Haemorrhage into an arachnoid cyst
20 Coleman SA, Cooper PD. Upper airway obstruction misdiagnosed as
asthma. Br J Hosp Med 1989;41:184.
21 Helmrich G, Stubbs TM, Stoerker J. Fatal maternal laryngeal
papillomatosis in pregnancy: a case report. Am J Obstet Gynecol

365
1992;166:524–5. [published erratum appears in Am J Obstet Gynecol
1992;166:1313.]
22 Balazic J, Masera A, Poljak M. Sudden death caused by laryngeal
papillomatosis. Acta Otolaryngol Suppl 1997;527:111–13.

Haemorrhage into an arachnoid cyst: a serious
complication of minor head trauma
K De, K Berry, S Denniston
.............................................................................................................................

Emerg Med J 2002;19:365–366

Arachnoid cysts are infra-arachnoidal cerebrospinal fluid
collections that are usually asymptomatic. However, they
can become acutely symptomatic because of haemorrhage and cyst enlargement, which may result from minor
head trauma. The range of symptoms is wide and many
are “soft” signs. Diagnosis is important as cysts causing
mass effect require surgery. A case is reported of a child
presenting with localised headaches after minor head
trauma. Computed tomography demonstrated an arachnoid cyst with evidence of haemorrhage, which required
surgical intervention. Other cases of arachnoid cyst
presenting to our hospital or reported in the literature are
reviewed with respect to presenting symptoms and signs.
Localised headaches, behavioural or cognitive changes
and ataxia are more commonly associated with this disorder than nausea, vomiting, visual disturbances or seizures.
This range of symptomatology following minor head
trauma may warrant computed tomography when other
criteria for this investigation are not met.

I

ntracranial arachnoid cysts are relatively rare, comprising
1% of all intracranial mass lesions,1 of which 75% occur in
children. They are benign collections of cerebrospinal fluid
that are usually primary developmental abnormalities. Most
are asymptomatic and found incidentally, most commonly in
the middle cranial fossa and more frequently on the left side,
however they may become acutely symptomatic after minor
head trauma. Cysts may rupture or intracystic vessels may
bleed into the cyst cavity resulting in mass effect and onset of
symptoms. This may be associated with a subdural haematoma. The diagnosis is usually apparent on computed tomography although a subacute haemorrhage may appear
isodense with adjacent brain tissue and require magnetic
resonance imaging.2 The treatment for arachnoid cysts with
intracystic haematoma is surgical decompression and marsupialisation of the cyst.3

CASE REPORT
A 2 year old previously healthy boy, with normal development,
presented eight days after a minor head injury. He had fallen
5–6 feet from a climbing frame onto a wood chip floor but had
seemed so well after the incident that no medical attention
was sought.
However, his parents noticed a new and unusual pattern of
behaviour: on running or jumping he would stop suddenly
and hold his left temporal region complaining of pain.
He had had no vomiting, visual disturbance or seizures.
Neurological examination and fundoscopy were normal. A

Figure 1

CT scan showing right temporal arachnoid cyst.

non-contrast CT scan demonstrated a left sided arachnoid cyst
with evidence of bleeding into the cyst cavity (fig 1).
The child was reviewed that day by a neurosurgeon and
listed for craniotomy within a few weeks.

DISCUSSION
In the accident and emergency department a large number of
children are seen each day after minor head injury. Some are
observed in the department or on a ward but the vast majority
are examined, reassured, and discharged with appropriate
advice.
The Royal College of Surgeons of England has recently
defined indications for skull radiography, admission, and
computed tomography in a report on “Management of
Patients with Head Injuries”.4 Although a CT scan is clearly
required to make, or exclude, the diagnosis of haemorrhage
within an arachnoid cyst, the symptoms and signs may be very
soft and not included within these standard guidelines.
For this reason we looked at a number of cases of arachnoid
cysts: 98 from our hospital and a further 74 reported in the
literature, to identify the common presenting features.2 5–9 The
majority of cysts in our series were found incidentally. Three
were identified after minor head injury: one cyst had ruptured
but none had intracystic haemorrhage.

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The most frequently reported presenting symptom was
headache, notable because it is often accurately localised
(even by very young children). Behavioural problems, a
change in personality and reduced mental function were the
second most frequently reported signs and occasionally the
only presenting features. They are very difficult to elicit and
rely on an accurate history from parents or other carers.
Ataxia, cerebellar signs, and falls to one side were reported
more commonly than nausea, vomiting, and visual disturbance, which are the more familiar indicators of intracranial
disorder. Seizures were seen in only one case.
Of additional interest were two cases who presented with
solitary ipsilateral cranial nerve lesions associated with arachnoid cysts.2 9
In conclusion, haemorrhage into a pre-existing arachnoid
cyst is a rare but important diagnosis after minor head
trauma. Symptoms and signs are non-specific and rely on an
accurate history and carer observations. With this in mind, the
emergency physician should have an index of suspicion and
consider computed tomography outside of standard guidelines when presenting features could be consistent with this
disorder.
Contributors
With thanks to Dr Helen Alton, consultant radiologist at Birmingham
Children’s Hospital who interpreted and aided us with the CT scan.
Funding: none.
Conflicts of interest: none.

Hagger, Constantinou, Shrotria
.....................

Authors’ affiliations
K De, K Berry, S Denniston , Paediatric Accident and Emergency,
Birmingham Children’s Hospital NHS Trust, UK
Correspondence to: Dr S Denniston, 52 Farnol Road, Yardley,
Birmingham B26 2AF, UK; sarah@denniston.org
Accepted for publication 20 August 2001

REFERENCES
1 Parsch C, Kraub J, Hofinann E, et al. Arachnoid cysts associated with
subdural haematomas and hygromas: analysis of 16 cases, long term
follow up, and review of the literature. Neurosurgery 1997;40:483–90.
2 Rodolfo I, Prabhakar P. Role of MR imaging in the diagnosis of
complicated arachnoid cyst. Pediatr Radiol 2000;30:329–31.
3 Nun R. Arachnoid cysts associated with post-traumatic and spontaneous
rupture into the subdural space. Comp Med Imag Graph
1997;21:341–4.
4 Royal College of Surgeons. Report of the Working Party on the
Management of Patients with Head Injuries. London: The Royal College
of Surgeons of England. 1999.
5 Kuhnley EJ, White DH, Granoff AL. Psychiatric presentation of an
arachnoid cyst. J Clin Psychiatry 1981;42:l67–8.
6 Rya H, Makino A, Hinokuma K. An arachnoid cyst involving only the
hypoglossal nerve: case report and review of the literature. Br J
Neurosurg 1999;13:492–5.
7 Jallo GI, Woo HH, Meshki C, et al. Arachnoid cysts of the
cerebellopontine angle: diagnosis and surgery. Neurosurgery
1997;40:31–7.
8 Koch CA, Voth D, Kraemer G, et al. Arachnoid cysts: does surgery
improve epileptic seizures and headaches? Neurosurg Rev
1995;18:173–81.
9 Nadkarni T, Hande A, Nagpal R. Arachnoid cyst within the fourth
ventricle - a case report. Br J Neurosurg 1995;9:675–8.

Acute appendicitis after a fall from a ladder: a traumatic
aetiology?
R Hagger, J Constantinou, S Shrotria
.............................................................................................................................

Emerg Med J 2002;19:366–367

A

cute appendicitis is the commonest emergency condition
requiring surgery in the United Kingdom. Its precise
aetiology, however, remains unproven: dietary, genetic
factors, and infectious agents have been implicated.1 Trauma
has also been proposed as a cause of acute appendicitis, but
there are doubts as to whether this is a casual or causal relation. In this case report we produce compelling evidence that
trauma can cause acute appendicitis.

CASE REPORT
A previously fit 60 year old man was admitted with abdominal
pain three days after a fall from a ladder. The mechanism of
injury was that the foot of the ladder slipped away with the
patient falling from about six feet to land prone on the rungs
of the ladder. The patient presented with increasing right
lower quadrant pain, worse on movement. Appetite was
reduced; the patient was not vomiting and was passing flatus.
He was becoming short of breath with a productive cough. On
examination he was feverish, 39.7°C, and tachycardic.
Abdominal examination revealed tenderness in the right iliac
fossa and right groin. There was a firm swelling in the right
groin with overlying bruising extending over the femoral
triangle of the right thigh with associated scrotal oedema.
Routine blood tests showed a leucocytosis. A chest roentgeno-

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Figure 1 Computed tomogram demonstrating dilated loops of
small bowel, and incarceration of oedematous bowel in a right
inguinal hernia (arrowed).

gram demonstrated patchy consolidation at the base of the
right lung; dilated loops of small bowel were seen on an
abdominal roentgenogram. Computed tomography revealed
dilated loops of small bowel, incarceration of oedematous
bowel in a right inguinal hernia, and oedematous changes in