Normal

• neuromotor function

  • somatic nervous system - voluntary movements -> skeletal muscle
  • autonomic nervous system (ANS) - involuntary movements -> visceral functions
  • sympathetic (fight or flight)
  • parasympathetic (rest and digest)
• neuromotor function alterations

  • muscle tone alterations: dystonia - disorders of muscle tone
  • atonia - absence of muscle tone
  • hypotonia - decreased muscle tone
  • hypertonia - increased muscle tone
• neuromotor function alterations

  • movement alterations: dyskinesia - abnormal muscle movement
  • akinesia - absence of muscle movement
  • hypokinesia - decreased muscle movement (slowed)
  • hyperkinesia - increased muscle movement (tremors, ticks, gait disturbances or restlessness)
• neuromotor function alterations

  • complete motor performance alterations: upper motor neuron or lower motor neuron
  • paresis - weakness of muscle motor function (reduced ability to move)
  • paralysis - loss of muscle motor function (inability to move)
• dystonia - disorders of muscle tone
• dystonia

  • etiology
  • trauma to motor system components (MVC, sports injuries, falls)
  • decreased perfusion to nerve tissue -> hypoxia and atherosclerosis
  • metabolic disorders
  • diabetes, renal disease (damage to peripheral nerves)
  • drug toxicity or side effects
  • tumors involving nervous system tissue
  • end result -> change in motor input to muscle = impaired action potential and conduction
• dystonia

  • patterns of dystonia (change in muscle tone)
  • flaccidity -> no resistance to stretch; muscle is paralyzed
  • usual cause: LMN disease (spinal or motor nerves, lower motor neuron disease)
  • spasticity -> lack of reflex control with continuous or intermittent spasm
  • hyperactive reflexes
  • usual cause: UMN disease (upper motor neuron disease) includes the brain
  • rigidity - continuous or intermittently firm muscles (hypertonia state)
• dystonia

  • spinal cord injury - complete or partial resection of spinal cord
  • primary - mechanical injury itself
  • force-induced
  • acceleration-deceleration (car accidents)
  • rotation with deformation (head or butt twists and tears the spinal cord)
  • compression (force on top of head or butt that compresses cord)
  • penetration (bullet, stabbing)
• dystonia

  • spinal cord injury
  • secondary (inflammation); (something happens and injury is further extended due to edema)
  • secondary injury: extension of injury due to edema
  • impedes blood flow, causes tissue hypoxia
  • hemorrhagic necrosis (bleeding within area necrosis the tissue)
• dystonia

  • spinal cord injury
  • complete transection
  • blockage of neurotransmission from UMNs to LMNs results in immediate loss of voluntary movement with paralysis below level of injury
  • quadriplegia (all four limbs)
  • paraplegia (bottom half gone)
  • hemiplegia (left or right side gone due to right or left brain injury, respectively)
  • paralysis of respiratory muscles with higher injury (C3 or HIGHER)
  • anesthesia below level of injury
  • initial loss of reflex activity
• dystonia

  • spinal cord injury
  • spinal shock- period immediately after traumatic event (complication of spinal cord injury)
  • loss of bladder and bowel control
  • lack of descending inputs from higher centers due to interruption of neural pathways to remainder of CNS
  • absent autonomic reflexes results in vasodilation
  • hypotension
  • loss of temperature control below injury
  • return of reflex activity as spinal shock subsides (7-20 days to resolve)
  • muscle and bladder spasms common stimuli
  • can stimulate autonomic hyper-reflexia
• dystonia

  • spinal cord injury
  • autonomic dysreflexia (hyper-reflexia)- life threatening excessive, uncontrolled ANS response
  • caused by stimulation of sensory receptors below the level of injury
  • sudden onset of hypertension
  • blurred vision, headache, bradycardia
• dystonia

  • spinal cord injury
  • incomplete (partial) spinal cord injury
  • symptoms vary depending on the area
• dystonia

  • spinal cord injury
  • intervertebral disk injury
  • herniation: nucleus pulposus herniates through annulus fibrosus
  • clinical manifestations: depend on area (neck or lumbar spine most common)
  • pain
  • numbness
  • reflexes
• dyskinesia - abnormal muscle movement
• dyskinesia

  • hyperkinesia - increased muscle movement (tremors, tics, gait disturbances) = movement is excessive
  • Huntington's Chorea - inherited autosomal dominant disease
  • severe degenerative disorder involving basal ganglia and cerebral cortex
  • associated with excess dopamine activity within the basal ganglia
  • loss of gamma-aminobutyric acid (GABA) in basal ganglia
  • progresses to frontal cerebral atrophy (loss of brain matter)
  • nonrepetitive, irregular, involuntary rapid muscle contractions beginning in face, arms
  • progressive dementia
• dyskinesia

  • hyperkinesia
  • alcohol withdrawal (delirium tremens: DTs)
  • overactive autonomic nervous system results in tremors, hallucinations, seizures, and increased BP
  • (chronic alcohol depresses nervous system and when that is taken away there is an exaggerated response)
• dyskinesia

  • hyperkinesia
  • Tourette's syndrome - neurotransmission problem involving limbic system
  • lack of muscle coordination, involuntary movements, vocal abnormality
• dyskinesia

  • hypokinesia - decreased muscle movement
  • Bell's palsy - facial nerve paralysis (7th cranial nerve) usually following inflammatory condition
  • one sided facial droop, weakness, or paralysis
  • stroke
• dyskinesia

  • combination
  • cerebral palsy - lesion on or damage to brain during fetal development
  • motor involvement
  • symptoms depend on area of brain damaged
  • spastic CP most common: spastic movements, coordination and gait problems, impaired speech
• dyskinesia

  • combination
  • Parkinson's Disease - degeneration of neurons that produce and store dopamine (neurotransmitters) with increased amounts of cholinergic activity
  • affects motor system due to low dopamine levels = increased cholinergic activity (excitation)
• dyskinesia

  • combination
  • Parkinson's disease
  • classic manifestations: tremor at rest
  • rigidity
  • bradykinesia
  • short, shuffled, quick gait
  • voice changes (monotone, soft), loss of smell
  • excessive daytime sleepiness, REM behavior disorder (act of dream)
  • diminished autonomic movements result in mask-like facial expression and infrequent blinking, (excess salivation)
  • orthostatic hypotension, neurogenic bladder, constipation
  • depression/anxiety, compulsive behaviors, hallucinations
  • advanced -> intellectual deterioration and dementia
• Mononeuropathies: damage to single nerve or nerve group
• mononeuropathies

  • carpal tunnel syndrome - compression of median nerve
  • etiology: trauma or inflammation (tendon) from repetitive use of hand
  • clinical manifestations: pain, loss of grip, numbness or tingling
  • can be repaired
• Demyelination disorders

  • polyneuropathies: conduction velocity depends on diameter of axon and whether it is myelinated: channels for ions
• Demyelination disorders

  • polyneuropathies
  • definition of demyelination disorder:
  • precipitating event (infection, trauma, inflammation)
  • damage causes degeneration of myelin which causes slowing and cessation of neurotransmission
• Demyelination disorders

  • polyneuropathies
  • multiple sclerosis: autoimmune or genetic (women age 20-40)
  • destruction of myelin and plaque formation in brain and spinal cord (demyelination)
  • inflammation around plaque -> scarring replaces axons affecting motor, sensory, and autonomic nerves
• Demyelination disorders

  • polyneuropathies
  • Guillain-Barre syndrome - acute, sudden onset
  • progressive inflammation of peripheral and sensory nerves causing myelin damage in ascending fashion
  • demyelination followed by remyelination
• Demyelination disorders

  • polyneuropathies
  • Amyotrophic lateral sclerosis (Lou Gehrig's disease) (ALS, 40-50 years)
  • NON-inflammatory degeneration of motor neurons in cortex, brain stem, and spinal cord
  • initially muscle weakness and fatigue in one muscle group
  • speech, swallowing issues, drooling, no change in mentation
  • aware, alert, orientated throughout disease progression even in advanced stages
• Demyelination disorders

  • polyneuropathies
  • multiple sclerosis, Guillain-barre syndrome, and ALS
  • clinical manifestations
  • weakness, gait disturbances, fatigue
  • speech
  • autonomic system
• Neuromuscular junction disorder

  • myastenia gravis: chronic, progressive disorder of neurotransmission affecting peripheral nerves
  • autoimmune production of autoantibodies (IgG antibody complexes) produced by thymus gland
  • acetylcholine receptor sites blocked at neuromuscular junction
  • clinical manifestations: eye muscles drooping, progressing down the face and proximal muscles