The Mysterious Episodes of Mary: A Case Study on Neuroanatomy Episode 1 Mary Lazarro, a 44-year-old mother of two, made an appointment with her physician after experiencing a prolonged episode of numbness in her chin and lower lip. Two days prior to her appointment, she felt a prickling sensation like “pins and needles” at the right corner of her mouth. The sensation extended to her lower lip and chin. The examination revealed only a superficial hypoesthesia of the chin and lower lip (numb chin syndrome). There was no clinical evidence of palpable regional lymph nodes or other systemic or neurologic abnormalities. Her physician scheduled her for a CT scan of the affected region. These tests showed no abnormalities in the jaw, neck, or pharynx. The numbness and hypoesthesia spontaneously disappeared gradually over a few weeks. Episode 2 Four months later, while eating dinner with her family, Mary felt a stabbing pain in her upper jaw and teeth that radiated out to the side of her nose. Over the next several days, she experienced several more episodes of this intense pain. A visit to the dentist revealed no abnormalities and she was referred to her physician for an evaluation. Prior to her appointment, she noticed that the symptoms were subsiding as they had previously. Her physician scheduled an appointment for a complete neurological exam the following week. Episode 3 Three nights prior to her scheduled visit to the neurologist, Mary stopped at an intersection and experienced intense double vision when looking to the right to check for traffic. The double vision was less intense when looking forward, and her vision when looking left was unaffected. Her husband noticed that her right eye appeared to be turned slightly inward when she looked straight ahead. A day later, Mary noticed that the vision in her left eye started to blur. The neurologist later suggested that the two visual problems she was experiencing were related. The double vision when looking right was found to be caused by cranial nerve palsy—a form of muscle paralysis caused by a dysfunction in one of the cranial nerves. The problem with the left eye was diagnosed as optic neuritis (inflammation). Both of these signs and symptoms, along with the previous episodes, pointed to a diagnosis of multiple sclerosis (MS). The neurologist prescribed oral steroids and ordered an MRI. As with her previous episodes, Mary’s visual symptoms began to diminish over time. Finale The results of the MRI, shown below, were consistent with a diagnosis of relapsing-remitting multiple sclerosis (RRMS). Relapsing-remitting multiple sclerosis is a form of MS in which symptoms randomly flare up (Mary’s episodes) and then resolve on their own. The lesions seen on the MRI on the left were associated with another episode in which Mary experienced sensory and motor disjunction in her left lower extremity. A subsequent MRI (image on the right) appeared to show improvement after three months. Sho.

1. The Mysterious Episodes of Mary: A Case Study on
Neuroanatomy
Episode 1
Mary Lazarro, a 44-year-old mother of two, made an
appointment with her physician after experiencing a prolonged
episode of numbness in her chin and lower lip. Two days prior
to her appointment, she felt a prickling sensation like “pins and
needles” at the right corner of her mouth. The sensation
extended to her lower lip and chin. The examination revealed
only a superficial hypoesthesia of the chin and lower lip (numb
chin syndrome). There was no clinical evidence of palpable
regional lymph nodes or other systemic or neurologic
abnormalities. Her physician scheduled her for a CT scan of the
affected region. These tests showed no abnormalities in the jaw,
neck, or pharynx. The numbness and hypoesthesia
spontaneously disappeared gradually over a few weeks.
Episode 2
Four months later, while eating dinner with her family, Mary
felt a stabbing pain in her upper jaw and teeth that radiated out
to the side of her nose. Over the next several days, she
experienced several more episodes of this intense pain. A visit
to the dentist revealed no abnormalities and she was referred to
her physician for an evaluation. Prior to her appointment, she
noticed that the symptoms were subsiding as they had
previously. Her physician scheduled an appointment for a
complete neurological exam the following week.
Episode 3
Three nights prior to her scheduled visit to the neurologist,

2. Mary stopped at an intersection and experienced intense double
vision when looking to the right to check for traffic. The double
vision was less intense when looking forward, and her vision
when looking left was unaffected. Her husband noticed that her
right eye appeared to be turned slightly inward when she looked
straight ahead. A day later, Mary noticed that the vision in her
left eye started to blur. The neurologist later suggested that the
two visual problems she was experiencing were related. The
double vision when looking right was found to be caused by
cranial nerve palsy—a form of muscle paralysis caused by a
dysfunction in one of the cranial nerves. The problem with the
left eye was diagnosed as optic neuritis (inflammation). Both of
these signs and symptoms, along with the previous episodes,
pointed to a diagnosis of multiple sclerosis (MS). The
neurologist prescribed oral steroids and ordered an MRI. As
with her previous episodes, Mary’s visual symptoms began to
diminish over time.
Finale
The results of the MRI, shown below, were consistent with a
diagnosis of relapsing-remitting multiple sclerosis (RRMS).
Relapsing-remitting multiple sclerosis is a form of MS in which
symptoms randomly flare up (Mary’s episodes) and then resolve
on their own. The lesions seen on the MRI on the left were
associated with another episode in which Mary experienced
sensory and motor disjunction in her left lower extremity. A
subsequent MRI (image on the right) appeared to show
improvement after three months.
Short answer questions

3. 1. Related to Episode 1:What is hypoesthesia? How does it
differ from paresthesia?
2. Related to Episode 1:Using the flowchart below, identify the
part of the human nervous system that is usually associated with
symptoms of hypoesthesia and paresthesia.
3. Related to Episode 1:Which of Mary’s cranial nerves is
affected in this episode?
4. Related to Episode 2:Which of Mary’s cranial nerves is
affected in this episode?
5. Related to Episode 3:Name all of the cranial nerves that are
involved with eye movements.
6. Related to Episode 3:Which of Mary’s affected cranial nerves
is responsible for her double vision when looking right? Why
does she not experience double vision when looking left?
7. Related to Episode 3:Which of Mary’s affected cranial nerves
is responsible for her blurred vision?
8. Related to Finale:In the MRI images shown in the case, you
can see the lesions as bright “white spots” on the brain. Using
what you know about the structure of a neuron, explain what is
causing this spot to appear in the MRI.
9. Related to Finale:Three months later, you can see that the
spots in the MRI appear to be smaller. Using what you know
about the structure of a neuron, explain what is happening to the
neurons in the area where the lesions are disappearing.

4. The Mysterious Episodes of Mary: A Case Study on
Neuroanatomy
Episode 1
Mary Lazarro, a 44-year-old mother of two, made an
appointment with her physician after experiencing a prolonged
episode of numbness in her chin and lower lip. Two days prior
to her appointment, she felt a prickling sensation like “pins and
needles” at the right corner of her mouth. The sensation
extended to her lower lip and chin. The examination revealed
only a superficial hypoesthesia of the chin and lower lip (numb
chin syndrome). There was no clinical evidence of palpable
regional lymph nodes or other systemic or neurologic
abnormalities. Her physician scheduled her for a CT scan of the
affected region. These tests showed no abnormalities in the jaw,
neck, or pharynx. The numbness and hypoesthesia
spontaneously disappeared gradually over a few weeks.
Episode 2
Four months later, while eating dinner with her family, Mary
felt a stabbing pain in her upper jaw and teeth that radiated out
to the side of her nose. Over the next several days, she
experienced several more episodes of this intense pain. A visit
to the dentist revealed no abnormalities and she was referred to

5. her physician for an evaluation. Prior to her appointment, she
noticed that the symptoms were subsiding as they had
previously. Her physician scheduled an appointment for a
complete neurological exam the following week.
Episode 3
Three nights prior to her scheduled visit to the neurologist,
Mary stopped at an intersection and experienced intense double
vision when looking to the right to check for traffic. The double
vision was less intense when looking forward, and her vision
when looking left was unaffected. Her husband noticed that her
right eye appeared to be turned slightly inward when she looked
straight ahead. A day later, Mary noticed that the vision in her
left eye started to blur. The neurologist later suggested that the
two visual problems she was experiencing were related. The
double vision when looking right was found to be caused by
cranial nerve palsy—a form of muscle paralysis caused by a
dysfunction in one of the cranial nerves. The problem with the
left eye was diagnosed as optic neuritis (inflammation). Both of
these signs and symptoms, along with the previous episodes,
pointed to a diagnosis of multiple sclerosis (MS). The
neurologist prescribed oral steroids and ordered an MRI. As
with her previous episodes, Mary’s visual symptoms began to
diminish over time.
Finale
The results of the MRI, shown below, were consistent with a
diagnosis of relapsing-remitting multiple sclerosis (RRMS).
Relapsing-remitting multiple sclerosis is a form of MS in which
symptoms randomly flare up (Mary’s episodes) and then resolve
on their own. The lesions seen on the MRI on the left were
associated with another episode in which Mary experienced
sensory and motor disjunction in her left lower extremity. A
subsequent MRI (image on the right) appeared to show

6. improvement after three months.
Short answer questions
1. Related to Episode 1:What is hypoesthesia? How does it
differ from paresthesia?
2. Related to Episode 1:Using the flowchart below, identify the
part of the human nervous system that is usually associated with
symptoms of hypoesthesia and paresthesia.
3. Related to Episode 1:Which of Mary’s cranial nerves is
affected in this episode?
4. Related to Episode 2:Which of Mary’s cranial nerves is
affected in this episode?
5. Related to Episode 3:Name all of the cranial nerves that are
involved with eye movements.
6. Related to Episode 3:Which of Mary’s affected cranial nerves
is responsible for her double vision when looking right? Why
does she not experience double vision when looking left?
7. Related to Episode 3:Which of Mary’s affected cranial nerves
is responsible for her blurred vision?
8. Related to Finale:In the MRI images shown in the case, you
can see the lesions as bright “white spots” on the brain. Using
what you know about the structure of a neuron, explain what is
causing this spot to appear in the MRI.

7. 9. Related to Finale:Three months later, you can see that the
spots in the MRI appear to be smaller. Using what you know
about the structure of a neuron, explain what is happening to the
neurons in the area where the lesions are disappearing.
CASE STUDY #2 CARDIO.
Maggie Silvers is a 48 year-old-woman who was involved
in a car accident resulting in a large amount of blood loss. She
is transported, via ambulance, to the hospital for treatment. In
transport, the paramedics obtain vitals (BP 80, diastolic
inaudible, HR 122bpm, skin is pale and clammy). Recognizing
these as signs of circulatory shock, Maggie is given NSS. After
arriving to the hospital, a fast hematocrit is drawn, and results
show a low/normal HCT. Further lab work is performed
including blood type and cross. Over the next hour, 2 additional
liters of NSS are transfused, the attending physician treats
Maggie’s injuries, and another HCT is drawn; this one showing
a drop below normal. Maggie is admitted to the hospital for
overnight observation.
When Maggie arrived at the hospital, she presented with
signs of cardiocirculatory hypovolemic shock, due to the

8. excessive amount of blood and fluid loss. Due to the importance
of blood in circulating oxygen to all areas of the body, this
decrease in blood volume can be life threatening if not treated.
A patient experiencing shock of this variety may present with
low blood pressure due to decreased blood volume and
inadequate pumping of the heart resulting in decreased cardiac
output, rapid heart rate as the heart beats faster to circulate
blood, and cool/clammy skin due to lack of blood/oxygen
moving through blood vessels (Procter, 2018). Without proper
function of the heart and blood flow, the rest of the body cannot
function properly either.
In order to fully determine the extent of Maggie’s injuries,
the hospital would need to perform lab work, to include an HCT
(hematocrit) draw. Normal range for an adult female HCT is
between 38-46% (other sources claim 34.9-44.5%). The fast
hematocrit revealed that Maggie’s HCT was low, but normal
with red blood cell volume at 7.1mm and plasma volume at
12.9mm.
HCT is calculated as follows:
HCT = Volume of red blood cells / (Volume of red blood cells +
volume of plasma) x 100
HCT = 7.1 mm / (7.1mm + 12.9 mm) /100
HCT = 0.355 / 100
HCT = 35.5 %
After receiving two liters of normal saline, Maggie’s HCT
dropped to a below normal range: Red blood cell volume was
1.45 mm and plasma volume was 3.55 mm, resulting in a
hematocrit of 29%. Despite no further blood loss, this change is
most likely a result of the normal saline (NSS) that was
administered. While NSS increases blood volume and plasma
volume, it does not restore RBC count; the blood is merely
“diluted” in a sense to restore flow. If Maggie were to receive a

9. blood transfusion, the RBC count would also increase rapidly,
but due to risk of complications with transfusions they are often
reserved for emergency situations. NSS is, instead, used to
temporarily restore blood volume levels in order to improve
blood pressure and ensure adequate flow to the flow.
Blood transfusions, while they can save lives in emergency
or otherwise indicated situations, also come with multiple risks.
The protocol for use is often extensive and involves cross
matching the patient with donor blood, obtainment of blood, and
consistent observation to ensure that the recipient doesn’t
present with any transfusion reactions/complications. The body
is capable of restoring itself through negative feedback systems
if time allows. For that reason, many doctors are reluctant to
push a transfusion unless absolutely necessary.
As mentioned, the negative feedback systems within the
body are capable of restoring homeostatic balance. When the
body experiences a loss of red blood cells, the HCT level drops.
Red blood cells are important for delivering oxygen
(hemoglobin) throughout the body, so when they are lost, the
body experiences hypoxia (oxygen deficiency) at a cellular
level. Hypoxia stimulates erythropoiesis (red blood cell
formation) in order to restore oxygen delivering capability to
the body (Tortora & Derrickson, 2016). As new red blood cells
are produced, the HCT level increases, increasing hemoglobin
levels and restoring the body to equilibrium. The link between
HCT levels and hemoglobin levels make the obtainment of
hemoglobin measurement levels an alternative for physicians to
get an understanding of oxygen carrying capacity within the
body. This physiological mechanism within the body is why
when Maggie returned for suture removal a week later, she had
improved without having needed a transfusion.
References:

10. Procter, L. (2018, March). Shock; Heart and blood vessel
disorders. Retrieved from
https://www.merckmanuals.com/home/heart-and-blood-vessel-
disorders/low-blood-pressure-and-shock/shock
Tortora, G. J., & Derrickson, B. (2016). Principles of anatomy
& physiology (15th ed., Vol. 1). Hoboken, NJ: John Wiley &
Sons.