Miscellaneous Flashcards
List the 3 layers of the meninges.
- dura mater
- Arachnoid mater
- Pia mater
Which layer of the meninges is the outer most layer?
Dura mater—outermost meninx; has 4 folds; lines the periosteum of the skull and protected the brain; subdural space separates this from the arachnoid mater
What layer of the meninges is the inner most layer?
Pia mater—innermost meninx; covers the contours of the brain; forms the choroid plexus in the ventricular system
What is the middle layer of the meninges?
Arachnoid mater—middle meninx; the arachnid is impermeable; surrounds the brain in a loose manner; subarachnoid space separates this form the pia mater
What separates the arachnoid mater from the pia mater?
The subarachnoid space
What is meningitis?
Inflammation of the meninges of the brain and spinal cord. Many forms of meningitis but with bacterial meningitis being potential fatal within hours of onset it is important for a PT to recognize the s+s of acute meningitis.
What are the signs and symptoms of meningitis?
- Fever, headache, vomiting
- Complaints of a stiff and painful neck, unchallenged rigidity
- Pain in the lumbar area and posterior thigh
- Brudzinski’s sign (flexion of the Neck facilitates flexion fo the hips and knees )
- Kernig’s sign (pain with hip flexion combined with knee extension)
- Sensitivity to light
*Early dx is important to avoid neurological damage
What is the gold standard for the diagnosis of meningitis?
Lumbar puncture
Name the dural spaces.
- Epidural space
- Subdural space
- subarachnoid space
Where is the epidural space located?
—An area b/t the skull and outer dura mater that can be abnormally occupied
—also the area in the spinal cord b/t the dura mater and the periosteum of the vertebrae
Where is the subdural space located?
The area b/t the dura and arachnoid meninges
Where is the subarachnoid space located?
Area b/t the arachnoid and pia mater that contains CSF and the Circulatory system for the cerebral cortex
What is the purpose and design of the ventricular system?
Designed to protect and nourish the brain
what is the ventricular system comprised of?
Four fluid filled cavities known as ventricles and multiple foramina which allow passage of CSF.
What does each ventricle contain?
Specialized tissue known as choroid plexus which makes the CSF
What can an excessive amount of CSF in the brain cause?
Enlargement in the ventricles causing hydrocephalus; excess fluid within the spinal cord is term syringomyelia
What is the purpose of CSF?
Cushions the brain and spinal cord from injury and provides mechanical buoyancy and support.
Serves as a conduit for removal of metabolites and is constantly being absorbed and replenished within the brain and spinal cord
How much CSF is yielded per day?
500-700 ml/day
What does the blood brain Barrier consist of?
- meninges
- protective glial cels
- Capillary beds of the brain
What is the blood-brain barrier responsible for?
Exchange of nutrients b/t the CNS and the vascular system. This provides protection for the CNS by restricting certain molecules from crossing the barrier while others are still able to do so freely
Where is the largest amount of gray matter found in the spinal cord?
Lumbar region
What arteries supply the spinal cord?
Vertebral Arteries form the anterior spinal artery and 2 posterior arteries
The spinal cord runs from __________ to ____________.
Foramen magnum to conus medullaries (between the 1st and 2nd Lumbar spine)
Where does the spinal cord end?
L2
T or F: each spinal nerve contains a dorsal root (sensory) with afferent fibers and a ventral root (motor) with efferent fibers
True
What is hydrocephalus?
Increase in CSF within the ventricles of the brain typically due to poor resorption, obstruction or flow or excessive production of CSF.
What can hydrocephalus be classified as?
Congenital
Acquired
Idiopathic
Communicating
What are signs of hydrocephalus or a blocked shunt?
- Enlarged head or bulging fotanelles in infants
- Headache
- Changes in vision
- Large veins noted on scalp
- Seizures
- Behavior changes
- Alteration in appetite, vomiting
- “Sun setting” sign or downward deviation fo the ease
- . incontinece
What is an UMN disease characterized by?
A lesion found in the DESCENDING motor tracts within the cerebral cortex, internal capsule, brainstem, or spinal cord.
What are symptoms of a UMN lesion?
- weakness of involved muscles
- hypertonicity
- hyperreflexia
- mild disuse atrophy
- abnormal reflexes
Where are the damaged tracts of a UMN lesion located?
Lateral white column of the spinal cord
What are examples UMN lesions?
- Cerebral palsy
- Hydrocephalus
- ALS (both UMN and LMN)
- CVA
- Birth injuries
- MS
- Huntington’s chorea
- TBI
- pseudobulbar palsy
- Brain tumors
LMN disease is characterized by?
A lesion that affects nerves or their axons at or below the level of the brainstem, usually within the “final common pathway.”
What other column of the spinal cord may be affected with a LMN lesion?
The ventral gray column of the spinal cord
What are the symptoms of a LMN lesion?
- Flaccidity or weakness of the involved muscles
- Decreased tone
- Fasciculations
- Muscle atrophy
- Decreased or absent reflexes
What are examples of LMN lesions?
- Poliomyelitis
- ALS (Both UMN and LMN)
- Guillian-Barre Syndrome
- Tumors involving the spinal cord
- Trauma
- Progressive muscular atrophy
- Infection
- Bell’s palsy
- Carpal tunnel syndrome
- Muscular dystrophy
- Spinal muscular atrophy
Describe the reflexes in an UMN disease and LMN Disease.
UMN: Hyperactive
LMN: Diminished or absent
Describe atrophy in UMN or LMN disease?
UMN: mild from disuse
LMN: Present
Are Fasciculations present during UMN and LMN diseases?
UMN: Absent
LMN: Present
Describe tone in UMN and LMN disease.
UMN: Hypertonic
LMN: Hypotonic to flaccid
What are the levels of consciousness
- Consciousness
- Lethargy
- Obtunded State
- Stupor
- Coma
Explain the level of consciousness
State of arousal accompanied by awareness of one’s environment
Conscious pt is awake, alert, and oriented (A&Ox3) to his/her surroundings
Explain the level of Lethargy
Altered consciousness in which a person’s level of arousal is diminished
Lethargic pt appears drowsy, but when question will open eyes and respond briefly. The pt easily falls asleep if not continually stimulated, and does not fully appreciate the environment. Communication attempts are difficult owing to deficits in maintaining focus (PT should speak in a loud voice while calling the pt’s name)
Explain level of obtunded state
Refers to diminished arsoual and awareness
This pt is difficult to arouse from sleeping and once aroused, appears confused. Attempts to interact with pt are generally nonproductive.Pt responds slowly and demonstrates little interest in or awareness of environment. PT should shake pt genial as if awakening someone from sleep and again use simple questions
Explain level of stupor
Referees to a state of altered mental stats and responsiveness to one’s environment. Pt can be aroused only with virogus or unpleasant stimuli (e.g painful stimuli such as flexion of the great toe, sharp pressure or pinch, or rolling a pencil across the nail bed)
Pt demonstrates little in the way of voluntary verbal or motor. Mass movement responses may be observers in response to painful stimuli or loud noises
Explain the level of coma
Pt cannot be aroused. Eyes remain closed and there are no sleep-wake cycles.
The patient does not respond to repeated painful stimuli and may be ventilator dependent . Reflex reactions may or may not be seen, depending on the location of the lesion(s) within CNS
When is the term persistent vegetative state used
Describes a patient who remains in a vegetative state for >1year after a TBI and 3 months or more of anoxic brain injury
This state is caused by a severe brain injury
Describe the minimally conscious (vegetative state)
Characterized by return of irregular sleep-wake cycles, and normalization of the so-called vegetative functions—respiration, digestion and BP control.
What is the gold standard instrument used to document level of consciousness in acute brain injury?
Glasgow Coma Scale (GCS
Describe the GCS.
Three ares of function are examined: eye opening, best motor response, and verbal response
Score Ranges from a low of 3 to a high 15; total score of <8 is indicative of severe brain injury and coma; score b/t 9 to 12 is indicative of moderate brain injury; score of 13 to 15 is indicative of mild brain injury
What tool is Widely used in rehabilitation to examine the return of a person with brain injury from coma to consciousness?
The ranchos Los Amigos Scale (levels of cognitive function (LOCF))
(Level I, no response-coma) to (Level VIII, purposeful-appropriate)
When examining the pupils, what would small bilateral pupils indicate?
Damage to the sympathetic pathways in the hypothalamus or metabolic encephalopathy
What are pinpoint pupils indicative of?
Hemorrhagic pontine lesion or narcotic overdose (e.g. morphine, heroin)
What are pupils that are fixed in mid-position and slightly dilated suggestive of?
Of midbrain damage
What are large bilaterally fixed and dilated pupils suggestive of?
Severe anoxia or drug toxicity (e.g. tricyclics antidepressants)
If only one pupil is fixed and dilated what would this indicate?
Temporal lobe herniation with compression of the oculomotor nerve and midbrain is likely
What is the inverted-U principle (Yerkes-Dodson law)
Appropriate level of arousal allows for optimal motor performance; but very low or high levels of carousel can cause deterioration in motor performance
Pts at either end of the arousal continuum may not respond at all or may respond in an unpredictable manner
