Download Acute confusion in a middle-aged woman

Hong Kong Journal of Emergency Medicine
Acute confusion in a middle-aged woman
AYS Wong, TW Wong, CC Lau
This is a report of a previously healthy 47-year-old lady who presented to the Accident & Emergency
Department (AED) with acute confusion. She was subsequently diagnosed to be suffering from acute
disseminated encephalomyelitis (ADEM). We report this rare case to alert emergency physicians to
consider acute disseminated encephalomyelitis when presented with a patient with acute confusion.
The diagnosis, investigation, management will be discussed. (Hong Kong j.emerg.med. 2000;7:46-50)
Keywords: Acute disseminated encephalomyelitis, confusion, multiple sclerosis
Introduction
Management of patients with acute confusion is a
challenging problem that we face in the AED. Acute
confusion, in a more severe form such as coma, is
mainly caused by higher brain dysfunction, and
therefore, the causes and investigations follow the
same path as those for comatose patient. The roles
o f an e me r g ency physician include ini ti a l
stabilisation, providing supportive care and
identifying treatable causes rapidly.
The Case
A 47 year old lady, who worked in a frozen meat
store, was brought in by her husband to the AED
because she was noticed to be confused. At the
Triage station, her vital signs were: blood pressure
145/87 mmHg, pulse 97 per minute, temperature
36.5 oC (tympanic), respiratory rate 16 per minute,
SaO2 100%, GCS 14/15. She was triaged under the
category of "Urgent". Her husband recalled that two
hours before her present state of confusion, the
Correspondence to:
Wong Yuk Sen Anna
Pamela Youde Nethersole Eastern Hospital, Accident &
Emergency Department, 3 Lok Man Road, Chaiwan, Hong
Kong
Email: [email protected]
TW Wong, Consultant
CC Lau, Chief of Service
patient had complained of headache of gradual onset
that was associated with nausea. There was no neck
pain. She also had mild upper respiratory tract
infection symptoms five days earlier. She enjoyed
good past health all along and was neither a drinker
nor a smoker. There was no history of diabetes
mellitus or hypertension. There was no history of
drug or herbal medicine ingestion recently.
The patient was brought in on a wheelchair. Her
vital signs were normal and she was afebrile. Her
pupils were equal and reactive. Cranial nerves were
intact. There was no papilloedema on fundi
examination. There was no neck rigidity. She moved
her four limbs spontaneously and power, reflexes
and plantar response of the limbs were all normal.
On mental examination, the patient was confused,
agitated and had a poor attention span. She was
disorientated in time, place and person and she could
not recognize any of her relatives. There was no
hallucination. The rest of the physical examination
was essentially normal. Hypoglycemia was excluded
by a normal haemoglucostix value. Chest radiograph
was performed and showed clear lung fields.
She was admitted to the medical ward for further
management. Initial blood tests including complete
blood counts, liver and renal function, glucose,
calcium level, arterial blood gas, blood culture and
sensitivity were all normal. Thyroid function and
syphilis serology tests were also normal. An urgent
CT scan of the brain (Figure 1) was performed which
showed a vague hypodense area over the right
Wong et al./Acute confusion in a middle-aged woman
47
Figure 1. CT Scan which showed no abnormalities.
anterior limb of internal capsule. Lumbar puncture
was performed and the CSF was clear with a pressure
of 12.5cm water. Analysis revealed no red blood
cells, no white blood cells, protein level of 0.34 g/
L, and glucose level of 4.2 mmol/L. Gram Stain
was negative. After admission, only supportive care
was provided and 12 hours later, her condition
improved and she became orientated.
EEG performed on the second day of admission
revealed no seizure activity but there was focal slow
wave activity over the left temporal area with
occasional suspicious epileptiform discharge.
Autoimmune screening tests were all unremarkable.
A repeat CT brain scan, this time with contrast
revealed ill-defined hypodensity in the white matter
of the frontal lobe suggesting inflammatory changes.
Patient remained well and asymptomatic during the
5 days of hospital stay and remained so on follow
up.
MRI examination was performed four months later
and showed multiple foci in the supratentorial white
matter showing hyperintense signal in proton
density, T2 and FLAIR images. Specifically, a
hyperdense focus was also noted in the anterior
portion of the left temporal lobe. The findings were
characteristic of multiple sclerosis. (Figures 2 & 3)
Discussion
Acute confusion represents the less severe end of a
spectrum of higher brain dysfunction ranging from
normal to comatose. It is essential to provide
supportive care immediately and identify treatable
causes rapidly. Causes of unconsciousness or acute
confusion can be broadly divided into intracranial
and extracranial causes. Surgically correctable causes
like subarachnoid hemorrhage, and space occupying
lesion should be identified early. The causes vary
according to the age group; drug overdose is mostly
seen in young people and the older age group may
become confused in response to mild physiological
insults such as chest and urinary infection or
minor cerebrovascular events. The causes of
unconsciousness or acute confusion can be
summarised in Table 1.
48
Hong Kong j. emerg. med.
n
Vol.7(1)
n
Jan 2000
Figure 2.
Figure 3.
Figures 2 & 3. MRI revealed multiple foci in the supratentorial white matter showing hyperintense signals.
Wong et al./Acute confusion in a middle-aged woman
49
Table 1 . Causes of unconsciousness or confusion : AEIOU FITS
Alcohol
Epilepsy
Insulin
Overdose
Uremia
Fever
Functional
Infection
Ischaemic
Trauma
Tumour
Stroke
Shock*
Intoxication, withdrawal, Wernicke Korsakoff syndrome*
Partial seizure*, temporal lobe epiepsy*, post-ictal state
Hypoglycemia*
Narcotics*, prescription medication
Hyponatremia*, hypercalcemia*, renal failure
Heat stroke*, hyperthermia*, hypothermia*
Hysteria catatonic state, figure state
Meningitis* encephalitis, cerebral abscess, sepsis*
Transient ischaemic attack, hypoxia*
Haematoma (subdural, extradural, intracerebral), diffuse damage, raised intracranial pressure
OTHERS
* Require urgent specific treatment started in the AED
The diagnosis in this patient was based on MRI
findings that were typical of multiple sclerosis (MS).
Multiple sclerosis is classically described as a
relapsing-remitting disorder of white matter tracts
within the central nervous system and it affects
young adult. There is marked clinical heterogeneity
in this disorder. In general, clinical remission
remains the clinical rule and about 55% will have
more than one sign or symptom during the first
episode. In this case the other differential diagnosis
would be acute disseminated encephalomyelitis
(ADEM), which shared similar MRI appearances1
with MS. The diagnoses of ADEM and MS are
favoured by the white matted lesions seen on MRI,
the paucity of findings in CSF analysis, and CT
brain.2 The patient could also be initially diagnosed
as ADEM and later reclassified as MS if the disease
becomes recurrent.3,4
ADEM has rarely been described in the adult
literature 5 and acute confusion as the first
presentation is seldom described. This condition was
first described 250 years ago by an English physician,
Clifton. It is also known as post-infectious, postvaccinial or allergic encephalomyelitis. T he
pathophysiology of this disease is not completely
understood though it is currently believed to be an
autoimmune disease. It constitutes one third of all
the encephalitides reported. The disease usually has
an acute onset, usually within five days after
immunisation, viral or bacterial infections. The
most common viral agent is measles,6 followed by
rubella, varicella, EBV, mumps and influenza.
Group A Streptococcus, tetanus and Mycoplasma
infection have also been incriminated.7 The clinical
presentation is similar despite different causes and
is usually monophasic. The illness usually begins
with non-specific symptoms such as fever, headache,
stiff neck, vomiting and anorexia, rapidly followed
by depression of the sensorium like confusion,
stupor and occasionally coma. The clinical sign that
correlates most closely with the prognosis is the level
of consciousness. The duration of these symptoms
is variable and severity ranges from mild attack
lasting a few days to rapidly fatal course over a few
days. The cornerstone for the establishment of this
diagnosis is MRI.8,9
The myriad of neuropsychiatric manifestations of
ADEM and MS including confusion, letharg y,
ir ritability has been well described. 3 Other
behavioural changes, which included mutism or
psychosis, have also been described. Classically, the
CSF shows only non-specific abnormalities. It is
important to realise that patients with MS have high
incidence of psychiatric presentations. The signs and
symptoms of MS are often mistaken for a
psychiatric disorder, and substantial proportions of
patients with MS are initially referred to
psychiatrists.
50
Since supporting data from MRI, evoked potential
and CSF studies are needed for the diagnosis, it is
necessary to involve the neurologist who will
complete these studies in the hospital.
The ideal form of treatment is for
immunomodulation to be instituted without delay
once the diagnosis is made. The treatment of choice
is steroids. Good recovery from extensive disease
has been reported with the use of high-dose
intravenous methylprednosolone within two days
after the onset of neurological symptoms. 10,11 Two
patients with extensive white matter abnormalities
who failed to improve on steroids showed
improvement with plasma exchange. Therefore
plasmapheresis may be beneficial in this disorder. 12
The diagnosis of this condition is difficult because
of nonspecific clinical manifestations and lack of
diagnostic tests but the management of the patient
with acute confusion in the emergency department
is straightforward. The patient's airway, breathing,
and circulatory status should be immediately
assessed and supported if necessary. Simple blood
tests allow the diagnosis of hypoglycemia and
electrolyte disturbances. If hypoglycemia is
suspected, glucose and thiamine should be
administered while awaiting for confirmation of
blood glucose level from the laboratory. CT scan is
often required to rule out treatable intracranial
lesions. If necessary, patients should be gently
restrained to avoid injury to themselves or others.
It is of utmost importance for the emergency
physician diagnose treatable causes of acute
confusion so that specific treatment can be instituted
in the emergency department. When in doubt,
Hong Kong j. emerg. med.
n
Vol.7(1)
n
Jan 2000
further imaging studies and neurologic consultation
should be obtained before psychiatric referral.
References
1. Triulzi F, Scotti G. Differential diagnosis of multiple
sclerosis: contribution of MRI. J Neurol Neurosurg
Psychiatry 1998;64 Suppl 1: S6-14.
2. Lukes SA, Norman D. Computed tomography in
acute disseminated encephalomyelitis. Ann Neurol
1983;13: 567-72.
3. Patel SP, Friedman RS. Neuropsychiatric features
of acute disseminated encephalomyelitis. J Neuro
psychiatry Clin Neurosci 1997; 9(4): 534-40.
4. Orshi M, Mochizuki Y. Multiple Sclerosis presenting
as acute disseminated encephalomyelitis. J Neurol
Sci 1998;160(1):100-1.
5. Wang PN, Fuh JL, Liu HC, et al. Acute disseminated
encephalomyelitis in middle-aged or elderly patients.
Eur Neurol.1996; 36(4): 219-23.
6. Byington CL. An encephalitic syndrome in a seven
year old. Paediatr Infect Dis J 1995; 14: 550-5.
7. Sztainbok J, Lignani L Jr, Bresolin AU. Acute
disseminated encephalomyelitis: an unusual cause of
encephalitic syndrome in childhood. Paediatr Emerg
Care 1998; 14(1): 36-8.
8. Murthy JM. MRI in ADEM following Semple antirabies
vaccine. Neuroradiology 1998; 40 (7): 420-3.
9. Johnson RT. Acute encephalitis. Clin Infect Dis 1996;
3(2): 219-24.
10. Straub J, Chofflon M, Delavelle J. Early high-dose
intravenous methyprednisolone in acute
disseminated encephalomyelitis, a successful
recovery. Neurology 1997; 49(4): 1145-7.
11. Hawley RJ. Early high-dose methylprednisolone on
acute disseminated encephalomyelitis. Neurology
1998;5(2):644-5.
12. K anter DS, Horensky D, Sperling RA, et al.
Plasmapheresis in fulminant acute disseminated
encephalomyelitis Neurology 1995; 45(4): 824-7.