Neurological System KNH 413. Nervous System Central nervous system (CNS) ◦ Processing of sensory information followed by responsive motor signal Peripheral

Neurological SystemNeurological System

KNH 413

Nervous SystemNervous System

Central nervous system (CNS)◦Processing of sensory information

followed by responsive motor signalPeripheral nervous system (PNS)

◦Transmission of impulses between CNS and peripheral organs

◦Somatic division - to and from CNS◦Autonomic division – involuntary

Sympathetic Parasympathetic


Cellular level - functional cells◦ Neurons – cell to cell transmission

Soma Dendrites Axon Axon terminals

◦ Glial cells - surround neurons

◦ Neurological disorders result from dysfunction of these cells or their communication


Cellular level - functional cells◦Neuron to neuron communication is

through release of neurotransmitters into synapses Neurotransmitters specific to synapses See Table 22.1 – neurotransmitters

◦Endorphins and neuromodulators, nitric oxide, and CO2 act like neurotransmitters

Central Nervous SystemCentral Nervous SystemBrain

◦ Corpus callosum – communication between hemispheres

◦ Distinct areas responsible for specific functions Frontal lobe - thinking, planning, emotion Parietal lobe – pain, touch, taste, temp., pressure Temporal lobe – hearing, memory, emotions Occipital lobe - visual Limbic lobe – emotional, sexual

◦ Spinal cord – messages to rest of body

Neurological DisordersNeurological Disorders

Epilepsy and seizure disorders – spontaneous, uncontrolled electrical activity among cerebral neurons◦Epilepsy – more than 2 unprovoked

seizures ◦Partial or generalized; simple or

complex◦Signs and symptoms depend on type

and location of focal point in brain

Neurological DisordersNeurological DisordersEpilepsy and Seizure Disorders

◦Tonic-clonic most common Loss of consciousness, stiffening of limbs

◦EEG used for diagnosis◦Treatment: epilepsy medications

Significant drug-nutrient interactions esp. phenytoin and folate

◦Ketogenic diet High fat (70-90% of kcal) Maintains state of ketosis which may

change neuron metabolism


Epilepsy and seizure disorders – nutrition implications◦Inadequate nutrient intake

Ensure adequate energy

◦Limited food choices◦Drug-nutrient interactions

Potential weight gain or loss

◦ ketogenic diet


Stroke – disruption of brain function d/t blockage or interruption of blood flow◦Ischemic stroke◦Hemorrhagic stroke◦TIA◦Aneurysm


Stroke◦Non-modifiable risk factors

Age, gender, ethnicity, genetics

◦Modifiable risk factors Htn., CVD, DM, hyperlipidemia, carotid

stenosis, cigarette smoking, alcohol use, illicit drug use, diet, oral contraceptive use, exercise


Stroke◦Signs/symptoms

Loss of vision or speech, paralysis, muscle weakness, change in mental status

◦Diagnosis National Institutes of Health Stroke Scale CT, MRI, PET imaging

Neurological DisordersNeurological DisordersStroke

◦Treatment Medical support, thrombolysis,

anticoagulants, neuroprotection Aspirin Rehabilitation


Stroke - Nutrition Implications/Interventions◦Impairment of ability to chew, swallow,

self-feed◦Dysphagia ◦Individualize nutrition support◦Modify consistency of food or liquids,

positioning of patient, swallow exercises◦Manage modifiable risk factors

Progressive Neurological Progressive Neurological DisordersDisorders

Neurodegenerative disorders◦Nutrition needs and status affected by

progression of disease◦Ethical decisions regarding nutrition

support ◦Nutrition therapy similar among

progressive disorders


Parkinson’s disease - neuromuscular, neurodegenerative disease caused by loss of dopamine-producing cells◦Progressive loss of dopamine;

imbalance between excitatory and inhibitory communication

◦Resting tremor, rigidity, bradykinesia, stooped posture, shuffling gait, cognitive dysfunction


Parkinson’s disease◦Primarily treated with L-dopa, other

medications, surgery◦Drug-nutrient interactions important

concern ◦Limit supplement levels of B6 to 15 mg

◦Closely monitor weight status◦Manage GI symptoms; gastroparesis


Parkinson’s disease◦High protein may interfere with L-dopa

levels Limit overall protein to .5-1 g/kg with even

distribution throughout all meals Limit protein during waking hours with

increased amounts at evening meal and before bed

High CHO-low protein ratio


Amyotrophic Lateral Sclerosis (ALS) - Lou Gehrig’s disease; affects motor neurons◦Destruction of neurons involved in

controlling stimulation of muscles◦Dead neurons replaced with non-

functional fibrous cells◦Muscle atrophy◦Bulbar and spinal forms


ALS – clinical manifestations◦Asymmetric muscle weakness and

atrophy, hyperflexia, fasciculations, leading to paralysis and vent and nutrition support

◦Treatment – Riluzole and control of symptoms

◦Address specific nutritional needs Texture, nutrient density, nutrition support


Guillain-Barré - acute peripheral nervous system disease characterized by progressive paralysis◦Autoimmune response to infectious

trigger◦Damage to myelin sheath, axons,

sensory nerves, roots◦Rapidly progressive paralysis involving

all limbs, dysphagia, respiratory failure


Guillain-Barré◦Treatment – high-dose IV

immunoglobin, plasmapheresis◦Full recovery can occur within several

months◦Modifications may be needed related to

mechanical ventilation, difficulty swallowing, chewing


Myasthenia Gravis – progressive neuromuscular disorder affecting skeletal muscles◦Autoimmune reaction destroys cellular

receptors for acetylcholine◦Muscles tire easily, muscle weakness

with physical activity◦May affect face, eyes, arms, legs◦Periods of remission and exacerbation


Myasthenia Gravis◦No cure◦Immunosuppressants, other

medications, stem cell transplant, removal of gland, plasmapheresis

◦Assess oral intake, meal preparation ability Increase nutrient density, modifications in

timing of meals Texture, consistency


Multiple Sclerosis – demyelination within cells within the CNS, inflammation, development of scar tissue; RRMS, SPMS, PPMS◦Genetic, autoimmune, infectious◦Anecdotally linked to high fat and

animal protein with low B12

© 2007 Thomson - Wadsworth

MRI results showing sclerotic plaques in MS


Multiple Sclerosis◦Symptoms vary depending on nerve

affected◦Numbness, tingling, ataxia, weakness,

visual problems, dysphagia, constipation, bladder dysfunction…

◦Immunosuppressive therapy, corticosteroids, other meds


Multiple Sclerosis◦Assess drug-nutrient interactions◦Supplement with omega-3 fatty acids

(?)◦Restrict saturated fat (?)◦Supplement antioxidants◦Vitamin D, calcium◦Weight management◦Regular exercise


Dementia – loss of memory, impairment in language, judgment, calculation, problem solving; Alzheimer’s disease◦Early-onset, late-onset, familial (type 1)◦Types 1, 2, 3, 4

Apolipoprotein E (type 2) Beta amyloid (3, 4)


Dementia - pathophysiology◦Beta amyloid plaques develop◦Plaques clump together and prevent

neurons from functioning normally◦Protein tau forms neurofibrillary tangles

within neurons


Dementia – clinical manifestations◦Affect memory, reasoning, language◦Cause disorientation, abstract thinking,

personality disorders, loss of purposeful action

◦Treated with medications◦Vitamin E for prevention and plaque

formation◦Prevent malnutrition


Dementia – problems affecting food intake◦Aphasia◦Apraxia◦Agnosia◦Amnesia◦Anorexia

Neurotrauma and Spinal Neurotrauma and Spinal Cord InjuryCord Injury

Traumatic brain injuries (TBI)◦d/t accidents, falls, violence, firearms,

sports◦Lacerations, crushing of brain tissue,

cerebral edema, hemorrhage, hematoma, infection

◦Swelling, bleeding, seizure, stroke, coma

◦Glasgow Coma Scale


Traumatic brain injuries (TBI)◦Focus on stabilization◦Prevent further complications◦Promote rehabilitation◦Nutrition therapy integral part of team


Traumatic brain injuries (TBI)◦Hypermetabolism◦Hyperglycemia◦Insulin resistance◦Increased gluconeogenesis◦Lipolysis◦Catabolism as evidenced by nitrogen

excretion


Traumatic brain injuries (TBI)◦Requires aggressive nutrition support

See Table 22.9

◦Energy at 140% of REE – non-paralyzed, 100% - paralyzed

◦Infants, children higher◦Protein 15-20% of energy, kcal:nitrogen

ratio of 125-150:1

© 2007 Thomson - Wadsworth


Spinal Cord Injury (SCI)◦Paraplegia◦Quadriplegia◦Level of injury determines signs and

symptoms◦Nutrition therapy for complications such

as bowel dysfunction, UT problems, pressure sores, weight control


Spinal Cord Injury (SCI)◦Nutritional needs similar to TBI◦Inflammatory and metabolic stress◦Increased energy needs,

gluconeogenesis, lipolysis, hyperglycemia, insulin resistance

◦Rehabilitation◦Prevent excessive weight gain◦Skin care and decubitus ulcer

prevention


Spinal Cord Injury (SCI) ◦Protein requirements elevated -

negative nitrogen balance persisting up to 7 weeks post-injury Provide 1.5-2 g/kg protein

◦Energy requirement 30-35 kcal/kg; progress to: 22.7 kcal/g – quadriplegia 27.9 kcal/g - paraplegia


Spinal Cord Injury (SCI) ◦Adequate hydration and fiber◦Vitamin & mineral supplementation

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Neurological System KNH 413. Nervous System Central nervous system (CNS) ◦ Processing of sensory information followed by responsive motor signal Peripheral