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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3644_Библиотеки_им_академика_М_И_Перельмана
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CAMS 3 has been very infrequently described and involves the midbrain, cerebellum, petrous bone, and mandible (Theron et al. 1974; Fischgold et al. 1952; Tamaki et al. 1971; Wong et al. 2003; Haw et al. 2003).
CAMS 3 is located in a strategic position at the crossroads of the complex
cephalic segmental arrangements and the relatively simplified spinal
metamers,and it may therefore bear transitional characteristics with features shared by either end of the spectrum.In the review of spinal arteriovenous malformations syndromes (SAMSs), Matsumaru et al. (1999)
showed that vertebral lesions and radicular lesions occur in 42% and 21%
of cases, respectively. It appears that in SAMS, there is a high propensity
6Cerebrofacial Arteriovenous Metameric Syndrome372
Fig. 6.9A–C. CAMS 2 revealed
over 6 years.A A 4-year-old
boy with only retinal AVM.
B, C Six years later a
diencephalic AVM is visible
of lesions in sclerotomal mesenchymal aggregates around the notochord
underlying the developing spinal cord.The lesion in the petrous bone in
one of our cases showed that a similar phenotype can be exhibited in
CAMS 3. On the other hand, the main targets for osseous involvement of
CAMS 1, 2 are the maxillary structures, with apparent sparing of the
corresponding skull base (ethmoid and sphenoid).
The rostral part of the notochord reveals many peculiarities in comparison to the trunk mesoderm, including a wide variation in the relationship of notochord with prechordal mesoderm in different
species (Barteczko and Jacob 1999). During development of the
cranial base, primordial cartilage develops from mesenchymal cell
aggregates, which extend cephalad. The otic capsules, destined to
develop into petromastoid temporal bones,are located directly lateral to the parachordal cartilage, which are the precursors for the future
basiocciput. The parachordal cartilage intimately surrounds the
rostral end of the notochord (Sperber 1989). In comparison, the prechordal mesenchymal centers for the facial skeleton are more distal
and cephalic to the rostral notochord.The rare skull base involvement
in CAMS 1, 2 might possibly be explained by the relatively remote
location of prechordal mesenchymal centers in comparison with the
otic capsules and the parachordal cartilage with respect to the notochord.
The presence of an AVM surrounding the left vestibulocochlear nerve
(subarachnoid location) in one of our patients sheds light on the transitional nature of CAMS 3. In CAMS 1, 2 patients, previous reports mentioned only the optic nerve as the “cranial nerve”being affected. It is important to note that the retina and optic nerve are direct extensions of the
forebrain, projecting directly from the optic vesicle.This significantly differs from other cranial nerves,which basically are peripheral nerves link-
373Introduction
Fig. 6.10A,B. Isolated optic nerve AVM. Is it an isolated lesion or the early expression
of a CAMS2? (Courtesy of M.Mursdorf)
ing the central nervous system to the peripheral tissues. The lesions involving the retina, optic nerve, and chiasm,in cases of CAMS 1, 2,should
therefore be regarded fundamentally as pial AVMs.On the contrary,a significantly higher proportion of cases of SAMS (21% from Matsumaru’s
series) have lesions along radicular nerves within the subarachnoid
space, reflecting a basic difference in selection of compartmental location.The cause of such diversity is not understood, but this may be related to the different influences of abluminal and intraluminal factors at the
spinal vs the cranial levels or the difference in their embryonic origin.
The topography of vascular malformations of CAMS 1, 2 appears to follow the same rule governing the location of sporadic AVMs,in that nidi of
the AVMs reside only within the subpial compartment, with the subarachnoid space spared. The occurrence of subarachnoidal AVMs in
CAMS 3 possibly suggests a transitory process toward the spinal distribution (Wong et al.2003).
6.2 Clinical Manifestations
The commonest presenting symptom is visual deterioration (reduced
acuity or field). This is sometimes detected several years before further
neurological symptoms lead to more detailed investigations (CT, MRI),
confirming the presence of a retinal AVM but also revealing an associated brain AVM. Epistaxis is encountered in patients in whom the presenting cause is the associated high-flow maxillofacial AVM. In the Bhattacharya et al. (2001) series,25% of the patients suffered from a intracranial hemorrhage (at 4, 6, 23, and 49 years of age) related to their brain
AVM, and none of the brain AVMs was considered curable.It is important
to note that only one-third of the patients were recorded as having any
facial involvement (although this was a retrospective study, and such
involvement could have been overlooked or not recorded).
There is no evidence to suggest an inherited basis of CAMS and there
are also no reports in the literature of brain or orbital AVMs occurring
among family members of CAMS patients. It has been intriguing, however, to find other cerebrofacial vascular lesions in close relatives in two
out of our 15 patients with CAMS.
6.2.1 Retinal AVMs and AVMs Along the Optic Nerve and Chiasm
6.2.1.1 Retinal AVMs
Retinal AVMs are present in most CAMS patients, but there are some reported cases without retinal involvement (Bhattachaya et al. 2001; Ponce
et al. 2001; Maeda et al. 1992) (Table 6.2). Jiarakongmun et al. (2002)
found among 14 CAMS 2 cases,nine patients with retinal AVMs, and suggested screening including ophthalmologic examination with visual field
testing, visual acuity, and fluorescein angiography for patients suspected
of having CAMS.
6Cerebrofacial Arteriovenous Metameric Syndrome374
375Retinal AVMs
Ta ble 6.2. Cerebrofacial arteriovenous metameric syndrome II (CAMS 2) with visual tract involvement (Jiarakongmun et al. 2002)
Reference Sex Age Visual pathway presentation Intracranial vascular Facial vascular lesion
(years) malformations
Present Symptoms Present Symptoms Present Symptoms
Jiarakongmun et al.2003; M 28 Optic nerve, Impaired Yes None Nose tip None
case I retina (diagnosed visual acuity (diagnosed at (diagnosed
at 7 years)15years) at 18 years)
Jiarakongmun et al.2003; M 4 Left optic None Yes Headache, right None None
case II nerve hemiparesis,
hemianopsia
Jiarakongmun et al.2003; M 6 Retina Right eye Yes Progressive neuro- None None
case III blindness (1 year later) logical deficit
Muthukumar M 12 Retinal Blindness Yes None None
and Sundaralingam (1998)
Ya s uhara et al. (1999) F 7 Retina, optic Left eye Yes, lesion None Left submaxilla Severe oral
nerve, left orbit blindness progress in size bleeding
Gibo et al. (1989) NA NA Optic chiasm Impaired Yes None Left maxilla None
visual acuity
To st et al. (1996) F 6 Retina Impaired None None Hemifacial None
visual acuity AVMs
Maeda et al. (1992) F 5 Retina Strabismus, Yes
impaired (2 years later) None Cheek nevus, None
visual acuity (present at 1year)
Daenis and Appen (1984) F 14 Optic nerve Impaired visual None None None None
and chiasm acuity, optic
atrophy
Hopen et al. (1983) F 56 Optic nerve Progressive None None None None
and chiasm chiasmal
syndrome
Kikuchi et al. (1988) F 7 Retina and Proptosis, Yes None None None
optic nerve injected eye
Fujita et al.(1989) F 5 Optic nerve Proptosis Yes None None None
Schlieter et al. (1976) M 39 Retina Impaired
visual acuity Yes Hemiparesis, hemia- None None
nopia,speech disability
Lalonde et al.(1979) F 16 Retina Impaired Yes None None None
visual acuity
Progressive visual loss, including decreased visual acuity and visual
field defects, appears to be the earliest presenting symptom of CAMS 2
disease, which tends to occur several years prior to the discovery of the
retinal lesions.Bhattacharya et al. (2001) showed 60% cases of CAMS patients presented with visual symptoms at a mean age of 18 years.The retinal arteriovenous malformation or arteriovenous communications of the
retina (AVCR),or so-called racemose hemangioma in the ophthalmological literature,is probably a misnomer because it does not show proliferative or tumor behavior. According to Archer’s classification, grade III
AV CR is the most severe form and is often linked with an intracranial
lesion or CAMS (Meinhold 1996).
Retinal AVMs or AVCR, are usually considered to be stable retinal lesions, despite progression of the coexisting intracranial AVMs (Yasuhara
et al. 1999).Clinical presentations of this lesion include loss of vision due
to intraretinal macular hemorrhage, central and peripheral retinal vein
occlusion, and vitreous hemorrhage, or even gradual reduction of vision
due to neovascular glaucoma in association with changes in the retinal
AVMs and retinal and choroidal ischemia (Effron et al.1985).
6.2.1.2 Optic Nerve and Chiasmatic AVMs
Optic nerve and chiasmatic AVMs are also hallmark findings in CAMS.
They often appear to be clinically silent, eventually resulting in a slowly
progressive functional deficit. The presenting symptoms include decreased visual acuity and field defects or blindness from optic nerve atrophy,and progressive dysfunction of the optic pathways.
Exophthalmos is a rare presenting symptom in CAMS,with optic nerve
AVMs and intraorbital congestion resulting in mass effect, as reported by
Fujita et al.(1989), Muthukumar and Sundaralingam (1998),and in one of
the cases of Jiarakongmun et al.(2002) (Fig. 6.8). Exophthalmos could also result from an enlarged ophthalmic vein, which may drain normal
brain tissue or cerebral AVMs related to increased intracranial venous
pressure caused by venous occlusion of draining intracranial veins.
Tr eatment of these orbital lesions remains a challenge because of the
complex anatomic and hemorrhagic characteristics of the malformation.
Attempts to treat these patients with combined surgery and careful preoperative embolization are not without risk (Goldberg et al.1993).
6.2.2 Cerebral AVMs
Considered as a metameric lesion,intracranial AVMs in CAMS are one of
the most common findings in such patients.We found cerebral AVMs in
three-quarters of our cases. The cerebral AVMs in CAMS may involve in
continuity the optic chiasm, hypothalamus, thalamus, the cortex around
a calcarine fissure or the cerebellum,depending on the subtype of CAMS
(1, 2, or 3). Infrequently they present as multiple scattered lesions in
the same segmental distribution. The corpus callosum or the olfactory
region belong to CAMS 1 arrangement and should be associated with
midline frontonasal vascular malformations (Figs. 6.11,6.12).
6Cerebrofacial Arteriovenous Metameric Syndrome376
Considering the angioarchitecture of cerebral AVMs in CAMS, we observed that there were certain findings in cerebral AVMs in CAMS, which
tend to differ from sporadic AVMs. In particular,the AVM nidus in CAMS
patients is usually described as a cluster or group of small vascular networks with intervening normal brain tissue and optic pathways and some
degree of angiogenesis. Transdural arterial supply was present in some
cases (Fig. 6.13). There are no reported cases of intradural high-flow arteriovenous fistulas (AVFs) or related findings of high-flow shunts such as
dysplastic flow-related arterial aneurysms or hugely dilated draining
veins, as we often seen in hereditary hemorrhagic telangiectasia (RenduOsler-Weber disease).
Progressive development and enlargement of cerebral AVMs is one of
the special observations in CAMS (Figs. 6.7, 6.13, 6.14) Yasuhara et al.
(1999) also reported similar observations with a progressive increase in
size and flow of the cerebral AVM with worsening neurological deficit.
377Cerebral AVMs
Fig. 6.11A–C. Yo ung CAMS 1
patient presenting with a
midline frontal AVM mostly
supplied by the ophthalmic
terminal branches (A). In
addition, the angiographic
exploration disclose a holocallosal AVM with an intrasplenial aneurysm representing
a priority target for a partial
embolization (B, C).
(Courtesy of G. Caldas)
These findings suggest that AVMs in CAMS are not static processes within the segment that carry the embryonic defect.
Multifocality and the continued progression of the expression of the
disease are characteristic of cerebral AVMs in CAMS, with lesions along
the visual pathways. Usually lesions are located in one hemisphere, but
there are some reports of bilateral involvement. Angiogenesis crossing
the midline could be related to ischemia of the midline structures from
chiasmatic or hypothalamic AVMs; however,bilateral neural crest migration exists (as seen with mirror aneurysms) and may not be restricted to
one side but expressed in separate but adjacent segments.
Despite the common occurrence of cerebral AVMs in CAMS, they are
usually clinically silent or asymptomatic at the time of discovery. They
rarely present with acute neurological symptoms caused by intracerebral
or subarachnoid hemorrhage (Bhattachaya et al. 2001),but rather reveal
with progressive neurological deterioration without evidence of intracranial bleeding (Jiarakongmun et al.2002).
6Cerebrofacial Arteriovenous Metameric Syndrome378
Fig. 6.12A–C. A 12-year-old girl with a nasal AVM and recurrent severe epistaxis;
presence of an associated olfactory AVM (CAMS 1) (A, B). The severity of the epistaxis led to nose resection (C)
379Cerebral AVMs
Fig. 6.13A–F. Legend see p. 380
6Cerebrofacial Arteriovenous Metameric Syndrome380
Fig. 6.13A–J. CAMS 2. Angiogenic activity over 8 years.A–C The child is 4 years old;
D–F the child is 6 years old; G–I,the child at 9 years of age. Note the increase in flow,
leading to aneurysm formation, but also transdural supply (J)
Fig. 6.14A–F. A 3.5-year-old girl presented with what was diagnosed as hemorrhagic
stroke (A, B). The angiogram failed to show anything but a faint local hyperemia.
Three years later, worsening of the aspect and the diagnosis of AVM is observed
(C, D). Another 3years later, the lesion continued to increase in size and there was
hyperemia of the optic nerve (E, F).Is this a CAMS 2 appearing?
▲
381Cerebral AVMs
Fig. 6.14A–F. Legend see p. 382
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