Clinical Considerations of the Nervous System

1. Clinical Considerations of the Nervous System

2. Neurologic Examination • The Neurological exam should consist of the following six subdivision: • Mental status • Cranial nerves • Motor exam • Reflexes • Coordination and gait • Sensory exam

3. Mental Status • Are the patients oriented to • Person • Place • Time • Ask specific questions that challenge: • Memory • Both long term and short term • Ability to perform calculations and judgment.

4. Cranial Nerves Review • Olfactory: identify familiar smells • Optic: Seeing • Oculomotor: Eye movement, opening of eyelid, constriction of pupil, focusing • Trochlear Nerve: Eye movement • Trigeminal Nerve: Sensory to face (touch, pain and temperature) and muscles of mastication • Abducens Nerve: lateral eye movement • Facial : Motor - facial expressions; salivary glands and tear, nasal and palatine glands Sensory - taste on anterior 2/3’s of tongue • Vestibulocochlear Nerve: Provides hearing and sense of balance • Glossopharyngeal Nerve: Swallowing, salivation, gagging, control of BP and respiration • Vagus: Swallowing, speech, regulation of viscera • Accessory Nerve: Swallowing, head, neck and shoulder movement • Hypoglossal Nerve: Tongue movements for speech, food manipulation and swallowing.

5. Reflex Test • Looks at the integrity of the monosynaptic loop. An abnormal response may indicate lesions within the central or peripheral nervous system. • Achilles tendon: Sciatic nerve S1-2 • Patella: Femoral L3-4 • Biceps : Musculocutaneous Nerve C5-6 • Triceps :Radial C7-8 • Brachioradialis : Radial C5-6

6. Reflexes • Scale • 0: No evidence of contraction • 1+ Decrease(hypo-reflexic) • 2+ Normal • 3+ above normal (hyper-reflexic) • 4+ Clonus: Repetitive shortening of the muscle after a single stimulation

7. Coordination Test • Finger to nose testing: • Rapid alternating finger ,hand and feet movements: • dysdiadokinesia may be indicative of cerebellar disease. • Gait assessment: • Quality of movement :look for symmetry • Antalgic Gait : looks for muscle weakness and pain. • Single leg stance and walking on heels and toes.

8. Sensory examination • Notice how the dermatomes correlate with the peripheral nerves. • Reflex test: test the monosynaptic reflex of a specific nerve root level. • Exaggerated reflex may suggest upper motor neuron lesion. • Diminished reflexes is suggestive of nerve root or peripheral nerve lesion • Proprioception and vibration: • large myelinated fiber and • dorsal column medial • Light touch and temperature • small unmyelinated nerve fibers • Anterior lateral tract (spinothalamic)

9. Cutaneous Innervation and Dermatomes • Each spinal nerve receive sensory input from a specific area of skin called dermatome

10. Peripheral Nerve Distribution

11. Myotomal Weakness • Look at # of motor units. • If you use all of them you go into neural fatigue in a few seconds. • Normally only use 25 % of motor units. • If you have 75-80% loss in motor units it will present as weakness. • A protrusion or osteophyte on nerve root. • Test with slow build up of pressure to allow max recruitment.

12. UMN Associated Conditions • Multiple Sclerosis • Cerebral Vascular Accident ( Stroke) • Traumatic Brain Injury • Spinal Cord Injury • Cerebral Palsy • Amyotrophic Lateral Sclerosis (ALS)

13. Upper Motor Neuron Lesion (UMN) • A motor dysfunction associated with lesions of cortical, subcortical, or spinal cord structures: • Muscle weakness to paralysis • Hyperreflexia, (spasticity and clonus) • (+) Babinski sign in LE • (+) Hoffman's sign in UE

14. Spasticity • Spasticity occurs when upper motor neurons of the primary motor cortex are damaged. • The result is a loss of inhibitory input from upper cortical areas to inhibitory interneurons in the spinal cords. • Inhibitory interneurons prevent muscle spindles from responding to all quick movements. • Spastic muscle contractions are in response to length change and not volitional thought.

15. Case Study 1 • Your treating a patient who has a pmhx of middle cerebral artery CVA . Predict the types of deficits you might expect to find.

16. Cerebral Vascular Accidents( Stroke) • Progressive arteriosclerosis can eventually lead to damage and occlusion of the arteries that supply the brain. • This may lead to complete occlusion or vascular rupture that will deprive the brain of O2 and nutrients. • Intracranial lesions will become a space occupying lesion that further compromises circulation and damages brain matter. • Looking at what area of the brain was damaged can explain what deficits patient may present with.

22. Cerebral Circulatory System

23. Blood Supply to the Brain • Anterior cerebral artery • Middle Cerebral Artery • PosteriorCerebral Artery

26. Anterior Cerebral Artery CVA • Frontal lobe • prefrontal cortex • mental impairments • Anosmia (smell) • primary motor cortex • ( LE’s >UE’s)

27. Middle Cerebral Artery CVA • primary motor cortex, (weakness UE’s > LE’s) • Speech areas ( aphasia) • Temporal lobe • memory • Parietal lobe • Contralateral neglect

28. Posterior Cerebral Artery CVA Visual agnosia (objects) Prosopagnisia( face) Thalamus leads to persistent pain

29. Case Study 2 • A patient presents with left-sided weakness. The weakness thought of following a really bad headache. Upon examination you notice the following. • 3+ reflexes left side • Clonus left ankle • Lower extremities tested more than half of extremities • Difficulty concentrating and impulsivity

30. Case Study 3 • 58 y/o with c/o vertigo especially with turning her head to the right. She have a history of falls, DM and dyslipidemia. She had previously been ruled out for cerebrovascular accident and cerebellar dysfunction. What’s a possible diagnosis?

31. Vertebral Arteries

32. Vertebrobasilar Insufficiency • Vertigo with associated Neurological signs • Diplopia (double vision) • Ataxia • Lateral nystagmus • Drop attacks • Dysarthria • Paralysis/weakness/Numbness • Risk factors (HTN, Diabetes, Coronary artery disease and DJD) • Look at the relationship the symptoms and the part of the brain effected.

34. Case Study 4 • A patient was in an MVA suffered a T12 fracture. Following the accident the patient has difficulty walking. • Exam results: • Hyper-reflexia in lower extremities. • Sensory loss in the lower extremities. • Strength 5/5(normal)

35. Spinal Cord Trauma: Transection • Cross sectioning of the spinal cord at any level results in total motor and sensory loss in regions inferior to the cut • Paraplegia – transection between T1 and L1 • Quadriplegia – transection in the cervical region

36. SCI: Subtypes • Complete: complete transection of motor and sensory tracts • Incomplete: • Anterior Cord Syndrome • Central Cord Syndrome • Posterior Cord Syndrome • Brown Sequard Syndrome

37. Picture

38. Anterior Cord Syndrome • Results from compression or hyper flexion injury. • Loss of motor, pain and temperature. • Proprioception and vibratory sense preserved

39. Central Cord Syndrome • Central cord may result from compression of spinal cord, intramedullary tumors or ischemia. • Upper extremities more involved then lower extremities. • Sensory less then motor

40. Posterior Cord Syndrome • May result from hyper flexion injury. • Profound sensory loss • Ataxic presentation without procrioceptive feed back ascending the cord. • Motor functions is spared.

41. Brown Sequard Syndrome • Damage to half the SC usually from a gun shot or a knife. • Contralateral presentation: • Loss of pain and temp • Ipsilateral presentation: • Motor loss • Sensation • Proprioception • Hyperreflexia • + babinski

42. Why is it worse to have a disease that attacks the CNS vs. PNS

45. Lower Motor Neuron Lesion (LMN) Lesions affecting the ant. horn cell or peripheral nerve • Atrophy • Weakness • Decreased or absent tone • Hypo-reflexia

46. LMN Associated Conditions • Bell’s Palsy • Poliomyelitis • Guillain-Barre syndrome • ALS • Myasthenia Gravis • Duchenne Muscular Dystrophy • Traction Nerve Injuries (Whiplash) • Herniated disc

47. Case Study 5 • The patient presents with 6/10 LBP pain that radiates to the left foot. Pain is worse with prolonged sitting and bending over. The patient noticed the symptoms following shoveling snow. • Your exam reveals the following. • Painful straight leg raise test to 30°. • L4 and L5 vertebrae very tender to touch • Tingling along the dorsal surface of the foot.

48. Parkinson's Disease • Results from a loss of dopamine production in the Substantia Nigra • This effects the other nuclei in the basal ganglia related to voluntary movement and postural adjustments. • These pathways can both stimulate wanted movements (direct pathway) and inhibit unwanted movements( indirect pathways) • Some common signs and symptoms include • Akinesia, rigidity • Pill rolling tremor • Fesitinating gait

49. Pain • Pain receptors are the most primitive receptors. • They respond to a broad spectrum of stimuli • Pain has a sensory component :allow you to localize it. • Pain has a drive like qualities: • Pain pathways also go to the midbrain (arousal) • Limbic system (motivational) makes you deal with it.

50. Pain Signal Destinations • General pathway – conscious pain • 2nd order neurons decussate and send fibers up spinothalamic tract or through medulla to thalamus • 3rd order neurons from thalamus reach primary somesthetic cortex as sensory homunculus • Spinoreticular tract • pain signals reach reticular formation, hypothalamus and limbic • trigger visceral, emotional, and behavioral reactions