About the Authors:
Sandra Rao is Resident Physician at University of Toronto. Lawrence Jacobs is Associate Dean at the University of Windsor.
Correspondence to Sandra Rao: sandra.rao@wchospital.ca
Submitted: November 30, 2017. Accepted: February 3, 2018. Published: November 9, 2018. DOI: 10.22374/cjgim.v13i4.259
Abstract
Delirium is an acute change in mental status with a fluctuating course. It has numerous precipitating
factors that can be classified using the DIMS-R framework, including structural changes and
metabolic disturbances. Delirium is often under-recognized and numerous screening tools have
been developed to aid diagnosis.
RESUME
Le délire est un changement aigu de l’état mental avec une évolution fluctuante. Il contient
de nombreux facteurs précipitants pouvant être classés à laide du cadre DIMS-R, notamment
des changements structurels et des perturbations métaboliques. Le délire est souvent méconnu
et de nombreux outils de dépistage ont été développés pour faciliter le diagnostic.
Case
A 52-year-old female with a history of cerebral palsy was admitted to hospital for hypernatremia
and a first episode of hyperosmolar hyperglycemic state. Upon resolution of her metabolic
disturbances, she developed visual hallucinations which prompted further investigations revealing
a surprising diagnosis.
Conclusion
Visual hallucinations are the most common psychotic feature associated with delirium and are
more likely to be associated with multiple medical conditions. Delirium is often multi-factorial
and a full diagnostic workup, including imaging studies, should be considered to address all
possible underlying etiologies. Effective treatment of delirium is dependent on treatment of all
of its precipitants.
An Unexpected Precipitant of Delirium in a
Patient with Developmental Delay
Sandra Rao MD, and Lawrence Jacobs
Case
A 52-year-old female of French descent with cerebral palsy initially
presented following a two-day history of weakness, polyuria,
and confusion. She had a lifelong history of developmental delay
and long-term memory loss, but could communicate with short
sentences in French. At baseline, the patient ambulated at home
independently with a cane.
At presentation, her temperature was 36.3°C, pulse was regular
at 76 beats per minute, blood pressure was 106/69, and oxygen
saturation 98% on room air. She was noted to have macrocephaly,
left-sided hemiparesis with decreased muscle bulk and atrophy,
all of which existed at baseline. Her general exam was notable
for signs of hypovolemia but was otherwise unremarkable. She
was admitted with a first episode of hyperosmolar hyperglycemic
Canadian Journal of General Internal Medicine
36 Volume 13, Issue 4, 2018
C a s e S t u d y
BrainLAB and a programmable ventriculoperitoneal (VP) shunt
was inserted. She recovered from this procedure with no acute
intracranial hemorrhage, although no change in the marked
enlargement of the ventricles was noted immediately post-
operatively. Her level of alertness, however, did soon return to
her baseline and her visual hallucinations resolved.
On her two-month follow-up, her hydrocephalus persisted
with no notable change in her ventriculomegaly; but, according
to her family, she was walking better, with less unsteadiness. She
was no longer experiencing any psychotic symptoms.
Discussion
Delirium is a common presentation of medical illness with
numerable precipitants. It has several hallmark features, including
disturbances in cognition that develop over short periods of
time – generally hours to days – that can be explained by a
medical condition, substance use, or medication side effect.
1
The
DIMS-R
2
criteria organizes the causes of delirium into groupings
including drugs, infection, metabolic abnormalities, structural
insults, and urinary or fecal retention. The cognitive features
associated include inattention, disorientation, and memory
changes. Features of psychosis and agitation may be present
as well.
2
Delirium has been found to be correlated with worse
outcomes, but is often under-recognized.
3
Approximately 60%
of cases are misdiagnosed, missed, or detected late. To address
this inconsistency, various delirium screening tools have been
state after investigative bloodwork, and was fluid-resuscitated and
treated with regular insulin. The patients initial bloodwork was
also significant for hypernatremia at 167, which was corrected with
parenteral and oral hydration. She was later transitioned to oral
anti-glycemic agents upon improvement of her hyperglycemia.
During her stay, the patients metabolic disturbances and
mental status stabilized initially, however she began having visual
hallucinations the morning of her pending discharge.
A computed tomography (CT) scan of the head without
contrast was then performed, revealing massive enlargement of
the ventricular system. The lateral ventricles exhibited a marked
degree of mass effect with very little remaining parenchyma.
On the left side, there was a thin rim of persistent cortical and
white matter, although due to the degree of hydrocephalus, it was
thinned and displaced to under the surface of the calvarium. On
the right side, there was essentially no tissue remaining within the
vicinity of the frontal lobe with very little within the vicinityof
the parietal lobe. There was also evidence for a low-density
extra-axial fluid collection along the right frontal lobe, likely
due to a chronic subdural hematoma or a hygroma. The findings
were consistent with an extreme degree of hydrocephalus. The
CT was followed by magnetic resonance imaging of the head;
the results were consistent with aqueductal stenosis based on
a normal sized fourth ventricle (Figure 1).
Neurosurgery was consulted following imaging studies.
A third ventriculostomy was performed with the guidance of
A
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Volume 13, Issue 4, 2018 37
Rao et al.
Figure 1. Magnetic resonance imaging demonstrating saggital (left) and axial (right) views of severe ventriculomegaly secondary to aqueductal stenosis. The
mass effect of the cerebrospinal fluid resulted in significant loss and displacement of brain tissue.
patient does have significant functional abilities, demonstrating
a remarkable discrepancy between her anatomy and clinical
outcome. Our patient could ambulate with cane assistance and
was able to hold short conversations with reasonable short-term
memory despite having very minimal cerebral cortex for motor
function and language processing. These findings are a significant
demonstration of the role of neuroplasticity in preservation
of cognitive and neurological function during infancy. It may
also be suggestive of the redundancy present in the cerebral
cortex, or an increased role of subcortical structures in higher
processing.
9
Another possible explanation for the degree of
functional preservation is that hydrocephalus is a disease of
white matter, but grey matter is relatively spared even in severe
ventriculomegaly.
10
Nevertheless, the patients lack of anatomical
improvement following VP shunt insertion sheds light on the
therapeutic challenges in treating LOVA as the brain loses
compliance with such a degree of hydrocephalus. Such a degree
of craniocerebral disproportion increases the risk of subdural
hematoma and low-ICP syndrome following shunt insertion.
8
This case is reflects the various complexities in cognitive
reserve. Despite the notable adaptive mechanisms of the brain seen
in our patients lifelong hydrocephalus, the onset of delirium also
attests to the neurochemical vulnerability of her brain from her
underlying cognitive impairment. As a consequence, identifying
and addressing risk factors for delirium will be paramount in
providing future medical care to improve clinical outcomes.
Disclaimer
This case report has never been published and has not been
submitted to any other journal for consideration. Our affiliations
lie with the Schulich School of Medicine & Dentistry and Windsor
Regional Hospital. Furthermore consent was obtained from
the patient in question to share their case in a case report for
academic and educational purposes.
References
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developed for the inpatient setting, including the 4 “As” Test
4
and the confusion assessment method (CAM).
5
In this case
report, we presented a patient who developed a multi-factorial
cause of delirium.
Changes in cognitive function from baseline should prompt
a full differential diagnosis. Following the DIMS-R framework
may aid in the workup, since delirium is a clinical diagnosis that
is generally not attributed to a single pathology.
2
Imaging studies
should be considered as part of the delirium workup to rule out
structural changes. Treatment of delirium is only effective when
all underlying causes are identified and addressed. Our patient
had multiple possible causes of delirium. Metabolically, she
presented with marked hypernatremia and hyperglycemia, which
are both classic precipitants of delirium. Structurally, the patients
profound hydrocephalus may have also contributed, considering
the clinical improvement she experienced following VP shunt
insertion. The key feature of her presentation which prompted
further workup of the patients disturbance in cognition is that
she developed unexplained visual hallucinations despite the
correction of her metabolic abnormalities and initial resolution
of her confusion. In the absence of infectious symptoms, this
suggested possible underlying cerebral pathology.
Hallucinations can be the product of one or more of the
following processes: organic brain disease, neurochemical
changes, or psychodynamic forces. While visual hallucinations
are a classical feature of psychosis, they are the most common
psychotic manifestations of delirium, and are more likely to be
associated with multiple medical disorders.
6
Other common
medical causes of visual hallucinations include dementia,
migraines, and seizure activity. Vision impairment can also cause
visual hallucinations, such as in Charles Bonnet syndrome and
Antons syndrome.
7
The clinical presentation of hydrocephalus and other structural
causes of delirium is highly variable and is related to the degree
and nature of anatomical deformity present. The patient in this
case was found to have severe ventriculomegaly consistent with
Long-standing Overt Ventriculomegaly (LOVA), which was first
described by Oi and his colleagues. Patients with LOVA have
infantile hydrocephalus secondary to congenital aqueductal
stenosis that slowly progresses into adulthood. In congenital
hydrocephalus, the duration of the injury is another factor that
determines the presentation of symptoms. LOVA presents as
a triad of headaches, subnormal IQ, and macrocephaly. Other
features such as gait disturbances, urinary incontinence, and
severe depression may be present as well.
8
In LOVA, there is marked progressive dilatation of ventricles
and significant loss of cerebral parenchyma. This was seen in this
patient, such that there was “virtually no brain.” Interestingly, this
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An Unexpected Precipitant of Delirium in a Patient with Developmental Delay
9. Canu EDG, Magnano I, Paulus KS, et al. Neuropsychophysiological findings
in a case of long-standing overt ventriculomegaly (LOVA). Neurosci Lett.
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10. Lewin R. Is your brain really necessary? Science 1980;210(4475):1232–34.
7. Teeple RC, Caplan JP, Stern TA. Visual hallucinations: differential diagnosis
and treatment. Prim Care Companion J Clin Psychiatr 2009;11(1):26–32.
Available at: http://www.ncbi.nlm.nih.gov/pubmed/19333408.
8. Oi S, Sato O, Matsumoto S. Neurological and medico-social problems
of spina bifida patients in adolescence and adulthood. Childs Nerv Syst
1996;12(4):181–87. doi:10.1007/BF00301248.
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