Exam 1: IS: Introduction to Clinical Neurology and Neuropathology (Neurology section)

Question 1

A 15-year-old cheerleader was referred to a pediatrician following positive scoliosis screening. She had no neurologic symptoms on exams. Imaging, however, showed elongation of her cerebellar tonsils. A cystic lesion was present within her spinal cord. What is the most likely diagnosis?

A. Arnold-Chari I

B. Arnold-Chiari II

C. Dandy-Walker

D. Encephalocele

E. Meningomyelocele

Answer 1

A.

Arnold-Chari I

Question 2

Her sister, 8 years old, was later found to have the same cystic lesion in her cervical and thoracic spinal cord and the Chiari 1 malformation. Although the lesion was central (i.e. within the spinal cord), there was extension beyond the central canal region, what was the most likely diagnosis?

A. Herniated disc

B. Hydromyelia

C. Spinal cored infarction

D. Syringomyelia

Answer 2

D.

Syringomyelia

This is a drawing of Syringomyelia. Note the cystic space within the spinal cord. If this is located centrally, pain and temperature would be preferentially affected. There is a relationship of syringomyelia with Chiari I malformation.

Question 3

Which of the following would be the most significant deficit in the younger sister that is secondary to the spinal lesion?

A. Cape-like loss of pain and temperature sensation

B. Flaccid paralysis of her arms

C. Lateral gaze paralysis.

D. Loss of light-touch and vibration sensation

E. Numbness of her face

F. Spastic paralysis of her arms

Answer 3

A.

Cape-like loss of pain and temperature sensation

Question 4

Identify the disorder

Answer 4

Arnold-Chiari Type I

Arnold-Chiari I malformation, MRI This MRI image of the brain in a sagittal view shows a small posterior fossa, and the cerebellar tonsils ( ) herniate through the foramen magnum. The third ventricle is enlarged, and the lateral ventricles may be enlarged. This is the milder form of the malformation, and many patients do not have any symptoms.

Question 5

Identify the disorder

Answer 5

Arnold-Chiari Type II

Note the components of Arnold-Chiari type II (infantile) including herniation of cerebellar vermis, elongation of medulla through foramen magnum, kinking of lower brainstem/upper spinal cord, hydrocephalus. In most cases, lumbar meningomyelocele is present.

Question 6

Identify the disorder

Answer 6

Dandy-Walker

Dandy-Walker has enlarged posterior fossa, a 4th ventricular cyst secondary to agenesis of cerebellar vermis , and hydrocephalus.

Compare with small posterior fossa in Arnold-Chiari malformations.

Question 7

A 15-year-old girl develops thrombosis of her left MCA (possibly as a consequence of prothrombotic oral contraceptives )that resulted in a cerebrovascular accident (stroke) involving her left cerebral hemisphere. She was an appropriate candidate for thrombolytic therapy that helped her symptoms/deficits to significantly improve by discharge 10 days after her infarction.

Where is the lesion?

Answer 7

• The left middle cerebral artery is hyperdense , a radiologic sign c/w thrombosis.
• The neurologic deficit is right-sided, a sign consistent with a left-sided stroke/CVA.
• The upper motor neuron signs (i.e. spasticity, hyperreflexivity) is consistent with involvement of the brain (vs. lower motor neuron).

*Everything is pointing to a lesion in the left cerebral hemisphere

Question 8

Upper motor neurons normally _____ the _____ arc?

Thus, an upper motor neuron lesion would reduce the _____ and led to _____.

Answer 8

Upper motor neurons normally dampen the reflex arc.

Thus, an upper motor neuron lesion would reduce the dampening and led to hyperreflexia.

Question 9

Why did they treat the patient with tPA (Tissue Plasminogen Activator)?

What would have been a contraindication?

Answer 9

• Patient had a stroke or cerebrovascular accident (CVA) due to a vascular occlusion by thrombus.
• Tissue Plasminogen Activator (tPA) was given to lyse the clot and to allow blood flow and oxygen delivery into the infarcted area.
• Increased oxygen delivery will hopefully preserved injured/ischemic areas that had not yet become dead/necrotic. However, reperfusion can also cause injury.
• Hemorrhage would be a contraindication. TPA could increase the size and consequences of hemorrhage.
• If there had been considerable time since the stroke, tPA would not be given due to the risks exceeding possible benefits.

Question 10

Describe how the lesion would have looked (radiologically or pathologically) after 3 and 10 days?

What would have been the appearance after 6 months?

Answer 10

Strokes change or evolve with time:

• In the first 2-3 days, edema is the key change in sizeable strokes. This is the time that herniation can occur as a consequence of the edema.
• Macrophages would then appear and eventually become the predominate cell type including at 10 days. These phagocytic cells would engulf the dead brain.
• The macrophages would eventually leave (to the venous circulation) and remove the dead brain. A cyst would result. The area surrounding the cysts would show proliferation of astrocytes (gliosis)