alterations of neurologic function

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Alterations of Neurologic Function

Chapter 15


Brain Trauma

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


Brain Trauma Closed (blunt, nonmissile) 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


Brain Trauma Coup injury- impact against an object(front of

skull) Injury directly below the point of impact

Contrecoup- impact within skull( front and back of skull) Injury on the pole opposite the site of impact

Compound fractures Basilar skull fracture


Brain Trauma


Focal Brain Injury Observable brain lesion Force of impact typically produces contusions Contusions can cause:

Extradural (epidural) hemorrhages or hematomas bleed between the dura mater , artery is usually the source of bleed, classically loose consciousness at injury,

Subdural hematomas-common in elderly or alcohol abuse, can be acute usually top of skull or chronic

Intracerebral hematomas – most common frontal and temporal lobes and associated with contusions, + bilateral Babinski reflex, ICP increased


Hematomas


Subdural (Epidural) Hematomas


Diffuse Brain Injury

Categories: Mild concussion Classical concussion Mild, moderate, and severe diffuse axonal

injuries (DAI) • Shaking• Acceleration/deceleration• Axonal damage• Severity corresponds to the amount of shearing force

applied to the brain and brain stem


Mild Concussion

Temporary axonal disturbance causing attention and memory deficits but no loss of consciousness I: confusion, disorientation, and momentary

amnesia momentary II: momentary confusion and retrograde

amnesia 5-10 min III: confusion with retrograde and anterograde

amnesia lasting less than 6 hours


Classic Cerebral Concussion Grade IV

Loss of consciousness (<6 hours) reflexes fail, causing falls symptoms disappear after responsiveness returns. Transient breathing stops, bradycardia occurs and BP falls. Vitals quickly stabilize

Anterograde and retrograde amnesia may last for hours to days

Postconcussive syndrome- HZ+A< nervousness, anxiety, irritability, insomnia, depression forgetfulness inability to consentrate


Diffuse Axonal Injury Produces a traumatic coma lasting more than 6

hours because of axonal disruption Mild –prolong periods of stupor or restlessness Moderate – unconsciousness for weeks usually

permanent memory defect ,Glasgow coma scale 4-8 Posttraumatic antergrade and retrograde amnesia Severe- ICP appears 4-6 days post injury . Severely

Compromised movements, verbal and written communication problems , autonomic dysfunction

Should know DIA consequences p.181 Must look for secondary problems due to brain injury

such as changes in neurotransmitters and electrolytes, breaking of blood brain barrier causing IICP


Spinal Cord Trauma Most commonly occurs due to vertebral injuries

Simple fracture, compressed fracture, and comminuted fracture and dislocation ,very common in elderly due to degeneration

Traumatic injury of vertebral and neural tissues as a result of compressing, pulling, or shearing forces , swelling temporarily increases dysfunction

Most common locations: cervical (1, 2, 4-7), and T1-L2 lumbar vertebrae Locations reflect most mobile portions of vertebral column

and the locations where the spinal cord occupies most of the vertebral canal injury worse at the level of injury and below


Spinal Cord Trauma


Spinal Cord Trauma 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( hypothalamus can not control body heat thru vasoconstriction , now have increased metabolism so patient assumes temperature of surrounding air(poikilothermia)

Cervical spinal injury worse due to injury of diaphragm ( phrenic nerve that exit cord at C3-C5


Spinal Cord Trauma Paraplegia Quadriplegia Autonomic hyperreflexia (dysreflexia) PRIORITY

QUESTION Massive, uncompensated cardiovascular response to

stimulation of the sympathetic nervous system Stimulation of the sensory receptors below the level of the

cord lesion SS= Increase BP systolic , pounding HA, blurred vision,

sweating above level so lesion , skin flushing, nasal congestion, nausea ,poiloerection caused by pilomotor spam and Bradycardia. Often associated with extended bladder and rectum.


Autonomic Hyperreflexia


Degenerative Disorders of the Spine

Degenerative disk disease (DDD) Spondylolysis- defect in vertebral lamina Spondylolisthesis- vetabra slides forward on the

vertebra below( 4 grades of anterior slipage) Spinal stenosis-narrowing of spinal canal causing

spinal cord pressure Low back pain-80% of population Herniated intervertebral disk most common

L4 – S1


Cerebrovascular Disorders Cerebrovascular accident

Leading cause of disability Third leading cause of death in United States Classified

• Global hypoperfusion- as in shock• Ischemia (thrombotic, embolic)• Hemorrhagic• Know factors who has increase likelihood of having stroke?


Cerebrovascular Disorders Cerebrovascular accidents (CVAs)

Thrombotic stroke• Arterial occlusions caused by thrombi formed in

arteries supplying the brain or in the intracranial vessels( atherosclerosis) break off and travel upstream. Causes – dehydration, hypotension, prolonged vasoconstriction

• Transient ischemic attacks (TIAs)-temporarily decrease brain blood flow. Brief change in brain function-vision, speech, motor function, dizziness of loss of consciences- neurologic defects disappear in 24 hours

Embolic stroke• Fragments that break from a thrombus formed

outside the brain


Cerebrovascular Disorders

Embolic stroke• Fragments that break from a thrombus formed outside

the brain , heart ,aorta, common carotid. Risk factors MI, aerial fib, endocarditis, Rheumatic Ht. Dz., atria-septal-defect.

Hemorrhagic stroke-hypertension , rupture aneurysms Lacunar stroke- Smoking, hypertension and DM Cerebral infarction- brain looses blood supply because of

vascular occlusion. Types are ischemic or hemorrhagic Cerebral hemorrhage- primary cause is hypertension

resulting in thickenig of vessels walls



Clinical manifestations Excruciating HA . Weakness, transient numbness and

tingling transient speech disturbance Signs- hemiparesis/paralysis, dysphasia,

homonymous hemianopsia(Same side of stroke eye blindness)



Intracranial aneurysm Congenital Diffuse arteriosclerotic changes


Intracranial Aneurysm



Subarachnoid hemorrhage Blood escapes from defective or injured

vasculature into the subarachnoid space Manifestations

Kernig sign- in sitting position have patient straighten knee , if has pain in neck and back = +

Brudzinski sign- passive neck flexion produces pain and rigidity


Infection and Inflammation of the CNS

Meningitis Bacterial meningitis Aseptic (viral, nonpurulent, lymphocytic) meningitis Fungal meningitis Tubercular (TB) meningitis


Infection and Inflammation of the CNS

Encephalitis Acute febrile illness, usually of viral origin with

nervous system involvement Most common forms of encephalitis are caused

by arthropod-borne 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


Demyelinating Disorders Multiple sclerosis (MS)- autoimmune disorder. Onset 20-

50 yrs old MS is a progressive, inflammatory, demyelinating axon

disorder of the CNS- spares peripheral nervous system. Has exacerbations and remissions. Starts on one side of body, loss of strength and grip, diplopia, hyper-reflexia foot drag and stumbling. Lhermitte sign- shocking and tingling sensations. Heat and increase serum Ca+ bring on symptoms

MRI definitive test All motor function eventfully lostAmyotrophic lateral sclerosis (ALS)- muscle wasting Dz, Onset 4—50 ys. Can be familiar. Classic bulbar palsy

and muscular atrophy


Peripheral Nervous System Disorders

Amyotrophic lateral sclerosis (ALS) Classic ALS—“Lou Gehrig disease” Diffusely affects upper and lower motor

neurons of the cerebral cortex, brain stem, and spinal cord (corticospinal tracts and anterior roots)

Disease leads to progressive weakness leading to respiratory failure and death

Patient has normal intellectual and sensory function until death



Neuropathies Generalized symmetrical polyneuropathies

• Distal axonal polyneuropathy• Demyelinating polyneuropathy

Generalized neuropathies• Sensory neuropathies

Focal or multifocal neuropathies



Guillain-Barré syndrome Acquired inflammatory disease causing

demyelination of the peripheral nerves with relative sparing of axons

Acute onset, ascending motor paralysis Humoral and cellular immunologic reaction



Myopathies- Primary muscle disorder Marked weakness

Symmetrical and proximal Radiculopathies Radiculitis- sciatica , herpes zoster

• Inflammation of the spinal nerve roots Radicular pain – following dermatome pattern

Plexus injures- cCrvical C1-5. Brachial C6-8, Lumbar T12- S2 Involves the nerve plexus distal to the spinal roots but

proximal to the formation of the peripheral nerves


Neuromuscular Junction Disorders

Myasthenia gravis Chronic autoimmune disease . Nerve impulse

transmission to neuromuscular junction is interrupted

Muscle weakness and fatigue of muscles of the eyes and the throat causing diplopia, difficulty chewing, talking, swallowing


Central Nervous System Tumors

Cranial tumors Spinal cord tumors

alterations of neurologic function

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