\-------------------------------------------\ \ ****** knowledge base on dizziness ****** \ \-------------------------------------------\ certification: "written by: james reggia, 1981" "testing: *incomplete and untested*" "this is an experimental system not for use in practice"% attachments: definition references management% quotations: htm1 "thorn et al: harrison's textbook of medicine," htm2 " mcgraw-hill, 1977" oh1 "polinsky et al: pharmacologic distinction of different" oh2 " orthostatic hypotension syndromes, neurology," oh3 " 31, 1981, 1-7." % \ ****** input attributes ****** \ attributes: dizziness (val) [elaboration: type(sgl): definite rotational sensation [synonyms: vertigo], sensation of impending faint [synonyms: syncopal], ill-defined light-headedness [synonyms: giddiness], loss of balance without head sensation [synonyms: imbalance]; course(sgl): acute or subacute persistent deficit lasting more than one hour [synonyms: acute and persistent], one or more clear-cut episodes [synonyms: episodic] [elaboration: episode duration(sgl): minutes, hours, days; predominant occurrence [synonyms: occurrence] (sgl): only upon assuming or maintaining a vertical position [synonyms: orthostatic], only upon rapidly changing or assuming a particular head position [synonyms: positional], only when sneezing or blowing nose, only during paroxysm of coughing, only while urinating, under non-specific or varying conditions [synonyms: non-specific] ], gradual onset or slow progression without clear-cut episodes [synonyms: chronic] ]. \ ****** history ****** \ *patient's age [synonyms: age] (int): from 20 to 30, from 30 to 40, from 40 to 50, from 50 to 65, from 65 to 80, from 80 thru 110 . *current medications(mlt): anticoagulants, aminoglycosides, large amounts of quinine, large amounts of salicylates, phenothiazines, antidepressants, antihypertensive agents, l-dopa, insulin, tolbutamide or other glucose-lowering medications, diuretics, barbiturates or other sedatives. *past medical history [synonyms: pmh] (mlt): diabetes mellitus, alcoholism, peptic ulcer disease, hypertension, angina, hepatic disease, otitis media, seizure disorder, vertebrobasilar tia's. *history of previous sympathectomy(val). *history of recent cataract extraction(val). *recent history (mlt): post-op, post-partum, prolonged recumbency or immobilization, hematemesis or melena or other blood loss, fracture or other injury to lower extremity. *impotence(val). *urinary incontinence or frequency(val). *family history (mlt): idiopathic hypertrophic subaortic stenosis, neurocutaneous syndrome, migraine, otosclerosis. general symptoms occurring with the dizziness [synonyms: gensx] (mlt): head pain [elaboration: predominant location(sgl): occipital, diffuse, intra-oral, periocular, periaural], palpitations, persistent shortness of breath, new onset of cough, chest pain, preceded by sensation of unpleasant odor. neuro-otological symptoms associated with the dizziness [synonyms: neursx] (mlt): diplopia [elaboration: duration(sgl): transient during dizziness, persistent], loss of or blurred vision [elaboration: duration(sgl): transient during dizziness, persistent], scintillating scotomas, focal symptoms referrable to cns [synonyms: focsx] [definition: "any symptoms clearly representing focal brain damage" "such as hemiparesis, aphasia, hemisensory deficit," "quadraplegia, etc."] [elaboration: duration(sgl): transient during dizziness, persistent], syncope, hearing loss by history, tinnitus. \ ****** examination ****** \ temperature(sgl): *normal, elevated. *hyperemic conjunctiva(val). ear examination(mlt): inflammation of middle ear, *perforated tympanic membrane, *occluded external canal. supraclavicular bruit(val) [elaboration: sides(mlt): left, right]. blood pressure examination(mlt): *hypertension, significant orthostatic hypotension [definition: "fall in systolic blood pressure below 80 mm hg" "or by more than 30 mm hg when patient assumes the" "vertical position"], more than 20mm hg difference in brachial blood pressure [elaboration: low side(sgl): left, right]. pulse during dizziness(sgl): marked bradycardia, *unremarkable, marked tachycardia. heart examination [synonyms: corex] (mlt): systolic murmur [elaboration: predominant location (sgl): base, left sternal border, apex], pathologically irregular rhythm, left ventricular lift, thrill at right second interspace. unilateral delayed or diminished radial pulse(val) [elaboration: side(sgl): left, right]. *thrombophlebitis evident in a lower extremity(val). carotid sinus stimulation for ten seconds(sgl): reproduces dizziness, * no significant effect. hyperventilation for three minutes(sgl): reproduces dizziness, * no significant effect. *pronounced cataracts(val). pronounced facial or lower extremity erythema after standing(val). abnormalities on neurological examination [synonyms: neurex] (mlt): optic atrophy, papilledema, homonymous field cut [elaboration: duration(sgl): transient during dizziness, persistent], nystagmus [elaboration: occurrence(mlt): positional, spontaneous; type(mlt): horizontal, vertical, rotatory; duration(sgl): transient during dizziness, persistent], impaired hearing, peripheral neuropathy, parkinsonism, focal cns findings [definition: "any findings clearly representing focal cns damage" "such as hemiparesis, hemisensory deficit, etc."] [elaboration: onset(sgl): sudden, gradual; duration(sgl): transient during dizziness, persistent]. \ ****** inferred attribute ****** \ etiology of dizziness [synonyms: diagnosis, dx, assessment, differential, etiology] (mlt): \ ****** causes of orthostatic hypotension ****** \ secondary to orthostatic hypotension [description: blood pressure examination = significant orthostatic hypotension ; dizziness [type= syncopal, giddiness , re ; course = episodic [episode duration = minutes , hours ; occurrence = orthostatic , re ]]; neursx = syncope , loss of or blurred vision [duration = transient during dizziness]; gensx = palpitations ] [elaboration: type (mlt): multiple system atrophy [synonyms: shy-drager syndrome] [references: oh1 oh2 oh3] [description: age = from 20 to 30 ; impotence ; urinary incontinence or frequency; focsx [duration = persistent]; neurex = nystagmus [occurrence = spontaneous; type = horizontal , vertical ; duration = persistent], parkinsonism, focal cns findings [onset = gradual; duration = persistent] ], idiopathic orthostatic hypotension [references: oh1 oh2 oh3] [description: impotence ; urinary incontinence or frequency ], sympathotonic orthostatic hypotension [references: oh1 oh2 oh3] [description: pulse during dizziness = marked tachycardia ], autonomic neuropathy [description: age = from 20 to 30 ; impotence ; urinary incontinence or frequency; past medical history = diabetes mellitus, alcoholism; pulse during dizziness = marked tachycardia; peripheral neuropathy], orthostatic hypotension secondary to phenothiazines [description: current medications = phenothiazines; pulse during dizziness = marked tachycardia; parkinsonism ], orthostatic hypotension secondary to antidepressants [description: current medications = antidepressants ; pulse during dizziness = marked tachycardia; parkinsonism ], orthostatic hypotension secondary to l-dopa [description: current medications = l-dopa ; pulse during dizziness = marked tachycardia; parkinsonism ], orthostatic hypotension secondary to antihypertensive medications [description: current medications = antihypertensive agents ; pulse during dizziness = marked tachycardia ], orthostatic hypotension secondary to diuretics [description: current medications = diuretics ; pulse during dizziness = marked tachycardia ], hyperbradykinism [description: pronounced facial or lower extremity erythema after standing ; pulse during dizziness = marked tachycardia ], orthostatic hypotension secondary to parkinsonism [description: neurex = parkinsonism ; age = from 20 to 40 ; current medications = l-dopa ], orthostatic hypotension secondary to previous sympathectomy [description: history of previous sympathectomy ], orthostatic hypotension secondary to prolonged recumbency [description: prolonged recumbency or immobilization ; pulse during dizziness = marked tachycardia ] ], \ ****** neurovascular etiologies ****** \ subclavian steel syndrome [description: dizziness [course = acute and persistent, episodic [episode duration = minutes , hours ; occurrence = positional , non-specific, orthostatic ]]; head pain [predominant location = occipital , re ]; neursx = diplopia, loss of or blurred vision, focsx, syncope; neurex = homonymous field cut, nystagmus [type = horizontal, vertical], focal cns findings [onset = sudden] ] [elaboration: side(sgl): left subclavian steel syndrome [description: supraclavicular bruit [sides = left]; unilateral delayed or diminished radial pulse [side = left]; more than 20mm hg difference in brachial blood pressure [low side = left] ], right subclavian steel syndrome [description: supraclavicular bruit [sides = right]; unilateral delayed or diminished radial pulse [side = right]; more than 20mm hg difference in brachial blood pressure [low side = right] ] ], vertebrobasilar transient ischemic attacks [description: age = from 20 to 40 ; pmh = diabetes mellitus , hypertension , vertebrobasilar tia's ; dizziness [course = acute and persistent, episodic [episode duration = minutes, hours; occurrence = non-specific , positional , orthostatic ]]; head pain [predominant location = occipital , re ]; neursx = diplopia, loss of or blurred vision, focsx, syncope ; neurex = homonymous field cut, nystagmus [type = horizontal, vertical], focal cns findings [onset = sudden] ], vertebrobasilar infarction [description: age = from 20 to 40 ; pmh = diabetes mellitus , hypertension , vertebrobasilar tia's ; dizziness [type = vertigo , imbalance, re ; course = acute and persistent]; head pain [predominant location = occipital , re ]; neursx = diplopia [duration = persistent], loss of or blurred vision [duration = persistent], focsx [duration = persistent], syncope; neurex = homonymous field cut [duration = persistent], nystagmus [type = horizontal, vertical; duration = persistent], focal cns findings [onset = sudden; duration = persistent] ], basilar migraine [references: "lancet, 1, 1961, p. 15"] [description: age= from 20 to 30 , 30 to 50 , 50 thru 110 ; dizziness [type= vertigo, re; course= episodic [episode duration= minutes, hours, days; occurrence = non-specific], acute and persistent]; head pain [predominant location = occipital , diffuse , periocular , periaural ]; neursx = tinnitus, diplopia [duration = transient during dizziness], loss of or blurred vision [duration = transient during dizziness], scintillating scotomas, focsx [duration = transient during dizziness], syncope ; neurex = homonymous field cut [duration= transient during dizziness], nystagmus [type = horizontal, vertical; occurrence = re; duration = transient during dizziness], focal cns findings [onset = sudden; duration = transient during dizziness]; family history = migraine ], glossopharyngeal neuralgia [description: age = from 20 to 24 ; dizziness [type = syncopal , giddiness ; course = episodic [episode duration = minutes; occurrence = non-specific]]; head pain [predominant location = intra-oral, periaural]; neursx = loss of or blurred vision [duration = transient during dizziness], syncope; pulse during dizziness = marked bradycardia ], vertiginous seizures [description: dizziness [type = vertigo , re ; course = acute and persistent , episodic [episode duration = minutes , hours ; occurrence = non-specific] ]; pmh = seizure disorder ; preceded by sensation of unpleasant odor; neursx = loss of or blurred vision , focsx, tinnitus ; hyperventilation for three minutes = reproduces dizziness ; neurex = papilledema , homonymous field cut, focal cns findings ], acoustic neuroma or other cerebello-pontine angle mass [synonyms: acoustic neuroma] [description: dizziness [type = vertigo , imbalance, re ; course = chronic , re ]; head pain [predominant location = periaural, occipital, diffuse ]; neursx = diplopia, loss of or blurred vision , focsx [duration = persistent], hearing loss by history, tinnitus; neurex = nystagmus [duration = persistent], impaired hearing , focal cns findings [duration = persistent]; family history = neurocutaneous syndrome ], acute cerebellar hematoma [description: age = from 20 to 30 ; pmh = hypertension ; current medications = anticoagulants ; dizziness [type = imbalance , syncopal , re; course = acute and persistent]; head pain [predominant location = occipital, diffuse, periaural ]; neursx = diplopia [duration = persistent], loss of or blurred vision [duration = persistent], focsx [duration = persistent]; blood pressure examination = hypertension ; pulse during dizziness = marked bradycardia ; neurex = papilledema , homonymous field cut [duration = persistent], nystagmus [type = horizontal, vertical; duration = persistent], focal cns findings [onset = sudden; duration = persistent] ], posterior fossa mass lesion [description: dizziness [type = vertigo , imbalance , re ; course = chronic , re ]; head pain [predominant location = occipital , diffuse , periaural , periocular ]; neursx = diplopia, loss of or blurred vision, syncope , focsx [duration = persistent]; pulse during dizziness = marked bradycardia ; neurex = papilledema , optic atrophy , homonymous field cut [duration = persistent], nystagmus [type = horizontal, vertical; duration = persistent], focal cns findings [onset = gradual , sudden ; duration = persistent ] ], multiple sclerosis [description: age = from 20 to 40 , from 50 thru 110 ; dizziness [type = vertigo , syncopal , re ; course = acute and persistent, episodic [episode duration = hours , days ; occurrence = non-specific ] ]; neursx = diplopia [duration = persistent], loss of or blurred vision [duration = persistent], focsx [duration = persistent], tinnitus ; neurex = optic atrophy, homonymous field cut [duration = persistent], nystagmus [type = horizontal, vertical; duration = persistent ], focal cns findings [onset = sudden , gradual ; duration = persistent ] ], \ ****** otologic etiologies ****** \ meniere's disease [synonyms: endolymphatic hydrops] [description: age = from 20 to 30 ; dizziness [type = vertigo; course = acute and persistent, episodic [episode duration = minutes , hours ; occurrence = positional , orthostatic , non-specific ] ]; head pain [predominant location = periaural]; neursx = hearing loss by history , tinnitus ; pulse during dizziness = marked tachycardia ; neurex = nystagmus [type = horizontal, rotatory], impaired hearing ], acute otitis media [description: ear examination = inflammation of middle ear ; dizziness [type = vertigo , imbalance , re ; course = acute and persistent]; head pain [predominant location = periaural]; neursx = hearing loss by history, tinnitus; temperature = elevated ; neurex = impaired hearing ], benign positional vertigo [synonyms: cupulolithiasis, benign paroxysmal positional vertigo] [description: dizziness [type = vertigo , giddiness , imbalance ; course = episodic [episode duration = minutes ; occurrence = positional , orthostatic , only when sneezing or blowing nose , only during paroxysm of coughing ] ]; nystagmus [occurrence = positional; type = horizontal, rotatory; duration = transient during dizziness] ], dizziness secondary to occluded external auditory canal [description: occluded external canal ; dizziness [type = vertigo , syncopal , re ]; neursx = hearing loss by history, tinnitus ; neurex = impaired hearing ], labyrinthine fistula [synonyms: perilabyrinthitis] [description: dizziness [type = vertigo , giddiness , imbalance ; course = episodic [episode duration = minutes , hours ; occurrence = orthostatic, positional, non-specific, only when sneezing or blowing nose, only during paroxysm of coughing ] ]; pmh = otitis media ; neursx = hearing loss by history, tinnitus; ear examination = perforated tympanic membrane ; neurex = impaired hearing, nystagmus [type = horizontal, rotatory] ], acute vestibulopathy [synonyms: acute labyrinthitis, vestibular neuronitis, benign recurrent vertigo, epidemic vertigo, epidemic labyrinthitis ] [definition: "this is a 'catch-all' category for a variety of abnormal conditions" "with involvement of labyrinthine structures or the peripheral vestibular" "nerves (see attached synonyms)."] [description: dizziness [type = vertigo ; course = acute and persistent, episodic [episode duration = minutes , hours , days ]]; head pain [predominant location = periaural]; neursx = diplopia [duration = transient during dizziness], loss of or blurred vision [duration = transient during dizziness], hearing loss by history , tinnitus; nystagmus [type = horizontal, rotatory; occurrence = spontaneous , positional ; duration = transient during dizziness , persistent] ], otosclerosis [references: "thomas and cody: neurologic perspectives of otosclerosis" " mayo clinic proceedings, 56, 1981, 17-21" ] [description: dizziness [type = vertigo , imbalance, re ; course = episodic [episode duration = hours , re; occurrence = non-specific , positional, orthostatic ], re ]; family history = otosclerosis ; head pain [predominant location = periaural]; neursx = hearing loss by history , tinnitus ; neurex = nystagmus , impaired hearing ], secondary to ototoxic substances [description: dizziness [type = vertigo , re ; course = acute and persistent, chronic, episodic [occurrence = positional , non-specific, orthostatic ] ]; neursx = hearing loss by history, tinnitus; neurex = nystagmus [type = horizontal, rotatory], impaired hearing ] [elaboration: type(mlt): ototoxicity secondary to aminoglycosides [description: current medications = aminoglycosides ], ototoxicity secondary to quinine [description: current medications = large amounts of quinine ], ototoxicity secondary to salicylates [description: current medications = large amounts of salicylates ] ], \ ****** cardiac etiologies ****** \ aortic stenosis [references: htm1 htm2] [description: corex = systolic murmur [predominant location = base , left sternal border, apex