新光醫院 神經科 許維志 醫師

1. 頭暈 新光醫院 神經科 許維志 醫師

2. Balance and Equilibrium • Equilibrium • The ability to maintain orientation of the body and its parts in relation to external space. • Interaction between self and environment. • Sensory input from visual, vestibular, and proprioceptive information. • Integration in the brain stem and cerebellum.

3. Disorders of Equilibrium • Diseases affect • Central or peripheral vestibular pathways • Cerebellum • Proprioceptive sensation • Mismatch of input signals and disintegration • Symptoms • Vertigo • Ataxia

4. Vertigo and Dizziness • Vertigo 眩暈 • Illusion of movement of the body or the environment. • Impulsion, oscillopsia, nausea, vomiting, cold sweating, or unsteadiness • Dizziness 頭昏 • No association of illusion of movement • Light-headedness, faintness, giddiness, swimming

5. Vestibular System • Semicircular canal • Sense angular acceleration • Head rotation • Otolith organs • Sense linear acceleration • Head translation and uprightness

6. The Vestibules

7. The Vestibule

8. The Ampulla

10. Functions of Semicircular Canals, Saccule and Utricle

12. Vertigo

23. Archicerebellum Flocculonodular lobe vestibulocerebellum Paleocerebellum Anterior lobe Spinocerebellum Neocerebellum Posterior lobe Pontocerebellum The oldest cerebellum Caudal part Eye/head movement The next oldest Midline Neck/trunk movement The newest cerebellum Hemsiphere Limb movement Cerebellar System

25. Origin and Classification of Vertigo

29. The Saccades, Pursuit, and Vestibular Control of Eye Movements

30. Dizziness History Near-faint Disequilibrium without vertigo Vertigo Psychological dizziness Physiological dizziness Central origin Peripheral origin

31. Distinguishing Vestibular From Nonvestibular Dizziness

32. Physiological Vertigo

34. Causes of Pathological Vertigo • Peripheral vertigo • Vestibular end organs: inner ear, labyrithine apparatus • Vestibular nerve • Central vertigo • Brainstem: vestibular nucleus • Archicerebellum (flocculonodular lobe)

35. Peripheral Causes of Vertigo • Benign paroxysmal positional vertigo • Meniere’s disease • Acute peripheral vestibulopathy (vestibular neuritis) • Head trauma • Cerebellopontine angle tumor • Toxic vestibulopathies

36. Vertigo (spinning of the environment or the self) Nystagmus Past-pointing of the limbs Ataxia Positive Romberg sign Turning during steppage test Tilt, a false sense of linear motion Vertical diplopia Skew deviation Ataxia Positive Romberg sign Translation on the steppage test Disorders of the Otolith Organs Disorders of the Semicircular Canal

37. Central Causes of Vertigo • Vertebrobasilar ischemia & infarction • Cerebellar hemorrhage • Alcoholic cerebellar degeneration • Multiple sclerosis • Posterior fossa tumors • Paraneoplastic cerebellar degeneration • Spinocerebellar degneration

38. Differentiating Peripheral From Central Vertigo

40. Systemic Causes of Vertigo • Drugs:anticonvulsants, sedatives, antihypertensives • Hypotension, presyncope:heart diseases, postural hypotension • Infectious diseases:syphilis, meningitis • Endocrine diseases:DM, hypothyroidism • Vasculitis:collagen vascular disease, giant-cell arteritis • Others:anemia, polycythemia, systemic toxins

41. Causes of Dysequilibrium without Vertigo • Disorders of afferent senses • Bilateral vestibular loss • Sensory ataxia • Multisensory disequilibrium • Disorders of central processing and motor responses • Cerebellar degeneration • Frontal lobe syndrome • Extrapyramidal syndrome

43. Approach to Vertigo and Dizziness • General examination • BP in the lying and standing • Look for cardiac arrhythmia • Examination of extracranial and peripheral vasculature

44. Approach to Vertigo and Dizziness • Neurological examination (1) • Consciousness and mental status • Visual acuity and visual field • Fundus • Screening for hearing impairment • Ocular motor examination • Nystagmus • Ocular motor palsy • Slow or ataxic ocular movement

45. assessing current history • Ask the patient to describe the symptoms without using the word dizzy. Have the patient differentiate vertigo from presyncope or near-syncope. • Determine if the patient has a sense of being pushed down or pushed to one side (pulsion). A peculiar sense of movement of objects viewed when the patient moves is termed oscillopsia. • Ascertain whether the symptoms are related to an anxiety attack; patients with agoraphobia may describe their symptoms as dizziness. • Determine if the sensation is continuous or episodic (ie, attacks); if episodic, find out if the sensation is fleeting or prolonged. • Ascertain whether the onset and progression of symptoms were slow and insidious or acute.

46. Ask the patient about head trauma and other illnesses to determine the setting of the initial symptoms. Trauma resulting in damage to an ear often manifests as unilateral hearing loss, which may be the cause of episodic vertigo even years later (posttraumatic hydrops). • Determine if the attacks are associated with turning the head, lying supine, or sitting upright. • Determine if symptoms of an upper respiratory infection or flu-like illness preceded the onset of vertigo. • Inquire about associated symptoms such as hearing loss or tinnitus (ringing in the ears), aural fullness, diaphoresis, nausea, or emesis. • Determine if the patient has an aura or warning before the symptoms start. • If hearing loss is evident, find out if hearing fluctuates. • Determine if the patient has a headache or visual symptoms such as scintillating scotoma. • Ask the patient about brainstem symptoms such as diplopia, dysarthria, facial paresthesia, or extremity numbness or weakness. • Ascertain the degree of impairment during an attack

47. Examination of Vestibulo-ocular Reflexes • Spontaneous nystagmus • Elicit slow phases with slow head rotation, in yaw (horizontal), pitch (vertical), and roll (torsion), and with high accelerations in yaw and pitch (head thrust) • Caloric test • Head-shaking nystagmus

50. Vestibulospinal Testing • Past-pointing with arms, with eyes closed • Romberg: feet apposed, in tandem, in tandem on toes, on one foot at a time, standing on compliant foam rubber • Fukuda stepping test or walking around a circle • Tandem gait, forward and backward