Medical Jurisprudence And Toxicology

256

MEDICAL JURISPRUDENCE

of the brain. It sometimes occurs without fracture of the skull from a slight
blow on the head or from a fall. The haemorrhage occurs slowly and is
localized in a small area, but it is usually diffused over both the cerebral
hemispheres, and tends to gravitate to the base of the brain.

(c) Subarachnoid Haemorrhage.—This occurs between the arachnoid
and the pia mater, and is usually found at the base of the brain. It is not
localized, but it is diffused, mixes
with the cerebrospinal fluid in the
subarachnoid space and spreads
upwards over the surface of the
brain. The haemorrhage is caused
by injury to the vessels crossing
the subarachnoid space, and' is
usually associated with fracture of
the skull bones and with contusion
or laceration of the cortex of the
brain.

(d) Intracerebral Haemorrhage.
—This may be found on the sur-
face or in the substance of the
brain, and may be a result of lace-
ration caused by injury to the
head. Haemorrhages of a fairly
large size in the substance of the
brain are usually associated with
fracture of the skull. Small pete-
chial haemorrhages in the brain
may "be found as a result of a blow
on the head without fracture of
the overlying bone.

Medico-Legal Questions.—The

questions that are usually raised
in court are—

f~n WTiPtViPr Ti^mnvrViacto fnnn/I Fi9- 120.—Effusion of blood upon the dura
(±) wnetner Jiaemorrnage tound mater from the ^dle meningeal sxtery tom

within the cranium at the across by a projecting piece of the fractured
post-mortem examination parietal bone caused by a lathi blow over the
was due to mechanical vio- head' The acc_used in this case was convicted
i ^ j. ., , under section 325, I.P.C.

lence, disease, or excitement

during a quarrel.
(2) How old the effusion was.

1. Extradural haemorrhage is always caused by mechanical violence.
Subdural haemorrhage is almost always traumatic in origin, but may some-
times be caused by local inflammation. Subarachnoid haemorrhage often
occurs spontaneously in individuals of any age from rupture of a congenital
miliary aneurysm of a blood Vessel in the arterial circle of Willis.

Haemorrhage deep in the tissues of the brain, pons and cerebellum
occasionally occurs in individuals after forty years of age, and is usually
produced by the diseased condition of the cerebral arteries, such as arterio-
sclerosis, atheroma or aneurysm. In many cases ihere may be evidence of
high blood pressure, chronic alcoholism, chronic heart or kidney disease or
syphilis. Sometimes there may be history of scurvy, purpura or haemo-
philia.

It must be borne in mind that a slight injury on the head may cause
cerebral haemorrhage .in a person previously predisposed to it from age or
disease and that the head may be injured during a fall from cerebral
haemorrhage caused by disease.

(From a photograph lent kindly by
Dr. G. B. Sahay.)