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International symposium. Syringomyelia 2010 Berlin, 9-11 December 2010
International Symposium Syringomyelia 2010 9-11 December 2010
CHIARI I MALFORMATION FINAL PROGRAMME IN CHILDREN International and national experts will report on the newest development in diagnosis, therapy and aftercare
Langenbeck-Virchow-Haus Berlin, Germany www.syringomyelia2010.org
Michel ZERAH. Service de Neurochirurgie Pédiatrique. Hopital Necker Enfants Malades. Assistance publique Hopitaux de Paris. Université René Descartes. INSERM U745 mercredi 28 mars 12
SYRINGOMYELIA IN CHILDREN N
% Scoliosis
188 (42%)
87 %
Chiari I without Syrinx
54
38 %
Chiari II (MMC)
44
87 %
Spinal cord Tumors
43
52 %
Spinal cord Tumors without Syrinx
12
37 %
Lumbar Dysraphysm
74
27 %
Isolated Syrinx
34
100 %
Diastematomyelia
15
92 %
Birth Injury
12
42 %
Achondroplasia
5
0 %
MPS
5
80 %
Dandy Walker
4
0 %
Neonatal spinal Injury
4
100 %
Craniosynostosis
4
0 %
Neurenteric cysts
3
100 %
Arachnoiditis
2
100 %
Congenital spinal cord section
2
100 %
NF1 without Chiari
2
100 %
442
76 %
Chiari I with Syrinx
Total mercredi 28 mars 12
p < 0.0001 p < 0.05
Zérah 1999
SYRINGOMYELIA IN CHILDREN N
% Scoliosis
188 (42%)
87 %
Chiari I without Syrinx
54
38 %
Chiari II (MMC)
44
87 %
Spinal cord Tumors
43
52 %
Spinal cord Tumors without Syrinx
12
37 %
Lumbar Dysraphysm
74
27 %
Isolated Syrinx
34
100 %
Diastematomyelia
15
92 %
Birth Injury
12
42 %
Achondroplasia
5
0 %
MPS
5
80 %
Dandy Walker
4
0 %
Neonatal spinal Injury
4
100 %
Craniosynostosis
4
0 %
Neurenteric cysts
3
100 %
Arachnoiditis
2
100 %
Congenital spinal cord section
2
100 %
NF1 without Chiari
2
100 %
442
76 %
Chiari I with Syrinx
1984 - 1999 Syrinx related to CVJ Problems : 2/3 Syrinx related to Chiari 1 : 50% Syrinx related to Dysraphysm : 25% Syrinx related to Chiari II : 10% Isolated Syrinx : 10% Others : 5% Total mercredi 28 mars 12
p < 0.0001 p < 0.05
2000-2010 50% 40% 25% 5% 25% 5% Zérah 1999
SURGICAL SERIES
1984 - 1993 :
109 children
1994 - 2003 :
148 children
2004 - 2010 :
103 children
Total :
360 children (23/ years : 1.7% cases)
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DIAGNOSIS
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DIAGNOSIS
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POLYSOMNOGRAPHY
SAS in 60% of the Chiari I 25% Central apnea (10% severe) 35 % Peripheral apnea No difference w or w/o syrinx
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TREATMENT
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TREATMENT
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TREATMENT 354 Foramen magnum decompression (FMD) 6 ETV 0 syringo - somewhere shunt 12 patients have been reoperated on (1 mo to 4 years) 9 failures + 3 reossifications (1 to 4 y-o at the first surgery) mercredi 28 mars 12
HOW TO TREAT ? 1984 - 1994 : Extensive surgery : large bone opening, dura and arachnoid opening, Magendie checking, Duroplasty (fascia lata) 1995 - 2003 : “Minimally invasive ” surgery : Small bone opening, extra-arachnoidal opening of the dura, no duroplasty 2004 - 2010 : “Sur Mesure” surgery. : Small bone opening then Ultrasound guided surgery
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DURAL OPENING ?
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DURAL OPENING ?
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ULTRASOUND
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FINAL US CONTROL
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PRE-SYRINX STATE
Pre-op
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PRE-SYRINX STATE
Pre-op
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PRE-SYRINX STATE
Pre-op
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D4 after ETV
2004- 2010. N= 103 ETV
3
non opening of the dura
19
Extraarachnoidal opening
70(10)
Dural patch (V4 - SAS catheter)
3 (1)
Amygdalectomy (unilateral) :
7 (6)
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2004-2010. COMPLICATIONS Second surgery :
2 (2mo, 2y)
Meningitis :
2
Headaches > 5days
20
Discharge > 5 days
7
Supra and infratentorial hygroma
1
Postop worsening mercredi 28 mars 12
0
Symptomatic subdural hygroma after foramen magnum decompression
J Neurosurg / September 17, 2010
1
Symptomatic posterior fossa and supratentorial subdural hygromas as a rare complication following foramen magnum decompression for Chiari malformation Type I Report of 2 cases BIJI BAHULEYAN, M.CH., GIRISH MENON, M.CH., D.N.B., EASWER HARIHARAN V, M.CH., MRIDUL SHARMA, M.S., AND SURESH NAIR, M.CH. Department of Neurosurgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India Symptomatic subdural hygroma due to foramen magnum decompression for Chiari malformation Type I is extremely rare. The authors present their experience with 2 patients harboring such lesions and discuss treatment issues. They conclude that the possibility of subdural hygromas should be considered in all patients presenting with increased intracranial tension following foramen magnum decompression for Chiari malformation Type I. Immediate neuroimaging and appropriate surgical intervention provides a good outcome. (DOI: 10.3171/2010.8.JNS10413)
KEY WORDS
B. Bahuleyan et al.
TABLE 1: Literature review of patients with posterior fossa SDH following FMD for CM-I*
FIG. 2. Case 2. A: Sagittal MR image showing tonsillar descent. B: Postoperative CT scan demonstrating posterior fossa SDH in the cerebellopontine angle and under the tentorium. C and D: Postoperative CT scans revealing frontoparietal SDHs.
Age Arachnoid Dayexamination, she had papilledema and nystagposterior fossa and supratentorial sub- Postop On is a small defect in the arachnoid, created during surgery groma following FMD for CM-I has mus, whichClinical had notFeatures been present (yrs), Tearonly at Symptoms at at the initial admission. Hydroor trauma.5 In patients with posttraumatic posterior fossa SDHs a similar arachnoid defect has been revealed at suren reported in the literature. our Computed tomography scanningLocation showed ofsupratentorial Authors & Year SexWe share Surgery Started 2nd Admission PF SDH Location of gery. ST SDH cephalus Treatment The arachnoid defect creates a 1-way slit valve–like h the treatment of such lesions in 2 patients and posterior fossa SDHs with dilated third and lateral mechanism through which CSF escapes from the subamanagement ventricles. The SDHsupracer, involvedconvexity the supracer-rt frontoparietal rachnoid space to the space. This subdural CSF Ranjan issues. et al., 55, F yes 14 HA, infratentorial vomiting, nosubduralconservative can cause separation of the arachnoid and dura due to ebellar cistern predominantly (Fig. 1B), and a thin SDH 1988 increased pressure in the subdural space. This separation was seen alongdrowsiness the petrosal surface of the cerebellum on has been hypothesized to be the triggering factor for the Case Reports the6 right side. supratentorial SDH was seen in thelt parafalcine Marshmann et 17, F yes HA,The vomiting, col- supracer & con- of posttraumatic yes EVD once, then 2VP development posterior fossa SDHs. The
TIC
al., 2005
55, F
yes
d Examination. An 18-year-old woman was
a symptomatic CM-I with syringomyelia underwent EltonFMD, et al.,C-1 posterior 10, M arch ?exciplasty. An2002 attempt was made to keep the ct, but it was accidentally punctured during 14, Fhole through ? producing a pinhead-sized ked under high pressure.14,The hole in F ? the left, and the wound was closed watertight. present case 18,period, F yesshe d a smooth postoperative but d with progressive headache and vomiting e initial surgery.
present case
38, M
yes
initially reaches the subdural space posterior to the lapse vexity CSF shunt foramen magnum from where it tracks superiorly along Soon after admission, the patient experienced frequent the subdural space in the convexity, petrosal surface, and 5 vomiting and an petrosal NA yes conservative episodes ofHA, bradycardia episode surface, of decerebrate then tracks to the supratentorial subdural space through posturing. supracer the tentorial hiatus. The associated supratentorial trivensome cases may be caused She was taken for emergency insertion 10 Operation. HA, vomiting supracer ? tricular hydrocephalus yesseen in EVD twice
of a right medium-pressure VP shunt. A VP shunt was preferred to drainage of the SDHs because the hygromas
5 24 sure). 7
HA HA, vomiting HA, vomiting
by elevated pressure in the posterior fossa and the torquing effect on the aqueduct.1 Another hypothesis behind the development of these subdural collections is the the? ory of increased permeability yes EVD once of the intracranial vessels,
supracer supracer ? J Neurosurg / September yes 17, 2010 EVD once petrosal surface, interhemispheric yes VP shunt Postoperative Course. The patient’s condition gradusupracer ally improved, and she remained asymptomatic at the 15 HA, vomiting, ver- petrosal surface, rt frontotemporopayes rt frontoparietal bur 6-month follow-up. tigo supracer rietal hole evacuation
Case 2 used in this paper: CM-I = Chiari malformation oramen magnum decompression; SDH = subdural * EVD = external ventricular drainage; HA = headache; = not applicable; PF = posterior fossa; ST = supratentorial; supracer = supracerebellar; ? = History andNA Examination. A 38-year-old man presententriculoperitoneal.
unknown.
September 17, 2010 mercredi 28 mars 12
1
which may be true in cases of head injury but is unlikely in our cases. The subdural CSF collection can get absorbed slowly or cause rapid neurological deterioration,2,4 leading to coma due to compression of the brainstem and posterior fossa structures. Thus, patients can have an acute or subacute presentation with features of increased intracranial tension about 3–15 days after FMD. Because of the lesion’s rarity, the ideal management protocol is not known. All efforts should be made to prevent this complication. Suggested management options include closing the tiny hole in the arachnoid or opening the arachnoid widely and suturing it to the dura.1,5,6 We believe that the arachnoid should be opened widely regardless of whether or not the arachnoid is damaged at surgery. Even if the arachnoid is not damaged at surgery, there is a chance that it will be damaged during wound closure, producing a pinhole with CSF leakage to the subdural space. We recommend that all patients presenting with persistent headache following FMD undergo a CT scan to 3
2w
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2w mercredi 28 mars 12
6mo
2y
RESULTS AT 5 YEARS 1984- 1994 : Extensive surgery : large bone opening, dura and arachnoid opening, Magendie checking, Duroplasty (fascia lata) 1995 - 2003 : “Minimally invasive ” surgery : Small bone opening, extra-arachnoidal opening of the dura, no duroplasty 2004 - 2010 : “Sur Mesure” surgery. : Small bone opening then Ultrasound guided suregery
No statistical difference mercredi 28 mars 12
LONG TERM CLINICAL RESULTS (> 10Y FU) Preop Post op
Grade 0
Grade 1
Grade 2
Grade 3
Grade 4
Total
Grade 0
27
60
1
0
0
88 (47%)
Grade 1
1
71
2
2
0
76 (40%)
Grade 2
0
5
10
2
0
17 (9%)
Grade 3
0
1
2
4
0
7 (4%)
Grade 4
0
0
0
0
0
0
Total
28 (15%)
137 (73%)
15 8%)
8 (4%)
0
188
Improved 67 (35%) mercredi 28 mars 12
Stable 112 (60%)
Worsened 9 (5%)
LONG TERM MR RESULTS (> 10Y FU) Preop Post op
No syrinx
VqI < 10%
VqI < 50%
VqI > 50%
Total
No syrinx
0
5
12
2
19 (10%)
VqI < 10%
0
16
33
31
80 (43%)
VqI < 50%
0
2
28
46
76 (40%)
VqI > 50%
0
0
4
9
13 (7%)
Total
0
23 (12%)
77 (41%)
88 (47%)
188
Improved 129 (69%) mercredi 28 mars 12
Stable 53 (28%)
Worsened 6 (3%)
RESULT ON THE SCOLIOSIS Between the surgery and the end of the spine growth (>18y-o). N = 67 15 % regressions > 15° 80% “Stabilisation” 5% deterioration > 5° 17% had had spine instrumentation.
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NEXT STEP Clinical indication ?
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INITIAL SYMPTOMS Scoliosis + minor neurological signs
162
45 %
Isolated Scoliosis
72
20 %
Pyramidal, motor or sensory signs
57
16 %
Headaches
22
6 %
Cranial nerves
18
5 %
Sphincter
11
3 %
Pain
11
3 %
Hydrocephalus
7
2 %
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INDICATIONS TO TREAT
Chiari + Syrinx (symptomatic or not) Chiari + evolutive or surgical scoliosis Chiari + Neurological symptoms Chiari + Headaches ? (pain clinic and sleep recording)
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ON GOING PROCESS Natural evolution ?
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ON GOING PROCESS 188
A. Guillen and J. M. Costa
Acta Neurochir (Wien) (2004) 146: 187–191 DOI 10.1007/s00701-003-0177-0
Case Report Spontaneous resolution of a Chiari I malformation associated syringomyelia in a child A. Guillen and J. M. Costa Department of Pediatric Neurosurgery, Hospital Sant Joan de D!eu, Barcelona, Spain Figs. 1 and 2. Sagittal T1-weighted MRI of the cervical and thoracic spine showing a Chiari I malformation and a large cervico-thoracic syrinx Published online January 8, 2004 # Springer-Verlag 2004 Orthopedic surgery for the scoliosis was performed at 14-years of age. The patient remains asymptomatic.
Summary A child with complete spontaneous resolution of a Chiari I malformation associated Syringomyelia without surgical intervention is presented. The child was followed clinically by serial magnetic resonance imaging (MRI) and remains neurologically stable after 8-years of follow-up. To our knowledge, only 6 pediatric cases with spontaneous resolution of a spinal cord syrinx documented by MRI without surgical intervention have been reported. This case is of interest in the light of the postulated theories to explain spontaneous resolution of syringomyelia. Keywords: Syringomyelia; Chiari I malformation; spontaneous resolution; spinal cord.
Introduction Traditionally, Chiari I malformation is defined as a congenital rather than an acquired defect. Chiari described type I malformations as ‘‘elongations of the tonsils and medial part of the inferior lobes of the cerebellum which go along with the medulla into the cervical canal’’. These malformations are associated with syringomyelia in 50% to 75% of patients [24]. More recently, cases of ‘‘acquired’’ Chiari mercredi 28 mars 12I malformation have been documented
We present a 6-year-old girl with Chiari I malformation and syringomyelia from C3 to T10 on MRI and thoracic scoliosis with convexity to the right. The neurological examination was normal. Eight years after her initial examination the MRI demonstrated complete and spontaneous resolution of syringomyelia and improvement of Chiari without surgery. Spontaneous resolution of syringomyelia and Chiari I malformation is rare and may be observed only if CSF flow obstruction resolves spontaneously. In young children, a period of observation is therefore warranted. If the tonsils rise together with the child’s continuing cranial growth, surgery may not be required. If the child’s symptoms persist or progress however, surgery should be recommended.
Discussion
Fig. 3. Sagittal T1-weighted MRI showing almost complete resolution of the syrinx
Clinical presentation A 6-year-old girl presented with a 6-months history of scoliosis, without any other symptomatology. No personal and family history report was documented. The neurological examination revealed a right dorso-lumbar scoliosis without any neurological disorder. The child had a 30! scoliosis in that time. A corset was prescribed. The patient exhib!
The Chiari type I malformation, as originally described in 1891, is defined as a congenital herniation of the cerebellar tonsils through the foramen magnum associated with a normal hindbrain [6, 7]. More recently, cases of ‘‘acquired’’ Chiari I malformation have been documented in patients with supratentorial mass lesions [18] and after removal of CSF via a spinal shunting procedure or multiple lumbar [17] punctures. The Chiari I malformation is associated with syringomyelia in 50% to 75% of patients [11]. To our knowledge, there have been 6 pediatric [1, 2, 40–42, 48] (Table 1) and 6 adult [5, 20, 21, 32, 33, 38] cases reported dealing with spontaneous resolution of
Table 1 Author
Age
Syrinx location
Initial Chiari I?
Follow-up
Neurological symptoms
Chiari I malformation
ra-
ong instic
ior n at and her ual duted ent
are ded ide soand om can ws
severity and duration of the infrequent headaches increased despite the institution of medication. The patient had grown from 122 cm at age 7 to 156 cm at age 13, and he had become sexually mature. A repeat MRI was performed to evaluate the Chiari I malformation. It was read as normal by the neuroradiologist: the Chiari I malformation completely resolved and the associated syringomyelia disappeared (Fig 1B). At the time this article was submitted, he was 16 years old and he continues to have recurrent severe migraine headaches every 2 to 3 months. He is being treated with Inderal prophylaxis and acute interventions. The neurologic examination remained nonfocal and the physical examination unremarkable.
The most common presenting symptom from a Chiari I malformation is pain, which can be a headache or nonradicular pain in the shoulder, back, and limbs. The headache differs from migraine and other forms of headaches in that it is usually suboccipital and upper cervical in location and is exacerbated by Valsalva maneuvers. Impaction of the tonsils against the cervicomedullary structures can cause brainstem dysfunction, sensory disturbance, and motor loss. The syringomyelia is associated with the development of a painful, rapidly progressive, or left-curving scoliosis. The cavitation within the central gray matter can produce a segmental or suspended sensory loss of pain and temperature by interrupting crossing fibers of the spinothalamic tract while preserving touch and the deep sensibility whose fibers ascend ipsilaterally in the dorsal column before entering the gray matter. Further compression by the Syrinx can affect the long tracts in the white matter and lead to spastic quadriparesis. Presentation during childhood is increasingly recognized.5–7 A detailed neurologic evaluation is essential, as the im-
ON GOING PROCESS DISCUSSION
Complete Spontaneous Resolution of Childhood Chiari I Malformation and Associated Syringomyelia ABSTRACT. The diagnosis of Chiari I malformation and associated syringomyelia is often made in childhood. Since the advent of magnetic resonance imaging, these abnormalities are increasingly detected incidentally. Despite incomplete understanding of the natural history of asymptomatic Chiari I malformations, the current recommendation is to consider prophylactic surgical intervention in those with an associated syringomyelia. This case report presents a complete spontaneous resolution of a Chiari I malformation and syringomyelia in a child. It illustrates the possibility that asymptomatic children with Chiari I malformations and syringomyelia may be followed conservatively. Pediatrics 2001;107:182–185; Chiari I malformation, resolution, syringomyelia, pediatric. ABBREVIATIONS. MRI, magnetic resonance imaging; CSF, cerebrospinal fluid.
e of ing hiari I malformation is the congenital downers ward displacement of the cerebellar tonsils ate into the cervical canal. It is often associated msyringomyelia, which is a cavitary dilation of mercrediwith 28 mars 12 sel-
C
In 1891, Chiari described 4 congenital anomalies of the lower brainstem and inferior cerebellum.3 The type I malformation consists of downward herniation of the cerebellar tonsils through the foramen magnum. Herniation of the tonsils !5 mm below the foramen magnum on MRI is considered diagnostic.4 A Chiari I malformation may also be occasionally acquired from increased intracranial pressure in conditions such as head injury, hydrocephalus, or craniosynostosis. Syringomyelia has been noted to accompany 50% to 70% of patients with Chiari I
Fig 1. Sagittal T1-weighted MRI with contrast demonstrating a Chiari I malformation with 13 mm of tonsillar herniation below the foramen magnum (large arrow). There is an associated cervical syringomyelia without enhancement (small arrow, A). Follow-up image reveals resolution of the Chiari I malformation with the tonsils "2 mm below the foramen magnum (arrow) and complete disappearance of the cervical syringomyelia (B). Dotted lines represent the foramen magnum.
EXPERIENCE AND REASON Downloaded from www.pediatrics.org at Bibliotheque Univ Paris V on June 5, 2009
183
ON GOING PROCESS
Spontaneous Resolution of Syringom
CASE REPORTS
Spontaneous Resolution of Chiari I Malformation and Syringomyelia: Case Report and Review of the Literature Jörg Klekamp, M.D., Giorgio Iaconetta, M.D., Madjid Samii, M.D. Department of Neurosurgery, Nordstadt Krankenhaus, Medizinische Hochschule, Hannover, Germany
OBJECTIVE AND IMPORTANCE: Indications for surgery and the surgical technique of foramen magnum decompression for patients with Chiari I malformation and syringomyelia are controversial issues. This case report supports the view that observation may be adequate for patients without progressive symptoms or with mild clinical symptoms. CLINICAL PRESENTATION: A 37-year-old woman presented with a 3-month history of burning dysesthesias and hypesthesia in her right arm. A neurological examination revealed hypesthesia in the right trigeminal distribution. A magnetic resonance imaging scan revealed a Chiari I malformation with syringomyelia between C2 and T2. No hydrocephalus was observed. CLINICAL COURSE: Because the patient’s symptoms regressed spontaneously, surgery was not performed. Thirty-two months after her initial examination, the patient was asymptomatic. A second magnetic resonance imaging scan was obtained, which demonstrated complete spontaneous resolution of the Chiari I malformation and syringomyelia. CONCLUSION: We attribute the regression of the patient’s symptoms to spontaneous recanalization of cerebrospinal fluid pathways at the foramen magnum, which most likely was due to rupture of the arachnoid membranes that had obstructed cerebrospinal fluid flow. (Neurosurgery 48:664–667, 2001) Key words: Arachnoiditis, Chiari malformation, Spinal cord, Syringomyelia
O
bstruction of cerebrospinal fluid (CSF) flow due to herniation of cerebellar tonsils into or even below the level of the foramen magnum (i.e., Chiari I malformation) is one of the most common causes of syringomyelia. A herniation of more than 5 mm is considered pathological for adults (5). Studies have mercredi 28shown marsthat 12about 75 to 85% of
second group of patients may acquire Chiari I malformation because of lumboperitoneal shunts (6), tumors of the posterior fossa (13), birth trauma (32), or meningeal reactions at the foramen magnum (34). The natural history of clinical symptoms in this anomaly is not well known. No general agreement exists with regard to which patients
patient who experienced spontaneous resolution of Chiari I malformation and syringomyelia during a period of 32 months.
CASE REPORT A 37-year-old woman presented with a 3-month history of burning-type dysesthesias in her right arm. A neurological examination revealed hypesthesia for light touch, pain, and temperature in her right arm and right trigeminal distribution. The remainder of the examination was normal, with no long-tract signs. A magnetic resonance imaging (MRI) scan showed a classic Chiari I malformation with syringomyelia between C2 and T2 (Fig. 1). The syrinx affected the right hemicord corresponding to the clinical findings. No hydrocephalus was observed. The advantages and risks of surgery were discussed with the patient. Within the next couple of months, symptoms started to regress spontaneously, and surgery was therefore postponed. Thirty-two months later, the patient was asymptomatic and underwent a second MRI examination, which showed complete resolution of the Chiari I malformation and syringomyelia (Fig. 2). The patient did not recall any specific incidents associated with sudden changes of symptoms inFIGURE these 32 1. Sagittal (A) and axial (B) months but reported a gradual disapT1-weighted MRI scans demonstrating pearance of sensory and dysesthetic Chiari I malformation with the tonsils symptoms.
reaching into the foramen magnum to the upper limit of C1, occluding the DISCUSSION cisterna magna and a large syrinx startMoriwaka et al. (20) published a naing at the level of C2. Because of the tionwide epidemiological survey on syringomyelia in Japan. Amongscoliosis 1243 pa- of the cervical spine, the cauextent of the syrinx to T2 cannot be tients with syringomyelia, 684dal (51.2%) had associated Chiari I malformation. appreciated on these scans. The axial The clinical course was slowlyscan progresat the level of C3 shows a considsive in the great majority of patients; in erably large syrinx in the right half of 202 patients (16.2%), however, a rather the sponspinal cord. stable course was observed, and taneous resolution of symptoms was ob-
FIGURE 2. T1-weighted MRI scans of the same patient shown in Figure 1, obtained 32 months after presentation. These images in the sagittal (A) and axial (B) planes show the regression of the tonsils into the posterior fossa, a normal-appearing cisterna magna, and complete resolution of the syrinx. The axial scan at C3 demonstrates a slight hypodense signal change in the right half of the cord, which may represent the former area of the syrinx.
patients with syringomyelia that was
mations disappeared com patient, however, the Ch tion and syringomyel without accompanying symptoms (30). Evidence is mounting myelia develops in assoc struction of CSF flow a magnum in Chiari I malf 13, 24, 26, 31–34). There ous resolution of a syrinx taneous improvement in children, the growth of th tinues after the cerebellu more than 90% of its fin years (25). Therefore, t regress intracranially in growing cranium (16) to free CSF passage is estab lowing the syrinx to dec even disappear complete A second possible m volves changes in venou posterior fossa. Girard e strated that Chiari I ma regular feature in childr Galen aneurysms due to disease. After successful the venous malformation, formation and syringomye disappeared. One may sp nous thrombosis involvin fossa may cause descent tonsils into the foramen m after recanalization or esta ficient collateral flow, the gress intracranially (30). T the patient described here, show evidence of cerebella one would expect if ven were present. Furthermore bosis capable of producing tion generally is associated nounced neurological sy from children with vein
ON GOING PROCESS
Natural history of Chiari malformation Type I
Natural history of Chiari malformation Type I
onding editorial in this issue, pp 177–178.
J Neurosurg Pediatrics 2:179–187, 2008
The natural history of the Chiari Type I anomaly FEDERICA NOVEGNO, M.D., MASSIMO CALDARELLI, M.D., ANTONIO MASSA, M.D., DANIELA CHIEFFO, PH.D., LUCA MASSIMI, M.D., BENEDETTA PETTORINI, M.D., GIANPIERO TAMBURRINI, M.D., AND CONCEZIO DI ROCCO, M.D. Department of Pediatric Neurosurgery, Catholic University Medical School, Rome, Italy Object. Since the advent of MR imaging, an increasing number of asymptomatic or oligosymptomatic patients have been diagnosed with Chiari malformation Type I (CM-I). The decision of whether or not to operate is more difficult in these patients than in those with clear symptoms because of the lack of information about the natural course of this disease. Methods. The authors report on their experience in a series of 22 patients with CM-I who were evaluated at the authors’ institution, and for whom a conservative approach to treatment was adopted. The patients ranged in age from 1 to 16 years (mean 6.3 years) at diagnosis. Neuroradiological and complete clinical examinations were performed in all patients 6 months after the first observation and every year thereafter. The follow-up period ranged from 3 to 19 years (mean 5.9 years). Results. Chiari malformation Type I was incidentally detected on MR images in 11 of 22 patients. The remaining 11 patients had minimal clinical signs at presentation that were not regarded as necessitating immediate surgical treatment. Seventeen patients (77.3%) showed progressive improvement in their symptoms or remained asymptomatic at the last follow-up whereas 5 patients (22.7%) experienced worsening, which was mild in 2 cases and required surgical correction in the remaining 3 cases. On MR imaging a mild reduction in tonsillar herniation was appreciated in 4 patients (18.18%), with complete spontaneous resolution in 1 of these. In 16 patients, tonsillar herniation remained stable during follow-up. Conclusions. The authors’ data confirm the common impression that in both asymptomatic and slightly symptomatic patients with CM-I, a conservative approach to treatment should be adopted with periodic clinical and radiological examinations. (DOI: 10.3171/PED/2008/2/9/179)
KEY WORDS • Chiari malformation Type I • clinical observation • syringomyelia
anomaly constitutes a heterogeneous and orial entity, comprising variants on a male base as well as acquired forms. It is a rare ndition with many controversial aspects, the gs being the abnormal position and to some rmal shape of the cerebellar tonsils which the cranial cavity and into the upper cervibly leading to an obliteration of the subs at the level of foramen magnum.5,6 In most y in the acquired variant that arises secon28 mars onmercredi in intracranial cavity 12 volume, the caudal
compartments. The genesis of the often-associated spinal cord cavitation is attributed to this kind of dynamic anomaly.25 The signs and symptoms in such patients are generally related to the compression of the neural structures by the herniated tonsils (long tract deficits, cranial nerve dysfunction, and cerebellar involvement) and/or by the presence of an associated syrinx.31 Once the condition has been recognized and confirmed on a neuroradiological investigation, the choice of the most appropriate management remains debatable. Clinical observation may be the best option in asymptomatic patients, whereas surgical correction is gen-
FIG. 1. Case 1. Representative T1sillar herniation is demonstrated in the in 1997 and performed for gait instabil obtained in 2000 (B), 2003 (C), 2005 the neuroradiological findings change resolution of the malformation (E). FIG. 1. Case 1. Representative T1-weighted MR images. Tonsillar herniation is demonstrated in the image in panel A obtained laminectomy. The postoperative in course wasperformed uneventful in instability. servedAdditional on postoperative MR imag 1997 and for gait images were dimensions, which were reduced in all cases and the patients experienced improveobtaineda indrastic 2000 (B), 2003 (C), 2005 (D), and 2007 (E). In 2007 the2neuroradiological findings ment in their symptoms in the first cases, and a mild im- changed totally, showing complete resolution of the malformation provement in the third. No significant changes were ob- (E). Neuropsychological Findings
Seven of the 10 children who u logical testing right-handed, 1 served on postoperative MR images except forwere ventricular had incomplete dominance. Eight c dimensions, which were reduced in the first 2 patients. level of intelligence (group mean IQ Neuropsychological Findings responding population 100 ! 15 [s children presented with a borderlin Seven of the 10 children whogence underwent (meanneuropsychoIQ 81.5). Naming sp logical testing were right-handed,5 1cases, was left-handed, and disturbanc 2 visual attention had incomplete dominance. Eightinchildren showed a normal 2 cases, and visual memory defic level of intelligence (group mean 5IQpatients 106.2; mean of the corwith naming speech del responding population 100 ! 15 [standard deviation]). tions " 10 mm. The Two visual attenti children presented with a borderline level of neurovisual global intelliciated with deficits in gence (mean IQ 81.5). Naming speech delay was found in short-te Language comprehension, 5 cases, visual attention disturbances in 4 cases, were dyspraxia fine movement normal in al in 2 cases, and visual memory deficits in 2 cases. Four of thedisorder presented with behavioral 5 patients with naming speech delays had tonsillar herniations " 10 mm. The visual attention disorders were assoDiscussion ciated with neurovisual deficits in only 1 case (Case 19). and availab Language comprehension, short-term verbalyears, memory, In recent the wide fine movement were normal in nal all MR patients. Twotechnology patients has le imaging presented with behavioral disorders such such as hyperkinesia. sicians, as pediatricians, neur cians, to use MR imaging to evalu complaints such as learning disab Discussion lems, and epileptic disorders, with In recent years, the wide availability of in cerebral spi- For thi of CM-I some and of them. phynal MR imaging technology has are led increasingly nonneurosurgeon faced with the dec sicians, such as pediatricians, neurologists, other clini-patients a the care of and asymptomatic cians, to use MR imaging to evaluate patients with with symptoms that varied may or may n complaints such as learning disabilities, behavioral probderlying hindbrain herniation, in FIG. 2. Case 19. Representative MR images. T1-weightlems, and Sagittal epileptic disorders, with the incidental discovery who present with the typical prese ed (A) and axial T2-weighted (B) of images obtained at diagnosis, CM-I in some of them. For this and reason, severe neurosurgeons neurological manifesta showing hindbrain herniation associated with mild ventriculomegare increasingly faced with the decision how toera manage pre–MRofimaging the diagnosis
laminectomy. The postoperative course was uneventful in all cases and the patients experienced a drastic improvement in their symptoms in the first 2 cases, and a mild improvement in the third. No significant changes were ob-
