Neurology and the Otolaryngologist: Clarifying the Clinical Confusion

Educational Objectives

The goal of this program is to improve the diagnosis and management of patients with dizziness, neurologic symp­tomatology, sleep apnea, or Bell's palsy. After hearing and assimilating this program, the clinician will be better able to:

1.   Review the differential diagnosis of dizziness.

2.   Diagnose and treat seizure disorders and migraine headaches.

3.   List risk factors for stroke and methods used for treatment, and primary and secondary prevention.

4.   Explain the scoring system and treatment of sleep apnea.

5.   Describe the natural history of Bell's palsy and explain the importance of early medical therapy and facial nerve decompression.

Faculty Disclosure

In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and members of the planning committee to disclose relevant financial relationships within the past 12 months that might create any per­sonal conflicts of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and not a proprietary business or commercial interest. For this program, the following has been disclosed: Dr. VanLandingham is an employee of GlaxoSmithKline.  Dr. Shelton and the planning committee re­ported nothing to disclose.

Acknowledgements

Dr. VanLandingham gave his scientific presentation at 77th Midwinter Conference, Clinical Frontiers in Otolaryngol­ogy, presented January 16-17, 2009, in Los Angeles, CA, and sponsored by The Research Study Club of Los Angeles.  Dr. Shelton addressed Stanford Otology and Neurotology Update 2008, presented November 6-8, 2008, in San Fran­cisco, CA, and sponsored by Stanford University School of Medicine and Stanford Hospital and Clinics. The Audio-Di­gest Foundation thanks the speakers and the sponsors for their cooperation in the production of this program.

“Spells”: Vertigo, Syncope, Seizure, and Migraine Variant

Kevan E. VanLandingham, MD, PhD, Consulting Neurologist, Duke University Medical Center, and Medical Di­rector, Neurosciences MDC (U.S. Clinical), GlaxoSmithKline, Durham, NC

Differential diagnosis of dizziness: patients usually lack satisfactory diagnosis or treatment, despite seeing multiple physicians; look for  —  evidence of loss of consciousness (LOC) to rule out cardiac syncope or loss of awareness (LOA) to rule out epilepsy; vertiginous symptoms determine whether based in periphery (eg, dysequilibrium) or central nervous system (CNS; eg, vertigo); history of trauma, eg, head or neck injury (explain to patient that im­provement will take time); orthostasis (determine whether positional; possibly due to antihypertensive medica­tions); evidence of focal neurologic deficit (if oculomotor, consider central etiology)

Work-up: orthostatic blood pressure (BP); detailed neurologic examination; look for evidence of trauma or degener­ative joint disease in cervical spine; determine whether peripheral neuropathy present (eg, loss of sensation in feet, loss of vasoconstrictor response on standing); use magnetic resonance imaging (MRI) sparingly (high sensitivity may lead to treatment of asymptomatic process)

Syncope vs seizure: normal electroencephalography (EEG) does not rule out seizure; normal electrocardiography (ECG) or Holter monitoring does not help determine diagnosis; look for precipitating factors, eg, shock; vasova­gal syncope easiest to diagnose; positional changes can lead to orthostasis and LOC; patients experiencing syn­cope should be left supine and observed until consciousness regained; did symptoms evolve or come on suddenly, as with arrhythmia? if evidence of orthostatic BP changes present, look for focality on neurologic ex­amination; to cause LOC, both anterior carotid arteries or basilar artery must be involved; syncope cardiac until proven otherwise; keep in mind psychogenic syncope (diagnosis of exclusion)

Diagnostic tests: cardiac loop monitoring  —  can be worn for months; helps rule out arrhythmia; if syncopal event occurs during monitoring, recorder must be reset so tracing of event not lost; tilt-table testing  —  not highly spe­cific or sensitive; vasovagal syncope clinical diagnosis

Epileptic seizures: diagnosis  —  detailed description required of what patient felt from symptom onset to LOA or LOC; witness must then describe what happened next; risk factors for seizures  —  significant closed head injury with LOC for ³1 hr (longer patient unconscious, higher likelihood that epileptic seizures will result); brain tumor; stroke; other mass lesion of brain; history of meningitis or encephalitis; family history of epilepsy; febrile convul­sions in childhood (may lead to temporal lobe epilepsy); neurologic examination  —  look for focality; if no focality, neuroimaging not done (epilepsy clinical diagnosis)

Seizure disorders: partial (initiated in one part of brain) or generalized (entire brain involved); associated with nor­mal intelligence or cognitive impairment (eg, mental retardation); psychogenic seizures (diagnosis of exclusion); diagnosis  —  first EEG »60% sensitive; must do 2 or 3 EEGs to detect focality or interictal epileptiform activity; unlikely for seizure to occur during random EEG

Treatment: in adults with partial seizures, in »50% of cases, first drug controls seizures; drug therapy not indicated after first seizure, since 50-50 chance patient will have second seizure; have firm diagnosis of epilepsy before starting treatment; factors that support immediate treatment  —  prolonged seizures (status epilepticus); general­ized seizures in which patient injured; known precipitant with high likelihood of additional seizures, eg, brain tu­mor; drug therapy  —  second drug effective in 50% of patients who fail first drug (»25% of total); once patient fails ³2 drugs, likelihood of success with subsequent drugs »5%, leaving »25% of patients with “medically re­fractive epilepsy”; can attempt alternative therapies, eg, epilepsy surgery, vagus nerve stimulation; consensus that all drugs on market equally efficacious (despite subtle differences) and differ only by side-effect profiles

Migraine headache: history  —  age at onset, description and details of headache; examination  —  look for focality; rule out mass lesion; rule out Meniere’s disease; aura and scintillating scotomas involve brain dysfunction; vascular process involved in throbbing headache, vertigo, and nausea; differential diagnosis  —  tension and stress headaches (some patients have both); side effects of medication, eg, fluoxetine (eg, Prozac); abuse headache (from high doses of nonsteroidal anti-inflammatory drugs); dietary habits; sleep habits; neurologic examination  —  often nonfocal; if normal, and history consistent with migraine, no further work-up needed; treatment  —  speaker prefers b-blockers

Overview of Neurology

Dr. VanLandingham

Introduction: formulation  —  ie, placing problem in conceptual framework; involves determining which part of ner­vous system implicated by presenting symptoms, time course, findings on neurologic examination, and history; provides guide to differential diagnosis and relevant tests; neurologic examination  —  history key; mental status ex­amination includes talking to patient and listening to how patient expresses self (do answers to questions make sense?); test cranial nerve function; observe patient’s gait; diagnostic tests  —  based on localization and differential diagnosis; be ready for unexpected results; imaging studies; angiography; lumbar puncture; EEG; electroneurogra­phy (ENG); magnetoencephalography (little clinical use); electromyography (EMG); transcortical magnetic stimu­lation (little clinical use); clinical tests, eg, chemistries, immunologic tests

Stroke: »750,000 cases per year in United States; third leading cause of death; number one cause of disability in adults; $60 billion annually in direct and indirect costs; primary prevention  —  reducing risk in those without history of stroke by identifying risk factors (eg, behavioral, genetic); secondary prevention  —  reducing risk in those with previous stroke; modifiable risk factors  —  include hypertension, lipid disorders, atrial fibrillation (AF), tobacco use, and diabetes mellitus; nonmodifiable risk factors  —  include age, sex, ethnicity, and genetics

Case 1: man 69 yr of age with history of hypertension and diabetes has sudden onset of left-sided weakness and sen­sory loss; large right-hemispheric stroke; no evidence of heart failure, AF, or mural thrombus; no large-vessel etiol­ogy; choice of antiplatelet agent  —  once-daily aspirin first choice (pennies per day); if patient allergic to aspirin, next choice clopidogrel (eg, Plavix; $4/day); dipyridamole-aspirin combination (eg, Aggrenox) $1.75/day; main point  —patient must take daily medication; if peptic ulcer disease present, prescribe proton pump inhibitor with as­pirin; cost main determinant

Case 2: man 71 yr of age with history of hypertension, tobacco use, and coronary artery disease presents with clinical evidence of right hemispheric stroke; patient hospitalized and makes significant improvement but has some residual deficits; secondary stroke prevention  —  if symptomatic intracranial vessel disease present (50%-99% occlusion), prescribe aspirin; anticoagulation with, eg, warfarin, not indicated (increases risk for hemorrhagic events); if AF present, anticoagulation indicated; if evidence of carotid artery disease, carotid endarterectomy or stent

Sleep apnea: criteria  —  apneic events ³10 sec of suppression of breathing (20% to 0% air movement); scoring  —  mild (<20 events/hr); moderate (20-40 events/hr; severe (>40 events/hr); for reimbursement, must have >5 events/hr; oxygen desaturation  —  response not linear; large difference in arterial oxygen concentration between oxygen saturation of 95% and 85%; desaturation classified as mild (85%-95%), moderate (75%-85%), and se­vere (<75%); associated disorders  —  include snoring, hypersomnolence, and hypertension; before sleep study  — perform head and neck examination; evaluate patient’s ability to breathe through nose; examine throat and neck for masses or obstructions

Treatment: continuous positive airway pressure (CPAP)  —if nose obstructed, CPAP of no benefit; if patient claus­trophobic, CPAP problematic (describe procedure to patient before sleep study); only 50% to 60% of patients tol­erate CPAP; surgical therapy  —  do not expect complete cure; if marked tonsillar hypertrophy or nasal obstruction present, surgery may provide significant benefit; surgical options include uvulopalatopharyngoplasty (UPPP), la­ser-assisted UPPP (LAUP), and tongue reduction; device therapy  —  patients with mild apnea may respond well to oral device that advances mandible and tongue slightly (especially if examination shows micrognathia); clini­cal pearl  —  significant sleep apnea can cause right heart strain and episodes of symptomatic asystole; treat pa­tient for sleep apnea; avoid placement of pacemaker because this precludes use of MRI, should patient suffer stroke

Bell’s palsy

Clough Shelton, MD, Professor and Chief, Otolaryn-gology-Head and Neck Surgery, and Adjunct Professor of Bioengineering, Pediatrics, and Communication Sciences, University of Utah School of Medicine, Salt Lake City

Introduction: most patients recover in first 3 wk; recurrence (rare) or lack of recovery red flag for facial nerve tumor; defined in past as idiopathic facial paralysis (diagnosis of exclusion)

Natural history: good recovery with no treatment in majority of patients; if patient has partial paralysis and main­tains some motion through day 14, good chance for recovery; reasons for imaging  —  concern about tumor; twitch­ing; palsy slowly progressive over 3 wk; other cranial nerve problems

Etiology: now good evidence for herpes simplex virus as causative agent; in Japanese study, herpes simplex DNA found in nerve sheath; double blind randomized placebo-controlled study of patients in Kaiser Permanente system found patients treated with acyclovir and prednisone had higher percentage of recovery than those treated with pla­cebo plus prednisone

Decision tree: rule out other causes of palsy, eg, middle ear mass, cholesteatoma, facial nerve neuroma, parotid mass; check other cranial nerves; check hearing (if unilateral hearing loss present, consider cerebellopontine angle tu­mor); if patient has partial facial motion, place on medical therapy (prednisone and acyclovir) and schedule follow-up for 3 wk, or sooner if complete paralysis develops; if patient has complete paralysis, place on medical therapy and perform electrical tests to assess chance for good recovery; if prognosis poor, (ie, ENG shows >90% degenera­tion) consider facial nerve decompression

Facial nerve decompression: Bell’s palsy affects labyrinthine portion of facial nerve (narrowest portion of fallopian canal), so middle fossa decompression performed; ENG  —key to assessment of prognosis; evoked EMG using sur­face electrodes; amplitude of involved side compared to amplitude of normal side and expressed as percentage; deblocking  —  caused by desynchronization of facial nerve; deblocked patients have good prognosis and do not need decompression; diagnose by placing EMG electrodes into facial muscles and asking patient for voluntary response; if response measurable on EMG, nerve merely desynchronized

Study data: during first 14 days of paralysis, if degeneration >90% on ENG and no deblocking, data show only »50% of patients have good recovery; remainder of patients have grade 3 or 4; Fisch showed that patients with poor prognosis have severe involvement of nerve and rapid degeneration on ENG; typically lose 10% of motion per day (follow closely with serial ENGs)

Gantz study: multi-institutional 15-yr study (71 patients); all patients received steroids, ENG, and ³7-mo follow-up; during decompression, facial nerve decompressed from internal auditory canal, through labyrinthine portion, geniculate ganglion, and into mid-tympanic portion; surgery shows beefy-red swollen nerve; results  — of pa­tients who had middle fossa decompression within first 14 days, 91% had good result; of those not decompressed but who had prednisone, <50% had good result; conclusion  —  steep shoulder in efficacy of decompression at »14 days; treat patients early

Speaker’s data: 6 patients over 5 yr; those decompressed before day 14 had grade-2 recovery; none of those decom­pressed after day 14 had grade-1 or grade-2 recovery; most patients decompressed at day 12, 13, or 14, and their nerves 95% to 100% degenerated on ENG

Conclusion: stress importance of early referral for work-up and possible surgery to emergency department physi­cians, other referring physicians, and appointment desk staff

Suggested Reading

Alaani A et al: An analysis of diagnostic delay in unilateral facial paralysis. J Laryngol Otol 119:184, 2005; Arya AK, Nunez DA: What proportion of patients referred to an otolaryngology vertigo clinic have an otological cause for their symptoms? J Laryngol Otol 122:145, 2008; Bigal ME et al: Obesity, migraine, and chronic migraine: possible mechanisms of interaction. Neurology 68:1851, 2007; Chan AS et al: Dental appliance treatment for obstructive sleep apnea. Chest 132:693, 2007; Dichter MA: Emerging concepts in the pathogenesis of epilepsy and epileptogen­esis. Arch Neurol. 66:443, 2009; Elkind MS: Outcomes after stroke: risk of recurrent ischemic stroke and other events. Am J Med 122(4 Suppl 2):S7, 2009; Fisch U: Surgery for Bell's palsy. Arch Otolaryngol 107:1, 1981; Fleisher KE, Krieger AC: Current trends in the treatment of obstructive sleep apnea. J Oral Maxillofac Surg 65:2056, 2007; Grogan PM, Gronseth GS: Practice parameter: Steroids, acyclovir, and surgery for Bell's palsy (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neu­rology 56:830, 2001; Krumholz A et al: Quality Standards Subcommittee of the American Academy of Neurology; American Epilepsy Society. Practice Parameter: evaluating an apparent unprovoked first seizure in adults (an evi­dence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology 69:1996, 2007; Lutsep HL: Recent clinical trials of antiplatelet therapy in secondary stroke prevention: expectations and results for application in primary care settings. Am J Med 122(4 Suppl 2):S21, 2009; Mehra R, Redline S: Sleep apnea: a proinflammatory disorder that coaggregates with obesity. J Al­lergy Clin Immunol 121:1096, 2008; Neuhauser HK et al: Migrainous vertigo: prevalence and impact on quality of life. Neurology 67:1028, 2006; Stjernquist-Desatnik A et al: Detection of herpes simplex and varicella-zoster vi­ruses in patients with Bell's palsy by the polymerase chain reaction technique. Ann Otol Rhinol Laryngol  115:306, 2006; Sullivan FM et al: Early treatment with prednisolone or acyclovir in Bell's palsy. N Engl J Med 357:1598, 2007.