Ch. 17 Flashcards
Brain Trauma
- Major head trauma
- Closed (blunt, non-missile) trauma
- Open (penetrating, missile) trauma
- Coup injury
- Contrecoup
- Compound fractures
- Basilar skull fracture
Major head trauma
- A traumatic insult to the brain possibly producing physical,
intellectual, emotional, social, and vocational changes - Transportation accidents
- Falls
- Sports-related event
- Violence
Closed (blunt, non-missile) trauma
- Head strikes hard surface or a rapidly moving object strikes
the head - The dura remains intact and brain tissues are not exposed to
the environment - Causes focal (local) or diffuse (general) brain injuries
Open (penetrating, missile) trauma
- Injury breaks the dura and exposes the cranial contents to the environment
- Causes primarily focal injuries
Coup injury
Injury directly below the point of impact
Contrecoup
Injury on the pole opposite the site of impact
Focal Brain Injury
- Observable brain lesion
- Force of impact typically produces contusions
- Contusions can cause:
- Extradural (epidural) hemorrhages or hematomas
- Subdural hematomas
- Intracerebral hematomas
Extradural (epidural) hemorrhages or hematomas
- Bleeding between the dura mater and the skull
- Natasha Richardson
- Lose consciousness at injury, then become lucid for a few minutes to a few days. As the hematoma accumulates a headache of increasing severity,
vomiting, drowsiness, confusion, seizure, and hemiparesis may develop.
Subdural hematomas
- Bleeding between the dura mater and the brain
- Acute-commonly within hours, located at the top of the skull, subacute over 48 hours to 2 weeks. Chronic develop over weeks to months
- Act like expanding masses, increasing intracranial pressure that eventually compresses the bleeding vessels. Brain herniation can result
Intracerebral hematomas
- Bleeding within the brain. Acts as an expanding mass, increasing intracranial
pressure, compressing brain tissues, and causing edema. May appear 3-10 days after head injury - Cause decreasing level of consciousness
Diffuse Brain Injury
- Diffuse axonal injury (DAI)
- Categories:
- Mild concussion
- Classical concussion
- Mild, moderate, and severe diffuse axonal injuries (DAI)
Diffuse axonal injury (DAI)
- Shaking, inertial effect (whiplash)
- Acceleration/deceleration
- Axonal damage
- Shearing, tearing, or stretching of nerve fibers
- Severity corresponds to the amount of shearing force applied
to the brain and brain stem
Mild concussion
- Characterized by immediate but transitory clinical
manifestations; CSF pressure rises, and ECG and EEG changes
occur without loss of consciousness. - Lasts for 1 to several minutes, possibly with amnesia for events
preceding the trauma - “Not being themselves” for up to a few days
Classical concussion
- Consciousness is lost for up to 6 hours and reflexes fail, causing
falls. Head pain, nausea, fatigue, attentional and memory system
impairments, and mood and affect changes
Spinal Cord Trauma
- Most commonly
occurs due to vertebral
injuries- Simple fracture
- Compressed fracture
- Comminuted fracture
and dislocation
- Traumatic injury of
vertebral and neural
tissues as a result of
compressing, pulling,
or shearing forces - Most common locations: cervical (1, 2, 4-7), and T1-L2
lumbar vertebrae - Spinal shock
- Paraplegia
- Quadriplegia
- Autonomic hyperreflexia
(dysreflexia)
Most common locations: cervical (1, 2, 4-7), and T1-L2
lumbar vertebrae reflects
reflect most mobile portions of vertebral column
and the locations where the spinal cord occupies most of the
vertebral canal
Spinal shock
- Normal activity of the
spinal cord ceases at and
below the level of injury;
sites lack continuous
nervous discharges from
the brain - Complete loss of reflex
function (skeletal,
bladder, bowel, sexual
function, thermal
control, and autonomic
control) below level of
lesion
Autonomic hyperreflexia
(dysreflexia)
- Massive, uncompensated
cardiovascular response to
stimulation of the
sympathetic nervous
system - Stimulation of the sensory
receptors below the level
of the cord lesion - Life threatening
Degenerative Disorders of the Spine
- Degenerative disk disease (DDD)
- Low back pain
- Herniated intervertebral disk-displacement of disk material
beyond the intervertebral disk space. Rupture is usually
caused by trauma, or degenerative disk disease (thoracic region is rare)
Cerebrovascular Disorders
- Cerebrovascular
accident - Hemorrhagic stroke
- Lacunar stroke
- Cerebral infarction
- Cerebral hemorrhage
- Intracranial aneurysm
- Vascular malformations
- Subarachnoid hemorrhage
Cerebrovascular
accident
- Leading cause of
disability - Third leading cause of
death in United States
Classified - Global hypoperfusion
- Ischemia (thrombotic,
embolic) - Hemorrhagic
Cerebrovascular accidents (CVAs)
Thrombotic stroke
* Arterial occlusions caused by thrombi formed in arteries
supplying the brain or in the intracranial vessels
* Transient ischemic attacks (TIAs)
Embolic stroke
* Fragments that break from a thrombus formed outside the brain
Hemorrhagic stroke
Hypertension, ruptured aneurysms or vascular malformation,
bleeding into a tumor or hemorrhage associated with anticoagulants
or clotting disorders, head trauma, or illicit drug use
Lacunar stroke
Caused by occlusion of a single deep perforating artery that supplies small penetrating subcortical vessels, causing ischemic lesions
Cerebral infarction
Results when an area of the brain loses its blood supply because of vascular occlusion
* Cerebral thrombi and cerebral emboli most commonly produce
occlusion but atherosclerosis and hypotension are the dominant underlying processes
Cerebral hemorrhage
Hypertension is the primary cause
Intracranial aneurysm
Saccular (berry) aneurysms
* Occur frequently and likely result from congenital abnormalities in the tunica media of the arterial wall and degenerative changes
* Sac gradually grows over time
Fusiform (giant) aneurysms
* Occur as a result of diffuse arteriosclerotic changes and are found most commonly in the basilar arteries or terminal portions of the internal carotid arteries
Vascular malformations
Arteriovenous malformation-tangled mass of dilated blood
vessels creating abnormal channels between the arterial and venous systems
Subarachnoid hemorrhage
Blood escapes from defective or injured vasculature into the
subarachnoid space
Cerebrovascular Disorders Manifestations
- Kernig sign-straightening the knee with the hip and knee in a
flexed position produces pain the back and neck regions - Brudzinski sign-passive flexion of the neck produces neck pain
and increased rigidity
Headaches
- Migraine
- Cluster
- Tension-type
Migraine
– Familial, episodic disorder whose marker is headache and is defined as repeated, episodic headache lasting 4 to 72 hours
– Usually women 25 to 55 years old
– Caused by combination of multiple genetic and environmental
factors
Migraine Diagnosis
- Unilateral, throbbing, worsened by movement, moderate or severe;
and any one of the following: nausea, vomiting, accompanied by photophobia or phonophobia
Migraine Phases
premonitory, aura, headache
Migraine Triggers
- Altered sleep patterns
- Skipping meals
- Overexertion
- Weather change
- Stress or relaxation from stress
- Hormonal changes (menstrual periods)
- Excess afferent stimulation (bright lights, strong smells)
- Chemicals (alcohol or nitrates)
Cluster
– Occur in clusters for a period of days followed by a long period of spontaneous remission
– Usually men between 20 to 50 years old
– Trigeminal activation and autonomic dysfunction
– Unilateral trigeminal distribution of severe pain with ipsilateral autonomic manifestations (tearing on affected side, ptosis of the ipsilateral eye, and stuffy nose)
– Chronic cluster headaches
Tension-type
– Most common
– Average onset 2nd decade
– Mild to moderate bilateral headache with a sensation of a tight band or pressure around the head with gradual onset of pain
– Occurs in episodes and may last for several hours or several days
– Occurs at least 15 days per month for at least 3 months
Infection and
Inflammation of the CNS
- Meningitis-inflammation of the brain or spinal cord
- Brain or spinal cord abscess
- Encephalitis
Meningitis-inflammation of the brain or spinal cord
- Bacterial meningitis
- Aseptic (viral, nonpurulent, lymphocytic) meningitis
- Fungal meningitis
Bacterial meningitis
- Primarily and infection of the pia mater and arachnoid, the
subarachnoid space, the ventricular system, and the CSF - Causes Neisseria meningitidis and stretococcus pneumoniae
Aseptic (viral, nonpurulent, lymphocytic) meningitis
Is believed to be limited to the meninges. It produces various
symptoms and is caused by several infections agents, primarily viruses. Bacterial infections not adequately treated also cause
aseptic meningitis.
Fungal meningitis
A chronic much less common condition than bacterial or viral.
The infection occurs most often in person s with impaired
immune responses or alteration sin normal body flora. It
develops gradually, usually over days or weeks.
Brain or spinal cord abscess
– Localized collection of pus within the parenchyma
– Causes:
* Open trauma and during neurosurgery
* Contiguous spread of infection from the middle ear, mastoid cells, nasal cavity, nasal sinuses
* Through metastatic or hematogenous spread from distant foci
* Cryptogenically: without other associated areas of infection
Brain abscess
- Early-low-grade fever, headache (most common symptom), neck pain and stiffness with mild nuchal rigidity, confusion, drowsiness, sensory deficits, and communication deficits
- Later: inattentiveness (distractibility), memory deficits, decreased visual acuity and narrowed visual fields, papilledema, ocular palsy,
ataxia, and dementia
Spinal cord abscess
Clinical manifestations stages:
* (1) Spinal aching
* (2) Severe root pain, accompanied by spasms of the back muscles and
limited vertebral movement
* (3) Weakness caused by progressive cord compression
* (4) Paralysis
Encephalitis
- Acute febrile illness, usually of viral origin with nervous system
involvement - Most common forms of encephalitis are caused by arthropod-borne (mosquitos) viruses and herpes simplex virus
Neurologic Complications of AIDS
- Human immunodeficiency-associated cognitive dysfunction
- HIV myelopathy
- HIV neuropathy
- Aseptic viral meningitis
- Opportunistic infections
- CNS neoplasms
HIV myelopathy
Involving diffuse degeneration of the spinal cord
HIV neuropathy
Isolated from peripheral nerves; consequently, the virus may directly infect nerves and cause neuropathy
