Nervous System Diseases & Disorders

Nervous System Diseases & Disorders

Mr. Nichols

PHHS

CNS anatomy Major parts of the brain

Cerebrum Cognitive center (thought, memory) Level of consciousness

Cerebellum Center of balance & coordination

Brain stem Center of automatic functions

Blood pressure, respiration, etc.

Headaches Any pain occurring in the head Acute or chronic Numerous etiologies Very common condition

May be a symptom of other diseases Infections, neoplasms, inflammatory diseases, etc.

Headaches Due to irritation, inflammation of any pain-

sensitive structure Brain itself is not a source of headache Diagnostic procedures and testing:

Physical exam (PE), CT scan, LP (lumbar puncture or spinal tap), EEG, routine x-rays, MRA, MRI and more

Migraine Headache Recurrent, usually severe headache of

vascular origin More common in females (3 to 1)

Family history in 70-80% Onset common in adolescence or early

adulthood 80% have first migraine by 30YOA

Usually become less frequent with age

Migraine Headache 10-20% US population have migraines 2nd most common cause of HA in US

Muscle tension HA is #1 S/S:

Intense throbbing headache, uni-or bilateral Nausea, vomiting, dizziness, tinnitus Visual disturbances With or without aura (classical vs. common) Duration from 4-72 hours

Migraine Headache Etiology:

Vasoactive chemicals (peptides) in brain (serotonin and dopamine)

Stimulate inflammatory cascade This causes vasodilation Serotonin appears to be most important factor

Subarachnoid Headache Due to a subarachnoid hemorrhage 80% SAH due to ruptured intracranial

aneurysm Berry aneurysm, saccular, acquired due to

hemodynamic stress at bifurcations About 28,000 SAH/yr in US Mean age is 50 YOA Accounts for 6-8% strokes in US

Subarachnoid Headache Most common etiology of non-traumatic

intracranial hemorrhages S/S: “worst headache of my life”

Rapid onset, neck stiffness (nuchal rigidity), low back pain, photophobia, nausea & vomiting, seizures in 10-25%

10% mortality immediately Up to 60% mortality in 1st month

Head Trauma #1 cause of trauma deaths in US Many possible mechanisms of injury:

Falls Motor vehicle crashes Assaults

Shaken Baby Syndrome Vigorous episode of shaking the baby by

the arms, torso, or chest Most victims less than 3 years of age

Produces characteristic injury pattern: Neurological injury

Mental retardation, seizures, hearing loss Intracranial hemorrhage or edema, coma

Retinal hemorrhages

Shaken Baby Syndrome One version of child abuse First described in 1946 Part of overall pattern of child abuse:

Multiple fractures Bruises in all stages of healing, often axial Often abuse from non-biological parent or

caregiver

Shaken Baby Syndrome Brain injuries:

Hemorrhage (SDH) Cerebral edema & raised pressure

More common

Prognosis: 1/3rd mortality 1/3rd with permanent neurological disabilities

Epidural and Subdural Hematomas Epidural Hematoma

Hemorrhage above the dura layer Arterial bleeding

Parietal skull fx, middle meningeal artery

“lucid” interval

Subdural Hematoma Below the dura Venous bleeding More common

EDH & SDH S/S:

Altered level of consciousness (coma or lethargy), headache

Hemiparesis (right or left) Unilateral dilated pupil

Treatment: Neurosurgical drainage of the hematoma

Cerebral Concussion Disruption of brain function without actual

physical brain injury Typically follows a blow to the head Often, not always, has loss of

consciousness S/S: headache, nausea, dizziness,

amnesias, disorientation, vertigo, photophobia

Concussion Testing is done to rule out other injuries Treatment: supportive, observation

Cerebral Contusion Bruising of the brain tissue

Cerebral edema around the contusion is common

Mechanism: a blow to the head, usually localized force

S/S: headache, variable loss of consciousness, variation from concussion-like symptoms to coma with hemiparesis

Cerebral Contusion Testing: CT scan to examine extent of

brain injury & possible brain herniation Treatment: variable

Monitoring of ICP, meds to decrease brain swelling, usually surgery is not helpful, other supportive care in ICU

Disorders that cause paralysis Hemiplegia

Loss of muscle control & sensation on one side of the body (L or R)

Paraplegia Loss of muscle control & sensation on the

lower part of the trunk and lower extremities Quadriplegia

Paralysis of all four extremities

Hemiplegia Etiology: most frequently stroke

Also intracranial tumor or hemorrhage Other S/S: weakness of half of the face,

aphasia, agnosia, apraxia, agraphia, alexia, etc.

Paraplegia & Quadriplegia Etiology: most commonly spinal cord

injuries due to trauma Other S/S: loss of bowel & bladder

control, sexual dysfunction S/S of quadriplegia also include:

Low blood pressure and pulse Variable loss of respiratory control

CNS Infections Acute Bacterial Meningitis

Acute inflammation & infection of the CSF & the meninges

Etiology: bacterial, viral, or fungal Source may be spread from blood or nasopharynx

Most severe type = bacterial Most common bacteria involved are Strep

pneumoniae & Neisseria meningitidis

Acute Bacterial Meningitis S/S: Headache, nausea, vomiting, fever,

seizure, nuchal rigidity, drowsiness, coma Testing: lumbar puncture makes the

diagnosis Characteristic rash with Neisseria m. Treatment: antibiotics or antifungals and

supportive care

Brain Abscesses Localized collection of pus Most commonly in:

Cerebellum Frontal or temporal lobes of cerebrum

Etiology: spread from some other nearby or distant infection

Brain abscesses S/S: depending on location, may resemble

hemorrhage or CVA Treatment:

Antibiotics Surgical drainage of the abscess

Peripheral Nerve Diseases Peripheral neuritis (peripheral neuropathy)

Noninflammatory degenerative disease of nerve supplying the distal extremities

Commonly males, 30-50 YOA Etiology: numerous, including alcohol,

heavy metal, drug, poisons, TB & infections, diabetes, lupus, nutritional, etc

Peripheral neuropathy S/S: muscle weakness, paresthesias, pain,

tenderness, atrophy, loss of reflexes Gradual in onset usually

Diagnostics: EMG Treatment: varies with cause

Bell’s Palsy Disorder of the facial nerve (cranial nerve

VII) Unilateral paralysis/paresis of the facial

muscles Usually transient Typically in patients 20-60 YOA

Bell’s Palsy Etiology: idiopathic technically

Viral etiology is strongly suspected Autoimmune, ischemic, etc

S/S: facial asymmetry, drooping mouth, drooling, incomplete closure of eye (Bell’s phenomenon)

Treatment: antiviral drugs and steroids usually

Cerebrovascular Accident (CVA) Focal neurological impairment due to lack

of blood supply to an area of the brain lasting more than 24 hours

Clinical condition is called stroke 2 types of stroke:

Ischemic: embolic or thrombotic, 75% CVA’s

Hemorrhagic: 25% CVA’s

CVA Risk factors: same as for cardiovascular

disease, smoking, HTN, hyperlipidemia, diabetes, etc. TIA’s, oral contraceptives

S/S: hemiplegia or hemiparesis, dysphagia, speech impairment, diplopia & loss of visual fields, lack of coordination, confusion, sensory impairment

CVA Diagnostics: CT scan to rule out

hemorrhage or tumor Treatment:

Thrombolytic medicines “Clot busters” if stroke symptoms of 3 hrs or less

Supportive care, nutritional, PT & OT

Transient Ischemic Attacks (TIA) Focal neurological impairment due to

transient lack of blood supply to an area of the brain, lasting less than 24 hrs.

TIA’s indicate increased risk of CVA in the future

Resolve completely Often 20-40 minutes in duration

Transient Ischemic Attacks Symptoms: most commonly upper

extremity clumsiness, weakness, paresthesias, visual field cuts (curtain-like)

Treatment: surgery for carotid plaque, anticoagulants

Epilepsy Chronic brain disorder characterized by seizures

(abnormal, rapid, intense neuronal discharge) Types of seizures:

Generalized (gran mal) Involve entire body, unconscious

Partial: part of the body is involve, conscious Petit mal: momentary, frequent unconscious

episodes

Epilepsy Etiology: mostly idiopathic

Trauma, tumors, CNS infection, drugs & toxins, etc

S/S: in classic generalized seizure Aura, tonic, clonic, post-ictal phases Respiratory insufficiency & cyanosis Incontinence of bowel & bladder

Epilepsy Treatment: acute and long-term

anticonvulsant meds

Degenerative Neurological Diseases Alzheimer’s Disease

Fatal, long-term disease of the brain Characterized by neurofibrillary tangles and

senile “plaques” Gradual & permanent deterioration of

memory, judgment, cognitive and verbal skills

Geriatric disorder in general

Alzheimer’s Disease Etiology: unknown S/S: previous section, end-stage is

complete inattention to self Diagnosis of exclusion Treatment: some meds slow progression,

supportive care of patient and family

Parkinson’s Disease Movement disorder characterized by

muscle rigidity & tremors Usually males over 65 YOA Etiology: unknown, related to dopamine

deficiency in brain

Parkinson’s Disease S/S: bradykinesia, involuntary tremors,

muscular rigidity Treatment: dopamine replacement meds,

PT, supportive

Multiple Sclerosis (MS) Chronic, progressive, demyelinating

autoimmune disorder Makes antibodies to myelin

Females (2:1) Occurs during adult years, not geriatric About 25,000 new cases/yr in US

MS S/S: variable, may last hours to weeks

Classically: eye symptoms, paresthesias, paralysis, mood swings, balance problems, often sudden onset with relapses

Treatment: beta-interferon products, corticosteroids, glatiramen acetate (synthetic myelin protein)

Usual cause of death is due to chronic disability issues

Amyotrophic Lateral Sclerosis (ALS) Adult-onset motor neuron disease Progressive degeneration & loss of motor

function Called Lou Gehrig’s Disease (1941) Males between 50-60 YOA About 6/100,000 adult population in US 25,000-30,000 cases total in US

ALS S/S: progressive muscle weakness,

atrophy, and fasciculations (twitching) Eventual involvement of mouth, respiratory

muscles, end-stage is complete paralysis 75-80% begin with limb involvement Slurred speech, hoarseness, dysphagia,

tripping & stumbling, trouble with usual daily activities

ALS Sporadic form (nonhereditary) 90-95%

cases Inherited version is autosomal dominant

Mean time till ventilator dependent or death: 2-4 years May survive 5-10 years on ventilator

Cancers of the CNS Primary brain tumors

Benign or malignant Most pediatric brain tumors are primary Examples are astrocytoma, glioblastoma

Secondary brain tumors Metastases from other sites Most common tumors of the brain