1. Disorders of Movement, Sensation, and Mental Function Chapter 21
Dr. Gary Mumaugh and Dr. Bruce Simet
University of Northwestern St. Paul

2. Context for Assessment of Dysfunction
Autonomic Nervous System (ANS) regulates homeostatic, reactive, and sensory functions
Efferent nerves traveling out of CNS
2 Divisions:
Parasympathetic
Sympathetic
Brain Stem regulates breathing and alertness and directs nerve connections
Midbrain, Pons, and Medulla
(see Table 21.2 for functions)

3. Cranial Nerves have sensory and motor functions
12 nerves (see Table 21.3 for functions)
Motor Neurons control voluntary movement
See Table 21.5 for Assessing Disorders of Movement
See Table 21.6 for Muscle Tissue Disorders

4. Disease Categories in Neurology
Myopathy – muscle diseases
Myelopathy – cord compression diseases
Neuropathy – nerve diseases
Radiculopathy – nerve root compression
Plexopathy – nerve plexus compression
Encephalopathy – brain diseases

5. Disorders of Neuromuscular Junction
Myasthenia Gravis (MG) Lambert-Eaton myasthenic syndrome (LEMS)

6. Myasthenia Gravis (MG)
Characterized by skeletal muscle weakness and malaise
Caused by an autoimmune disorder
Antibodies are produced against acetylcholine (Ach) receptors.
Antibodies bind to the receptor and are not easily released.
Bound antibodies stimulate phagocytosis of endplate muscle membrane
Bound antibodies induce degradation of receptor channels
Symptoms include Myasthenic crisis – acute muscle weakness resulting in inability to swallow, clear secretions, or breathe well.

10. Lambert-Eaton Myasthenic Syndrome (LEMS)
Similar to MG, but weakness improves with exertion
Caused by impaired release of Ach
Symptoms: Muscle weakness, dry mouth, decreased sweating, constipation
60% of patients have lung carcinomas prior to diagnosis

12. Peripheral Nerve Disorders
Diffuse Polyneuropathies
Guillain-Barre Syndrome
Entrapment Syndromes
Charcot-Marie-Tooth Disease (Peroneal Muscular Atrophy)

13. Diffuse Polyneuropathies
Characterized by peripheral nerve lesions
Caused by a variety of metabolic, toxic, and nutritional conditions
Symptoms include Glove-and-stocking anesthesia
Characterized by loss of sensation in the hands and feet; loss of larger fibers leads to impaired proprioception

14. Neuropathy Affects distal nerves in a glove like pattern
Paresthesias, weakness, sensory loss
Common in diabetes, RA, alcoholic abuse and B12 deficiency

15. Guillain-Barre Syndrome
Characterized by immune-mediated attack on sheaths of well-myelinated fibers
Typically occurs after an upper respiratory tract or flu viral infection. Idiopathic.
Symptoms: Varying degrees of weakness and tingling sensation in the legs leads to complete paralysis.
85% make complete recovery within months

16. Entrapment Syndromes
Characterized by focal slowing and loss of intensity of motor and sensory signals
Causes of Peripheral nerve lesions:
Local compression and trauma
(Ex. Saturday night palsy or tardy ulnar palsy)
Overuse, repetitive motion injury
(Ex. Pronator terres syndrome)
Combination of overuse and genetic predisposition
(Ex. Carpal tunnel syndrome)
Symptoms: Muscle wasting, eventually irreversible fibrosis

17. Charcot-Marie-Tooth Disease (Peroneal Muscular Atrophy)
Heritable, autosomal dominant
Characterized by atrophy of peripheral motor and sensory neurons
Characterized by onset in late adolescence
Symptoms: Weakness and atrophy in distal muscles of the legs

18. Disorders of the Spinal Cord
Syringomyelia
Subacute Combined Degeneration of the Cord (Lichtheim’s disease)
Amyotrophic Lateral Sclerosis (ALS)
Spinal Muscular Atrophies of Infancy and Childhood
Friedreick’s Ataxia

19. Syringomyelia
A rare condition that produces a syrinx (fluid filled cavity) in the central spinal cord.
Syrinx caused by spinal cord trauma
Cause is idiopathic
Symptoms include Shawl anesthesia - pain and temperature insensitivity in arms and upper trunk

20. Subacute Combined Degeneration of the Cord (Lichtheim’s disease)
Characterized by a generalized lesion of the posterior half of the spinal cord
Usually caused by chronic alcohol abuse

21. Amyotrophic Lateral Sclerosis (ALS)
Also called Lou Gerhig’s disease and Motor Neuron disease
Characterized by lower motor neuron lesion
and lateral scarring because of upper motor neuron lesion
Fatal; 80% of people die within 3 years of diagnosis; no effective treatments
Caused by: Environmental toxins, slow viruses
Symptom: Excitotoxicity (destructive response of neurons to excessive stimulation)

22. ALS – Amyotrophic Lateral Sclerosis
Degenerative disease of UMN & LMN lesions
Unknown cause autoimmune disorder
Usually fatal in 1-2 years
S & S
Weakness of hands, loss of grip, tripping, falling
Disease begins distally and works proximally
No sensation loss, no pain, no mental loss
Difficulty speaking and swallowing, drooling
Death in 1-3 years from respiratory failure
Diagnosis
History and muscle biopsy

23. Amyotrophic lateral sclerosis (ALS)
Classic ALS—“Lou Gehrig disease”
Diffusely affects upper and lower motor neurons of the cerebral cortex, brain stem, and spinal cord (corticospinal tracts and anterior roots)
Disease leads to progressive weakness leading to respiratory failure and death
Patient has normal intellectual and sensory function until death

24. ALS Lou Gehrig's Disease

25. Spinal Muscular Atrophies of Infancy and Childhood
Rare, heritable motor disorders that leave sensory capacities intact
Werdnig-Hoffman disease (floppy baby syndome)
Onset in infancy, rapidly progresses
Symptoms: Motor degeneration, but normal intelligence and development

26. Friedreick’s Ataxia Fatal motor-sensory disorder
Chronic, average course of years
Half of patients diagnosed develop cardiomyopathies
Caused by autosomal recessive disorder affecting production of frataxin
Results in mitochondrial dysfunction and free radical toxicity
Symptoms: Spinal cord is small and nerve fibers are depleted

27. Disorders Arising in the Basal Ganglia
Parkinson’s Disease
Huntington’s Disease

28. Parkinson Disease
Severe degeneration of the basal ganglia (corpus striatum) involving the dopaminergic nigrostriatal pathway
Parkinsonian tremor
Parkinsonian rigidity
Parkinsonian bradykinesia
Postural disturbances
Autonomic and neuroendocrine symptoms
Cognitive-affective symptoms

29. Parkinson’s Disease Slow, degenerative CNS disorder
Course of disease lasts years
Affects twice as many men as women
Caused by damage to the substantia negra
Normally provides outflow pathway from basal ganglia to the cortex and a feedback loop to the caudate and putamen

30. Typically idiopathic Symptoms
Impairs flow of motor programs from the basal ganglia
Causes bradykinesia (slow movement) and difficulty initiating movement
Loss of feedback loop expresses itself as resting tremor
Gradual loss of dopamine-producing cells
Typically idiopathic
Known to result from lesion by toxins
Symptoms
Muscle rigidity, bradykinesia, palsy (resting tremor), tiredness and weakness, poor balance, dementia

32. Degenerative disorder of the basal ganglia
Usually in men over 50
One million cases in USA
S & S
Four classic symptoms:
Resting muscle tremor
Slowness of voluntary movement – bradykinesia
Impaired postural reflexes – simian posture
Inability to maintain balance when being shoved or bumped
Other symptoms:
Increased muscle tone or rigidity
Small “steppage” gaits
Frozen facial expression – “masked face”
Handwriting changes - micrographia

33. Diagnosis Treatment No classic diagnostic tests or lab studies
Dopamine is used for the first five years
Anticholinergic drugs, MAO inhibitors, Symmetryl
The meds do not stop the progression, they only provide symptomatic relief
Surgical treatment is currently experimental
Implanting cadaver or fetal basal ganglion cells
Progress and Promise in Parkinson's Disease

34. Huntington’s Disease
Characterized by dominant genetic defect on chromosome 4
Dementia consists of progressive loss of cognitive function
Massive cellular loss from caudate and putamen
Course of disease is about 15 years
Symptoms: rapid, writhing contortions of hands, arms, face, trunk and profound dementia

36. Huntington Disease Also known as “chorea”
Autosomal dominant hereditary-degenerative disorder
Severe degeneration of the basal ganglia (caudate nucleus) and frontal cerebral atrophy
Depletion of gamma-aminobutyric acid (GABA)

37. Cerebral Palsy
General term that applies to disabilities that derive from perinatal brain injury
Movement problems, sensory and cognitive impairment
CP is commonly classified based on the area of the body most affected
Quadriplegic CP – all 4 limbs affected
Diplegic CP – lower limbs affected more than upper
Monoplegic CP – only 1 limb affected
Diplegic/Paraplegic

38. Multiple Sclerosis (MS)
Possibly caused by an interaction between a viral illness in teen years and a genetic predisposition
Arises through a single mechanism of lesion
Focal, chronic, progressive
Areas of demyelination are called plaques
Confined to white matter
Optic neuritis is often the first symptom
Chronic exacerbation and remission
Triggers: infection, medication, stress, fatigue

39. Demyelinating Disorders
Multiple sclerosis (MS)
MS is a progressive, inflammatory, demyelinating disorder of the CNS
Types
Mixed (general)
Spinal
Cerebellar

42. Common symptoms:
Visual impairment or blindness
Hyperreflexia
Difficulty urinating
Difficulty swallowing
Extreme intolerance of heat
Emotional outbursts
Depression or euphoria

43. Alzheimer’s Disease Dementia is the loss of ordered neural function
Main characteristic of Alzheimer’s is a slow progression of dementia, 5 years
Initially only short-term storage and retrieval is affected
Gradually well-consolidated memories are affected
Patient experiences restlessness and wandering
Eventually patient is mute and paralyzed
Death usually comes from infection of a weakened, dehydrated patient

44. Atrophy
Pyramidal cells die along with axons → loss of white matter → Gyri shrink → ventricles expand
Severity and progression of disease due to
Neurofibrillary tangles
Neurotic plaques
Made up of Amyloid (starchlike) proteins
Amyloid beta protein
Directly toxic to neural tissue
Triggers inflammatory response

45. Dementia
Progressive failure of cerebral functions that is not caused by an impaired level of consciousness
Classifications
Cortical
Subcortical
Cortical and subcortical

46. Alzheimer Disease (AD)
Familial, early and late onset
Nonhereditary (sporadic, late onset)
Theories
Mutation for encoding amyloid precursor protein
Alteration in apolipoprotein E
Loss of neurotransmitter stimulation of choline acetyltransferase

47. Alzheimer Disease (AD)
Neurofibrillary tangles
Senile plaques
Clinical manifestations
Forgetfulness, emotional upset, disorientation, confusion, lack of concentration, decline in abstraction, problem solving, and judgment
Diagnosis is made by ruling out other causes of dementia