nervous system diseases & disorders
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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. - PowerPoint PPT PresentationTRANSCRIPT
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