacral mass. The child had bilateral equinovarus deformities and exstrophy. shows a huge double compartment cystic The spinal cord ends in a terminal and is surrounded a larger dilatation the thecal giving the within a sac. (Courtesy Keith Aronyk, Alberta at Edmonton.) T1-weighted lumbosacral the distal sacrum (white arrows), caudal spinal column, most commonly including part or fused vertebrae also be seen. baseline lumbosacral confirming the absence distal conus medullaris. Although sacral agenesis static malformation which, be treated, tethering lesions, such cord malformations, lipomas, dermoid tumors, fibrous bands, thickened filum terminale, can all cause neurologic deterioration in these be treated found.7o In addition, bony or cause progressive deterioration also require treatment. infant positioning Operative normalization in sagittal synostosis. PEDIATRIC NEUROSURGICAL Aoki N: Extracerebral fluid collections magnetic r

37 esonance imaging differentiation between
esonance imaging differentiation between 16 cases. Am their treatment. Antimicrob Chemo- ther 15259,1985 Hereditary stenosis congenital hydrocephalus. ventricular cerebrospinal fluid al: Benign extra-axial collections Pediatr Neurosci 12140-144,1986 particular reference (eds): Disorders Blackwell Scientific, infections: Prevention treatment. Clin tracts. Concepts Pediatr al: Tonsillar herniation: The rule rather than the exception after lumboperitoneal shunting in the pediatric population. Death from tonsillar herniation patient with Crouzon’s disease case report. The etiology Diagnosis, Evaluation, Management. New Raven Press, Jane JA: Cranial deformation Di Rocco Pediatric Neurosurgery. London, Churchill-Livingstone, Occipital plagiocephaly: Deformation or unifying theory pathogenesis. Pediatr Hydrocephalus in the myelomeningocele. Neuro- Pediatric Spine: The embryogenesis gastrulation? Pediatr Occipital plagincephaly: Deformation synostosis? Part Clinical description the results morphometric measurements. 24:61-68, 1996 Sainte-Rose C (eds):

38 The Blackwell Scientific, neural tube O
The Blackwell Scientific, neural tube Oxford, Oxford University vertex craniectomy for Radiologic evaluation tethered conus. Am RJ, Walji AH, Mielke Anatomic details in the parasagittal dura: A fluid. Neurosurg Clin Genet 3:258, 1973 dysplastic parasagittal arachnoidal granulations. differential diagnosis on Pediatrics American Association Neurological Surgeons, arachnoid granulations relationship to extracerebral fluid Unicoronal synostosis: surgical intervention. 2:641-653, 1991 Clinical characteris- imaging and Pediatr Neurosurg the aqueduct Etiology and Progressive cranial in craniosynostosis. disproportion: A the treat- 2:167-176, 1976 Sagittal synostosis: the cauda equina other fatty to neurospinal dysraphism. Dev Med al: Prospective cerebrospinal fluid Kelly PJ: patients with nontumoral adolescent/ onset aqueductal stenosis symptomatic hydrocephalus. (ed): Hydrocephalus: Concepts in Baltimore, Williams Haemophilus influenzae cerebrospinal fluid 54:261-263, 1981 Cerebrospinal fluid shunts: Surgical management quantitative evaluation and dif

39 ferentiation from cerebral atrophy. McCo
ferentiation from cerebral atrophy. McComb JG: dermal sinus. Pang D (ed): Raven Press, synostosis. Neurosurg al: Adipose in the filum terminale: computed tomographic indicate tethering cord. Neuro- 22:873, 1988 Surgery, ed with a Terminal myelocystocele. hydrocephalus. Neurosurg Central nervous system infections as factor in children born with myelomeningocele. Pediatrics nasal dermoids. subarachnoid space nonorthotic treatment occipital plagiocephaly: is the natural history neonatal head? Hoffman HJ, synostosis Part malformations, hydromyelia, syringomyelia. widened frontal subarachnoid macrocephalic, microcephalic, Nasal dermal and dermoid intrafalcial extension. literature. Childs Nerv Syst Computerized tomography in chronic Sacral agenesis caudal spinal cord malformations. Split cord malformation. Part syndrome. Neurosurgery 500, 1992 diabetic mothers: philus influenzae. Pediatr resonance imaging myelocystoceles: Report Neurological Surgery, Pottage JC Haemophilus influenzae meningitis in the cerebrospinal fluid with head growth parallel compu

40 terized tomography findings full term in
terized tomography findings full term infants. JHJ: Physical examination patients with cerebrospinal fluid in pumping the shunt? Pumping the A longitudinal study. Pediatr Neurosurg cerebrospinal fluid in infants: etiological factors. Cerebrospinal fluid infections: Report critical review literature. Pediatr the tethered Spina bifida. (ed): Pediatric Neurosurgery: or not to shunt: Hydrocephalus Intracranial pressure craniosynostosis: Pre- with functional results. Foundations and Surgical Treatment Baltimore, Williams haemophilus influenzae type children with cerebrospinal fluid al: Treatment plagiocephaly with Craniofacial Surg in congenital et al: Benim subdural intracranial pressure, Shunt failure. Pediatr Neurosurg Quantitative analysis cerebrospinal fluid children with occipital plagiocephaly. 2:83-89, 1986 metopic synostosis. al: Surgical decompression for symptomatic malformation in neonates with al: Variants synostosis: Strategies 61:557-562, 1984 Cerebrospinal fluid antibiotic levels mantle in treated infantile hydrocephalus: 52:38, 1973 Pe