Ch 41: Nervous System

What are the parts of the Central Nervous System?

• brain

• spinal cord

What actions does the CNS control

• voluntary actions (muscle movement)

• involuntary actions (breahting, heartbeat)

What is the peripheral nervous system (PNS)

nerves that extend from the spinal cord to the rest of the body (neck, chest, abdomen, arms, legs, muscles, internal organs)

Nerve tracts coming to and from the brain __________ in the CNS

cross to opposite sides

Issues with the 12 cranial nerves could…

affect nutrition status (dysphagia, mouth movement, tongue movement issues, etc)

Frontal lobe

psychiatric manifestations (depression, mania, personality change); muscle movement (motor apraxia)

Parietal lobe

right parietal lobe mass or insult may result in chronic inability to focus attention to the body’s left side (AKA neglect); language centers located near the junction of the left temporal, parietal, and frontal lobes, pathologic conditions may cause aphasia (inability to process language)

Temporal lobe

memory and speech (as in Alzheimer dementia, stroke, seizures); aphasia

Occipital lobe

primary area for vision; cortical blindness (dysfunction of primary occipital cortex area)

Cerebellum and brain stem issues

may obstruct the ventricular system causing life-threatening hydrocephalus (increased intracranial pressure that may quickly result in death due to increased accumulation of fluid in the brain); signs: trouble with balance, walking and coordination, sleepiness, headache that is worse on awakening

Lesions in the brainstem may infiltrate any of the cranial nerves that innervate

the face and head (eyes, ears, jaw, tongue, pharynx, facial muscles)

Lesions in the medulla oblongata (the lower half of the brainstem) may infiltrate

respiratory and cardiac centers

Skull base can affect changes in

smell and vision

Anosmia

absence of smell

hyperosmia

increased sensitivity of smell

dysosmia

distortion of normal smell

Pituitary gland and hypothalamus lesions

• symptoms often manifest systemically (ie electrolyte and metabolic abnormalities secondary to adrenocortical, thyroid, and antidiuretic hormone dysregulation)

• changes may occur in visual field or acuity

• syndrome of inappropriate antidiuretic hormone secretion (SIADH) is often a complication

• volume status and hyponatremia may occur

• anorexia or overeating (hunger cues)

Peripheral nerve and neuromuscular junction lesions

affect ability to maintain proper nutrition from fluctuating weakness and easy fatigability in voluntary muscle movements

Guillain-Barré syndrome and myasthenia gravis

are autoimmune disorders that damage the PNS —>respiratory and limb muscles affected, plus the impact of weakness on oral, pharyngeal, and laryngeal muscles

Spinal cord lesions are much ___ common than brain tumors

less

Spinal cord lesions cause

lower motor neuron signs at the level of the lesion and upper motor signs in segments below the level of the lesion

What is the most common pathologic condition in the spinal cord region

Spinal cord injury (SCI)

Injuries to spinal cord may result in ______ dysfunction requiring assisted ventilation

respiratory

Brain consumes up to ___% of the energy needed to maintain resting metabolic rate

20%

~__% of the brain is water

75

__% of the remaining brain matter is made of lipids

60

The brain is sensitive to ____ _____ & _____

oxidative stress inflammation

The brain does not have access to as many __________ enzymes as other area of the body

endogenous antioxidant

Dysphagia definition

difficulty swallowing

Aspiration definition

inhalation of foreign matter (food, liquid) into lungs

Aspiration pneumonia results from the ____ in saliva that is carried into the ____

bacteria; lungs

Development of aspiration pneumonia is contingent on the condition of the ______ system, _____ and ___ of the aspirated bolus, and potential _____ present

• pulmonary

• volume and pH

• pathogens

What part of the body creates the greatest risk for aspiration pneumonia

oral cavity

Regarding dysphagia, coordination of care should be with a ____

Speech Language pathologist (SLP)

What is the first phase of swallowing and is it voluntary or involuntary?

Oral; voluntary

What happens in the oral (first) phase of swallowing

• food is formed into a bolus

• tongue pushes the food to the back of the oral cavity, squeezing it against the hard and soft palate

What are some potential issues for people during the oral (first phase of swallowing)

Dental issues, someone can’t move mouth or jaw, drooling, pocketing of foods (dementia), weak lip/mouth muscles

What is the second phase of swallowing and is it voluntary or involuntary?

pharyngeal; involuntary

What are the four events that must occur in rapid succession during the pharyngeal (2nd) phase

After the bolus is propelled past the faucial arches:

• the soft palate elevates to close off the nasopharynx and prevent oropharyngeal regurgitation

• the hyoid bone and larynx elevate, causing the epiglottis to flip downward + vocal cords adduct to protect the airway

• pharynx contracts while cricopharyngeal sphincter relaxes, allowing food to pass into the esophagus

• Breathing resumes with exhalation at end of the pharyngeal phase

Symptoms of poor coordination during the pharyngeal (2nd) phase of swallowing

gagging, choking, nasopharyngeal regurgitation

What is the third phase of swallowing and is it voluntary or involuntary?

Esophageal; involuntary

What happens during the esophageal (third) phase of swallowing

bolus continues through the esophagus into the stomach

How long does a normal esophageal transit take

8-20 seconds

Difficulties that occur during this phase are generally the result of a _______ _______, but neurologic disease cannot be ruled out

mechanical obstruction

What does IDDSI stand for

International Dysphagia Diet Standardization Initiative

Level 0 of IDDSI

thin

• flows like water, can drink through nipple, cup, straw

Level 1 of IDDSI

slightly thick

• thicker than water, requires more effort, flows through straw, syringe, nipple

Level 2 of IDDSI

mildly thick

• flows off a spoon, sippable but requires more effort to drink through straw

Level 3 IDDSI

Moderately thick + liquidized

• can be drunk from a cup; effort required for using a straw

• cannot be molded on a plate nor eaten with fork; no chewing needed; no lumps, fibers, particles

Level 4 of IDDSI

Extremely thick + pureed

• eaten with a spoon though a fork is possible

• can’t be drunk from a cup

• will maintain molding on a plate

• falls off spoon when tilted and holds shape

• no lumps; not sticky

Level 5 of IDDSI

Minced and moist

• eaten with a fork or spoon, can be shaped or scooped

• no separate thin liquid

• small lumps visible; lumps mashed with tongue pressure

• 2 mm for pediatrics; 4 mm for adults

Level 6 of IDDSI

soft and bite sized

• can be mashed down with pressure form a fork; knife not required to cut

• chewing required before swallowing

• no separate thin liquid

• bite-sized pieces; 8 mm pediatric; 15 mm adults

Level 7 of IDDSI

regular/easy to chew

• normal, everyday foods

• hard, tough, chewy, fibrous, stringy, dry, crispy, crunchy, or crumbly textures permitted

• mixed consistency foods and liquids

What is the frazier free water protocol?

It allows for drinking water in those who otherwise require thickened liquids

What are the four assumptions the frazier free water protocol is based upon?

• aspiration of water poses little risk to the patient if oral bacteria associated with the development of aspiration pneumonia can be minimized

• allowing free water decreases the risk of dehydration

• allowing free water increases patient compliance with swallowing precautions and improves quality of life

• good oral hygiene is a key ingredient of the water protocol and offers other benefits to swallow function

MNT for someone with a texture modified diet (2 points)

• vitamin and mineral supplementation (chewable or liquid form)

• Small, frequent meals

Most neurologic symptoms arising from primary nutritional deficiency or excess can be corrected with _______

increased or decreased food or supplement intake

Dietary deficiencies/toxicities of which four vitamins can result in neurologic symptoms

vitamin B12, folate, niacin, thiamin

What is Wernicke-Korsakoff syndrome?

It is a serious neurological condition caused by a severe and acute thiamin deficiency, secondary to alcoholism

Neurologic disorders could stem from ____ sensitivity (headaches, ataxia, brain atrophy)

gluten

How does a cerebrovascular accident (CVA) AKA stroke occur?

Occurs when brain’s blood supply is suddenly interrupted or when a BV in brain bursts causing brain cells to die within minutes, either due to loss of oxygen and nutrients or bleeding around the brain

Strokes could be preceded by…

transient ischemic attacks: brief attacks of cerebral dysfunction of vascular origin with no persistent neurologic defect

What are stroke/CVA risk factors?

hypertension and smoking are major contributors; other: poor diet, obesity, coronary heart disease, diabetes, physical inactivity, excessive alcohol intake, genetics

What are 3 stroke medical management interventions?

• rehabilitative services (PT, OT, SLP)

• Thrombolytic drugs (lysing clots)

• Surgical procedures

What is an embolic stroke?

when cholesterol plaque is dislodged from a proximal vessel, travels to the brain, and blocks an artery (middle cerebral artery)

What is a thrombotic stroke?

when cholesterol plaque within an artery ruptures, platelets subsequently aggregate to clog an already narrowed artery (aggravated by atherosclerosis, HTN, DM, & gout)

What are the two types of intracranial hemorrhages?

• intraparenchymal hemorrhage

• intracranial hemorrhage

What is an intraparenchymal hemorrhage?

when a vessel inside the brain ruptures, causing bleeding directly into the brain tissue (parenchyma)

What is a subarachnoid hemorrhage?

occurs as result of head trauma but more often as a result of a ruptured aneurysm of a vessel in the subarachnoid space

What are 3 eating patterns/diets associated with lower risk of strokes

Mediterranean diet, DASH, plant-based

MNT for strokes (foods/drinks to consume)

fruits and veggies, nuts, whole grains (and low glycemic load carbs), legumes, fish, olive oil, moderate intake of dark chocolate, low-fat milk/dairy, moderate intake of coffee, tea (esp green tea), moderate intake of alcohol, at least 25 g fiber

Stroke MNT: vitamins and minerals

calcium, magnesium, potassium, folate, vitamin C, vitamin D

What dietary patterns may increase the risk of strokes?

Western diet, processed meat, sodium (<2g/day), saturated fats, excessive sweetened beverages

Use extreme caution when prescribing _____ supplements, unless needed to correct proven deficits; may increase risk of myocardial infarction and stroke esp in post-menopausal women

calcium

Both higher dietary and supplemented vitamin __ intakes are associated with increased risk of hemorrhagic stroke

vitamin E

What is a traumatic brain injury (TBI)?

a brain injury, skull fractures, extraparenchymal hemorrhage (epidural, subdural, subarachnoid), or hemorrhage into the brain tissue itself (intraparenchymal or intraventricular hemorrhage)

Traumatic brain injury (TBI): what is a concussion?

brief loss of consciousness, <6hrs, with no damage found on computed tomography (CT) or magnetic resonance imaging (MRI)

Traumatic brain injury (TBI): what is a contusion (bruise)?

characterized by damaged capillaries and swelling, followed by resolution of the damage; large contusions may dramatically increase ICP and may lead to ischemia or herniation; can be detected by CT or MRI scans

Traumatic brain injury (TBI): what is a diffuse axonal injury?

Results from the shearing of axons by a rotational acceleration of the brain inside the skull (car crash, falls, shaking); damaged areas are often found in the corpus callosum (the bridge between the two hemispheres) and the upper, outer portion of the brainstem

Traumatic brain injury (TBI): what are the two types of skull fractures?

open or closed (exposed to air or not)

Open skull fractures increase the risk of…

infection (osteomyelitis) and carry an increased risk for meningitis because the dura mater is often violated

Traumatic brain injury (TBI): what are epidural and subdural hematomas

Life-threatening brain bleeds caused by trauma

• often corrected by surgical intervention

• volume of lesions often displaces the brain tissue and may cause diffuse axonal injury and swelling; may cause herniation of brain contents through various openings of the skull base —>consequent compression and ischemia of vital brain structures often rapidly lead to death

MNT for TBIs: What are the Brain Trauma Foundation Guidelines (3)?

• feed patients to replace basal caloric needs within 5-7 days postinjury to decrease mortality

• use trans-gastric jejunal feeding to reduce incidence of ventilator associated pneumonia

• Nitrogen needs are higher at 14-25g/day for fasting, compared to normal fasting of 3-5g/day

Hypermetabolism due to TBIs contribute to increased..

energy expenditure

What is the Glasglow coma scale?

based on a 15-point scale for estimating and categorizing the outcomes of brain injury

What supplement may be helpful for TBIs to support cell membrane integrity? What are dietary sources?

Citicoline supplementation of 500-1000 mg/d

Dietary sources of choline: eggs, beef, soybeans, chicken, cod shiitake mushrooms, red potatoes

TBIs: immune-enhancing nutrition

glutamine, arginine, omega-3 fats

What is a complete spinal cord injury (SCI)?

a lesion in which there is no preservation of motor or sensory function more than three segments below the level of the injury

What is an incomplete spinal cord injury (SCI)?

some degree of residual motor or sensory function more than three segments below the lesion

______ of the SCI and the ______ of the descending axons determine the extent of paralysis

• Location

• Disruption

What is tetraplegia (AKA quadriplegia)?

When the injury to the spinal cord affects all four extremities

What is paraplegia?

When SCI location only involves the lower extremities

3% of patients with complete spinal cord insults recover some function after __ hours

24

Initially in SCIs, paralytic ileus may occur but often resolves within ___ hours postinjury

72 hours

In the acute phase of SCIs, calorie estimates should be based on energy expenditure measured by ______ and are at least 10% ____ than predicted levels

• indirect calorimetry

• lower

In the acute phase of SCIs, what are the protein needs?

2 g/kg of IBW

People with SCIs may benefit from what supplementation?

fish oil (DHA + EPA)

What are some long term effects of SCIs?

impaired ability to prepare food and self-feed; presence of constipation, pressure ulcers, changes in weight status, and pain

In the rehabilitation phase, tetraplegics may require ~__-__% fewer calories than conventional estimated needs

~25-50%

individuals with SCI have significantly _____ fat mass and ____ lean mass; plus a predisposition to what disease?

• higher fat mass

• lower lean mass

• osteoporosis (calcium and vitamin D supplementation to help)