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USMLE Step 2 (Subject) / Neurology (Lesson)

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• Nightmare disorder REM sleep arousal disorder (patient remembers dream) Epidemiology:- Prevalence: Up to 2% of adults, most common in early adulthood- F > M Risk factors: PTSD Clinical features:- Recurring frightening dreams during the second half of the sleep cycle (middle of the night or early in the morning)- Patient is fully alert, remembers the dream, and can usually be consoled- Causes functional impairment or distress Differential diagnosis: REM sleep behavior disorder – motor activity, sleep-related injury, older men Treatment:- Reassurance if the disorder is mild- Imagery rehearsal therapy: involves modifying a recurrent nightmare by writing it down and rehearsing new endings that make it less frightening when they occur again
• Optic neuritis Epidemiology:- Primarily in young women- Associated with multiple sclerosis- Immune-mediated demyelination Clinical features:- Acute, peaks at 2 weeks- Monocular vision loss- Eye pain with movement- "Washed-out" color vision- Afferent pupillary defect Diagnosis:- MRI of the orbits & brain Treatment:- Intravenous corticosteroids- 35% of cases recur
• Alcohol cerebellar degeneration Epidemiology:- > 10 years heavy alcohol use- Degeneration of Purkinje cells (cerebellar vermis) Clinical features:- Usually develops over weeks to months- Wide-based gait- Incoordintion in legs- Cognition usually intact Diagnostics:- Clinical: → Impaired tandem walking/heel-knee-shin→ Preserved finger-nose testing- CT/MRI: Cerebellar atrophy Treatment:- Alcohol cessation- Nutritional supplements- Ambulatory assistance devices (eg, walker) 
• Acute causes of hemiplegia in children Seizure:- History of generalized limb jerking or loss of consciousness- Presence of postictal confusion or Todd paralysis- Symptoms self-resolve Intracranial hemorrhage:- History of trauma &/or bleeding disorder (eg, hemophilia)- Signs of increased intracranial pressure (eg, vomiting, bradycardia) Ischemic stroke:- History of prothrombotic disorder (eg, antithrombin III deficiency) or cardiac disease (eg, patent foramen ovale) Hemiplegic migraine:- Onset in adolescence & often positive family history- History of headache & visual aura- Symptoms self-resolve
• Conus medullaris syndrome Damage to the spinal cord segments S3-S5 (conus medullaris), which are situated at the level of L1 vertebra. Etiology:- Spinal tumors- Trauma (e.g., vertebral fracture, spondylolisthesis) Onset: Sudden bilateral onset Pain: Lower back pain. Less severe radicular pain. Motor symptoms:- Symmetric, hyperreflexic distal paresis of lower limbs- Achilles reflex might be absent Sensory symptoms:- Symmetric, bilateral perianal numbness (saddle block anesthesia)- Sensory dissociation Urogenital and rectal symptoms:- Early onset of bladder and fecal incontinence- Erectile dysfunction
• Cauda equina syndrome Etiology: - Damage to or compression of the cauda equina with nerve fibers of L3-S5 (below L2).- Large posteromedial disc herniation, trauma, or tumors Onset: Gradual unilateral onset Pain: Severe radicular pain Motor symptoms:- Asymmetric, areflexic, flaccid paresis of the legs- Muscle atrophy Sensory symptoms:- Saddle block anesthesia- Asymmetric, unilateral numbness and/or paresthesia in lower limb dermatomes Urogenital and rectal symptoms:- Late onset of urinary retention- Change in bowel habits- Decreased rectal tone or bulbocavernous reflex- Erectile dysfunction
• Brain abscess Microbiology:- Viridans streptococci (∼50% of cases), often secondary to sinusitis- Staphylococcus aureus (10-15% of cases)- Coagulase-negative staphylococci (∼10% of cases)- Obligate anaerobes (e.g., Bacteroides species; 15–40% of cases) Pathogenesis:- Direct spread (eg, otitis media, mastoiditis, sinusitis)- Hematogenous spread (eg, endocarditis) Clinical features:- Dull, persistent headache- Symptoms of raised intracranial pressure (e.g., vomiting, papilledema, altered mental status)- Fever- Focal neurologic deficits: Commonly oculomotor or abducens nerve palsies secondary to increased intracranial pressure- Seizures Diagnostics:- Lab- CT/MRI: intraparenchymal lesions with a central hypodense (necrotic) area and peripheral ring enhancement- Biopsy Treatment:- Early surgical drainage and biopsy of the abscess- Antibiotic therapy for 6-8 weeks (usually IV)→ Initial empirical therapy (e.g., third-generation cephalosporin + metronidazole ± vancomycin)
• Evaluation of head trauma in children age 2-18 Any of the following:- Focal neurologic findings- Skull fracture, especially signs of basilar skull fracture- Seizure- Persistent altered mental status (e.g., agitation, lethargy, slow response)- Prolonged loss of consciousness→ Head CT without contrast GCS = 15 with any of the following:- Vomiting- Headache- Questionable or brief loss of consciousness- Severe mechanism of injury→ Clinician preference: Observation for 4-6 hours OR Head CT without contrast Minor head trauma (GCS = 15 with non-severe mechanism & no vomiting, headache, loss of consciousness, or signs of fracture)→ No head CT
• Multiple system atrophy (Shy-Drager syndrome) Clinical features:1. Parkinsonism2. Autonomic dysfunction: Postural hypotension, abnormal sweating, disturbance of bowel or bladder control, abnormal salivation or lacrimation, impotence, gastroparesis, etc3. Widespread neurological signs: Cerebellar, pyramidal, or lower motor neuron Diagnostics:- MRI: Atrophy of the regions in the brainstem and cerebellum Treatment:- Anti-Parkinsonism drugs are ineffective- Intravascular volume expansion with fludrocortisone, salt supplementation, alpha-adrenergic agonists
• Lacunar stroke Etiology: Small penetrating artery occlusion due to hypertensive arteriolar sclerosis Affected areas:- Basal ganglia- Subcortical white matter (e.g., internal capsule, corona radiata)- Pons Risk factors:- Hypertension- Diabetes mellitus, advanced age, ↑ LDL, smoking Clinical features:- Absence of cortical signs (e.g., aphasia, agnosia, neglect, apraxia, hemianopia), seizure, or mental status changes- Common syndromes:→ Pure motor hemiparesis (most frequent)→ Pure sensory stroke→ Ataxic hemiparesis→ Dysarthria-clumsy hand
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• Autonomic dysreflexia Potentially life-threatening complication of spinal cord injury above T6. Noxious stimuli (eg, urinary retention, constipation, pressure ulcers) can precipitate an unregulated sympathetic response, leading to vasoconstriction and severe hypertension. Above the lesion, a compensatory parasympathetic response causes diaphoresis, flushing, bradycardia, nasal congestion. Severe disease can result in intracranial hemorrhage or progressive bradycardia with cardiac arrest. Management:- Close monitoring of blood pressure- Place patient in upright position to encourage orthostatic blood pressure reduction- Remove tight-fitting clothes- Evaluate for urinary retention, fecal impaction, pressure sores- Short-duration antihypertensives (eg, nitrates, hydralazine) may be indicated for blood pressure control
• Presbyacusis Age-related, sensorineural hearing loss. Epidemiology:- Most common cause of sensorineural hearing loss- Incidence increases with age:→ Age 50: 10-15%→ Age 75: > 50%→ Age 90: nearly 100% Pathophysiology: Progessive damage of the Organ of Corti, especially near the basal turn of the cochlea, which impaires high-pitched hearing. Clincal featuers:- Progressive bilateral hearing loss, particularly of higher frequencies → Using a low-pitched voice with older patients can improve communication.- Usually noticed in the sixth decade of life- Difficulty hearing in noisy, crowded environments- Can cause depression or isolation Treatment: Hearing aids, cochlea implants
• Otosclerosis Epidemiology:- W > M- Age of onset: 20-40 years Etiology: 50% of cases show autosomal dominant inheritance with incomplete penetrance Pathophysiology: Stapedial otosclerosis → fixation of stapes to oval window → conductive hearing loss Clinical features:- Slowly progressive conductive hearing loss- Tinnitus- Mild vertigo (approx. 25%)- Paracusis willisii: patients hear better in noisy rather than quiet surroundings (vs. presbyacusis)- Quiet speech (patients hear their voice loudly)- Schwartze sign: red-blue hue seen through tympanic membrane- Symptoms may increase during pregnancy or following menopause due to hormonal changes Diagnostics:- Pure tone audiometry: ↓ Air conduction (especially for lower frequencies)- Impedance audiometry: absent stapedius reflex Treatment: Stapedotomy, cochlear implant
• Clinical characteristics of major stroke subtypes Ischemic (thrombotic):- Atherosclerotic risk factors (eg, uncontrolled hypertension, diabetes) ± history of transient ischemic attack- Local obstruction of an artery (eg, carotid, cerebral, vertebral)- Symptoms may alternate with periods of improvement (stuttering progression) Ischemic (embolic):- History of cardiac disease (eg, atrial fibrillation, endocarditis) or carotid atherosclerosis- Onset of symptoms is abrupt & usually maximal at the start- Multiple infarcts in different vascular territories Intracerebral hemorrhage:- History of uncontrolled hypertension, coagulopathy, illicit drug use (eg, amphetamines, cocaine)- Symptoms progress over minutes to hours- Focal neurologic symptoms appear early, followed by features of increased intracranial pressure (eg, vomiting, headache, bradycardia, reduced alertness) Spontaneous subarachnoid hemorrhage:- Bleeding from arterial saccular ("berry") aneurysm or AV malformation- Severe headache at onset- Meningeal irritation (eg, neck stiffness)- Focal deficits uncommon
• Clinical features of pineal gland masses Parinaud syndrome (dorsal midbrain syndrome)- Upper eyelid retraction (Collier sign)- Pupils non-reactive to light, reactive to accommodation- Vertical gaze abnormalitites- Nystagmus Obstructive hydrocephalus:- Papilledema- Headache, vomiting- Ataxia
• Oculomotor nerve palsy CN III has parasympathetic and motor nerve fibers. Parasympathetic fibers:- Pupil constriction → pupilary dilation Motor fibers:- Ptosis: paralysis of levator palpebrae superioris- Down-and-outward position of the eye: unopposed pull of the superior oblique (innervated by CN IV) and lateral rectus muscle (innervated by CN VI) → diplopia Etiology:- Compression: Aneurysm, tumor- Microvascular ischemia The motor components of CN III run within the nerve and are typically damaged by both etiologies.The parasympathetic fibers responsible for pupil constriction run on the outside of the CN III fascicle and are less susceptible to ischemia but are invariably affected by an extrinsic compression.→ Pupillary involvement can distinguish the etiology of isolated CN III palsy. Non-pupil-sparing CN III palsies are frequently caused by mass effect and should be considered due to an intracranial aneurysm until proved otherwise. Patients should undergo immediate MR or CT angiography of the head for evaluation. Pupil-sparing CN III palsies are typically caused by microvascular ischemia and are associated with diabetes, hypertension, hyperlipidemia, and advanced age.
• Causes of delirium Predisposing risk factors:- Dementia- Parkinson disease- Prior stroke- Advanced age- Sensory impairment Precipitating factors:- Drugs (e.g., narcotics, sedatives, antihistamines, muscle relaxers, polypharmacy)- Infections (e.g., pneumonia, UTI, meningitis)- Electrolyte disturbances (e.g., hyponatremia, hypercalcemia)- Metabolic derangements (e.g., volume depletion, vitamin B12 deficiency, hyperglycemia)- Systemic illnesses (e.g., congestive heart failure, hepatic failure, malignany)- Central nervous system conditions (e.g., seizure, stroke, head injury, subdural hematoma)
• Wallenberg syndrome Lateral medullary infarction, which results from occlusion of either the posterior inferior cerebellar artery (PICA) or branches of the vertebral artery. Vestibulocerebellar symptoms:- Vertigo, falling to the side of the lesion- Difficulty sitting upright without support- Diplopia & nystagmus (horizontal & vertical)- Ipsilateral limb ataxia Sensory:- Abnormal facial sensation or pain- Loss of pain & temperature in ipsilateral face & contralateral trunk & limbs Ipsilateral bulbar muscle weakness (Nucleus ambiguus):- Dysphagia & aspiration- Dysarthria, dysphonia & hoarseness (paralysis) Autonomic dysfunction:- Ipsilateral Horner's syndrome (miosis, ptoyis & anhidrosis)- Intractable hiccups- Lack of automatic respiration (especially during sleep)
• Sturge-Weber syndrome (encephalotrigeminal angiomatosis) - Port-wine stain (nevus flammeus/"birthmark" in the dermatome regions V1 and V2 of the face)- Vascular malformations of the choroid and the CNS (e.g., leptomeningeal angioma, often as the same side as the nevus flammeus)- Early-onset glaucoma- Epilepsy- Intellectual disability
• Von Hippel-Lindau disease Characterized by the development of numerous benign and malignant tumors:- Hemangioblastomas in the retina, cerebellum, brain stem, and spine- Bilateral renal cell carcinoma- Pheochromocytoma- Renal and pancreatic cysts
• Wernicke encephalopathy and Korsakoff syndrome Etiology: Wernicke encephalopathy and Korsakoff syndrome are caused by a severe deficiency of thiamine (vitamin B1). Wernicke encephalopathy (acute, reversible):1. Confusion (most common)2. Oculomotor dysfunction: Gaze-induced horizontal/vertical nystagmus (most common), diplopia, conjugate gaze palsy3. Gait ataxia: wide-based, small steps - Autonomic dysfunction: hypotension, syncope, hypothermia- Peripheral neuropathy: paresthesia, foot drop, decreased deep tendon reflexes- Cardiovascular dysfunction: tachycardia, exertional dyspnea- Diencephalic involvement: vegetative disorders (coma and stupor) Korsakoff syndrome (chronic, irreversible):- Personality changes (in frontal lobe lesions): apathy, indifference- Anterograde and retrograde amnesia- Confabulation: Patients produce fabricated memories to fill in lapses of memory.- Disorientation to time, place, and person- Hallucinations Diagnostics:- Laboratory tests: ↓ Serum thiamine levels, ↓ Erythrocyte transketolase activity (thiamine-dependant), ↑ Serum lactate and pyruvate- In patients with alcohol use disorder: evidence of alcohol-related liver dysfunction- Neuropathologic findings:→ WE: Mamillary body atrophy, dorsomedial thalamic neuron loss→ Korsakoff: Lesions in the anterior and medial thalami as well as the corpus callsoum Therapy:Wernicke encephalopathy:- Immediate IV administration of high-dose vitamin B1/thiamine until symptoms recede, followed by a lower dose- Long-term oral replacement of vitamins B1, B6, B12, and folic acid (vitamin B complex)Korsakoff syndrome:- Oral thiamine supplementation to prevent further insult- Psychiatric and psychological therapy- Memory strengthening exercises and aids- The use of signs and arrows at home can help with orientation.
• Migraine Epidemiology:- Prevalence: ∼18% of females and ∼6% of males- Peak incidence: 30-40 years Potential triggers:- Emotional stress- Weather changes- Certain food and beverages: alcohol, nicotine, citrus fruits, dairy products, food containing tyramine (e.g., chocolate, red wine)- Poor sleeping habits- Hormonal changes in women: menstruation, hormone intake (oral contraceptive pills) Clinical features:1. Prodrome (facultative): 24-48 hours before the headache starts:- Excessive yawning, difficulties writing or reading, sudden hunger or lack of appetite, mood changes2. Aura (only present in ∼25% of patients): paroxysmal reversible focal neurologic symptoms- Visual disturbances: scintillating scotoma, central scotoma, flashing lights, distorted color perception, fortification spectra (Star-like, zigzag figures)- Impaired sensibility, paresthesia- Dizziness, aphasia3. Headache- Localization: typically unilateral, but bilateral is possible- Duration: usually 4-24 hours, rarely over 72 hours- Course: progression of pulsating, throbbing, or pounding pain- Exacerbated by physical activity- Accompanying symptoms: photophobia, phonophobia, and nausea/vomiting4. Postdrome (facultative)- Feeling of exhaustion or euphoria- Muscle weakness- Anorexia or food cravings Diagnostics:- Neuroimaging should be used in headaches with an unusual clinical presentation or persistent neurologic or psychopathologic abnormalities.- Patients diagnosed with migraines should be screened for cardiovascular disease (especially in smokers and/or if taking oral contraceptives) Abortive therapy:- General measures: limit stimuli (i.e., light, loud noises) and activity (bed rest)- Mild to moderate attacks: NSAIDs (e.g., aspirin or ibuprofen)- Severe attacks: triptans (e.g., sumatriptan) or ergotamine (do not combine these agents!)- Initial therapy if nausea/vomiting is present: antiemetics (e.g., prochlorperazine, chlorpromazine) - Children: ibuprofen and family counseling Prophylactic therapy:- Beta blocker (e.g., metoprolol, propranolol, bisoprolol)- Tricyclic antidepressant (e.g., amitriptyline)- Anticonvulsants (e.g., topiramate or valproate)- Calcium channel blockers
• Medication overuse headache Secondary headache disorder caused by frequent use of analgesics Clinical presentation:- Dull, long-lasting headache- Headache does not respond well to analgesics- Malaise, nausea, and sensitivity to noise and light may occur Diagnosis:- History of pre-existing headache disorder (e.g., migraine)- Frequent use of analgesia (≥ 10 days/month for more than 3 months)- Headache present on ≥ 15 days/month Treatment:- Complete discontinuation of all analgesic medications, potentially in an inpatient setting- In the case of nausea → metoclopramide or domperidone- Headaches may be relieved with glucocorticoids or antipsychotics- Behavioral therapy
• Trigeminal neuralgia Epidemiology:- Sex: ♀ > ♂ (2:1)- Peak incidence: 60-70 years Etiology:- Classical trigeminal neuralgia: caused by neurovascular compression, generally by an aberrant loop of a neighboring artery or vein (usually the superior cerebellar artery)- Painful trigeminal neuropathy: may be caused by underlying disease (e.g., multiple sclerosis), structural lesions (e.g., tumor, cyst, aneurysms), or ischemia in the trigeminal nerve. Clinical features: - Unilateral facial pain: paroxysmal, severe shooting or stabbing (like an electric shock), followed by a burning ache- Lasts several seconds (in rare cases, several minutes) and may appear up to 100 times per day- Typically shoots from mouth to the angle of the jaw on the affected side in most cases- Occurs either at rest or triggered by movements such as chewing, talking or touch (e.g., brushing teeth, washing face); becomes worse with stimulation- Facial spasms may occur- Psychological distress: ranging from dysphoria to severe depression with suicidal tendencies- Usually progressive course Diagnostics: MRI to rule out compressive myelopathies Treatment: Carbamazepine
• Musculoskeletal back pain Most common cause of back pain Clinical features:- Inciting event (e.g., heavy lifting, straining)- Symmetric pain in a belt-like fashion- Ache Diagnostics: Clinical Treatment:- Analgesia- Exercise and stretching Give patients 4-6 weeks before returning.If symptoms do not improve, follow-up with an X-ray then MRI
• Cognitive impairment Normal changes of aging:- Forgetfulness without cognitive impairment- Language and vocabulary always retain- Neuropsychiatric testing is normal Mild cognitive impairment:- Dementia that isn't bad enough to impair them in society or independence- MMSE 20-24 Dementia:- Significant loss of cognition, executive function, social graces, or memory
• Disorders of consciousness Persistent vegetative state- Perceptual and self-awareness: Absent- Sleep-wake cycles: Present- Motor function: No purposeful movement- Brainstem reflexes: Variable- Respiratory function: Present Coma:- Perceptual and self-awareness: Absent- Sleep-wake cycles: Absent- Motor function: No purposeful movement- Brainstem reflexes: Variable- Respiratory function: Depressed, variable Locked-in syndrome:- Perceptual and self-awareness: Present- Sleep-wake cycles: Present- Motor function: Quadriplegia and pseudobulbar palsy; eye movement preserved- Brainstem reflexes: Variable- Respiratory function: Variable Brain death:- Perceptual and self-awareness: Absent- Sleep-wake cycles: Absent- Motor function: None or only reflex spinal movements- Brainstem reflexes: Absent- Respiratory function: Absent
• Neurogenic shock Pathophysiology: Injury to the descending spinal tracts → loss of sympathetic vascular tone → peripheral vasodilation → pooling of peripheral blood Etiology:- Spinal cord injury- Spinal anesthesia- Traumatic brain injury- Cerebral hemorrhage- Severe pain Clinical features:- Initial period (several minutes) of massive sympathetic stimulation (leading to hypertension and tachycardia)- Flushed, warm skin- Bradycardia- Hypotension with a normal pulse pressure Treatment:- Fluid resuscitation- Atropine to treat bradycardia- If fluid resuscitation fails to increase MAP beyond 90 mm Hg- If bradycardia is absent: phenylephrine- If bradycardia is present: epinephrine
• Classification of herpes zoster pain Acute herpetic neuralgia:- Persists ≤ 30 days from rash onset- Treatment: NSAIDs, analgesics Subacute herpetic neuralgia:- Persists > 30 days but resolves within 4 months of rash onset- Treatment: NSAIDs, analgesics Postherpetic neuralgia:- Persists > 3 months from rash onset- Treatment: Tricyclic antidepressants, gabapentin, pregabalin→ TCA – Relative contraindications: patients with heart disease, epilepsy, or glaucoma
• Friedreich ataxia Friedreich ataxia is an autosomal recessive disorder involving trinucleotide repeat expansion (GAA), resulting in an abnormalitiy of the frataxin protein. Epidemiology:- Peak incidence: 8-15 years (most cases < 25 years)- Most common in white populations Clinical features:- Progressive ataxia (muscle weakness and impaired coordination) of all limbs- Associated impaired proprioception, vibration sense (pallhypesthesia), and loss of deep tendon reflexes- Scoliosis- Foot deformity: foot inversion (pes cavus) with hammer toes- Concentric hypertrophic cardiomyopathy- Diabetes mellitus- Personality changes (e.g., emotional lability) Treatment: Multidisciplinary supportive care: genetic counseling, physiotherapy, and speech and language therapy Prognosis:- Cause of death: Most common heart failure due to hypertrophic cardiomyopathy
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• Bell palsy Peripheral neuropathy involving the facial nerve. Pathophysiology: Reactivation of a neurotrophic virus → inflammation and edema of the facial nerve → nerve compression and degeneration of the myelin sheath Clinical features:- Unilateral mouth drooping- Disappearance of the nasolabial fold with involvement of the upper face- Decreased ipsilateral eye lacrimation- Hyperacusis- Decreased sensation of taste over the anterior two-thirds of the ipsilateral tongue- Weakness typically develops acutely over a course of hours- Often occurs at night- Symptoms typically progress over 2-3 weeks, with gradual improvement over the following 3-6 months Treatment: - Glucocorticoids
• Exertional heat stroke Risk factors:- Strenuous activity during hot & humid weather- Dehydration- Poor acclimatization- Lack of physical fitness- Obesity- Medications: Anticholinergics, antihistamines, phenothiazines, tricyclics Clinical features:- Core temperature > 40° C immediately after collapseAND- Central nervous system dysfunction: Altered mental status, confusion, irritability, seizure- Additional organ or tissue damage: Renal/hepatic failure, DIC, ARDS Management:- Rapid cooling: Ice water immersion preferred; can consider high-flow cool water doushing, ice/wet towel rotation, evaporative cooling- Fluid resuscitation- Electrolyte correction- Management of end-organ complications
• Galactokinase deficiency Autosomal recessive deficiency of galactokinase.- Mild condition Galactitol accumulates if galactose is present in diet.  Symptoms:- Galactosemia, galactosuria- Infantile cataracts- Failure to track objects or to develop a social smile
• Classic galactosemia Autosomal recessive absence of galactose-1-phosphate uridyltransferase. Symptoms:- Develop when infant begins feeding (lactose present in breast milk and routine formula)- Failure to thrive- Jaundice- Hepatomegaly- Infantile cataracts- Intellectual disability- E coli sepsis Treatment: Exclude galatose and lactose (galactose + glucose) from diet
• Myasthenic crisis Epidemiology:- Affects 15-20% of patients with MG- Generally occurs during the active phase within 5-7 years after onset Precipitating factors:- Infection or surgery- Pregnancy or childbirth- Tapering of immunosuppressive drugs- Medications (e.g., aminoglycosides, beta blockers) Clinical features:- ↑ Generalized & oropharyngeal weakness- Respiratory insufficiency/dyspnea Treatment:- Intubation for deteriorating respiratory status- Plasmapharesis or IVIG as well as corticosteroids
• Cervical myelopathy Myelopathies are neurological disorders due to compression of the spinal cord. Epidemiology:- Age > 55 years- Degenerative cervical spine/discs → canal stenosis → cord compression- Blunt or penetrating trauma (e.g., fracture, epidural hematoma)- Infection (e.g., abscess) Clinical features:- Gait dysfunction – usually first- Neck, shoulder, upper limb, or lower limb pain (neck stiffness may be present)- LMN signs at the level of the lesion (e.g., weakness and atrophy in the arms and/or hands in lesions of the thoracic spine)- UMN signs below the level of the lesion (e.g., abnormal spastic gait is often an early sign; hyperreflexia or a positive Babinski's sign may be present)- Impaired sensation (e.g., numbness, impaired proprioception, ataxia)- Impaired bladder and bowel control Diagnosis:- MRI of the spine: determines the site of narrowing of the medulla and the underlying pathology- Myelography (possibly with CT): when MRI is contraindicated (e.g., in patients with metal implants) Treatment:- Conservative treatment (i.e., analgesia, corticosteroid therapy, bracing, physiotherapy): indicated perioperatively, for severe cases (e.g., degenerative cervical myelopathy), and mild cases- Decompression surgery: typically indicated in acute or advanced cases
• Cerebral venous thrombosis A thrombotic obstruction of the cerebral veins and/or related anatomical structures (dural sinuses) which drain blood from the brain. Epidemiology:- Sex: ♀ > ♂, 3:1- Age of onset: ≤ 40 years Etiology: - Oral contraceptives, pregnancy, and postpartum period- Hypercoagulable states: Blood clotting disorders, hematologic diseases (e.g., polycythemia, sickle-cell anemia), pregnancy, malignancies- Neurosurgical procedures (e.g., lumbar puncture)- Infectious: Otogenic (e.g., after acute otitis media), rhinogenic (e.g., after sinusitis), meningitis Clinical features:- Headache (acute, subacute, or chronic)- Nausea, vomiting, vision impairment, bilateral papilledema on ophthalmoscopy- Cranial nerve symptoms (e.g., diplopia, tinnitus, unilateral deafness, facial palsy) - Focal epileptic seizures- Impaired consciousness and awareness- Hemispheric symptoms- In cases of cavernous sinus thrombosis: patients may develop cavernous sinus syndrome Diagnostics: If CVT is suspected, D-dimer levels and imaging studies are first steps of diagnosis- D-dimers: > 500 μg/L- CT/MRI (with or without venography) Treatment:- Acute phase: heparinization- Antibiotic therapy for infectious CVT- Possibly anticonvulsants
• Miller-Fisher syndrome A limited variant of GBS characterized by cranial nerve involvement. Etiology: Autoantibodies directed against ganglioside GQ1b, GT1a Clinical features:- Ophthalmoplegia- Ataxia- Areflexia Treatment: IVIG
• Uncal herniation Medial temporal lobe (the uncus) herniates at the tentorial incisure → Compression of:- Ipsilateral oculomotor nerve palsy → fixed and dilated pupil- Ipsilateral posterior cerebral artery → cortical blindness with contralateral homonymous hemianopia- Contralateral cerebral peduncle → ipsilateral paralysis + Kernohan's phenomenon → Downward shift of the brainstem → brainstem hemorrhages → focal deficits, impaired consciousness, death
• Local anesthetic agents Local anesthetics have a lipophilic group linked with a hydrophilic group Ester group:- Metabolized in the serum by esterases- Have a higher risk of causing allergic reactions or systemic toxicityAmide group- Metabolized in the liver- Are safer than the ester agents Ester group:- Procaine: Short- Chloroprocaine: Short- Tetracaine: Long Amide type:- Lidocaine: Intermediate- Prilocaine: Intermediate- Mepivacaine: Intermediate- Bupivacaine: Long- Etidocaine: Long- Ropivacaine: Long Ester LAs do not have an “i” in their names preceding “-caine.” Amide LAs have an "i" in their name preceding “-caine.”
• Malignant otitis externa Necrotizing inflammation of the external auditory canal Pathogen: Pseudomonas aeruginosa (95% of cases) Risk factors:- Elderly patients with poorly controlled diabetes- Immunosuppression Clinical features:- Severe ear pain- Red and swollen periauricular soft tissue- Otorrhea- Conductive hearing loss- Otoscopic findings: granulation tissue at the transition between the cartilaginous and the osseous part of the ear canal Complications:- Facial nerve palsy- Osteomyelitis of the skull base → extradural abscess, venous sinus thrombosis, paralysis of other cranial nerves Diagnostics:- CT scan to identify bone destruction- MRI to identify intracranial extension (e.g., venous sinus thrombosis, cranial abscess)- Gallium-67 scan in order to monitor response to treatment- Biopsy: distinguishes malignant otitis externa from a tumor and helps optimize treatment Treatment:- Prompt IV antibiotic therapy for several weeks→ First-line: high-dose ciprofloxacin→ Second-line: other antipseudomonal antibiotics (e.g., piperacillin-tazobactam, ticarcillin, cefepime, ceftazidime)- Surgical debridement is indicated for abscess drainage and removal of bony sequestrum Prognosis: The mortality rate is high even with appropriate antibiotic therapy
• Otitis externa - Bacterial infections: → Pseudomonas aeruginosa (∼ 40% of cases), commonly from swimming activities→ Staphylococcus aureus, Proteus mirabilis, Escherichia coli- Fungal infections: Aspergillus (accounts for 90% of all fungal otitis externa), Candida- Viral infections (rare): Herpes zoster, Influenza viruses Risk factors:- Injury to the skin of the external auditory canal (e.g., cleaning, insertion of foreign objects such as hearing aids or earplugs, excessive itching)- Increased moisture in the external auditory canal (e.g., swimming, humid climate) Clinical features: - Severe ear pain, particularly at night- Otorrhea- Intense itching in the external auditory canal- The tragus is tender to touch- Pulling up and back on the auricle causes pain- Conductive hearing loss- Localized OE: Furuncle- Diffuse OE: Edematous and reddened external auditory canal Diagnostics: Primarily a clinical diagnosis.- Check blood glucose levels to rule out diabetes- Culture and sensitivity tests are not routinely performed; they may be indicated if antibiotic treatment is not effective.- Fungal otitis externa should be suspected when symptoms do not resolve with local and/or systemic antibiotic therapy (especially among immunocompromised and diabetic patients)! Treatment:- Antibiotic eardrops (typically ofloxacin, ciprofloxacin, or gentamycin) - Topical hydrocortisone to control itching and inflammation- Aural toilet: clean the external auditory canal and keep it dry using an ear wick and/or astringents (e.g., mixture of isopropyl alcohol and acetic acid)- Systemic treatment: oral ciprofloxacin→ Indications: Immunosuppression, diabetes mellitus, severe otitis externa with cellulitis of the face and neck- NSAIDs for pain relief
• Chronic inflammatory demyelinating polyneuropathy (CIDP) Chronic variant of Guillain‑Barré syndrome. Etiology: - CIDP has not been linked to any infectious agent in particular.- Autoantibodies against GM1gangliosides Clinical features:- Similar to those of GBS, but lasting > 2 months Treatment:Glucocorticoids, azathioprine, cyclophosphamide, plasmapheresis, or intravenous immunoglobulin therapy (IVIg)
• Subfalcine herniation Cingulate gyrus of one hemisphere is compressed and herniates under the falx cerebri → compression of:- Contralateral hemisphere → obstruction of the foramen of Monro → hydrocephalus- Pericallosal arteries → hemiparesis (predominantly lower limbs)
• Transient global amnesia Epidemiology: - Peak incidence: 50-70 years (patients are rarely < 40 years) Precipitating factors:- Vigorous physical exercise or exhaustion due to overwork- Working bent over (e.g., gardening)- Psychological stress- Sudden immersion in cold or hot water Clinical features: - Abrupt onset- Episodes last between 1-24 h, but never > 24 h (mean duration 6-8 h)- Nature of amnesia: anterograde or partial retrograde - The patient may appear anxious and distraught, with desperate attempts to orientate themselves.- The attack resolves over hours, with older memories returning first, followed by a gradually increasing capacity to retain new information. Treatment:- Outpatient management is possible under the supervision of a caregiver.- Monitoring for at least 24 h is advisable if an alternative diagnosis is suspected.- No medical therapy
• Dissection of the carotid and the vertebral artery Epidemiology: - Mean age: ∼ 45 years- Important causes of stroke in young patients Etiology:- Frequently caused by penetrating or blunt trauma (e.g., high impact car accidents) but up to 40% of cases result from mild trauma (e.g., minor sports injuries) or other mechanical triggering events (e.g., coughing, sneezing, chiropractic maneuvers) - Ehlers-Danlos syndrome and Marfan syndrome- Fibromuscular dysplasia- Hypertension Clinical features:- Ipsilateral headache and facial/neck pain (constant, severe, throbbing or sharp)- Partial horner syndrome: ptosis and miosis- Pulse-synchronous tinnitus- Neck swelling with ecchymosis- Reduced taste sensation- Cranial nerve lesions, usually caudal nerves (VI-XII) - Symptomatic middle cerebral artery infarction - Amaurosis fugax (ischemic retina) Diagnostics:- Duplex ultrasonography: high resistance flow or complete absence of flow in affected artery- Helical CT angiography: Changed caliber of vessel- MR angiography Treatment:- Treatment should be initiated after an intracerebral hemorrhage has been ruled out→ Heparin therapy followed by oral anticoagulation for 3-6 months and/or→ Antiplatelet agents for 1 year
• Foster-Kennedy syndrome Etiology:- Frontal lobe tumors, typically parasellar or subfrontal meningiomas- Especially olfactory groove meningioma: meningiomas arising from the cribriform plate and frontosphenoidal suture Clinical features:- Ipsilateral atrophy of the optic nerve- Contralateral papilledema- Anosmia
• Cholesteatoma A special form of chronic otitis media in which keratinizing squamous epithelium grows from the tympanic membrane or the auditory canal into the middle ear mucosa or mastoid. Pathophysiology: Keratinizing squamous epithelium grows from the tympanic membrane or the auditory canal into the middle ear mucosa or mastoid air cells. Clinical features: - May be asymptomatic- Painless otorrhea (scant but foul-smelling discharge from the affected ear)- Conductive hearing loss Diagnostics Otoscopic findings:→ Primary acquired: retraction pocket with squamous epithelium and debris that often appears as a brownish, irregular mass→ Congenital and secondary acquired: white or pearly mass behind the tympanic membrane- Imaging: to assess the degree of bone destruction- Audiometry: to assess the degree of hearing loss Treatment: Surgery is always indicated because of the risk of complications Complications:- Destruction of ear ossicles- Perilymph fistula- Facial nerve paralysis- Erosion of temporal bone → extradural abscess, meningitis, sigmoid sinus thrombosis
• Tension headache Epidemiology :- Most common type of headache (∼ 70% of primary headaches)- Sex: ♀ > ♂- Peak incidence: 30-40 years- Ethnicity: increased prevalence in white populations Exacerbating factors: fatigue, lack of sleep, poor posture, anxiety, stress, depression Clinical features:- Episodic nature: headaches last 30 minutes to a couple days- Holocranial or bifrontal, dull headache (mild to moderate intensity)- Dull, pressing, non-pulsating ("vice"-like) quality- Headache does not increase with exertion.- No autonomic symptoms (vomiting, nausea, phonophobia, or photophobia) are present. Treatment:- Episodic: aspirin, acetaminophen, and other NSAIDs- Chronic: amitriptyline - Lifestyle and behavioral modification: regular exercise, adequate sleep, avoidance of stress, muscle relaxation exercises, treatment of depression
• Ulnar nerve entrapment Cubital tunnel syndrome:- Leaning on the elbow or prolonged elbow flexion during occupational activities (e.g., leaning on a desk), athletic activities, or surgical procedures (e.g., during general anesthesia)- Blunt trauma- Masses (e.g., tumors, hematomas)- Metabolic abnormalities (i.e., diabetes) Guyon canal syndrome:- Idiopathic: may be associated with cycling, probably caused by direct pressure from the handlebars- Masses, with ganglion cyst being the most common- Blunt trauma (e.g., hook of hamate fracture) Clinical features:- Muscle weakness and atrophy→ Claw hand deformity: little and ring finger loss of extension at proximal interphalangeal joint and loss of flexion at metacarpal phalangeal joint→ Wartenberg sign: little finger in persistent abduction due to weak third palmar interosseous muscle→ Froment sign: The thumb flexes at the interphalangeal joint while pinching a piece of paper to compensate for a weak adductor pollicismuscle.- Sensory loss→ Loss of sensation over the hypothenar eminence, ulnar 1 ½ fingers.→ Lesion at the elbow: positive Tinel test → Marked paresthesias can be reproduced in the ulnar portion of the hand by tapping on the medial epicondyle of the humerus.→ Lesion at the wrist: Sensory symptoms may or may not be present.→ Pain: Elbow lesions typically present with referred pain in the forearm.

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