Salivary gland neoplasms

DEFINITION
Salivary gland neoplasms are benign or malignant tumors of a salivary gland (parotid, submandibular, or sublingual).
PHYSICAL FINDINGS AND CLINICAL PRESENTATION
● Parotid gland
● Painless swelling overlying the masseter muscle (under the temporomandibular joint)
● Pain
● Facial nerve palsy
● Cervical lymph nodes
● Mass in oral cavity
● Submandibular gland: swelling under anterior portion of the mandible
● Sublingual gland: intraoral swelling under the tongue, medial to the mandible
● Salivary gland neoplasms most often present as slowgrowing, well-circumscribed masses. Pain, rapid growth,
nerve weakness, fixation to skin or underlying muscle, and paresthesias usually are indicative of malignancy.

DIFFERENTIAL DIAGNOSIS
Benign tumors
● Mixed tumor (usually parotid)
● Adenolymphoma (Warthin’s tumor)
● Pleomorphic adenoma
● Capillary hemangioma, lymphangioma (in children)
● Intraductal papilloma
● Other (e.g., myoepithelioma, canalicular adenoma, basal cell adenoma)
Malignant tumors
● Mucoepidermoid carcinoma (most common malignant tumor of the parotid gland)
● Adenoid cystic carcinoma
● Adenocarcinoma
● Malignant mixed tumor
● Squamous cell carcinoma
● Other
WORKUP
● Fine-needle aspiration. The sensitivity, specifi city, and accuracy of parotid gland aspirates are approximately 92%,
100%, and 98%, respectively
● Imaging by CT scan  or MRI
● Open biopsy (rarely indicated)

TREATMENT
Malignant tumors
● Surgery is the mainstay of treatment; gland resection and neck dissection if lymph nodes are involved
● A lateral lobectomy with preservation of facial nerve should be considered for tumors confi ned to the superfi cial
lobe of the parotid gland. Gross tumor should not be left in situ, but if the facial nerve is able to be preserved by “peeling” the tumor off the nerve, it should be attempted, followed by radiation therapy for microscopic disease.
● Postoperative radiation is indicated for high-grade malignancies demonstrating extraglandular disease, perineural
invasion, direct invasion of surrounding tissues, or regional metastases.
● Chemotherapy
Benign tumors
● Surgery for tumor resection

Perirectal abscess

DEFINITION
A perirectal abscess is a localized inflammatory process that can be associated with infections of soft tissue and anal glands based on anatomic location. Perianal and perirectal abscesses may be simple or complex, causing suppuration. Infections in these spaces may be classified as superficial perianal or perirectal with involvement in the following anatomic spaces: ischiorectal, intersphincteric, perianal, and supralevator.
PHYSICAL FINDINGS AND CLINICAL PRESENTATION
● Localized perirectal or anal pain—often worsened with movement or straining
● Perirectal erythema or cellulitis
● Perirectal mass by inspection or palpation
● Fever and signs of sepsis with deep abscess
● Urinary retention

CAUSE
● Polymicrobial aerobic and anerobic bacteria involving one of the anatomic spaces (see Defi nition), often associated
with localized trauma
● Microbiology: most bacteria are polymicrobial, mixed enteric and skin flora
● Predominant anerobic bacteria: Bacteroides fragilis, Peptostreptococcus spp., Prevotella spp.
● Predominant agrobic bacteria: Staphylococcus aureus, Streptococcus spp., Escherichia coli
DIAGNOSIS
● Many patients will have predisposing underlying conditions including:
● Malignancy or leukemia
● Immune defi ciency
● Diabetes mellitus
● Recent surgery
● Steroid therapy

DIFFERENTIAL DIAGNOSIS
● Crohn’s disease (infl ammatory bowel disease)
● Pilonidal disease
● Hidradenitis suppurativa
● Hemorrhoids
● Cancerous lesions
● Anal fi ssure
● Fistula
● Proctitis—often STD-associated, including: syphilis, gonococcal, chlamydia, chancroid, condylomata acuminata, HSV
● AIDS-associated: Kaposi’s sarcoma, lymphoma, CMV.

WORKUP
● Examination of rectal, perirectal/perineal areas
● Rule out necrotic process and crepitance suggesting deep tissue involvement
● Local aerobic and anaerobic cultures
● Blood cultures if toxic, febrile, or compromised
● Possible sigmoidoscopy
TREATMENT
● Incision and drainage of abscess
● Débridement of necrotic tissue
● Rule out need for fi stulectomy
● Local wound care-packing
● Sitz baths
● Antibiotic treatment: Directed toward coverage for mixed skins and enteric flora
● Outpatient-oral: Amoxicillin/clavulanic acid, ciprofloxacin plus metronidazole or clindamycin
● Inpatient-intravenous: Ampicillin/sulbactam, cefotetan, piperacillin/tazobactam, imipenem

Esophageal spasm and Esophageal varices

DEFINITION
● Diffuse esophageal spasm (DES) is an esophageal motility disorder manifesting clinically with chest pain and/or
dysphagia
● The character of the chest pain may mimic myocardial ischemia and is responsible for innumerable hospital
admission to rule out myocardial infarction.
● The origin of DES is unknown. Emotional stress, peptic ulcer disease, pancreatitis, and gallstones may trigger
esophageal spasm in susceptible patients.

DIAGNOSIS
● Diagnosis: Barium swallow may reveal the classic “corkscrew“ appearance . Manometry may reveal
repetitive contractions. However, both studies may be normal if the patient is not experiencing spasms at the
time of the test.
TREATMENT
● Treatment: avoidance of trigger factors, calcium channel blockers, nitrates. Thoracic esophagomyotomy in resistant case; however, results have been disappointing.

 Esophageal varices

DEFINITION
● Esophageal varices are dilated sumucosal veins that communicate with the portocollateral circulation and the systemic venous system. They are a common complication of cirrhosis.
DIAGNOSIS
● Diagnosis is best made with endoscopy (Fig. 153–1). UGI series  will also identify varices.
● Patients with cirrhosis should undergo an upper endoscopy examination once a year to evaluate for varices .

TREATMENT
● Esophageal bleeding is a major cause of death in patients with cirrhosis and hypertension.
● The risk factors for variceal hemorrhage include continued alcohol use, poor liver function, portal venous pressure gradient greater than 2 mm Hg, and large varices. Nonselective beta blockers (propranolol or nadolol given in a dose to reduce resting heart rate 25%) are recommended as primary prophylaxis to prevent esophageal variceal bleeding in patients with medium-large esophageal varices. Endoscopic variceal ligation (EVL) can be used in patients who are intolerant to beta-blocker therapy.
● The acute management of bleeding varices includes the following:
a. Resuscitation (intravenous fl uids and blood transfusion) and correction of any coagulation abnormalities (fresh frozen plasma).
b. Octreotide, terlipressin, somatostatin
c. Emergency endoscopic sclerotherapy or variceal band ligation

LUNG ABSCESS

DEFINITION
A lung abscess is an infection of the lung parenchyma resulting in a necrotic cavity containing pus.
PHYSICAL FINDINGS AND CLINICAL PRESENTATION
● Symptoms are generally insidious and prolonged, occurring for weeks to months
● Fever, chills, and sweats
● Cough
● Sputum production (purulent with foul odor)
● Pleuritic chest pain
● Hemoptysis
● Dyspnea
● Malaise, fatigue, and weakness
● Tachycardia and tachypnea
● Dullness to percussion, whispered pectoriloquy, and bronchophony
● Amphoric breath sounds (low-pitched sound of air moving across a large open cavity)

CAUSE
● The most important factor predisposing to lung abscess is aspiration.
● Following aspiration as a major predisposing factor is periodontal disease.
● Lung abscess is rare in an edentulous person.
● Approximately 90% of lung abscesses are caused by anaerobic microorganisms (Bacteroides fragilis, Fusobacterium nucleatum, Peptostreptococcus, microaerophilic Streptococcus).
Pulmonary actinomycosis will also generate lung abscess.
● In most cases, anaerobic infection is mixed with aerobic or facultative anaerobic organisms (S. aureus, E. coli, K. pneumoniae, P. aeruginosa).
● Parasitic organisms, including Paragonimus westermani and Entamoeba histolytica ● Fungi, including Aspergillus, Cryptococcus, Histoplasma, Blastomyces, and Coccidioides
● Immunocompromised hosts may become infected with Aspergillus, mycobacteria, Nocardia, Legionella micdadei, and Rhodococcus equi.

DIAGNOSIS
Lung abscess may be primary or secondary.
● Primary lung abscess refers to infection from normal host organisms within the lung (e.g., aspiration, pneumonia).
● Secondary lung abscess results from other preexisting conditions (e.g., endocarditis, underlying lung cancer, pulmonary emboli).
Lung abscess may be acute or chronic.
● Acute lung abscess is present if symptoms are less than 4 to 6 weeks.
● Chronic lung abscess is present if symptoms are longer than 6 weeks.
DIFFERENTIAL DIAGNOSIS
The differential diagnosis is similar to that for cavitary lung lesions:
● Bacterial (anaerobic, aerobic, infected bulla, empyema, actinomycosis, tuberculosis)
● Fungal (histoplasmosis, coccidioidomycosis, blastomycosis, aspergillosis, cryptococcosis)
● Parasitic (amebiasis, echinococcosis)
● Malignancy (primary lung carcinoma, metastatic lung disease, lymphoma, Hodgkin’s disease)
● Wegener’s granulomatosis, sarcoidosis, endocarditis, septic pulmonary emboli
LABORATORY TESTS
● CBC with leukocytosis
● Bacteriologic studies
1. Sputum Gram stain and culture (commonly contaminated by oral flora)
2. Percutaneous transtracheal aspiration
3. Percutaneous transthoracic aspiration
4. Fiberoptic bronchoscopy using bronchial brushings or bronchoalveolar lavage is the most widely used intervention
when trying to obtain diagnostic bacteriologic cultures .
● Blood cultures on some occasions may be positive
● If an empyema is present, obtaining empyema fluid via thoracentesis may isolate the organism.

IMAGING STUDIES
● Chest x-ray reveals cavitary lesion with an air fluid level .
● Lung abscesses are most commonly found in the posteriorn segment of the right upper lobe.
● Chest CT scan  can localize and size the lesion and assist in differentiating lung abscesses from other pathologic processes (e.g., tumor, empyema, infected bulla, etc.)
TREATMENT
● Penicillin, 1 to 2 million U IV, every 4 hours until improvement (e.g., afebrile, decrease in sputum production) followed by penicillin VK 500 mg PO daily for the next 2 to 3 weeks but usually requiring longer 6- to 8-week courses
● Metronidazole is given with penicillin at doses of 7.5 mg/kg IV every 6 hours, followed by metronidazole PO, 500 mg twice to four times daily.
● Clindamycin is an alternative choice if concerned about penicillin-resistant organisms. The dose is 600 mg IV every
8 hours until improvement, followed by 300 mg PO every 6 hours.

Atelectasis

DEFINITION
Atelectasis is the collapse of lung volume.
PHYSICAL FINDINGS AND CLINICAL PRESENTATION
● Decreased or absent breath sounds
● Abnormal chest percussion
● Cough, dyspnea, decreased vocal fremitus and vocal resonance
● Diminished chest expansion, tachypnea, tachycardia.

CAUSE
● Mechanical ventilation with higher FiO2
● Chronic bronchitis
● Cystic fibrosis
● Endobronchial neoplasms
● Foreign bodies
● Infections (e.g., TB, histoplasmosis)
● Extrinsic bronchial compression from neoplasms, aneurysms of ascending aorta, enlarged left atrium
● Sarcoidosis
● Silicosis
● Anterior chest wall injury, pneumothorax
● Alveolar injury (e.g., toxic fumes, aspiration of gastric contents)
● Pleural effusion, expanding bullae
● Chest wall deformity (e.g., scoliosis)
● Muscular weaknesses or abnormalities (e.g., neuromuscular disease)
● Mucus plugs from asthma, allergic bronchopulmonary aspergillosis, postoperative state.

DIFFERENTIAL DIAGNOSIS
● Neoplasm
● Pneumonia
● Encapsulated pleural effusion
● Abnormalities of the brachiocephalic vein and left pulmonary ligament
IMAGING STUDIES
● Chest x-ray will confirm the diagnosis .
● CT scan  indicated with suspected endobronchial neoplasm or extrinsic bronchial compression
● Fiberoptic bronchoscopy (select patients) is useful for removal of foreign body or evaluation of endobronchial and
peribronchial lesions.
TREATMENT
● Deep breathing, mobilization of the patient
● Incentive spirometry
● Tracheal suctioning
● Humidifi cation
● Chest physiotherapy with percussion and postural drainage
● Positive-pressure breathing (continuous positive airway pressure [CPAP] by face mask, positive end-expiratory pressure [PEEP] for patients on mechanical ventilation)
● Use of mucolytic agents (e.g., acetylcysteine)
● Recombinant human DNase in patients with cystic fi brosis
● Bronchodilator therapy in select patients

Otitis media Treatment

DEFINITION
Otitis media is the presence of fluid in the middle ear accompanied by signs and symptoms of infection.
PHYSICAL FINDINGS AND CLINICAL PRESENTATION
● Fluid in the middle ear along with signs and symptoms of local inflammation
1. Erythema with diminished light reflex
● Erythema of the tympanic membrane without other abnormalities is not a diagnostic criterion for acute otitis media because it may occur with any inflammation of the upper respiratory tract, crying, or nose blowing.
● As infection progresses, middle ear exudation occurs (exudative phase); the exudate rapidly changes from serous to
purulent (suppurative phase).
● Retraction and poor motility of the tympanic membrane, which then becomes bulging and convex. Air bubbles may
be seen.
● At any time during the suppurative phase, the tympanic membrane may rupture , releasing the middle ear contents.

● Symptoms
1. Otalgia, ranging from slight discomfort to severe, spreading to the temporal region
2. Ear stuffiness and hearing loss may precede or follow otalgia.
3. Otorrhea
4. Vertigo, nystagmus, tinnitus, fever, lethargy, irritability, nausea, vomiting, anorexia
● After an episode of acute otitis media
1. Persistence of effusion for weeks or months (called secretory, serous, or nonsuppurative otitis media)
2. Fever and otalgia usually absent
3. Hearing loss possible (10 to 50 dB, with predominant involvement of the low frequencies)
CAUSE
● Most common causative factor is an upper respiratory tract infection (often viral), which causes inflammation and obstruction of the eustachian tube. Bacterial colonization of the nasopharynx in conjunction with eustachian tube dysfunction leads to infection.
● May occasionally develop as a result of hematogenous spread or via direct invasion from the nasopharynx
● Most common bacterial pathogens
1. Streptococcus pneumoniae causes 40% to 50% of cases and is the least likely of the major pathogens to resolve without treatment.
2. Haemophilus infl uenzae causes 20% to 30% of cases.
3. Moraxella catarrhalis causes 10% to 15% of cases.
4. Of increasing importance, infection caused by penicillinnonsusceptible S. pneumoniae (PNSSP).
● Viral pathogens
1. Respiratory syncytial virus
2. Rhinovirus
3. Adenovirus
4. Influenza
● Others
1. Mycoplasma pneumoniae
2. Chlamydia trachomatis

DIFFERENTIAL DIAGNOSIS
● Otitis externa
● Referred pain
1. Mouth
2. Nasopharynx
3. Tonsils
4. Other parts of the upper respiratory tract
WORKUP
● Thorough otoscopic examination; adequate visualization of the tympanic membrane requires removal of cerumen and debris.
● Tympanometry
1. Measures compliance of the tympanic membrane and middle ear pressure
2. Detects the presence of fluid
● Acoustic reflectometry
1. Measures sound waves refl ected from the middle ear
2. Useful for infants older than 3 months
3. Increased refl ected sound correlated with the presence of
effusion
LABORATORY TESTS
● Tympanocentesis
1. Not necessary in most cases, because the microbiology of middle ear effusions has been shown to be quite consistent
2. May be indicated for:
a. Highly toxic patients
b. Patients who fail to respond to treatment in 48 to 72 hours
c. Immunocompromised patients
● Cultures of the nasopharynx: sensitive but not specifi c
● Blood counts: usually show a leukocytosis with polymorphonuclear elevation
● Plain mastoid radiographs: generally not indicated; will reveal haziness in the periantral cells that may extend to entire mastoid
● CT or MRI may be indicated if serious complications suspected (meningitis, brain abscess)
TREATMENT
Most uncomplicated cases of acute otitis media resolve spontaneously, without complications.

Medications
Studies have demonstrated limited therapeutic benefit from antibiotic therapy. However, when opting to use antibiotic therapy, consider the folllowing:
● Amoxicillin remains the drug of choice for first-line treatment of uncomplicated acute otitis media, despite increasing prevalence of drug-resistant S. pneumoniae.
● Treatment failure is defined by lack of clinical improvement of signs or symptoms after 3 days of therapy.
● With treatment failure, in the absence of an identified causative pathogen, therapy should be redirected to cover
these:
1. Drug-resistant S. pneumoniae
2. Beta-lactamase–producing strains of H. influenzae and M. catarrhalis
● Agents fulfilling these criteria include amoxicillinclavulanate, second-generation cephalosporins (e.g., cefuroxime
axetil, cefaclor), and ceftriaxone (given IM). Cefaclor, cefixime, loracarbef, and ceftibuten are active against
H. influenzae and M. catarrhalis, but less active against pneumococci, especially drug-resistant strains, than the
agents listed previously.
● Trimethoprim-sulfamethoxazole (TMP-SMZ) and macrolides have been used as first- and second-line agents, but
pneumococcal resistance to these agents is rising (up to 25% resistance to TMP-SMZ, and up to 10% resistance to
erythromycin).
● Cross-resistance between these drugs and the beta-lactams exist; therefore, patients who are treatment failures on
amoxicillin are more likely to have infections resistant to TMP-SMZ and macrolides.
● Newer fluoroquinolones (levofloxacin, moxifl oxacin) have enhanced activity against pneumococci compared with
older agents (ciprofloxacin, ofloxacin).
● Treatment should be modifi ed according to cultures and sensitivities.
Note: Effusions may persist for 2 to 6 weeks or longer in many patients with adequately treated otitis media.
Surgical therapy
● No evidence to support the routine of myringotomy, but in severe cases it provides prompt pain relief and accelerates resolution of infection
● Purulent secretions retained in the middle ear lead to increased pressure that may lead to spread of infection to
contiguous areas. Myringotomy to decompress the middle ear is necessary to avoid complications.
● Complications include mastoiditis, facial nerve paralysis, labyrinthitis, meningitis, and brain abscess.
● Other procedures used for drainage of the middle ear include insertion of a ventilation tube and simple mastoidectomy.
Chronic therapy
● Myringotomy and tympanostomy tube placement for persistent middle ear effusion unresponsive to medical
therapy for 3 months or longer if bilateral or 6 months or longer if unilateral
● Adenoidectomy, with or without tonsillectomy, often advocated for treatment of recurrent otitis media, although
indications for this procedure are controversial
● Chronic complications include tympanic membrane perforations, cholesteatoma, tympanosclerosis, ossicular
necrosis, toxic or suppurative labyrinthitis, and intracranial suppuration.

Urethral Trauma in the Male and Erectile Dysfunction

Although rare, direct trauma to the corpora cavernosa can occur. Rupture of the thick tunica albuginea usually involves the deep fascia of the penis (Buck’s fascia), and blood can extravasate quickly, causing penile swelling. Urethral rupture is more common and involves one of three mechanisms:
● External trauma or a penetrating injury
● Internal injury (caused by a catheter, instrument, or foreign body)
● Spontaneous rupture (caused by increased intraurethral pressure or periurethral inflammation)

Erectile dysfunction (ED) is an inability to achieve and/or maintain penile erection suffi cient for sexual intercourse. Its occurrence increases with age, and some of the probable causes are illustrated. Normal erectile function occurs when a sexual stimulus causes the release of nitric oxide from nerve endings and endothelial cells of the corpora cavernosa, thus relaxing the smooth muscle tone of the vessels and increasing blood fl ow into the erectile tissues. As the erectile tissue becomes engorged with blood, it compresses the veins in the tunica albuginea so that the blood remains in the cavernous bodies.
The available drugs to treat ED aid in relaxing the smooth muscle of the blood vessels of the erectile tissues. Erectile dysfunction can also occur from damage to the nerves innervating the perineum (e.g., a complication of prostatic surgery). Afferent impulses conveying stimulation/arousal sensations are conveyed by the pudendal nerve (S2-S4, somatic fibers), whereas the autonomic efferent innervation of the cavernous vasculature is via the pelvic splanchnics (S2-S4, parasympathetic fibers).

The deep perineal space in males includes the following:
● Membranous urethra: a continuation of the prostatic urethra
● Deep transversus perineal muscles: extend from the ischiotuberosities and rami to the perineal body; stabilize the perineal body.
● Bulbourethral glands: their ducts pass from the deep pouch to enter the proximal part of the spongy urethra; provide a mucus-like secretion that lubricates the spongy urethra
● External urethral sphincter: skeletal muscle that encircles the membranous urethra, is under voluntary control (via the pudendal nerve), and extends superiorly over the anterior aspect of the prostate gland but does not possess sphincter action on the gland
These structures, along with their respective neurovascular bundles, lie between the perineal membrane
(thick fascial sheath) and the fascia covering the inferior aspect of the levator ani. The neurovascular
components include the following:
● Pudendal nerve: somatic innervation (S2-S4) of the skin and skeletal muscles of the perineum; includes the inferior rectal (anal), perineal, scrotal, and dorsal nerves of the penis
● Internal pudendal artery: arises from the internal iliac artery; passes out the greater
sciatic foramen with the pudendal nerve, around the sacrospinous ligament, and into the lesser
sciatic foramen to enter the pudendal (Alcock’s) canal and distribute to the perineum as the inferior
rectal, perineal, scrotal, and dorsal arteries of the penis as well as the artery of the bulb

Development of the Reproductive Organs
The reproductive systems of the female and male develop from undifferentiated primordia and follow the sexual differentiation of each sex based on the genetic makeup of the embryo (XX for females and XY for males). In females, mesonephric ducts degenerate while the paramesonephric ducts develop into the uterine tubes, uterus, and upper
portion of the vagina . In males, the mesonephric ducts persist and become the ductus deferens, ejaculatory ducts, and seminal vesicles.
Development of the External Genitalia
The female and male external genitalia develop from the genital tubercle (the phallic structures), paired urogenital folds, and labioscrotal folds.

Down syndrome

DEFINITION
Down syndrome is a disorder characterized by mental retardation and multiple organ defects. It is caused by a chromosomal abnormality (trisomy 21).

PHYSICAL FINDINGS AND CLINICAL PRESENTATION
● Microcephaly
● Flattening of occiput and face
● Upward slant to eyes with epicanthal folds
● Brushfi eld spots in iris
● Broad stocky neck
● Small feet, hands, digits
● Single palmar crease
● Hypotonia
● Short stature
● Associated with congenital heart disease, malformations of the GI tract, cataracts, hypothyroidism, hip dysplasia
● About half of children with Down syndrome are born with congenital heart disease, with the most common lesions being atrial septal defect and ventricular septal defect

● Persistent primary congenital hypothyroidism is found in 1 in 141 newborns with Down syndrome, as compared with 1 in 4000 in the general population.
● Ophthalmologic disorders increase in frequency with age. Over 80% of children aged 5 to 12 years have disorders that need monitoring or intervention, such as refractive errors, strabismus, or cataracts.
CAUSE
● Nondisjunction of chromosome 21
DIAGNOSIS
● Prenatal cytogenic diagnosis by amniocentesis or chorionic villus sampling
● Combined use of serum screening and fetal ultrasound testing for thickened nuchal fold has 80% detection rate, with 5% false-positives
● Postnatal chromosomal karyotype.

DIFFERENTIAL DIAGNOSIS
● Congenital hypothyroidism
● Other chromosomal abnormalities
WORKUP
● Postnatal karyotype
● Thyroid screening at birth, at age 6 months, and yearly thereafter
● Echocardiography, usually performed in neonatal period
TREATMENT
● Treatment consists of vigilant monitoring for comorbid states, such as obesity, hypothyroidism, leukemia, hearing
loss, and valvular heart disease.
● Thyroid screening at birth, at age 6 months, and yearly thereafter
● Prevention of obesity with low-calorie, high-fi ber diet
● Monitoring for hematologic problems
● Auditory brainstem responses in all newborns and aggressive testing for hearing loss in children with chronic otitis
media
● Echocardiography in all newborns and cardiac assessment of adolescents for development of mitral valve prolapse
● Ophthalmologic assessment by age 6 months for congenital cataracts and annual examinations for monitoring of refractive errors and strabismus
● Regular dental care
● Pelvic examination of women who are sexually active or who have menstrual problems
● Dermatologic issues such as folliculitis can become problematic in adolescents and require careful attention to hygiene and topical antibiotics

Bell’s palsy

DEFINITION
Bell’s palsy is an idiopathic, isolated, usually unilateral facial weakness in the distribution of the seventh cranial nerve; less than 1% are bilateral.

PHYSICAL FINDINGS AND CLINICAL PRESENTATION
● Unilateral paralysis of the upper and lower facial muscles (asymmetrical eye closure, brow, and smile; Fig. 49–1).
● Ipsilateral loss of taste
● Ipsilateral ear pain, usually 2 to 3 days before presentation
● Increased or decreased unilateral eye tearing
● Hyperacusis
● Subjective ipsilateral facial numbness
● In about 8% of cases, other cranial neuropathies may occur.

CAUSE
● Most cases are idiopathic, although the cause is often viral (herpes simplex).
● Herpes zoster can cause Bell’s palsy in association with herpetic blisters affecting the outer ear canal or the area behind the ear (Ramsay-Hunt syndrome).
● Bell’s palsy can also be one of the manifestations of Lyme disease.
DIFFERENTIAL DIAGNOSIS
● Neoplasms affecting the base of the skull or the parotid gland
● Infectious process (meningitis, otitis media, osteomyelitis of the skull base)
● Brainstem stroke
● Multiple sclerosis
● Head trauma, temporal bone fracture
● Other: sarcoidosis, Guillain-Barré syndrome, carcinomatous or leukemic meningitis, leprosy, Melkersson-Rosenthal syndrome
LABORATORY TESTS
● Consider CBC, fasting glucose, VDRL, ESR, angiotensinconverting enzyme (ACE) level in select patients.
● Lyme titer in endemic areas.

IMAGING STUDIES
● Contrast-enhanced MRI to exclude neoplasms is indicated only in patients with atypical features or course.
● Chest x-ray may be useful to exclude sarcoidosis or rule out TB in select patients before treating with steroids.
TREATMENT
● Reassure patient that the prognosis is usually good and the disease is most likely a result of a virus attacking the nerve, not a stroke.
● Avoid corneal drying by patching the eye. Ophthalmic ointment at night and artificial tears during the day are also
useful to prevent excessive drying.
● A short course of oral prednisone is commonly used, although the evidence from randomized controlled trials
demonstrating its efficacy is inadequate. If used, prednisone therapy should be started within 24 to 48 hours of symptom onset. Optimal steroid dose is unknown.
● Combination therapy with acyclovir and prednisone may be effective in improving clinical recovery, although robust evidence from high-quality, randomized controlled trials is lacking.
● Botulinum toxin may be helpful for treatment of synkinesis and hemifacial spasm, two late sequelae of Bell’s palsy.

Multiple sclerosis

DEFINITION
Multiple sclerosis is a chronic demyelinating disease of unknown cause. It is characterized pathologically by zones of
demyelinization (plaques) scattered throughout the white matter.

CLINICAL MANIFESTATIONS
The disease can manifest in varied patterns:
● Relapsing-remitting MS (RRMS): most common type (80% of patients at onset, 55% of all patients at any given
time). Full recovery of attacks may occur early but, with subsequent attacks, recovery is incomplete.
● Secondary progressive MS (SPMS): worsening disability because of accumulating axonal loss and new inflammation. SPMS is the long-term outcome of most RRMS cases.
● Primary progressive MS (PPMS): gradual insidious worsening from onset without relapses
● Progressive-relapsing MS (PRMS): progressive course with superimposed relapses; least common form                (5% of patients)

The clinical signs vary with the location of plaques. The more common manifestations are as follows:
● Weakness: usually involving the lower extremities; the patient may complain of diffi culty ambulating, tendency to
drop things, easy fatigability.
● Sensory disturbances: numbness, tingling, pins and needles sensation
● Visual disturbances: diplopia, blurred vision, visual loss, nystagmus, impaired visual acuity
● Incoordination: gait impairment, clumsiness of upper extremities
● Others: vertigo, incontinence, loss of sexual function, slurred speech, depression, fatigue
PHYSICAL EXAMINATION
Visual abnormalities
● Paresis of medial rectus muscle on lateral conjugate gaze (internuclear ophthalmoplegia) and horizontal nystagmus
of the adducting eye
● Central scotoma, decreased visual acuity (optic neuritis)
● A Marcus Gunn pupil (pupil that paradoxically dilates with direct light), indicating damage to the optic nerve anterior to the chiasm, is frequently present.
● Nystagmus Abnormalities of reflexes
● Increased deep tendon ref exes
● Positive Hoffmann’s sign, positive Babinski’s sign
● Decreased abdominal skin reflex, decreased cremasteric reflex
● Lhermitte’s sign: flexion of the neck while the patient is lying down elicits an electrical sensation extending bilaterally down the arms, back, and lower trunk.
● Charcot’s triad: nystagmus, scanning speech, and intention tremor
● Impaired recognition of objects by touch alone (astereognosis)

DIFFERENTIAL DIAGNOSIS
● Autoimmune: acute disseminated encephalomyelitis (ADEM), postvaccination encephalomyelitis
● Degenerative: subacute combined degeneration (vitamin B12 defi ciency), inherited spastic paraparesis
● Infections: Lyme disease, progressive multifocal leukoencephalopathy, syphilis, HIV, human T-cell leukemia virus
(HTLV-1), Whipple’s disease, expanded differential in immunocompromised patients
● Inflammatory: sarcoidosis, SLE, Sjögren’s syndrome, Behçet’s disease, vasculitis, celiac disease
● Spinal cord compression (cervical spondylosis, tumor, herniated disc, Chiari malformation)
● Inherited metabolic disorders: leukodystrophies, hereditary myelopathy
● Mitochondrial: Leber’s hereditary optic neuropathy; mitochondrial encephalopathy, lactic acidosis, and stroke-like
episodes (MELAS)
● MS variants: recurrent optic neuropathy, neuromyelitis optica (Devic disease), acute tumor-like lesion (Marburg
variant), Baló’s concentric sclerosis, myelinoclastic diffuse sclerosis (Schilder’s disease)
● Neoplasms: metastases, CNS lymphoma
● Vascular: subcortical infarcts caused by diabetes mellitus (DM), hypertension, Binswanger’s disease
● Somatoform disorders, factitious disorders.

DIAGNOSTIC EVALUATION
● The diagnosis should be based on objective evidence of two or more neurologic signs occurring in different parts of the CNS more than 3 months apart (neurologic signs disseminated in time and space).
● MRI of the brain with gadolinium  can identify lesions as small as 3 to 4 mm and is frequently diagnostic in
suspected cases; it can also be used to assess disease load, activity, and progression. MRI typically reveals multiple,
predominantly periventricular plaques; however, a normal MRI scan cannot be used conclusively to exclude multiple
sclerosis.
● Lumbar puncture is indicated for all fi rst-time relapses and recommended for all evaluations when the diagnosis of MS is not definite. Lumbar puncture is particularly useful when MRI is inconclusive, because Lyme disease, acute disseminated encephalopathy, and hypertensive changes may mimic multiple sclerosis.
1. In patients with multiple sclerosis, the CSF may show increased gamma globulin (mostly IgG, but often IgA and IgM).
2. Agarose electrophoresis discloses discrete oligoclonal bands in the gamma region in approximately 90% of patients, including some with normal IgG levels.
3. Other possible CSF abnormalities: increased total protein, increased mononuclear white blood cells, presence of
myelin basic protein (elevated in acute attacks, indicates active myelin destruction)