Trauma

Question 1

The ___________ of the brain for functional repair are
major determinants of the consequences of CNS trauma.

Answer 1

anatomic location of the lesion and the limited capacity

Question 2

Injury of several cubic centimeters of
brain parenchyma may be____________

, severely disabling),

or fatal ______________

Answer 2

• clinically silent (e.g., in the frontal lobe)
• (in thespinal cord)
• (in the brainstem)

Question 3

The physical forces associated with head injury may result in_________, ______ and __________ ; all three can coexist.

Answer 3

1. skull fractures,
2. parenchymal injury,
3. and vascular injury

Question 4

The magnitude and distribution of a traumatic
brain lesion depend on the _______________, ____________ and __________ . A blow to the head may be penetrating or
blunt; it may cause either an open or a closed injury .

Answer 4

• shape of the object causing the trauma,
• the force of impact,
• and whether the head is in motion at the time of injury

Question 5

A fracture in which bone is displaced into the cranial cavity by a distance greater than the
thickness of the bone is called a _____________

.

Answer 5

displaced skull fracture

Question 7

The thickness of the cranial bones
varies; therefore, their resistance to fracture differs greatly.

Also, the relative incidence of
fractures among skull bones is related to the pattern of falls.

Question 8

When an individual falls while
awake, such as might occur when stepping off a ladder, the site of impact is often in the
_________

Answer 8

occipital portion of the skull;

Question 9

in contrast, a fall that follows loss of consciousness, as might follow
a syncopal attack, commonly results in a______

Answer 9

frontal impact.

Question 10

Symptoms referable to the lower cranial
nerves or the cervicomedullary region,and thepresence of orbital or mastoid hematomas
distant from the point of impact, raise the suspicion of a ____________, which typically
follows impact to the occiput or sides of the head.

CSF discharge from the nose or ear and
infection (meningitis) may follow

Answer 10

basal skull fracture

Question 11

. The kinetic energy that causes a fracture is dissipated at a
fused suture; fractures that cross sutures are termed______.

With multiple points of impact or
repeated blows to the head, the fracture lines of subsequent injuries do not extend across
fracture lines of prior injury.

Answer 11

diastatic

Question 12

PARENCHYMAL INJURIES

Answer 12

1. Concussion
2. Direct Parenchymal Injury
3. Diffuse Axonal Injury

Question 13

__________ is a clinical syndrome of altered consciousness secondary to head injury typically
brought about by a change in the momentum of the head (when a moving head is suddenly
arrested by impact on a rigid surface).

Answer 13

Concussion

“Concussion, from the Latin concutere (“to shake violently”) or concussus (“action of striking together”

Question 14

What is the characteristic neurologic feature of concussion?

Answer 14

The characteristic neurologic picture includes

• instantaneous onset of transient neurologic dysfunction, including loss of consciousness,
• temporary respiratory arrest, and loss of reflexes. Although neurologic recovery is complete,
• amnesia for the event persists.
• The pathogenesis of the sudden disruption of neurologic
• function is unknown; it probably involves dysregulation of the reticular activating system in the
• brainstem.
• Postconcussive neuropsychiatric syndromes, typically associated with repetitive injuries, are well recognized.

Question 15

_______ and______are lesions associated with direct parenchymal injury of the brain

Answer 15

1. Contusion
2. and laceration

Question 16

,
Direct parenchymal injury is either through transmission of kinetic energy to the brain and bruising analogous to what is
seen in soft tissues __________ or by penetration of an object and tearing of tissue____________

Answer 16

• (contusion)
• (laceration).

Question 17

In direct parenchymal injury what are most susceptible, since this is
where the direct force is greatest.

Answer 17

crests of gyri

Question 18

The most common locations for contusions correspond to the
most frequent sites of direct impact and to regions of the brain that overlie a rough and
irregular inner skull surface, such as the _____________ and _________

Contusions are less frequent over the occipital lobes, brainstem, and cerebellum unless
these sites are adjacent to a skull fracture (fracture contusions).

Answer 18

frontal lobes along the orbital ridges and the temporal
lobes.

Question 19

Answer 19

Multiple contusions involving the inferior surfaces of frontal lobes, anterior
temporal lobes, and cerebellum.

Question 20

Answer 20

B, Acute contusions are present in both temporal lobes, with
areas of hemorrhage and tissue disruption (arrows).

Question 21

Answer 21

Remote contusions are present on
the inferior frontal surface of this brain, with a yellow color (associated with the term plaque
jaune).

Question 22

A person who suffers a blow to the head may develop a contusion at the point of contact ____________-) or a contusion on the brain surface diametrically opposite to it (______________).

Answer 22

• (a coup injury)
• **a contrecoup injury) **

Question 23

Since their macroscopic and microscopic appearance in Direct parenchymal injury is indistinguishable, the _________________

Answer 23

distinction
between them is based on forensic identification of the point of impact and the circumstances
attending the incident.

Question 24

In general, if the head is immobile at the time of trauma, only a ___________
injury is found.

Answer 24

coup

Question 25

If the head is **mobile,** both __________ may be

Answer 25

coup and contrecoup lesions

Question 26

Whereas the **coup lesion** is caused by the \_\_\_\_\_\_\_\_\_\_\_\_,

Answer 26

y

Question 27

the contrecoup contusion is thought to develop when the brain **strikes the opposite inner surface** of the skull **after sudden deceleration. found. **

Question 28

Sudden impacts that result in violent posterior or lateral hyperextension of the neck (as occurs when a pedestrian is struck from the rear by a vehicle) may **avulse the pons from the medulla or the medulla from the cervical cord, causing instantaneous death.**

Question 29

When seen on cross-section, contusions are\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 29

wedge shaped, with the broad base lying along the surface, deep to the point of impact

Question 30

The histologic appearance of contusions is **independent of the type of trauma.** In the **earliest stages**, there is \_\_\_\_\_\_\_\_\_\_, which is often pericapillary. During the next few hours, the **extravasation of blood extends** throughout the involved tissue, across the width of the cerebral cortex, and into the white matter and subarachnoid space.

Answer 30

edema and hemorrhage

Question 31

Morphologic evidence of neuronal injury \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_-) takes about **24 hours** to appear, **although functional deficits may occur earlier.**

Answer 31

* (pyknosis of the nucleus, * eosinophilia of the cytoplasm, * and disintegration of the cell

Question 32

Axonal swellings develop in the vicinity of damaged neurons or at great distances away. The **inflammatory response** to the injured tissue follows its usual course, with the \_\_\_\_\_\_\_\_\_\_\_ followed by macrophages.

Answer 32

appearance of neutrophils

Question 33

Old traumatic lesions on the surface of the brain have a characteristic macroscopic appearance. They are\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_** **most commonly located at the sites of **contrecoup lesions** **(inferior frontal cortex, temporal and occipital poles).**

Answer 33

* ** depressed,** * **retracted,** * **yellowish brown** * **patches involving the crests of gyri**

Question 34

Old traumatic lesions on the surface of the brain have a characteristic macroscopic appearance. They are depressed, retracted, yellowish brown patches involving the crests of gyri most commonly located at the sites of\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_-

Answer 34

contrecoup lesions (inferior frontal cortex, temporal and occipital poles). The term plaque jaune is applied to these lesions ( Fig. 28-9C ); they can become epileptic foci. More extensive hemorrhagic regions of brain trauma give rise to larger cavitated lesions, which can resemble remote infarcts. In sites of old contusions, gliosis and residual hemosiderin-laden macrophages

Question 35

Diffuse Axonal Injury Although it is most often affected, the surface of the brain is not the only region of damage in traumatic injury. Also affected may be the deep white matter regions (the corpus callosum, paraventricular, and hippocampal areas in the supratentorial compartment), cerebral peduncles, brachium conjunctivum, superior colliculi, and deep reticular formation in the brainstem.

Question 36

The microscopic findings include\_\_\_\_\_\_\_\_\_\_\_\_\_, indicative of diffuse axonal injury , and focal hemorrhagic lesions.

Answer 36

axonal swelling

Question 37

\_\_\_\_\_\_\_\_\_, in the absence of impact, can cause d**iffuse axonal injury as well as** **hemorrhage.**

Answer 37

Angular acceleration alone

Question 38

As many as 50% of individuals who develop coma shortly after trauma, **even without cerebral contusions,** are believed to hav**e diffuse axonal injury.** The mechanical forces associated with trauma are believed to damage the integrity of the axon at the node of Ranvier, with subsequent alterations in axoplasmic flow.

Question 39

Diffuse axonal injury is characterized by the **widespread but often asymmetric** axonal swellings that appear **within hours of the injury and may persist for much longer.** These are best demonstrated with \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Later, there are increased numbers of microglia in related areas of the cerebral cortex and, subsequently, degeneration of the involved fiber tracts.

Answer 39

* *silver impregnation techniques or with immunoperoxidase** * *stains**

Question 40

silver impregnation techniques or with immunoperoxidase stains for

Answer 40

axonally transported proteins, including **amyloid precursor protein and α-synuclein.**

Question 41

TRAUMATIC VASCULAR INJURY

Answer 41

1. Epidural Hematoma 2. Subdural Hematoma

Question 42

\_\_\_\_\_\_\_\_\_\_- is a frequent component of CNS trauma. It results from direct trauma and disruption of the vessel wall, and leads to hemorrhage. Depending on the anatomic posi tion of the ruptured vessel, **hemorrhage may occur in the epidural, subdural, subarachnoid, and intraparenchymal compartments, sometimes in combination (** Fig. 28-10 ).

Answer 42

Vascular injury

Question 43

**\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_** most often occur **concomitantly in the setting of brain trauma** that also results in superficial contusions and lacerations. A traumatic tear of the carotid artery where it traverses the carotid sinus may lead to the formation of an arteriovenous fistula.

Answer 43

* **Subarachnoid and** * **intraparenchymal hemorrhage**s

Question 44

Normally the dura is fused with the periosteum on the internal surface of the skull. Dural arteries, most importantly the\_\_\_\_\_\_\_\_\_\_\_ are vulnerable to injury, particularly with **temporal skull fractures** in which the **fracture lines cross the course of the vessel.** In children, in whom the skull is deformable, a temporary displacement of the skull bones leading to laceration of a vessel can occur in the absence of a skull fracture.

Answer 44

middle meningeal artery,

Question 45

Once a vessel has been torn, the _______________ can cause the dura to separate from the inner surface of the skull ( Fig. 28-11 ). The expanding hematoma has a smooth inner contour that compresses the brain surface. When blood accumulates slowly patients may be **lucid for several hours before the onset of neurologic signs.**

Answer 45

extravasation of blood under arterial pressure

Question 46

An epidural hematoma may expand rapidly and is a **neurosurgical emergency requiring prompt drainage.**

Question 47

Where does the subdural space lies?.

Answer 47

Between the inner surface of the dura mater and the outer arachnoid layer of the leptomeninges lies the

Question 48

Bridging veins travel from the convexities of the cerebral hemispheres through the subarachnoid space and the subdural space to empty into the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_-

Answer 48

superior sagittal sinus

Question 49

. Similar anatomic relationships exist with other dural sinuses. These vessels are particularly prone to tearing along their course through the subdural space and are the **source of bleeding in most cases of subdural hematoma.** It is thought that the **brain, floating** freely bathed in CSF, can move within the skull, but the **venous sinuses are fixed.** Thedisplacement of the brain that occurs in trauma can tear the veins at the point where they penetrate the dura. In elderly individuals with brain atrophy, the bridging veins are stretched out and the brain has additional space for movement, hence the increased rate of subdural hematomas in these patients, even after relatively minor head trauma

Question 50

Why are infants also particularly susceptible to subdural hematomas ?

Answer 50

because their bridging veins are thin-walled

Question 51

Morphology. On macroscopic examination, the acute subdural hematoma appears as a:

Answer 51

* collection of freshly clotted blood along the brain surface, without extension into the depths of sulci ( Fig. 28-12 ). * The underlying brain is flattened and the subarachnoid space is often clear. * Typically, venous bleeding is self-limited; breakdown and organization of the hematoma take place over time.

Question 52

The underlying brain is flattened and the subarachnoid space is often clear. Typically, venous bleeding is self-limited; breakdown and organization of the hematoma take place over time. This usually occurs in the following sequence:

Answer 52

* Lysis of the clot (about 1 week) * Growth of fibroblasts from the dural surface into the hematoma (2 weeks) * Early development of hyalinized connective tissue (1 to 3 months)

Question 53

Typically, the organized hematoma is firmly attached by fibrous tissue **only to the inner surface of the dura** and **is not adherent to the underlying smooth arachnoid,** **which does not contribute to its formation.** The lesion can eventually retract as the granulation tissue matures, until there is only a thin layer of reactive connective tissue **(“subdural membranes”)** .

Question 54

A **common finding in subdural hematomas**, however, is the \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ The risk of repeat bleeding is **greatest in the first few months after the initial hemorrhage.**

Answer 54

occurrence of multiple episodes of repeat bleeding **(chronic subdural hematomas)**, presumably from the thin-walled vessels of the granulation tissue.

Question 55

Subdural hematomas most often manifest within \_\_\_\_\_\_\_\_\_\_\_hours of injury.

Answer 55

48

Question 56

Where are subdural hematomas most common?

Answer 56

They are most common over the **lateral aspects of the cerebral hemispheres** and are **bilateral in about 10% of cases.**

Question 57

How many percent is subdural hematoma bilateral?

Answer 57

10 %

Question 58

Neurologic signs commonly observed in subdural hematomas are attributable to the pressure exerted on the adjacent brain. There may be focal signs, but often the clinical manifestations are :

Answer 58

nonlocalizing and include headache and confusion. Slowly progressive neurologic deterioration is typical, but acute decompensation may occur.

Question 59

The treatment of subdural hematomas is to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 59

remove the blood and associated organizing tissue

Question 60

A broad range of neurologic syndromes may become manifest months or years after brain trauma of any cause. These have gained increasing notice in the context of legal medicine and litigation involving issues of compensation for those in the civilian work force and the military services.

Question 61

Post-traumatic hydrocephalus is largely due to \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ .

Answer 61

obstruction of CSF resorption from hemorrhage into the subarachnoid spaces

Question 62

Post-traumatic dementia and the punch-drunk syndrome (dementia pugilistica) follow repeated head trauma during a protracted period; the neuropathologic findings include \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.

Answer 62

* hydrocephalus, * thinning of the corpus callosum, * diffuse axonal injury, * neurofibrillary tangles (mainly in the medial temporal areas), and * diffuse amyloid β (Aβ)- positive plaques (see “Alzheimer Disease”)

Question 63

Other important sequelae of brain trauma include :

Answer 63

1. post-traumatic epilepsy, 2. tumors (meningioma), 3. infectious diseases, 4. and psychiatric disorders

Question 64

The spinal cord, normally protected within the bony vertebral canal, is vulnerable to trauma from its\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 64

skeletal encasement.

Question 65

Most injuries that damage the cord are associated with **displacement of the vertebral column, either rapid and temporary or persistent.**

Question 66

\_\_\_\_\_\_\_\_\_\_\_\_\_\_ determines the extent of neurologic manifestations:

Answer 66

The level of cord injury

Question 67

lesions involving the thoracic vertebrae or below can lead to

Answer 67

paraplegia

Question 68

; cervical lesions result in

Answer 68

quadriplegia;

Question 69

those above C4 can, in addition, lead to

Answer 69

respiratory compromise from paralysis of the diaphragm.

Question 70

Segmental damage to the descending and ascending white matter tracts **isolates** the **distal spinal cord from its cortical connections**with the cerebrum and brainstem; this interruption,**rather than the segmental gray matter damage that may occur at the level of the impact, is the principal cause of neurological deficits**

Question 71

The histologic changes of traumatic injury of the spinal cord are\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 71

* similar to those found at other sites in the CNS.

Question 72

In spinal cord injury , at the level of injury the acute phase consists of

Answer 72

* hemorrhage, * necrosis, * and axonal swelling in the surrounding white matter. * The lesion tapers above and below the level of injury. * In time the central necrotic lesion becomes **cystic and gliotic**; * cord sections above and below the lesion show **secondary ascending and descending wallerian degeneration,** respectively**, involving the long white-matter tracts affected at the site of trauma.**