Nervous System

Question 1

A baby born with a small skin defect on her lower back could not move her legs. What is the most likely cause of her congenital paralysis? What is the blood test that is used for prenatal diagnosis of this disease?

Answer 1

Neural tube defect (spina bifida). The maternal serum screen (triple screen or quad screen) is performed on the mother during her second trimester to screen for a variety of problems and includes an AFP (alpha-fetoprotein) test. An increased level of AFP in the mother’s blood has been associated with an increased risk of an open NTD in the baby.

Question 2

A 60-year old man with hypertension suddenly developed an excruciating headache, collapsed, and became unconscious. What is the cause of this man’s collapse?

Answer 2

Saccular (berry) aneurysm

Question 3

A 20-year old woman had a car accident. When she was removed from the car, she could not move her legs. Is she paralyzed for life?

Answer 3

Spinal cord injury occurs when the bony protection surrounding the cord is damaged by way of fractures, dislocation, burst; compression, hyperextension or hyperflexion. A spinal cord injury — damage to any part of the spinal cord or nerves at the end of the spinal canal — often causes permanent changes in strength, sensation and other body functions below the site of the injury.

Question 4

A 30-year old woman had a bout of flu accompanied by fever and nasal congestion. On the third day of her disease, she experienced severe headache, blurry vision and neck rigidity. What is the cause of these symptoms?

Answer 4

Viral meningitis is the most common viral disease in the central nervous system.

Question 5

The family of a 70-year old man noticed that he had become very forgetful. He could not remember anything and was dismissed from his office job. What is the most likely diagnosis?

Answer 5

Alzheimer disease

Question 6

A small proteinaceous infectious disease-causing agent that is believed to be the smallest infectious particle. Is not bacterial, fungal, or viral in nature and contains no genetic material. These proteins can fold in multiple, structurally distinct ways, at least one of which is transmissible to other proteins:

Answer 6

Prion

Mad cow disease, Creutzfeldt-Jakob disease, and kuru.

Characterized pathologically by the presence of “spongiform degeneration”.

Question 7

Can cause compression of the brain stem leading to loss of breathing and heart rate:

Answer 7

Hematomas

Question 8

Part of the brain responsible for emotion, reasoning, speech, and movement (motor cortex and sensory cortex):

Answer 8

Frontal lobe

Question 9

Part of the brain that controls movement:

Answer 9

Motor cortex

Question 10

Part of the brain responsible for sensation:

Answer 10

Sensory cortex

Question 11

Part of the brain responsible for reactions and recognition:

Answer 11

Parietal lobe

Question 12

Part of the brain responsible for memory, hearing, and language:

Answer 12

Temporal lobe

Question 13

Part of the brain responsible for performing the basic functions of life such as breathing and pumping blood throughout the body.

Answer 13

Brain stem

Question 14

Part of the brain that governs posture and balance:

Answer 14

Cerebellum

Question 15

Part of the brain responsible for processing data seen and perceived by the eyes:

Answer 15

Occipital lobe

Question 16

Accumulation of blood between the calvarium and dura. It is usually the result of trauma to the side of head that fractures the temporal bone and transects the middle meningeal artery. Often fatal if not surgically treated:

Answer 16

Epidural hematoma

Question 17

Accumulation of blood in the subdural space as a consequence of bleeding from torn bridging veins. Caused by rapid rotation of the head. A history of trauma may or may not be present. To tear the bridging veins requires that the brain be accelerated to a critical rate within the head. Most often fatal.

Answer 17

Subdural hematoma

Question 18

A bruise on the cortical surface resulting from head trauma:

Answer 18

Cerebral contusion

Question 19

Occur at the branch points of arteries at the base of the brain, e.g., circle of Willis. Risk factors for rupture include hypertension, female sex, atherosclerosis, and collagen deficiency. Rupture is a life-threatening event:

Answer 19

Saccular (berry) aneurysm

Question 20

Typically involve large intracranial arteries, vertebral arteries, and the basilar artery. The major complication of in the brain is thrombosis:

Answer 20

Atherosclerotic aneurysms

Question 21

This hemorrhage occurs most often (65%) in the basal ganglia-thalamus. Approximately 15% occur in the pons, resulting in loss of consciousness:

Answer 21

Hypertensive intracerebral hemorrhage

Question 22

During shock (hypoxia due to poor blood circulation or low blood volume) ischemia & necrosis occurs in the brain in wedge shapes associated with tributary veins:

Answer 22

Watershed zones of infarction

Question 23

Physical obstruction to flow of CSF, resulting in dilatation of the ventricular system of the brain:

Answer 23

Noncommunicating hydrocephalus

Question 24

Most commonly an acquired abnormality in reabsorption of CSF, most frequently secondary to infection, hemorrhage, or tumor:

Answer 24

Communicating hydrocephalus

Question 25

Inflammation of the leptomeninges, the thin membranes enveloping the brain. This compartment contains the CSF and provides a rich culture medium for bacteria. The most common bacterial causes are E. coli, H. influenza, Streptococcus pneumoniae and Neisseria meningitidis. The presence of polymorphonuclear leukocytes (neutrophils) in the CSF is a reliable marker:

Answer 25

Leptomeningitis (bacterial meningitis)

Question 26

The most common viral disease in the central nervous system. Almost always self-limited and benign. Patients present with fever and severe headache. It is most commonly caused by enteroviruses such as coxsackievirus, but may be caused by mumps virus, Epstein-Barr virus, or herpes simplex virus.

Answer 26

Viral meningitis

Question 27

Occurs when bacteria lodge in capillaries in the brain and elicit an acute inflammatory reaction (cerebritis). Multiplication of organisms and the ensuing inflammatory response can result in the formation of this:

Answer 27

Cerebral abscess

Question 28

Inflammation primarily involves the brain parenchyma. Typical symptoms include serious neurologic deficits and impaired consciousness. Viral infections of the brain parenchyma are caused by herpes simplex virus, rabies, poliomyelitis, and arboviruses.

Answer 28

Viral encephalitis

Question 29

Most common cause of sporadic cases of viral encephalitis and causes a hemorrhagic, necrotizing encephalitis. It is the most important viral infection of the human nervous system:

Answer 29

Herpes simplex virus

Question 30

Transmitted to humans through the saliva of an infected animal. However, there are reports of patients with no known bite exposure. Several of these cases involve people visiting caves inhabited by bats, where inhalation of viral particles in bat feces appears to be the route of infection:

Answer 30

Rabies

Question 31

Caused by a small non-enveloped single-stranded RNA virus. The virus infects neurons in the spinal cord and brain stem. Mortality ranges from 5 to 25% with death resulting from respiratory failure:

Answer 31

Poliomyelitis

Question 32

A chronic demyelinating disease of the CNS in which there are numerous patches of demyelination throughout the white matter. The disease has a genetic contribution and a possible autoimmune etiology. The plaque is the hallmark of multiple sclerosis. Patients frequently present with blurred vision or loss of vision in one eye. Plaques within the spinal cord cause weakness of one or both legs.

Answer 32

Multiple sclerosis

Question 33

An encephalopathy caused by deficiency of thiamine. Patients exhibit lateral rectus palsy, nystagmus, ataxia and mental confusion. Seen most commonly in association with chronic alcoholism:

Answer 33

Wernicke syndrome

Question 34

A progressive dementing illness that occurs predominantly in persons over 45 years of age, with the highest incidence in the ninth decade of life. The most common cause of senile dementia among the elderly. Defined pathologically by the presence of numerous senile plaques, neurofibrillary tangles, and neuronal loss:

Answer 34

Alzheimer disease

Question 35

A progressive neurodegenerative disease characterized clinically by involuntary movements and cognitive deterioration. Gross examination of the brain reveals marked atrophy of the caudate nucleus. There is a clinically observed phenomenon of “anticipation”, in which future generations show symptoms of disease at a younger age:

Answer 35

Huntington disease

Question 36

Characterized pathologically by loss of neurons in the substantia nigra and disruption of specific dopaminergic pathways. Clinically, patients have tremors at rest and muscular rigidity:

Answer 36

Parkinson disease

Question 37

A degenerative disease of motor neurons. The most common form of adult onset, progressive motor neuron disease. The principal clinical features of this disease are muscular weakness and atrophy:

Answer 37

ALS

Question 38

Tumors of astrocytic origin. They represent the largest and most diverse group of glial cell tumors:

Answer 38

Astrocytomas

Question 39

Glial cells that support neurons and can form tumors called glioblastomas:

Answer 39

Astrocytes

Question 40

The myelin-producing cells of the central nervous system:

Answer 40

Oligodendroglial cells

Question 41

This highly malignant glial cell neoplasm shows numerous mitoses, endothelial cell proliferation, and necrosis. The most likely diagnosis is:

Answer 41

Glioblastoma multiforme