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Nervous System Diseases & Disorders Introduction to Human Diseases Chapter 13.

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Presentation on theme: "Nervous System Diseases & Disorders Introduction to Human Diseases Chapter 13."— Presentation transcript:

1 Nervous System Diseases & Disorders Introduction to Human Diseases Chapter 13

2 Nervous System Anatomy Divisions of the nervous system: Central Nervous System Brain and spinal cord Peripheral Nervous System Peripheral nerves Autonomic Nervous System Symphathetic nervous system Parasympathetic nervous system

3 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.

4 Meninges Dura Outermost layer Thick, fibrous Arachnoid Thin, filmy like a spiderweb Pia Thin, vascular layer of loose connective tissue, inseparable from the outer brain surface

5 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.

6 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

7 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

8 Migraine Headache 10-20% US population have migraines 2 nd 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

9 Migraine Headache Etiology: Vasoactive chemicals (peptides) in brain (serotonin and dopamine) Stimulate inflammatory cascade This causes vasodilation Serotonin appears to be most important factor

10 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

11 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 1 st month

12 Head Trauma #1 cause of trauma deaths in US Many possible mechanisms of injury: Falls Motor vehicle crashes Assaults

13 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

14 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

15 Shaken Baby Syndrome Brain injuries: Hemorrhage (SDH) Cerebral edema & raised pressure More common Prognosis: 1/3 rd mortality 1/3 rd with permanent neurological disabilities

16 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

17 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

18 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

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

20 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

21 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

22 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

23 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.

24 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

25 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

26 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

27 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

28 Brain abscesses S/S: depending on location, may resemble hemorrhage or CVA Treatment: Antibiotics Surgical drainage of the abscess

29 Peripheral Nerve Diseases Peripheral neuritis (peripheral neuropathy) Noninflammatory degenerative disease of nerve supplying the distal extremities Commonly males, YOA Etiology: numerous, including alcohol, heavy metal, drug, poisons, TB & infections, diabetes, lupus, nutritional, etc

30 Peripheral neuropathy S/S: muscle weakness, paresthesias, pain, tenderness, atrophy, loss of reflexes Gradual in onset usually Diagnostics: EMG Treatment: varies with cause

31 Bell’s Palsy Disorder of the facial nerve (cranial nerve VII) Unilateral paralysis/paresis of the facial muscles Usually transient Typically in patients YOA

32 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

33 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

34 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

35 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

36 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 minutes in duration

37 Transient Ischemic Attacks Symptoms: most commonly upper extremity clumsiness, weakness, paresthesias, visual field cuts (curtain-like) Treatment: surgery for carotid plaque, anticoagulants

38 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

39 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

40 Epilepsy Treatment: acute and long-term anticonvulsant meds

41 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

42 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

43 Parkinson’s Disease Movement disorder characterized by muscle rigidity & tremors Usually males over 65 YOA Etiology: unknown, related to dopamine deficiency in brain

44 Parkinson’s Disease S/S: bradykinesia, involuntary tremors, muscular rigidity Treatment: dopamine replacement meds, PT, supportive

45 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

46 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

47 Amyotrophic Lateral Sclerosis (ALS) Adult-onset motor neuron disease Progressive degeneration & loss of motor function Called Lou Gehrig’s Disease (1941) Males between YOA About 6/100,000 adult population in US 25,000-30,000 cases total in US

48 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

49 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

50 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


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