d by touching the skin of the affected area, by washing, shaving, eating, or talking. TN of ten pres- ents in older men, with most cases resulting from microvascular compres- sion of the trigeminal nerve roots as they exit the brainstem but can occur due to other mass lesio ns and multiple sclerosis (MS) as well (consider this especially in a younger, female patie nt). All patients should be imaged with a high-resolution contrast-enhanced brain MRI, with heavily T2-weighted thin cuts through the brainstem and trigeminal nerves to assess for ca usative lesions. Treatment : Carbamazepine (start at 100 mg/12 h PO; max 400 mg/6 h; oxcarb azepine working up to as high as 900 mg bid; lamotrigine (slow to titrate but well-tolerate d); phenytoin 200 \200\223400 mg/24 h; or gabapentin up to 1,800 mg tid. Baclofen may work rapidly for rescue, and, in extreme cases, IV anticonvulsants may be required. The conditio n is often surgi- cally curable; after imaging, we recommend referring all cases to neuro- surgery early to discuss options if medications fail or cause intolerable side 347 effects. Interventions may be directed at the peripheral nerve, the trigeminal ganglion (rh izotomy with radiation, radiofrequency, or glycerol lesioning), or the nerve root with surg ical microvascular decompression to separate anomalous vessels from the nerve. Headaches of subacute onset Giant cell arteritis: Exclude in all patients >50 presenting wi th a headache that has lasted a few weeks. Look for tender, thickened, pulseless temporal a rteries with an extremely elevated ESR. Ask about jaw claudication during eating (specific, not sensitive), systemic symptoms (malaise, sweats, muscle aches, weakness of limb girdles /polymyalgia rheumatica), and episodes of vision loss (amaurosis fugax). Prompt diagnosis a nd immediate treatment with steroids (starting at 60 \200\22380 mg of PO prednisone) are es sential for avoiding blindness or potential strokes. The temporal arteries should be biopsi ed to confirm the diagnosis; start steroids first to prevent compli- cations, then ensure t hat adequate 4 cm+ biopsies, ideally bilaterally, are performed within 10 d. Chronic headaches Raised ICP: Headache is a complaint of 50% patients with \206\221 ICP, whether idiopathic intracranial hypertension (IIH, aka pseudotumor cerebri or \200\234benig n \200\235 intracranial hypertension) or due to hydrocephalus or other mass lesion. Althoug h variable in nature, headaches are characteristically present on waking or may awaken the patient overnight. They are gener- ally not severe and are worse lying down. If accompanied by other signs of \206\221 ICP, such as vomiting, papilledema, seizures, focal deficits, or men- tal status change, admit the patient urgently for diagnostic imaging. Any space-occ upying lesion (neoplasm, abscess, subdural hematoma) may pres- ent in this way, as may IIH, or cerebral venous thrombosis. Lumbar punc- ture is the diagnostic test of choice in patie nts with unremarkable imaging ; cerebellar herniation may be risked if there is obstructive hydrocephalus or mass lesion. Classically, patients with IIH are overweight women of child -bearing age (20-fold elevated risk over general population, but still 100-fold less com- m on than chronic migraine in this group) who have constant dull head pain and vision changes . Think of this diagnosis in those presenting as if with a mass (headache, \206\221 ICP, a nd papilledema) when no mass is found and when there is no venous occlusion. Consciousness and cognition are preserved. Opening pressure during LP is elevated. Cause : Unknown. Rule out elevated ICP secondary to venous sinus thrombosis (contrast-enhanced MRV, CTV, or angio graphy are the best studies) or drugs (e.g., tetracycline, minocy- cline, nitrofurantoin, v itamin A, isotretinoin, danazol, and somatropin). Treatment : Treatment should be geared to ward preserving vision rather than headache. Refer all suspected cases of ICP elevation ear ly and often to ophthalmology; urgent optic nerve sheath fenestration or neurosurgi- cal tr eatment may prevent permanent blindness. Ophthalmological workup should include funduscopy (ideally with photo documentation), perimetry, and color vision testing. Urgent and even se rial lumbar punctures (LPs) (with measurement of the opening pressure) with drainage of 20+ cc of cerebrospinal fluid (CSF) may be indicated in patients with worsening symp- toms. Ac etazolamide is the mainstay of medical treatment; consider loop diuretics and advise weight loss in all patients. High-dose topiramate may be useful in causing both weight loss and C SF pressure-lowering effects. Surgical shunting or even venous stenting may be indicated in specific cases. Prognosis: Often self-limiting. Permanent significant visual loss in 10% ( i.e., not so benign), higher if not treated. 348 Intracranial hypotension: An internal leak of CSF, whether iatrogenic (LP, surgery, overshu nting), due to trauma, or spontaneous (SIH), tends to pres- ent with a postural headache, w orsening when upright and improving when recumbent, particularly with prolonged sleep. Some SIH patients experi- ence thunderclap headache at onset. When mild, the disorder presents as a daily recurring headache absent in the morning that comes on gradually and then worsen s toward the end of the day. Valsalva or straining, such as during bouts of cough may exace rbate symptoms, and meningeal irritation may cause increased pain during jarring motions. R arely, there are associ- ated cranial neuropathies, ataxia, a frontotemporal dementia-like picture, or even a reduced level of consciousness. Patients with certain connective tissue or genetic disorders that cause weakening or outpouchings of the spinal meninges may be par ticularly susceptible (Ehlers-Danlos, Marfan \200\231s, neurofibromatosis). Characteristic imaging findings on contrast brain MRI include signs of downward displacement of brain stru ctures ( \200\234sag \200\235), includ- ing the cerebellar tonsils (resembling Chiari I mal formation), engorgement of vascular structures such as the pituitary and venous sinuses, an d avid enhancement of the pachymeninges (dura), which in coronal cross-section through the posterior fossa may resemble a Mercedes-Benz symbol drawn in white. Opening pressure on rec umbent LP is often <7 cm H 2 O, but may be normal. Leaks can be localized by a variety of t echniques. In skull base leaks, CT may reveal fluid in the sinuses, and collection of nasal discharge will test positive for 2 -transferrin, found only in CSF and endolymph but no t in mucous. Spinal leaks, often at the cervical-thoracic junction, at dilated nerve root s heaths/Tarlov cysts, or due to osteophytes, can be local- ized by CT myelography, CSF radio cisternography (include nasal pledgets if skull base leak is suspected), and noninvasively by high-resolution heavily T2-weighted MRI. SIH is well worth knowing about \200\224it may be as com- mon as subarachnoid hemorrhage, is commonly missed, can be extremely disabling, and is entirely curable through interventional procedures such as empiric or radiographical ly directed epidural blood patch or fibrin gluing. y g o o r u e N l Chronic daily headache from medication overuse (aka rebound headache): The main culprits ar e mixed analgesics containing narcotics, the barbiturate butalbital, ergotamine, triptans, and most over-the-counter combination \200\234headache medications \200\235 containing caf feine (or even with caffeine-containing beverages). Consider this diagnosis in a migraineur who develops daily headache in the setting of increasing medication usage, even when the m edication is being used to treat another condition. Typically, patients are using medicatio ns >10 times per month over a period of several months, but cases can occur with barbiturat es use as infrequent as 5 d per month, and in narcotics in as few as 8 d per month. Acetami nophen and NSAIDs are only rarely implicated. It is a common reason for episodic migraines \200\234transforming \200\235 into a daily headache. Aggressive treatment is directed at t he underlying migraine condition with initiation of a preventive medication, potentially wi th a short course of an adjunctive \200\234bridge \200\235 therapy of another class (steroi d, round-the-clock NSAID), and complete withdrawal of the offending medication(s). In gener al, it is best to entirely avoid narcotic and barbiturate-containing analgesics in migraine urs; the syndrome is often easier to avoid than to treat . 349 Migraine Because migraine headaches are both severe, causing limitation of routine activiti es, and prevalent, affecting 12% of the adult population, they are overwhelmingly the most common headache type coming to attention in any medical setting, including in the ER. It i s essential for healthcare provid- ers to recognize the disorder and understand the fundame ntals of treatment. Few other conditions will strike down an otherwise healthy adult, rendering them unable to attend work, school, chores, or social activities. The over- whelming majority of patients presenting with a chief complaint of episodic, disabling headaches will have migraine, part icularly if attacks are accompanied by any nausea or sensitivity to light. Symptoms and dia gnosis Migraine is a syndrome of episodically recur- ring, self-limiting headaches accompan ied by oversensitivity to other stim- uli. See Table 10.8 for formal diagnostic criteria. O nly 25% of migraineurs ever experience an aura (see below). The individual headache typical ly progresses gradually to become at least moderately severe, is often uni- lateral and des cribed as throbbing or pounding with the heartbeat. The hallmark of migraine is intolerance to other stimuli \200\224photophobia, phono- phobia, osmophobia (odor aversion), and exace rbation with routine activi- ties (running up a flight of stairs, bending, jumping). Allody nia (nonpainful stimuli producing pain) is an underrecognized but very common symptom; pati ents may not be able to brush hair, wear earrings or glasses, or shave due to pain. If pati ents with recurring headaches say they would prefer to curl up in a ball in a dark, quiet p lace during attacks, they almost certainly have migraine. Aura Transient stereotyped episod es of neurological dysfunction caused by the complex underlying phenomenon known as cortica l spreading depres- sion, auras are characterized by the gradual or progressive march of fo cal neurological symptoms over 20 mins \200\2231 h, immediately preceding the headache pha se of the attack (or sometimes in isolation), usually involving both positive and negative symptomatology. Most typical is the classical visual/occipital lobe aura, consisting of fla shing lights or zig-zag lines (+) followed by scotoma ( ). Sensory/parietal auras are next most common, with a march of tingling (+) and numbness ( ), typically from hand to face. Left hemisphere involvement may lead to language disturbances (aphasia). Bizarre, higher or der perceptual distortions (aka Alice-in-Wonderland/Todd syndrome) are of great curiosity b ut fairly rare. Brainstem or bilateral symptoms can occur in the relatively uncommon basila r-type migraines. The true neurological weakness of the genetic hemiplegic migraine syndrom es is extremely rare. Weakness, brainstem symptoms, or any other unusual or sudden-onset ne urological symptoms should prompt workup, unless absolutely characteristic of multiple prev i- ous attacks with a firm diagnosis of migraine. 350 Table 10.8 Migraine diagnostic criteria The patient must have experienced five headaches lasting 4 \200\22372 h meeting the criteri a below. The mnemonic SULTANS (from neurologist Morris Maizel, AAN Headache Toolkit ) encap sulates the International Classification of Headache Disorders criteria for migraine: 2/4 o f: S everity is at least moderate U ni L ateral T hrobbing or pounding (with heartbeat) A ctiv ity intolerance 1/2 of: N ausea S ensitivity to light/sound (phonophobia, photophobia) In some cases, alterations in mood, energy, or appetite change may occur hours before the a ura or headache; these nonfocal symptoms are properly referred to as prodromal. \200\234Tr iggers \200\235 Individual migraines may be provoked by exposure to certain internal or ext ernal stimuli, which may in combination exceed some sort of internal \200\234headache thre shold. \200\235 The fall of estrogen prior to menses, change in sleep schedule, skipping a meal, dehydration, altitude, alcohol, overexer- tion, irregular or overconsumption of caffe ine, stress, and let-down after a stressful period are all potential contributors. Airplane travel across time zones involves a particularly potent combination of triggers. There is a substantial body of widely propagated but ultimately apocryphal beliefs about so-called d ietary migraine triggers, but there is very little evi- dence for food items provoking indi vidual headaches, including chocolate (thankfully, there is actually randomized controlled trial evidence to the contrary), nuts, cheese, and items containing nitrates, nitrites, or vasoactive amines. Prodromal symptoms may lead a patient to feel unwell or develop cravings . She reaches for a chocolate bar and shortly thereafter develops a headache. The patient f alsely attributes the headaches to the snack, when the reverse was true \200\224the impendi ng headache caused her to consume the chocolate! Alcohol is certainly a trigger in many pat ients, as is possibly monosodium glutamate (MSG) and the artificial sweetener aspartame. Hu nger from skipping a meal is probably much more likely to provoke a migraine than any indiv idual food item. While advocating a strict so-called migraine elimination diet may seem har mless, it has close to zero scientific evidence and can lead to social isolation or even th e unhealthily obsessive food avoidance of so-called orthorexia . It is often more productiv e to focus efforts on overall lifestyle factors (obesity, sleep hygiene, lack of exercise) and preventive medications. Differential There are few conditions that are confused with ep isodic migraines. As mentioned earlier, nearly all cases of recurring \200\234sinus \200 \235 head- aches are in fact migraines that have been misdiagnosed. Cluster headaches are b riefer, more excruciating and agitating, often occurring more than once per day. Occipital lobe seizures may present with dramatic visual disturbances followed by postictal headache. It is worth noting that in migraineurs, any change in headache pattern may represent the e mergence of another underlying pathology that is \200\234setting off \200\235 migraine sym ptoms. Treatment Migraines often strike when the patient is vulnerable due to the buildup o f triggers (see above). Lifestyle modification should be recom- mended or at least consider ed in all migraineurs. Trigger avoidance, and a generally even-keeled lifestyle devoid of \200\234rocking the boat, \200\235 may reduce attacks. Obesity, disrupted sleep (whether ap nea, insomnia, insufficient sleep, erratic schedule, or otherwise poor sleep hygiene), exce ss or irregular caffeine consumption, under-treated psychiatric disorders, and use of anal- gesics more than twice per week are all potentially modifiable risk factors for worsening/ more frequent migraines. Pharmacological prophylaxis If headache frequency is >2 per month, or if individual headaches are severe, have dramatic neurological symptoms, or do not resp ond well to available acute treatment, the patient should be offered a daily maintenance me dication. The analogy to asthma is obvious: Patients who wheeze on rare occasions may be tr eated with an inhaled -agonist prn alone; those with more frequent or severe attacks add ition- ally are placed on maintenance medication. Tip: As a starting point for the patient, ask \200\234Would you consider taking a medication every day to potentially cut your head aches in half? \200\235 Most medications used to prevent migraines are drawn from the \200 \234three anti \200\235 classes: antihypertensives, antidepressants, and anticonvulsants. M any y g o o r u e N l 351 are used off-label, and none was specifically designed as a migraine preven- tive. Learn th e ins-and-outs (dosing, side effects) of one drug from each class and you will be able to m anage most patients without neurological referral. If possible, try to choose a drug that w ill potentially benefit the patient in some other way (e.g., a tricyclic may help insomnia, topiramate may cause weight loss, a \222 -blocker may treat hypertension) to add secondar y benefit and improve compliance. Conversely, avoid medications that might worsen preexisti ng conditions (e.g., \222 -blockers in athletes, erectile dysfunc- tion, asthma, or a stro ng family history of diabetes; divalproex in those with obesity). Try to use once-daily for mulations. In general, do not switch medications until a trial of 2 \200\2233 months at max i- mum recommended or maximal tolerated dose is tried. \212Antihypertensives: Propranolol or nadolol 40 \200\223160 mg/24 h (gastroesopha- geal reflux disease [GERD], reduced exerci se tolerance, erectile dysfunc- tion, syncope, asthma exacerbation, small risk of weight ga in and diabetes mellitus [DM]), verapamil up to 360 mg/24 h (constipation common, periphera l edema), lisinopril up to 40 mg/24 h (cough), candesartan up to 32 mg/24 h \212Antidepressants: Nortriptyline or amitriptyline 20 \200\22375 mg per night (weight gai n, sedation/improved sleep, dry mouth, tachycardia, constipation, avoid in patients with ab normal electrocardiograms [ECGs]), venlafaxine up to 225 mg/24 h (useful to treat comorbid depression; typical antidepres- sant adverse effects but also sweating and significant with drawal adverse effects if stopped suddenly or with variable compliance) \212Anticonvulsants: Divalproex 500 \200\2231,000 mg/24 h (weight gain, hair loss, tremor, GI effects; rare hematologic, hepatic effects; avoid in potential pregnancy ). Topiramate, working up to as high as 400 mg/24 h if tolerated (paresthesias and weight loss very commo n; cognitive adverse effects, particularly on language (dysgeusia); may interfere with horm onal con- traception at doses >200 mg, increases cleft-lip/palate in pregnancy). Gabapentin up to 3,600 mg/24 h (dose-limiting sedation, peripheral edema) Acute attack treatment Success in aborting migraine attacks is related to three factors: Sp eed of administration of the agent (how long from first symptom it takes for medication to be administered), absorption/bioavail- ability of the agent, and the efficacy of the medica tion. In general, abortive medications are less effective the longer the patient waits to t ake them, particularly if the patient progresses to allodynia, when normally nonpainful sti muli such as brushing the hair becomes uncomfortable. \200\234 Waiting to see how bad it g ets \200\235 before taking medication is generally counterproductive . Also, there is evide nce indicating that many migraineurs have delayed gastric emptying times (related to their nausea), and thus pills or dissolving tablets may not achieve the same rapid bioavailabilit y as injections or nasal sprays. Finally, medications can differ in pharmacology, their rel ative efficacy, time to onset of analgesia, and half-life. The triptans are serotonergic ag onists at 5HT 1B/D/F receptors. Although they were designed to and do result in constrictio n of the cranial arteries (and, unfortunately, the coronary arteries to some extent), this effect may not be necessary for their beneficial effects, as they also bind nerve terminals in the trigeminal system (reducing neurogenic inflammation) and potentially in the brainst em itself. There are a variety of formulations including pills, dissolv- ing wafers, inject ions, and nasal sprays. Nonoral routes may be preferred in patients who awaken with migrain es or in those who have severe nausea at onset. Paresthesias or vague feelings of discomfor t or even initial exacerba- tion of headache symptoms are not uncommon, but serious side ef fects are extremely rare. They are contraindicated in uncontrolled hypertension and 352 known or strongly suspected vascular disease. Although they are labeled as interacting with antidepressants to cause the potentially dangerous sero- tonin syndrome, there are nearly no rigorously documented cases related to a high incidence of coadministration (see informa tion sheets and publica- tions from the American Headache Society for more information). Al l NSAIDs can benefit migraine at sufficient doses (a formulation of ibu- profen and a powde red form of diclofenac are FDA approved), as can acetaminophen, and they can be safely comb ined with triptans for added efficacy (a sumatriptan-naproxen combination pill is available ). Dopaminergic antiemetics/neuroleptics from metoclopramide to haloperi- dol have been sho wn to benefit migraine headache as well as accompanying nausea. IV/IM preparations are ofte n part of so-called \200\234migraine cocktails \200\235 in ERs or neurology offices. Acute extrapyramidal side effects including akathisia (an intolerable inner restlessness) and dy stonic reactions may be limited by coadministration of diphenhydramine or benztropine, but there is concern about potential for inducing tardive dyskinesia over longer peri- ods of o ngoing or repeated use. Dihydroergotamine (currently available as a nasal spray and in an i njectable and IV formulation; soon likely to be available as an inhaled formulation) is oft en useful in triptan nonresponders and in \200\234rescue \200\235 treatment of a patient i n status migrainosus (severe migraine for >72 h). Single doses of dexamethasone up to 20 mg PO or IV have been shown to reduce rate of recurrence within 24 \200\22348 h in ER setting s. y g o o r u e N l Altered mental status Delirium (acute confusional state) Common in hospitalized patients (5 \200\22315% patients in general medical or surgical wards), so consider any unex- plained behavior change in a hospitalized patient as possible delirium and investigate for possible underlying organic cause(s). There are seven major signs: 1 Consciousness is impaired (ons et over hours or days). This has been described as an impairment of thinking, attention, an d concentration \200\224or more simply as a mild global impairment of cognitive processes a ssoci- ated with a reduced awareness. Level of consciousness fluctuates through- out the da y, with confusion typically worsening in the late afternoon and at night ( \200\234sundowni ng \200\235). 353 2 Disorientation in time (does not know time, day, or year) and place (often more marked) 3 Behavior Inactivity, quietness, reduced speech, and perseveration (repeti- tion of words) or else hyperactivity, noisiness, and irritability 4 Thinking: Slow and confused, commonly with ideas of reference or delu- sions (e.g., accuse staff of plotting against them) 5 Perception: Disturbed, often with illusions and visual or tactile hallucina- tions (unlike in schizophrenia, where auditory modality dominates) 6 Mood: Lability, anxiety, perplexity, fear, agitation, or depression 7 Memory: Impaired. L ater, patients may be amnesic for this episode. Causes Pain and other psychological states are important cofactors. \212Infections: Pneumonia, urinary tract infection (UTI), wounds; IV lines \212Drugs: Opiates, anticonvulsants, L-dopa, sedatives, recreational, postanes- thesia, cephalosporil antibiotics \212Alcohol withdrawal 2 \200\2235 d postadmission; may or may not be associated with elev ated liver function tests (LFTs) and raised mean cell volume (MCV); history of alcohol abus e); also drug withdrawal. \212Metabolic: Hypoglycemia, uremia, liver failure, anemia \212Hypoxia: Respiratory or ca rdiac failure \212Vascular: Stroke (particularly bilateral occipital/parietal), myocardial infarction (MI) \212Intracranial infection: Encephalitis, meningitis \212Raised ICP/space-occupying lesio ns \212Epilepsy: Nonconvulsive status epilepticus (see Table 10.9), postictal states \212Trauma, head injury (especially subdural hematoma) \212Nutritional: Thiamine, nicotin ic acid, or B 12 deficiency Rarely, specific focal CNS lesions can present as delirium: Rig ht parietal processes, bilateral \200\234watershed \200\235 (hypoperfusion from hypotensio n) infarcts, bilateral occipital infarcts; visual field examination is critical in detectin g these. Nonconvulsive status epilepticus (NCSE) is a potentially underrecog- nized cause o f delirium states (Table 10.9). Evaluation and workup Once the diagnosis of delirium is est ablished, a thorough attempt to identify the underlying causes should be undertaken. Obtain ing vital signs, including oxygen saturation and blood glucose; per- forming a thorough gen eral physical and neurological exam; and obtaining appropriate lab tests (i.e., electrolyte s, arterial blood gas [ABG]) and pos- sibly an electrocardiogram are warranted first steps. Reviewing medication administration records can be extremely helpful in identifying causes of altered mental status. Management After identifying and treating the underlying cause, aim to: 1 Reduce distress and take measures to prevent accidents/falls. Close moni- toring is prudent. Repeated reassurance and orientation to time and place may help. 2 Minimize medication (especially sedatives). If agitated and disruptive, however, some sed ation may be necessary. Use haloperidol 0.5 \200\2232 mg IM/ PO, judiciously. Wait 20 min t o judge effect; further doses can be given if needed. Benzodiazepines may be used for night time sedation, but can worsen delirium. Table 10.9 Nonconvulsive status epilepticus as a cause of confusion 354 NCSE is underdiagnosed and may manifest itself as confusion, oddly hesi- tant speech, impai red cognition/memory, odd behavior, dreamy state, aggression, or rarely psychosis abnorm alities of eye movement, after psychosis eyelid myoclonus, or odd postures including the \200\234waxy rigid- ity \200\235 associated with catalepsy. It may or may not occur in the context of classic seizures or ischemic brain injury. Other causes and associa- tions: Drug s (e.g., antidepressants), infections (e.g., arboviruses; HIV; syphilis), neoplasia, dement ias, sepsis, sudden changes in calcium lev- els, renal failure. It may be most common in IC U settings. Diagnosis : Electroencephalogram (EEG). Treatment : May respond acutely (and di ag- nostically) to cautiously administered low doses of IV benzodiazepines, as well as anti convulsants. In general, nonconvulsive status epilepticus is not considered to be as danger ous as generalized convulsive status epi- lepticus (typically lacks the accompanying metabo lic changes). Thus, the treatment algorithm is quite different, with a goal of avoiding iat rogenic overmedication and subsequent need for intubation. Dizziness Dizziness and vertigo Concerns of \200\234dizzy spells \200\235 are very common and are used by patients to describe many different sensations. The key to making a diagnos is is to find out exactly what the patient means by \200\234dizzy \200\235 and then decide whether or not this represents vertigo. y g o o r u e N l Does the patient have true vertigo? Definition: An illusion of movement, often rotatory, of the patient or their surroundings. In practice, straightforward \200\234spinning \200\235 is rare \200\224the floor may tilt, sink, rise, or rock. Vertigo is nearly always worsened by movement, including by standing upright. Associated symptoms: Difficulty walking or sta nding, relief on lying or sitting still, nausea, vomiting, pallor, sweating. Attacks may ev en cause patients to fall suddenly to the ground. Associated hearing loss, otalgia, or tinn itus implies labyrinth or eighth-nerve involvement. What is not vertigo: Faintness or presy ncope due to hypotension may be described as dizziness, often with an orthostatic quality a nd a graying out of vision. Anxiety with associated palpitations, tremor, and sweating may also be described as feeling dizzy, which is complicated by the fact that vertigo is nearly always anxiety provoking. Loss of consciousness during attacks should prompt thoughts of e pilepsy or syncope rather than vertigo. Causes Disorders of the labyrinth, vestibular nerve , vestibular nuclei, or their central connections are responsible for practically all verti go. Only rarely are other structures implicated (see Table 10.10). Labyrinthine vertigo Ben ign paroxysmal positional vertigo (BPPV): Displace- ment of the otoconia (otoliths) from th e maculae (the receptor for sensing gravity and other acceleration) into the semicircular c anals, the organs that sense head motion. This results in dramatic but transient head-posit ion-related attacks of vertigo. The posterior canal is most often affected. Otoconia settle due to gravitational forces on the lowest part of the labyrinth (which changes with head p osition), leading to an illusory perception of motion. Classically, patients describe verti go with rolling over in bed or looking up. The diagnostic Dix-Hallpike (Nylen-Barany) maneu ver results in reproduction of symptoms with dramatic upward and outward rotatory nystagmus when the head is tipped backward with the symptomatic ear downward and lowered below the b ody in supine position. Posterior canal BPPV is easily curable by the modified Epley maneuv er, which repositions the particles. The Dix-Hallpike test is a recommended part of the exa mination of all patients presenting with dizziness or vertigo , as posterior canal BPPV can be almost miraculously cured noninvasively by what appears to the uninitiated to be a mere parlor trick. There are few other diseases in all of medicine that rely so dramatically on the physical examination for diagnosis, and the laying-on- of-hands for nearly instantaneo us cure; such patients are eternally grateful. M ni re \200\231s disease: Recurrent, spontaneous attacks of vertigo, tinnitus, and a sense of aural fullness caused by endolymph atic hydrops, typically result- ing in some degree of permanent low frequency sensorineural hearing loss within the first year of onset. Vertigo is severe and rotational, lasts 20 mi n to hours, and is often accompanied by nausea and vomiting. Drop attacks may rarely be exp erienced (no loss of consciousness or vertigo, but sudden falling or even flinging to one s ide). Treatment includes low-salt diet and diuretics, and may progress to surgical or inter ventional procedures that may be as extreme as deliberate destruction of the dysfunctional vestibular apparatus, allowing for re-equilibration/compensation. Absent hearing loss shoul d cause rethinking of the diagnosis. 355 Vestibular nerve Damage in the petrous temporal bone or cerebellopontine angle often involv es the auditory nerve, causing deafness or tinnitus. Causes: Trauma, vestibular schwannomas (acoustic neuromas), neuromas, or bony compression s uch as found in fibrous dysplasia. Acoustic neuromas: Usually present with slowly progressi ve hearing loss, with vertigo as a later possible manifestation. With progressive tumor gro wth, ipsilateral cranial nerves V, VI, IX, and X may be affected (also ipsi- lateral cerebe llum). Paradoxically, there is only rarely VII nerve involvement preoperatively. Signs of \206\221 ICP occur late and indicate a large tumor. Vestibular neuronitis: Abrupt onset of severe vertigo, nausea, and vomiting, with prostration and immobility, perhaps after an upp er respiratory infection. No deafness or tinnitus. May be from a virus in the young or a va scular lesion in the elderly (essentially an end-artery stroke of a branch of the anterior inferior cerebellar artery [AICA]). Severe vertigo subsides in days, complete recovery take s 3 \200\2234 wks. Some studies indicate that early treatment with ste- roids can improve c hance for and degree of eventual return of function. Herpes zoster oticus (Ramsay Hunt synd rome): Herpetic eruption of the external auditory meatus from latent varicella zoster virus , with symptoms due to dysfunction of the seventh and adjacent eighth cranial nerves; ear p ain with associated facial palsy deafness, tinnitus, and vertigo. Brainstem Infarction o f the brainstem (vertebrobasilar circulation) may produce marked vertigo, but other lesions may also be responsible (see Table 10.10). Vertigo is protracted, as are the associated na usea, vomiting, nystag- mus, and potential skew deviation (uneven vertical alignment of the eyes). It is exceptional for vertigo to be the only symptom of brainstem disease; mul- tip le cranial nerve palsies and sensory and motor tract defects are commonly also seen. Hearin g is typically spared. The aura of basilar-type migraine may cause vertigo along with other transient brainstem symptoms. Migrainous (also called vestibular migraine, migraine associ ated ver- tigo). Migraineurs not uncommonly experience dizziness/vertigo even in headache-f ree intervals, typically in a patient with susceptibility to motion-sickness, often with in tolerance to intricate or moving visual stimuli (visual-evoked vertigo). Only consider the diagnosis in a patient with definite migraine, when routine vestibular testing and brain im aging are normal. 356 Table 10.10 Causes of vertigo Vestibular end organs and vestibular nerve M ni re \200\231s disease Vestibular neuronitis (acute labyrinthitis) Benign position al vertigo Motion sickness Trauma Ototoxicity (aminoglycosides) Herpes zoster oticus (Ramsa y-Hunt syndrome) Brainstem, cerebellum, and cerebellopontine angle MS Infarction/transient ischemic attack (TIA) Hemorrhage Migraine aura (basilar-type, uncom mon) Vestibular schwannoma (acoustic neuroma) Cerebral cortex Vertiginous epilepsy Alcohol or other intoxication Migrainous vertigo Cervical vertigo (con troversial; neck symptoms are more commonly a result of a patient keeping the neck stiff to avoid exacerbating vertigo) Deafness Simple hearing tests To establish a clinical finding of hearing loss, the examiner should whisper a number increasingly loudly in one ear while blocking the other ear with a finger. The patient is asked to repeat the number. Make sure that failure is not due to mi sunderstanding. Rinne \200\231s test Place the base of a vibrating 256 (or 512) Hz tuning f ork on the mastoid process. When the patient no longer perceives sound, move the fork so th at the prongs are 4 cm from the external acoustic meatus. The energy in the fork will be le ssening, but the sound will be heard again if air conduction (AC) is better than bone condu ction (BC), as in the normal situation. If on the other hand, BC > AC, there is either cond uctive hearing loss or a false-negative result due to sensorineural deafness with \200\234h earing \200\235 of sound in the other ear. Distinguish these possibilities with Weber \200 \231s test (below). If there is hearing loss and AC is better than BC, this suggests sensor ineural deafness. Weber \200\231s test Place a vibrating tuning fork in the middle of the f orehead. Ask which side the patient localizes the sound to \200\224or is it heard in the mi ddle? In unilateral sensorineural deafness, the patient will localize the sound to the good side. In conduction deafness, the sound is located to the bad side (as if the sensitivity of the nerve has been turned up to allow for poor AC). Neither of these tests is completely reliable. Conductive deafness Mechanical in nature, usually due to wax, otoscle- rosis, or otitis media. Causes of sensorineural deafness Due to dysfunction of the cochlea or the au ditory nerve. Presbycusis (senile deafness, typically higher frequen- cies); previous noise exposure; M ni re \200\231s disease (lower frequency); menin- gitis; acute labyrinth itis; head injury; acoustic neuroma; MS (rarely); Paget \200\231s disease; ototoxic drugs, such as aminoglycosides; autoimmune disorders or vasculitides; maternal infections during p regnancy; several rare congenital syndromes. Brain MRI can assess for AICA strokes, masses or lesions of the eighth nerve, and the MS-like lesions seen in Susac \200\231s syndrome, a vasculitis that presents with sensorineural hearing loss, branch retinal artery occlusions (BRAO, best identified on fluorescein angiography), and focal CNS symptoms. y g o o r u e N l 357 Tinnitus This symptom is the perception of ringing, buzzing, or other noises gener- ally wi thout external sound. It is a common phenomenon. In most cases, the sound is an illusory su bjective perception of a high-pitched whine, but there are conditions where there is object ively measurable sound. Causes Unknown, hearing loss (20%), wax, viral, presbyacusis, noise (e.g., gunfire), head injury, suppurative otitis media, post-stapedectomy, M ni re \200\231s (often lower pitched/hissing/roaring/staticky), head injury, anemia, hyper- tensi on (found in up to 16%, but it may not be causative). Drugs: Aspirin or other salicylates, loop diuretics, aminoglycosides (e.g., gentamicin). Causes of pulsatile tinnitus: i.e., wit h heartbeat; potentially audible with stethoscope; do MRI. Carotid artery stenosis/dissecti on, arteriovenous (AV) fistula, glomus jugulare tumors, radiating cardiac murmur, elevated intracranial pressure, dehiscence of temporal bone near a branch of the carotid. Treatment Identify and treat the underlying pathology if possible. Specific treatments for tinnitus i tself are often unsatisfactory and may involve the use of masking hearing devices or white- noise and behavioral conditioning. Abnormal movements Dyskinesia (abnormal involuntary movements) Tremor Rest tremor is rhythm ic, present at rest during waking, and abolished on voluntary movement. It occurs in parkin sonism (with rigidity/bradykinesia) and may respond to dopaminergic medications. Intention tremor is an irregular, large-amplitude shaking worse on reaching out for something, typica lly more dramatic the closer the movement is to the target. It is typical of cerebellar dis ease (e.g., MS). Medical treatment is difficult; use of wrist weights or extra-heavy utensi ls may improve function- ing by dampening the oscillations. Some patients may benefit from thalamic deep brain stimulation. Postural tremor is absent at rest, present on maintained p osture (e.g., arms outstretched), and may persist (but is not exaggerated) on movement. Cau ses: Familial essential tremor (autosomal dominant; improved with alco- hol, \222 -blocker s, primidone, or, in severe cases, with deep brain stimulation), thyrotoxicosis, anxiety, c affeine or other stimulants, withdrawal from alco- hol or benzodiazepines. Chorea, athetosi s, and hemiballismus Chorea: Nonrhythmic, jerky, purposeless movements that flit from one p art of the body to another. Causes include Huntington \200\231s and Sydenham \200\231s chor ea (choreoathetoid movements) \200\224a rare complication of streptococcal infection. Chore a gravi- darum is a poorly understood condition typically self-limited to pregnancy. The an atomical basis of chorea is uncertain but it is thought of as the phar- macological mirror image of Parkinson \200\231s disease (PD) (levodopa worsens chorea). Hemiballismus: Large-a mplitude, flinging hemichorea (affects proxi- mal muscles) contralateral to a lesion of the subthalamic nucleus (often a lacunar infarction in an elderly diabetic). Recovers spontane ously over months. Athetosis: Slow, sinuous, confluent, purposeless writhing move- ments (e