i n i \ i i

nasntl sinuses. 1 hese aKo ,nc eiuomiU'ied almiKi v.uh<nti exieption in
cluldien ami adoleacnK 1 01 tin. ;-ioup ,i . .1 whole (he teim IPXIC
h\dioivphalus lus been Miy.'e ,lcil h\ \K \lpme KaieK h\diocephahis
mas follow head injui\ \\ithout e\idcn»eot ,m\ ;.MOV, lesion (o account
for il. This condition a",un i-. m«"e otK'n inci \\uli m i hildrcn than in
adults,

In sonic instances the HICHMM' ol \olunu* «»| ^Mchji'spiiial lluul is onl\
compensaloi y J'oi Iov» ol btaiu \olinnr, ,r. in i onycniial t»r aci|uued
cerebral ntfophy. In such condition1, tlu'jc r-. an mcieasc ot tluv thud
<///«/ within the \entiicles (internal hso*ioi,i*phahis) ami in tlu< Mihaiat hnoid
luv ^il^ U^teinal hulroccphalns). I he au'itmtiLition i»| iluul in these
disease* is of no clinical impoiumcc In ,ill nthci \.mrlics oi h\di'o-
cephalus the excess of fluid is inulet inciea'.ed pifvanv. As a lesult of
this in the infant or vonnj* v.tnld the siituics '.epaute and the skull is
vfcH//'V'W expanded. In older chilttrcn and adolescents Ions' lontwued pjcssnrc
causes erosion and thinning, of Ihc bones 1 hose ot ihc \anlt ha\c
iinpressetl upon their inner surfaces the outlines of the piommcnt j»\ri
(see Plate VII), and at the base thcie are exp.insion t>f (he sella turcica
and erosion of the clinoid processes. The harder hours of the adult are
less apt to su Her, and if there is aii> atroplu it is usuallv ctuilined to
the clinoid processes. In proportion to the distension of the lateial
ventricles, the cerebral hemispheres arc computed and ma\ eventually
suller atrophy. If the hydrocephalus is ohstruetive, the distension is
naturally limited to those parts of the ventricular svstein winch lie
between the obstruction and the choroid plexuses.

4.~C:i,INK:AL I'ICTURK
Congenital hyJrocephahui
The enlargement of the head may be present at birth and produce
dysioeia (see Vol. V, p. 369), or it may be apparent in the early days of
extra-uterine life- The head is uniformly enlarged, the frontal bones bulge
forwards above the eyes, and the eyes are displaced forwards and
downwards. The scalp is taut and thin, and its veins are distended* In
severe cases the weight of the head prevents the child from retaining
a vertical posture, and sores are apt to develop from pressure of the
head upon the pillow. Optic atrophy is usually present and sometimes
squint or nystagmus. Convulsions are common. The limbs, especially
the lower limbs, are often spastic and the plantar responses extensor.
Acquired hydrocephalus
The symptoms of acquired hydrocephalus are those of increased