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N eurochirurgia 2 9 (198 6)

Neurochir urgia 29 (1986) 238- 240
© Georg Th ieme Verlag Srurtga rt . New Yo rk

Summary

Unusual case of
dolichomegavertebrobasilar anomaly. CT and
angiographic picture.
Case report

We recentl y ob served a patient affected by DMVB ano maly, whose d inical a nd neuroracliological find ings are
quit e unusua l.
Ein ungew öhnlicher Fall einer dolichomegavertebrobasilären Anomali e und deren Darstellung im CT und Angiogramm - Fallberic ht
Bericht über einen Patienten mit einer dolichome gaverrebro basilär en Ano malie bei auffa llen d ungewö hnlichen

klinischen und radiologischen Befunden.
L. Casentini" ", D. Curri". A. Benedetti" ", P. Detto ri",
L. Bernardi", A. Alexandre" >I-

Key-Words: verteb roba silar anomaly - er - angiograp hy

Fig.la

Fig.lb

Fig.1c

Fig.ld

Fig.1 e

Fig.lI

Fig.l
a: Axial CT scan without con trast med ium . In the region of the left cerebello- pcntine angle a hypodense area w ith hyperdense borders and
calcification is de tectable .
b. c: Same scan afte r cantrast me dium . Enhancement ot the borde rs and visualisation of the hype rdense me dian band wi th ty pical vascul ar
appearance .
d : Note the ectatic carotid siphans.
e. f : Caronal views.

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lstit uto cli Ne uradiologie. O spedale Civile di Vicenzaflta ly
. .. Divisione di Neuroc hirur gia, Ospe dale Civile Vicenta /Italy

Since CT scan is a widely employed diagnostic measure, several
cases of dolichomegaverrebro-basilar (DMVB) anomal y have
been reported, in which ehe diagnosis was possible with the aid
of CT and was then con firmed by angiography (2, 4, 5, 6, 7).
The CT picture is genera lly quite peculiar, as described by orher
authors (6).
Case rep ort
A 32-ye ar-old man presented a sudden left hemiparesis, dysphagia and
speech diso rders.
At the age of [Wo he had been rreared surgically for a congenital cleft of
the soft palate; no dysphag ia o r speech disorder s were nored rbereafter.
Two years before admis sion to o ur hospital, rhe pa tienr exper ienced
sudden paraesthesiae of right Iimbs with slighr right dysmetria . In a few
da ys the sympto ms disappeared; cerebral scintigram was negative.
On admissio n rhe neurological exa minanon revealed . paresis of the lefr
limb s, lefr facial paresi s wirh preservatio n of rhe musdes of the upper
pa rt of rhe face, mar ked dysphonia with absence of arehing of the palare
on the lefr side and pa resis of the lefr hemilarynx, dysphagia, slighr
devianon of rhe tongue toward the left side, impairment of the strengrh

Neurochirurgia 29 (1986)

239

of the left srernom asroid and trape aius musdes. Left miosis witho ut
ptosis and enophthalmos with preservarion of pupi llary reaction ro light
were also noted.
He aring loss, nystagm us, disord ers of ocula r movemenrs and papilloe dema were not detectable. Sensat ion was preserved.
Compured to mography witho ur ce ntrast medium sho wed a rou nded
a rea of low atte nua tion with hyperdense rim and calcificatio n in rhe
regio n of rhe left cerebello-po ntine angle (Fig. la). No mass effecr on the
fourt h venrricle nor dila rarion of rhe ventricular sysrem was derecta ble.
Cavum Vergae was also presenr.
CT scan with bolus enha ncemenr and coronal sectio ns revealed a ringlike struct ure in the lefr-cerebello-ponrine angle and a large, hyper dense
ban d crossing rhe midline in rhe prepontine cistems (Fig. Ib, c, e, f).
An enlargement of rbe caroti d siphons was also present (Fig. I d). Bilateral vertebral and carorid angiography were perfo rmed. Th e calib re of
the four vessels was increased. Tbe left and the right verte bral arteries
were elongate d and tortuous; both formed a large loop at the level of rhe
left cerebello-pontine angle. Th e basilar artery was very ecraric and
elon gared; its proximal segment crossed rhe pons rransversely fro m o ne
side of the cerebello-po ntine angle cistems ro the orhe r {Fig. 2).
The cerebellar an d poste rior cerebral arteries, as weil as int rac ranial
branches of rhe caro tid arteries, were dilarated and to rruous.

Fig. 2a

Fig.2b

Fig. 2c

Fig.2d

Fig.2
a. b: Left verte bral angiography .
c. d : Right ver teb ral angiography.
Pietores c1ea rly show the loop farmed by the
ve rteb ral arte ries in the left ce rebello-pon tine region and the ect atic basilar arterv .

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Unusual case of dolichomegavertebro-basilar anom aly. CT and angiographic pictu re

Neu rochirurgia 29 (1986)

L. Casent ini, D. Curri, A . Benedett i, P. Dett ori, L. Bernardi, A. Alex andre

Discussion
In th is case the symptoms ar e quite typica l: in fact involvement
of cran ia l nerves is associated wirh la ng tract signs (3, 5). T he
a brupt on set of the sympto ms observed in Dur patient is proba bly due to sudden haemodynamic distu rbances caused by the
mal forma rion . H owever severa l cases of rhe lireratu re a re
cha racrerised by a lan g c1i nical history (l , 2, 5,7).
T he young age and th e a bsence o f a rterial hypertension, as weil
as the association of orher malfor mation (elefr pala re) or
anoma lies (cavum Vergae, bilateral megadolichoca rot id sysrem)
ar e qu ite unco mmon and suggest the ex isten ce of a complex
dysp lastic co ndition ra ther than an atheromarous aetiology suspected in the other cases previously repo rted (5).
From a radiol ogreal poi nr of view, our case emphasises the
imp ortan ce of a co rrect CT scan eva luat ion : rhe ent ire po srerio r
fossa must be carefully ex a mined (6) and cont rast medium must
be given. In fact incomplete scann ing of the po srerio r fossa
allow s one to detect only par tially the com plex ma lformation,
leading to misd iagnosis, In our case CT scan before co nt ras t
medium disp lays a hypodense a rea sur ro unded by hyperdense
bo rders w ith calcifica tions: this pictu re mirnies a cystic tu mo ur
of the cerebello-pontine region . T he hypodensity is probably
ca used by a di lat ed cistern in the cerebe llo-po ntine angle.
Ce ntrast medium enha nces the vascular an om aly and sho ws t he
thick tr ansversal band prod uced by the ecratic bas ilar arte ry.
On ly th e accurate CT st udy of the po sterior fossa and the use of
contrast medi um allows one to ob ta in a co rrecr diagno sis with our a ngiogra phi c exa mina tions.

We believe tha r in patien ts in whom a DMVB an oma ly is suspected, digita l venou s angiograp hy could be usefully and mo re
safely performed to avo id the c1assical vertebral an giography
(2) : in facr the possibility o f co mplicanons afrer vertebra l angiography cannot be excluded in patients in whom haemodynam ic altera tions o f cereb ral circula tion ex ist.
References
(1) Azar -Kia, B., E. Pa lacios, M . Spa k:
Tbe megadolichobasilar arte ry ano ma Iy an d expansio n of rhe inte rna l a udirory meatu s. Neu roradiology 11

(1976) 109- 111
(2) Cerkilt. G. , M. Sarwa r, C. Vira -

pongse: Evolution ofdolichoecrasia of
the verre b robasilar sysrem as evide nced
by seria l co mpu ted tomograph y. Surg.
Neuro!' 18 (1982) 262-266
(3) Frasso n, F., G. Ferr a ri, C. Fuga zzo la, A. Fiaschi: Megad o licho basilar
anornaly ca using bra in srem synd ro me.
A case rep ort. Ne uro rad io lo gy 13

(1977) 279- 281
(4) Ma rre1li, A., F. Rognone, G. Bono ,

L. Gozzo li, A. Cecchini, G. Nappi:
Dclic bo megavertebrobasilar anomaly:

L. Casentini
Divisione di Neu rochirurgia
Ospedale Civiledi v icenza
Vicenzallta /y

d iagnosis by CT. Acta Neurol.
(N apo li) 37 (1982) 62-67
(5) Moseley, I. F., I. M . Holla nd : Ecrasia of rhe basilar arrery: rhe breadrh
of the chnic al spect rum an d the di agno sric valu e of co mputed tom ography.
Neu roradiology 18 (1979) 93-97

(6) Pererson, N. T., P. M. Duchesneau,
E. L. Westb roo k, M . A. Weinstein:
Basila r artery ectasia demonstrated by
computed rom ography. Radio logy 122

(1977 ) 7 13-715
(7) Scom, G ., C. De G ra nd i, A. Co lom bo: Ecrasia of the in rracra nial arteries
dia gnosed by co mputed tomograph y.
Megadolichobasilar artery: CT diagnosis. Ne uroradiology 15 (1978) 183184

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