Transcript LWW PPT Slide Template Master

Welcome to week 6
Chapter 16
Neurology and the Brain
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Review of errors from the bones
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
The Nervous System
Neurology: diagnosis and treatment of diseases
and disorders of the nervous system
Neurologist: specializes in the field of neurology
Neurosurgeon: focuses on a surgical approach
to treatment
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
The Brain
• Housed in the skull and connected to the spinal cord
through the opening at the skull base called the
foramen magnum
• 10,000 varieties of neurons and trillions of
supportive cells (called glia) and nerve connections
• Miles of tiny blood vessels
• Messages are transmitted through nerve fibers on
pathways throughout the central nervous system
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• The Cerebrum
– Uppermost and largest part of the brain
– Composed of tissue that encompasses about twothirds of total brain mass
– Is the site where highest neural processing takes
place—language, memory function.
– Divided into right and left hemisphere
• Separated by great longitudinal fissure
• Communicate with each other through corpus callosum
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Cerebral cortex
– Covers the surface of the cerebrum and carries out the
functions of the cerebrum
– Composed of millions of neurons and glia
– Called the “thinking brain” and the “gray matter” of the
brain because of its appearance
– Formed by folds (gyri) and grooves between them (sulci)
which permit the brain to perform more complex tasks
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• White matter: Beneath the cerebral cortex
– Does not do any real thinking but connects parts of
the brain to each other
– Basal ganglia: Islands of nerve-cell clusters which
play a role in control of movement
• Right and left hemisphere divided into 4 lobes:
– Frontal: Largest of the four lobes – motor and speech
skills
– Parietal: Interpret sensory information
– Temporal: Auditory sensors
– Occipital: Visual processing centers of the brain
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Limbic System
• Located in the cerebrum and part of the cerebral cortex
• Called “the feeling brain” because it is the brain’s center
of emotion and involved in controlling emotional
responses and behaviors that are necessary for survival
• Structures:
– Hippocampus: Called “the brain’s memory center” and
involved in the formation and retrieval of memories
– Amygdala: Controls emotional impact of thoughts and
situations
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Limbic System (continued)
– Pituitary: Actually an endocrine gland and produces
hormones that respond to various situations
– Hypothalamus: Regulates automatic functions such
as temperature, hormone production, sleep and
wake cycles, and appetite
– Thalamus: Serves as a relay station for almost all
sensory impulses coming and going through cerebral
cortex
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Brainstem
– Lowest extension of the brain that connects
cerebrum to the spinal cord
– Major sensory and motor pathway for impulses
running to and from the cerebral cortex
– Regulates critical vital functions such as heartbeat
and respirations
• Cerebellum
– Attached to the brainstem
– Called “little brain” because it has folds and grooves
like cortex
– Performs functions below level of conscious thought
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Three protective Meninges
connective tissue layers
– Dura mater: thick outermost layer
– Arachnoid membrane: web-like middle layer
• Subdural space: The space between dura and
arachnoid membrane
– Pia mater: The inner layer of meninges closest to
the brain
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Ventricles
– Four chambers where cerebral spinal fluids (CSF) is
produced
• Lateral ventricles (2): Located in cerebral hemispheres
• Third ventricle: Located in the midline cavity of the brain
• Fourth ventricle: Located near the brainstem
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Ventricles produce cerebral spinal fluid (CSF)
which:
– Surrounds the brain and protects it from damage
– Gives the brain buoyancy
– Takes harmful substances away from the brain
– Transports hormones to other areas of the brain
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Spinal Cord: A long, tube-like column of nerve
tissue extending form the base of the skull to
the lumbar spine
– The main pathway of communication between the
brain and the rest of the body
– Surrounded by bony covering, meninges, and CSF
– Is actually a complex organ consisting of gray matter
and white matter, like the brain, as well as a system
of nerves that enable it to possess an intelligence of
its own
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Peripheral Nervous System
• Lies outside the central nervous system
• Consists mainly of nerves that connect the brain and
spinal cord to sensory receipts. Muscles, and glands
• Delivers messages from the CNS to other nerves outside
the CNS and from those nerves back to the CNS
– Afferent nerves: Carry information to the CNS from the rest of
the body
– Efferent nerves: Carry information from the CNS to the rest of
the body
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Cranial Nerves
– Total of 12 pairs of nerves that exit from the brain
– Most control sensory and motor functions of the
head and neck
• Spinal Nerves
– Total of 31 pairs located between the vertebrae of
the spine
– Each communicate with a different area of the body
– Cauda equina: bottom of the spinal cord, shape of a
horse’s tail
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Types of Spinal Nerves:
- Motor nerves: from brain to spinal cord and body
- Sensory nerves: from body back to spinal cord and
brain
- Dermatomes: regions of the body supplied by
sensory nerves
Autonomic Nervous System: supplies nerves to all the
internal organs
Also called visceral nerves because they related to
the viscera, the soft internal organs of the body
Control involuntary movements of smooth muscle,
cardiac muscle and endocrine glands.
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Common Neurologic Diseases and
Treatments
• Meningitis: Infection causing inflammation of the
meninges
– Bacterial meningitis: from bacteria in the blood
(bacteremia)
– Viral meningitis: most common form of meningitis
• Treatments
– Immediate, aggressive treatment with antibiotics
– Vaccines: Hib and Prevnar
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Hydrocephalus: Excess buildup of CSF in the
brain
– Congenital hydrocephalus: present a birth
– Acquired hydrocephalus: developed later in life
– Noncommunicating: obstruction in the ventricles
– Communicating: problems with actual production or
absorption of CSF
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Treatments
– Drugs to reduce pressure from CSF buildup (Diamox,
Lasix)
– Lumbar puncture (LP) to reduce pressure from CSF
buildup and to test CSF fluid for problems
– Ventriculoperitoneal (VP) shunt: Allows excess CSF to
flow away from the brain to other parts of the body
where it can be absorbed
– Ventriculostomy: Opening made surgically between
the ventricles, allowing CSF to flow unobstructed
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Aneurysm: An abnormal dilation in a vessel’s
wall
– Cerebral aneurysm: aneurysm at the base of the
brain
– Hemorrhage: ruptured aneurysm
– Subarachnoid hemorrhage: rupture of aneurysm into
the subarachnoid space
• Treatments
– Microvascular clipping: Cutting off the flow of blood
to the aneurysm
– Coil embolization: Packing the aneurysm with
platinum coils to block blood flow to the aneurysm
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Seizure Disorder and Epilepsy
– Seizure: a sudden abnormal discharge of electrical
activity in the brain
– Epilepsy: neurologic disorder characterized by
recurrent seizures
• Seizure: Two Main Categories:
– Partial Seizures: Those that begin in a particular area
of the brain
• Simple partial seizures: No change in consciousness
• Complex partial seizures: Consciousness altered
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Generalized Seizures: Originate in several areas
of the brain
– Tonic-clonic (grand mal) seizures
– Absence (petit mal) seizures
– Myoclonic seizures
• Status epilepticus: A prolonged seizure, or series of
seizures, that lasts more than 30 minutes during which
time patient is unconscious. A medical emergency
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Epilepsy: A group of neurological disorders
characterized by uncontrolled electrical
discharges from the cerebral cortex –
considered a chronic, incurable condition unless
there is a reversible cause (illness, toxicities)
• Treatments:
– Oral anticonvulsants (many brand names: Depakene,
Depakote, Dilantin, Keppra, Klonopin, Lamictal,
Neurontin, Topamax, Tegretol, Trileptal)
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Treatments (Continued)
– Surgical Options:
• Temporal lobectomy: Removal of the portion of the
temporal lobe causing seizures
• Subpial resection: A series of cuts in the brain to help
isolate the section of the brain causing seizures
• Corpus callosotomy: Severs the right and left hemispheres
of the brain
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Parkinson Disease: Motor system disorder as a result of
nerve cells in the brain that control body movement
begin to deteriorate
– Nerves that produce dopamine become impaired, causing
extreme loss of muscle control, resulting in rigid limbs,
slowness of movement (bradykinesia), or impaired balance
and coordination.
• Treatments: Control of symptoms
– Dopamine agonists: mimic effects of dopamine (common
drugs: carbidopa/levodopa, Parlodel, selegiline, coenzyme Q10)
– Deep brain stimulation (DBS): Implanted device delivers mild
electrical stimulation to brain to block brain signals that cause
tremors
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Multiple Sclerosis: An inflammatory disease of the
nervous system that disrupts communication
between the brain and other parts of the body
– Caused by destruction of myelin (in the sheath) that
surrounds neuron, called demyelination
– Name refers to the multiple areas of hardening on the
myelin sheaths covering neurons
– Relapsing-remitting MS—most common form
• Treatments
–
–
–
–
Corticosteroids: Reduce inflammation
Muscle relaxants
Pain medication
Plasmapheresis: Plasma exchange
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Bell’s palsy: Attack on the facial nerve
– Cause unknown; viral infection may be a factor
• Treatments:
– Antiviral medications (acyclovir)
– Corticosteroids to reduce swelling of facial nerve
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Trigeminal neuralgia: Disorder of the trigeminal
nerve (cranial nerve V)
– Also called tic douloureux
– Sudden bursts of pain on one side of the face
• Treatments
– Drugs to relieve pain and to reduce muscle spasms in
the face (seizure-type medications such as Tegretol,
Dilantin, Neurontin, or Trileptal)
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Treatments (Continued)
– Surgical Treatments
• Microvascular decompression: Exposing and displacing the
nerve away from the point of compression
• Percutaneous stereotactic rhizotomy: Destroying part of
the nerve that causes pain
• Stereotactic radiosurgery: Applying ionizing radiation to
the trigeminal nerve root, forming a lesion that interrupts
transmission of pain signals to the brain
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Brain Tumor: Abnormal growth of cells or
tissue in the brain
– Benign: Tumor does not contain cancer cells
– Malignant: Tumor is life-threatening
– Primary brain tumor: Originates in brain tissue
– Secondary brain tumor: A brain tumor caused by a
cancer that originates in another part of the body
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Glioma: Most common type of tumor that originates in the glial (supportive)
tissue of the brain
– Types of gliomas and where they form:
• Astrocytoma: also called glioblastoma multiforme
• Ependymoma: lining of the ventricles
• Oligodendroglioma: cells that produce myelin
• Medulloblastoma: primitive (developing) nerve cells
• Meningioma: from the meninges
• Schwannoma: begins in Schwann cells
• Craniopharyngioma: pituitary gland
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Treatments
– Craniotomy: Temporarily removing portion of skull to
remove tumor
– Craniectomy: Permanently removing portion of skull and
replacing with synthetic plate
– Debulking: Surgically reducing the size of a tumor that
cannot be completely removed
– Transsphenoidal surgery: Accessing tumor through
incision in the sphenoid bone
– Photodynamic therapy (PDT): Uses a light-sensitive drug
and laser light to kill cancer cells
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Diagnostic Studies and Procedures
• Neurological Assessments
– Glasgow Coma Scale (GCS): Assesses patient’s level
of consciousness
– Mental status examination: Determines level of
disordered thought processes
– Cranial nerve assessment: Reveals information about
condition of the central nervous system
– Motor examination: Evaluates cerebral cortex and
initiation of motor activity
• Pronator drift test
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Neurological Assessments (Continued)
– Sensory examination: Tests reaction to various
sensations
– Cerebellar function tests: Evaluate coordination
and balance
• Gait: Walking test (antalgic – limping)
• Romberg: Tests for falling
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
– Cerebellar Function Tests (Continued)
• Finger-to-nose test: Involves brain remembering position
sense with eyes closed
• Heel-to-shin: Evaluates distance, power, and speed of
movement
– Reflex testing: Testing body’s automatic responses to
outside stimuli
• Deep tendon reflexes: Knee jerks, ankle jerks
• Babinski sign: Tests proper development of spine and
cerebral cortex
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Laboratory Tests
– Biopsy
– Lumbar puncture (spinal tap)
– Neurosonography (ultrasound)
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
• Imaging Studies
– Cerebral angiogram
– CT scan
– MRI/MRA
– PET Scan
– SPECT scan
– EEG
– Wada test
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Q and A
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins