Neuro ICU

Subclassification: pediatric, in-hospital (IHCA, higher ROSC), and out-of-hospital (OHCA, lower survival). "Two-Hit" Model: Primary[…] brain injury from ischemia during pulselessness → made worse by reperfusion[…] injury via ROS and inflammation.

Impaired aerobic metabolism → loss of ATP → anoxic depolarization → cytotoxic edema[…].

Increased anaerobic metabolism → lactate accumulation → intracellular acidosis → increased intracellular Ca+2 → mitochondrial toxicity[…].

Disproportionately hits metabolically active structures: cortex, hippocampus, basal ganglia, thalami, cerebellar vermis[…].

Secondary[…] brain injury: neuroinflammation from imbalance between O2 delivery and metabolic demand.

Triggers: fever, seizures[…], cerebral edema, and disrupted autoregulation.

The lower limit of cerebral autoregulation shifts right[…] or is absent → CPP insufficient even at normal MAP.

Ventilation: Target normoxia (PaO2 75-100)[…] — hyperoxia or hypoxia → oxidative stress.

Target normocapnia (PaCO2 35-45)[…]. Hypocapnia → cerebral vasoconstriction → ischemia. Hypercapnia → cerebral vasodilation → increased ICP.

ICP & edema: edema can worsen after rewarming (rewarm gradually) or rapid correction of hyperosmolar states[…] (hyperglycemia, uremia). Temperature control: Hypothermia reduces metabolism → decreased apoptosis + reduces ICP and seizure risk.

Actively avoid fever[…]; each 1°C over 37°C worsens outcomes.

Prevent shivering with sedation and neuromuscular blockade[…].

Preferred sedatives: fentanyl (μ-opioid), propofol (GABAa), dexmedetomidine (α2)[…].

Avoid benzodiazepines[…] (delay awakening).

Propofol SE: propofol infusion syndrome[…]. Precedex SE: bradycardia.

Seizures: treat GTC, myoclonus, NCSE[…], and IIDs with reactive/continuous backgrounds.

Lance-Adams[…] syndrome = chronic post-hypoxic myoclonus with preserved consciousness — these patients may have a continuous EEG background despite jerking.

Pre-test conditions: ensure normocapnia, oxia, thermia, tension, glycemia[…], off sedation and NMB, no other toxic/metabolic injury (sepsis).

Clinical exam: Pupillary light[…] reflex (use pupillometer if available); Corneal reflex[…] + motor response.

EEG: suppressed background ± periodic discharges or burst suppression[…] predict poor outcomes.

SSEPs: bilateral absence of N20[…] cortical responses → poor outcome.

Biomarkers: neuron-specific enolase (NSE)[…] increasing between days 1-3 → poor outcome.

Imaging: CT showing cerebral edema or MRI diffusion restriction[…] patterns are unfavorable. Myoclonus that is continuous and generalized for >30 minutes is unfavorable.

Timing: most patients who regain consciousness do so in the first week[…], sometimes delayed up to 2 weeks[…] with TTM/sedation. Deaths days 1-3 are usually cardiac/multiorgan; after day 3 typically brain injury.

Most common cause of death overall: WLST[…].

Background: 2015 trials (MR CLEAN, ESCAPE, REVASCAT, SWIFT-PRIME, EXTEND-IA[…]) established mechanical thrombectomy <6-8 hours for anterior-circulation LVO.

Late-window (>6h) and large core[…] populations now also eligible.

Tenecteplase[…] replacing alteplase as preferred thrombolytic.

Monitoring: Serial neuro exams q15 min[…] immediately after thrombectomy → q1-2h by 8h post-thrombectomy (exam changes and hemorrhage occur early); Add pupillometry[…] for comatose patients.

BP control: After IVT or successful EVT: SBP <185[…]; avoid variability or hypotension (increased ICH risk).

After unsuccessful recanalization or non-EVT candidates: permissive hypertension up to SBP 220[…] to preserve ischemic penumbra; vasopressors PRN to prevent hypotension.

SHINE[…] trial: intensive glucose control (80-130) via insulin gtt vs <180 SC insulin → no improvement, more hypoglycemia.

Maintain BG 140-180[…]. Hyperthermia (>37.5°C): worsens outcomes; treat with antipyretics + nonpharm cooling. Induced hypothermia is not routinely recommended.

Postop imaging: dual-energy CT[…] to distinguish hemorrhage from contrast staining[…] (subtracts iodine). Contrast hyperdensity is NOT benign — predicts delayed HT.

Pathophys: ischemia → BBB permeability via MMP-9[…] activation; worsens with IV thrombolytics. Heidelberg classification: HI 1-2, PH 1-2.

BP management with HT: Highest hemorrhage risk at SBP >220/105[…] mmHg; Target SBP <140[…] with rapid IV antihypertensives; Discontinue IVT[…] or reverse with FFP or Kcentra (4F PCC)[…].

Access complications: Radial: rare distal hand ischemia[…]; closure with compressive band. Femoral: groin checks + limb perfusion checks; hip joint must remain straight for 4-6h.

Complications: limb ischemia, groin hematoma, retroperitoneal hematoma[…].

Hypotension after femoral access → suspect retroperitoneal hemorrhage[…] → manual pressure, volume resuscitation, abdominal/pelvic imaging.

Antiplatelets/anticoagulation post-EVT: MR CLEAN-MED[…]: routine periop AC/AP increased ICH[…] without improving outcomes (exceptions: stenting); ASA[…] ASAP, hold for thrombolytic × 24h, hemorrhagic conversion, or potential surgery; DAPT[…] (ASA + clopidogrel × 21-30 days) for TIA/minor stroke, not extended to LVO except: ICAD (SAMMPRIS[…] × 90 days), carotid stenosis pending stent/CEA, or AFib-related stroke when DOAC delayed.

Anticoagulation timing (AHA/ASA: 4-14 days post-stroke; DOACs > warfarin): ELAN[…] trial (2023): early DOAC (48h minor/moderate stroke, day 6-7 for major) → no increased bleeding, decreased recurrent ischemic stroke.

Tracheostomy: SETPOINT2[…] (2022) — early trach <5 days vs after 10 days → no survival difference, but trach reduces sedation and ICU complications.

DVT prophylaxis: intermittent pneumatic compression[…] (CLOTS 3[…]); pharmacologic PPX with SQH per PREVAIL[…] (LMWH favored, started <48h).

Stimulants: amantadine, modafinil[…] for depressed level of consciousness, 5-7 days post-stroke for ~2 weeks.

Incidence: ICH accounts for 10-15%[…] of strokes — most severe type.

Pathophys: primary injury from hematoma + secondary injury from inflammation and oxidative stress[…].

Causes: Deep perforator arteriopathy[…] (chronic HTN) → microaneurysm → ICH, or lipohyalinosis → lacunar infarction.

Common locations: basal ganglia, thalamus, deep cerebellum, brainstem[…].

CAA[…] (Aβ in cortical vessels) → lobar[…] ICH.

Expansion: ICH expands in the first 6 hours[…] with peak in the first 3 hours; More common in deep[…] than lobar ICH; Risk factors: short symptom-to-imaging time, larger baseline volume, pre-ICH antithrombotics, "spot sign[…]" on CTA (active iodine extravasation). Three key interventions to limit expansion: (1) acute BP lowering, (2) coagulopathy reversal, (3) hemostatic agents.

AHA guidelines: target SBP 130-150[…] mmHg when presenting SBP is 150-220; avoid peaks and variability; initiate within 2 hours[…] of symptom onset.

Trials: INTERACT2[…]: intensive SBP <140 vs liberal 140-180 → nonsignificant trend toward favorable outcomes; ATACH-2[…]: intensive SBP <140 → no primary benefit; post hoc analysis showed reduced hematoma expansion and better functional outcomes in deep[…] ICH when initiated <2h; Pooled analysis: BP fluctuations[…] during acute phase associated with hematoma expansion, death, disability.

General: immediately discontinue[…] the antithrombotic and emergently correct coagulopathy.

Factor Xa[…] inhibitor-related ICH has better outcomes than warfarin-related.

Antiplatelet-related: PATCH[…] trial: platelet transfusions associated with major disability/death — NOT recommended except for emergent surgical intervention; DDAVP[…]: increases vWF and factor VIII; role in limiting hematoma expansion unclear.

Anticoagulation reversal: UFH → protamine sulfate[…]; LMWH → protamine (partial only); Warfarin → 4F PCC (Kcentra)[…] + vitamin K (faster than FFP); Dabigatran → idarucizumab[…] (Ab fragment); alternative RRT ± PCC; Direct Xa inhibitors (apixaban, rivaroxaban, edoxaban) → andexanet alfa or PCC[…]; ANNEXA-4[…]: andexanet alfa has ~10% thrombotic event rate; cost-effectiveness favors PCC.

Hemostatic agents (do not improve functional outcomes): FAST[…]: rFVIIa reduced hematoma but didn't improve outcomes; TICH-2[…]: TXA neutral for outcomes but reduced expansion and early mortality; FASTEST[…] (ongoing): ultra-early rFVIIa <2h.

Seizures: Most occur in the first week after ICH; Prophylactic ASMs not recommended[…] due to sedative/cognitive effects; ASMs only for clinical or electrographic seizures; CAVE[…] score for long-term seizure risk: Cortical, Age <65, Volume small, Early seizures <7 days.

Airway: intubate with GCS <8[…], worsening exam, or for transfer. Temperature: fever in ~1/3 of ICH patients; treat aggressively.

Glucose: avoid hypo (<60) and hyper (>180) — target liberal control <180[…].

NICE-SUGAR[…]: intensive glucose control → higher mortality.

VTE PPX: SCDs per CLOTS 3[…]; pharmacologic PPX with SQH or LMWH starting 24-48h after stable hematoma. ~40% of ICH patients with severe disability at 1 month have very good 1-year recovery — avoid therapeutic nihilism.

2015 ILAE operational definition (two time points): T1 (start treatment) — convulsive SE: 5[…] min; focal SE: 10[…] min; T2 (neuronal damage begins) — convulsive SE: 30[…] min; focal SE: 60 min.

Four progressive stages: Early/Impending[…] SE: continuous/intermittent seizures >5 min without recovery; Established[…] SE: develops 10-30 min after onset; refractory to benzo; Refractory[…] SE: continues despite two ASMs, first being adequate benzo; Super-Refractory[…] SE: continues ≥24h after anesthesia initiation.

Special subtypes: NORSE[…]: refractory SE in patients without preexisting neurologic disorders or clear cause; FIRES[…]: NORSE subcategory with preceding febrile infection (2 weeks to 24h before); If workup unrevealing within 72h → consider autoimmune[…] etiologies.

Within milliseconds-seconds: neurotransmitter release, ion channel changes, protein phosphorylation. Within seconds-minutes: receptor trafficking — more excitatory AMPA and NMDA[…] receptors → glutamate-mediated Ca+2 influx → apoptosis and mitochondrial dysfunction.

Concurrently, inhibitory GABAa[…] β2/β3/γ2 subunits internalized[…] → reduced GABA receptors → diminished response to benzos/barbiturates → refractory state.

Within minutes-hours: neuropeptide changes — increased excitatory substance P[…] and decreased inhibitory neuropeptide Y[…]. Days-weeks: epigenetic changes → epileptogenesis and neuronal damage.

ICP monitoring trials: BEST-TRIP[…]: no difference between ICP-monitor protocol vs imaging/clinical exam; SYNAPSE-ICU[…] (2021): invasive ICP monitoring was better.

Brain Trauma Foundation targets (adults): SBP >100[…]; ICP <22[…]; CPP >60[…].

Tier management for high ICP: Tier 0 (universal for severe TBI): intubation, MV, positioning, sedation/analgesia, prevent fever/hypotension/hypoxia; Tier 1-2: hyperosmolar therapy, CSF drainage, adjust parameters; Tier 3: barbiturates[…] (pentobarbital), moderate hypothermia (35-36°C)[…].

Decompressive craniectomy: recommended against for early refractory ICP elevation; recommended for late[…] refractory ICP elevation.

Brain tissue hypoxia: SjvO2[…] (jugular venous O2): global measure; target >50%.

PbtO2[…] (parenchymal brain tissue O2): local measure.

BOOST II[…] trial: ICP + PbtO2-guided management feasible, reduced PbtO2 <20 burden.

Cerebrovascular complications: Blunt cerebrovascular injury (BCVI)[…]: distraction/stretch trauma → intimal disruption → dissection → strokes within first 72 hours[…].

Graded by Denver (Biffl)[…] scale; CTA modality of choice. EAST: antithrombotic therapy in BCVI without associated stroke. Post-traumatic CVST: common with skull fracture. Cortical spreading depolarization (CSD): pathologic waves through gray matter at <10 mm/min → collapse of membrane potentials → Ca+2 influx → excitotoxic injury.

Blocked by NMDA antagonists (ketamine, memantine)[…].

Paroxysmal sympathetic hyperactivity (PSH): recurrent transient episodes of tachycardia, HTN, tachypnea, fever, rigidity[…] from catecholamine surges. Pathophys: disconnection in central autonomic network. Starts at end of first week as sedation weaned.

Treat: nonselective β-blockers[…], bromocriptine, opioids, central α-agonists, GABAergic agents.

Diffuse axonal injury (DAI): results from angular/rotational acceleration-deceleration.: Grade 1: microscopic axonal damage; Grade 2: corpus callosum[…] lesions; Grade 3: rostral brainstem[…] lesions; MRI: SWI/GRE[…] best for hemorrhagic axonal injury; FLAIR[…] best for nonhemorrhagic; Serum biomarkers: GFAP and UCH-L1[…] FDA-approved for concussion evaluation.

Overview: cervical[…] SCI most common and most disabling.: High cervical (C1-C3): often from falls, more incomplete; Lower cervical: more from MVC/sports, more complete; Kids <9yo: vertebral column more flexible — more susceptible to traumatic SCI.

Initial assessment: Cervical collar[…] for spinal motion restriction; Above C3[…]: respiratory arrest within minutes; Above C5[…]: respiratory failure from loss of diaphragm — intubate ASAP; Maintain SpO2 >92%; hypoxemia in cervical SCI → unopposed vagal activity → bradycardia/arrest.

Cardiovascular failure: disruption of descending sympathetic fibers (T1-T5).: Neurogenic shock[…] (injury at or above T5[…]): distributive shock without compensatory tachycardia; Spinal shock[…]: hyperacute loss of spinal function with flaccid paralysis and areflexia. Diagnostics: CT cervical spine initial; MRI for all with neurologic deficits.

ASIA[…] grading.

Treatment: Early stabilization and decompressive surgery; MAP > 85 × 7 days[…] with pressors if needed; Neurogenic shock: fluid resuscitation → pressors (norepinephrine[…] preferred for balanced α/β effects); phenylephrine for vasoplegia without bradycardia in SCI below T6; VTE PPX with LMWH[…] <72h of SCI; Prevent: pressure injuries (reposition q2h), pulmonary infections (mucolytics, abdominal binders, chest PT).

Encephalitis/myelitis empiric treatment — do NOT delay for LP.: HSV: most common viral encephalitis; hits parafalcine, insular, temporal[…] cortices; Treat HSV/VZV: acyclovir[…] (foscarnet if resistant); CMV: ganciclovir or foscarnet[…]; Rabies: human rabies Ig + 14-day vaccine series; Steroids if direct vs postviral inflammatory can't be distinguished.

Meningitis empiric treatment: Community-acquired (adults/children >2y): vancomycin + ceftriaxone + dexamethasone[…]; Dexamethasone benefit for all organisms except Listeria and Cryptococcus[…]; >50yo or immunosuppressed: add ampicillin[…] (Listeria); Neonates: ampicillin + cefotaxime or aminoglycoside; Healthcare-associated: vanc + Pseudomonas coverage + remove infected hardware; Intrathecal antibiotics: ID/pharmacy consult; high direct toxicity and seizure risk; preservative-free diluents.

Brain abscess vs empyema: Abscess[…]: collection within parenchyma or epidural space; Empyema[…]: collection in subdural space; Source: otitis, sinusitis, mastoiditis, dental → direct or hematogenous spread; Spinal abscess: usually epidural; can cause discitis/osteomyelitis.

Botulism: C. botulinum toxin → inhibits ACh release at NMJ → bulbar weakness → symmetric descending flaccid[…] paralysis (proximal first). Risk of dysautonomia (parasympathetic ACh blocked).

Treatment: botulinum antitoxin[…].

Tetanus: C. tetani toxin internalized by peripheral nerves → retrograde to CNS → prevents GABA[…] release from motor neurons → muscle spasm. Mistaken for tonic seizures.

Treatment: tetanus immunoglobulin[…] + benzos/propofol + wound debridement + abx.

Avoid pancuronium[…] (inhibits catecholamine reuptake).

Hydrocephalus: Obstructive[…]: enlarged ventricles from blocked CSF flow.

LP contraindicated[…] (herniation risk) → place EVD. Posterior fossa swelling: minimize CSF drainage to prevent upward herniation unless suboccipital craniectomy also performed.

Communicating[…]: debris blocks absorption at arachnoid granulations. CAN do LP or lumbar drainage.

Vasculopathy and stroke: angioinvasive infections classically Aspergillus and Mucor[…] → high ICH rates.

Viral endotheliopathy: VZV, HSV, parvovirus B19[…].

Cerebral venous sinus thrombosis (CVST): septic CVST from cerebral/orbital/sinus infection — most common in cavernous[…] sinus. Septic cavernous: fever + periorbital pain/swelling → meningitis, carotid narrowing, multiple strokes. AC debated due to hemorrhage risk.

Infection-related ICH: Most common cause: mycotic aneurysm from infective endocarditis[…]; Imaging: CTA preferred (MRA may miss distal aneurysms); DSA definitive; Mycotic aneurysms often fusiform and distal[…] — surgical/endovascular treatment may require sacrificing proximal vessel; Lyme vasculitis + angioinvasive species (Aspergillus, Mucor) prefer perforating arteries[…] — up to 6 months of antimicrobials needed.

Spinal epidural abscess: image entire spine[…] (multiple areas possible from hematogenous seeding). Treatment: broad-spectrum antimicrobials × 4-12 weeks + posterior epidural abscess decompressive laminectomy.

Avoid seizure-lowering antimicrobials: carbapenems, 4th-gen cephalosporins, fluoroquinolones[…].

Carbapenems significantly reduce valproate[…] levels; voriconazole is a strong CYP inhibitor.

Tumefactive lesions: >2 cm on MRI, resemble tumors. Usually initial presentation of demyelinating disease. Aggressive demyelination can also be non-tumefactive (many small ADEM lesions or critical-location lesions like RAS or bilateral thalami). DDX ("VITAMINS"): infections (abscess, PML, toxo, crypto), inflammatory (neurosarcoid, Behcet), neoplasms, primary autoimmune (MS/NMO/MOGAD/ADEM). Distinguishing features: CT hypodensity[…] + MRI gadolinium enhancement in same location → demyelination (vs hyper/isodense tumors); MRI: incomplete rim[…] enhancement, mixed T2 iso/hyperintensity, absence of mass effect, absence of cortical involvement; Hemosiderin[…] is very rare in tumefactive demyelination; MR perfusion: low CBV[…] in demyelination vs high in gliomas (cannot differentiate from lymphoma).

ADEM: Simultaneous multifocal CNS inflammation, usually monophasic[…]; 75%[…] have infection 1-3 weeks before; MRI: bilateral asymmetric FLAIR hyperintensities; lesions in deep gray (thalami/BG)[…] are highly suggestive; Spinal involvement up to 1/3; open-ring enhancement; CSF: pleocytosis, elevated protein, OCBs rare. Acute Hemorrhagic Leukoencephalopathy: hyperacute severe ADEM variant; small vessel necrosis with neutrophil/macrophage infiltrates (vs lymphocytic in classic ADEM). Higher mortality.

NMOSD: Astrocytopathy: anti-AQP4[…] antibodies on astrocytes → complement activation → astrocyte injury → secondary demyelination.

Symptoms: longitudinally extensive >3-segment myelitis[…] + optic neuritis common.

Lesions in areas of high AQP4: circumventricular organs (area postrema → n/v/hiccups) and hypothalamus[…] (narcolepsy, hypothermia, SIADH). Majority experience recurrent events.

MOGAD: Anti-MOG IgG on myelin → complement activation; astrocytes relatively preserved; More common in children[…]; Symptoms: optic neuritis, ADEM, myelitis; Diagnosis: anti-MOG titers >1:20; CSF OCBs absent; Visual recovery better[…] than NMOSD.

MS variants: Baló[…]: concentric "onion-ring" lesions; lower OCB prevalence; Marburg[…]: fulminant demyelination — often fatal within months; Schilder[…]: rare, pediatric; 1-2 large bilateral symmetric lesions in centrum semiovale.

FLAMES[…]: rare focal encephalitis with unilateral cortical FLAIR lesions + seizures + meningeal enhancement.

Initial treatment (similar regardless of underlying disorder; exclude infection first): 1st-line: IV methylprednisolone 30 mg/kg/day (max 1000 mg) × 3-5 days[…]. ADEM: oral taper over 4-6 weeks. Pediatric MOGAD: oral prednisone taper over 3 months. Monitor glucose + GI prophylaxis.

If prednisone >20 mg/d for >5 weeks → TMP-SMX[…] PPX.

2nd-line PLEX × 5-7 cycles: In NMOSD: may be adjunctive first-line; If concurrent with steroids, give steroids at the end of PLEX session[…] to avoid clearance; Monitor fibrinogen q24-48h; give cryoprecipitate if low; Do NOT do PLEX shortly after IVIG[…] (would remove it).

3rd-line: rituximab[…] or cyclophosphamide for refractory disease — both require TMP-SMX PPX.

Long-term: avoid fingolimod[…] in MS (tumefactive lesions) and NMOSD (can worsen).

Spasticity complications: paroxysmal tonic spasms respond to carbamazepine[…]; neuropathic pain to SNRIs/gabapentinoids/TCAs.

Common endpoint: bulbar and respiratory muscle dysfunction → can't protect airway or maintain ventilation. Localization — four anatomic levels: anterior horn cell, root/peripheral nerve, NMJ, muscle[…].

Bedside assessment: Neck flexion[…] strength approximates diaphragmatic strength; Paradoxical breathing[…] ("thoracoabdominal desynchrony") = impending respiratory failure; Bulbar[…] dysfunction predicts need for respiratory support.

Parameters: FVC[…] (forced vital capacity): max exhaled volume after max inhalation. Normal 4-5L (men), 3-3.5L (women).

High risk if <1500 mL or <20 mL/kg[…]. <60% predicted correlates with impending failure. Supine FVC decrease >30% vs sitting = severe diaphragmatic weakness.

Single-breath counting[…]: <20 suggests respiratory compromise.

NIF[…] (negative inspiratory force): more negative than -60 cmH2O is normal. Less negative than -30 = severe weakness. Most sensitive metric for mild weakness.

MEP[…] (maximal expiratory pressure): proxy for cough; >60 = adequate. ABG: with mild weakness, PaCO2 is lower than normal (compensatory hyperventilation).

Normal PaCO2 in a tachypneic patient[…] signals impending failure.

20/30/40 rule for intubation: FVC <20 mL/kg[…], NIF less negative than -30 cmH2O, MEP <40 cmH2O, or >30% reduction within 24h.

AIDP family: Guillain-Barré syndrome[…]: distal and proximal symmetric weakness after infection/vaccination; reflexes diminish as condition progresses; Variants: Miller Fisher, AMSAN, AMAN; Caution: GBS unlikely if completely lacks sensory symptoms, has fever, progresses beyond 4 weeks[…], or has dramatic CSF pleocytosis; Treatment first-line: IVIG 2 g/kg over 5 days[…] OR 5 PLEX sessions; repeat treatment doesn't help; Axonal[…] subtype predicts prolonged ventilation/trach.

Myasthenia gravis: Hallmark: fatigable[…] weakness; Steroids effective but up to 26%[…] initial transient worsening with induction; MG crisis: dramatic strength increase after plasma exchange[…] — less often needs trach; BiPAP failure predictor: initial PaCO2 >45 mmHg.

Botulism: C. botulinum toxin → inhibits ACh release → symmetric descending flaccid[…] paralysis starting bulbar → proximal first.: Treatment: botulinum antitoxin[…]. ALS: all progress to respiratory failure. FVC <50% = imminent respiratory failure.

Cough peak flow <270 L/min → mechanical insufflation-exsufflation[…]. IMNM: more rapid than other IIMs; very high CK (often >5000); necrosis without lymphocytic infiltrates.

Predilection for proximal weakness[…] + dysphagia.

Anti-SRP and HMGCR[…] antibodies. Only 2/3 of HMGCR+ have statin exposure. Treatment: high-dose steroids → MTX, rituximab, or IVIG.

ICI-associated myopathy: higher rate of ocular involvement and myocarditis[…]; often seronegative with lower CK. Treatment: discontinue ICI + high-dose steroids ± PLEX/IVIG.

Categories: direct tumor-mediated, indirect (seizures, paraneoplastic, stroke, CVT, ICH), and treatment-related. Most common: Malignant primary CNS tumor: glioblastoma[…] (WHO grade 4).

Nonmalignant CNS tumor: meningioma[…]. Brain metastases > primary tumors.

Most common: lung, breast, renal, melanoma[…].

Vasogenic edema[…] is most common in malignancy; partly mediated by VEGF[…] (target for bevacizumab).

Herniation is most common cause of death: Uncal[…] herniation: ipsilateral mydriasis + contralateral hemiparesis + decreased consciousness.

Kernohan-Woltman[…] notch: massive uncal herniation → contralateral peduncle compression → ipsilateral hemiparesis[…] (false localizing sign).

Central/downward[…]: loss of upgaze (forced downgaze) + abnormal breathing + decreased consciousness. CSF diversion can exacerbate herniation in posterior fossa lesions — keep drain at 15-20 cm H2O.

LP contraindicated[…] with posterior fossa lesions (tonsillar herniation).

Cord compression: thoracolumbar[…] spine most common (via Batson plexus). Pain is often nocturnal.

Treatment: HOB >30°, head neutral; Dexamethasone[…] 10 mg IV load → 16 mg/d for peritumoral edema; positive response 24-72h; For cord compression: corticosteroids most effective within 12 hours[…] of symptom onset; Caveat: empiric steroids lower yield of lymphoma[…] histopathologic diagnosis; Gross total resection for solitary mets >3 cm with KPS >70%.

Seizures: most common in IDH 1/2[…] variant tumors (D-2-hydroxyglutarate mimics glutamate).

Keppra[…] most common ASM; avoid enzyme-inducing ASMs.

Paraneoplastic autonomic: high-risk antibodies include ANNA-1, CRMP-5, NMDAr, AChR, GABAb[…] (GABAb can present with refractory SE + dysautonomia).

Stroke: intra-axial neoplasms with coagulopathy → contraindication[…] for thrombolysis (extra-axial neoplasms not a CI).

Spontaneous ICH: Primary CNS tumors prone to hemorrhage: GBM, oligodendroglioma, meningioma; Metastatic tumors prone to ICH: lung/breast adenocarcinoma, RCC, melanoma, papillary thyroid, hepatocellular, choriocarcinoma[…]; Bevacizumab: ~3x ICH risk; Pituitary apoplexy[…]: sudden HA, vision changes, ophthalmoparesis (CN III/IV/VI) + panhypopituitarism → glucocorticoid + mineralocorticoid + surgery. ICI complications: Anti-CTLA-4 has highest risk for severe neurotoxicity; Majority within first 6 cycles; Treatment: stop ICI + IVMP → prednisone 1 mg/kg/d × 1-2 weeks with taper; PLEX/IVIG if higher grade.

CAR-T: CRS (cytokine release syndrome)[…] or ICANS[…] → toxic encephalopathy, aphasia, seizures, cerebral edema.: First-line: anti-IL-6[…] (tocilizumab or siltuximab) → high-dose steroids → anakinra[…] (IL-1R antagonist) for refractory. Radiation neurotoxicity: Acute: edema → responsive to steroids. Early delayed (within 3 months): temporary myelin delay → may resolve.

Delayed (3 months-years): oligodendrocyte and endothelium injury[…] → progressive.

Radiation necrosis[…]: peak up to 3 years after; treat with steroids ± bevacizumab.

Distinguish from tumor recurrence: tumor has high plasma volume on MR perfusion and choline peaks[…] on MR spectroscopy.

The final required step to confirm brain death is apnea testing[…] showing no respiratory effort as CO2 rises, in a patient with complete absence of brainstem reflexes[…] and a known, irreversible brain injury. Ancillary tests (EEG, MRI) are not needed unless the apnea test cannot be done or interpreted.

In post-arrest patients who received hypothermia and sedation, lingering sedative[…] medication confounds outcome prediction.

Reliable neuroprognostication requires at least 72 hours[…] and full drug clearance.

High-dose or prolonged propofol can cause propofol infusion syndrome (PRIS) with severe unexplained metabolic acidosis[…] as the key lab abnormality.

Other findings: cardiovascular collapse, rhabdomyolysis, renal failure, hyperkalemia[…]. Treatment: stop the infusion ASAP.

On CT, Marshall classification V indicates an evacuated mass lesion[…]. Marshall III with Rotterdam 4 = severe diffuse injury but still recoverable.

First-line therapy for acutely raised ICP in severe TBI is hyperosmolar therapy[…] (HTS preferred in hemorrhagic shock to avoid hypotension).

Stimulus-induced fever, tachycardia, hypertension, tachypnea, and posturing about 1 week[…] after a TBI suggest paroxysmal sympathetic hyperactivity[…]. Treatment: nonselective beta-blockers, bromocriptine, opioids, central α-agonists, gabapentin.

NCSE[…] is the most common type of SE in the ICU. Electrographic SE = seizure ≥10 min continuous or ≥20% of any 60-min epoch.

Periodic discharges 1-2.5 Hz[…] on the IIC warrant a benzodiazepine trial.

The most common reason for failure to terminate SE in the initial stage is underdosed benzodiazepine[…]. Per ESETT, dosing is adequate less than 25% of the time.

IV lorazepam is preferred when IV access is available; IM midazolam[…] is preferred without IV access (noninferior).

Carbapenems[…] significantly lower valproate levels — avoid the combination in patients with epilepsy.

Cerebellar ICH > 15 mL[…] (or >3 cm diameter) or with early neurologic decline requires early decompressive suboccipital craniotomy[…].

EVD alone is risky due to upward cerebellar herniation[…].

The "spot sign[…]" on CTA represents an actively bleeding vessel from extravasation of contrast within the hematoma — predicts hematoma expansion.

Warfarin-related ICH: reverse with 4F PCC (Kcentra)[…] + vitamin K (faster than FFP).

Dabigatran: reverse with idarucizumab[…].

Direct Xa inhibitors: reverse with andexanet alfa or PCC (cost-effectiveness favors PCC[…]).

Per the PATCH[…] trial, platelet transfusion in antiplatelet-related ICH increases mortality/disability — NOT recommended except when patient needs emergent surgery[…].

Hypotension and tachycardia after femoral-access thrombectomy should raise concern for retroperitoneal hemorrhage[…] → apply manual pressure, resuscitate volume (transfuse blood PRN), and obtain abdominal/pelvic imaging[…].

Most LVO patients have post-thrombectomy contrast hyperdensities — use dual-energy CT[…] to distinguish from true hemorrhage.

Contrast staining is NOT benign — predicts delayed hemorrhagic transformation[…].

Hemicraniectomy benefits patients <60[…] years with large MCA territory infarction (>2/3 of MCA territory) and reduced consciousness, performed within 24-48[…] hours of stroke onset.

Transcranial Doppler (TCD)[…] is the most sensitive bedside test for MCA vasospasm.

Perimesencephalic SAH pattern with negative CTA[…] has a benign course.

Aneurysmal SAH can cause neurogenic stunned myocardium[…] — apical hypokinesis on echo and diffuse T-wave inversion on EKG.

A clear sensory level[…] on exam after trauma mandates urgent MRI of the cervical spine. Intoxication mandates CT clearance regardless of exam findings.

Central cord syndrome (degenerative cervical stenosis with hyperextension) causes weakness that is UE > LE[…]. ASIA grade predicts outcome.

Adults >50yo or immunocompromised with bacterial meningitis need ampicillin[…] added to standard vancomycin + ceftriaxone for Listeria coverage.

Dexamethasone is given for all organisms except Listeria and Cryptococcus[…].

HSV encephalitis hits the parafalcine, insular, and temporal[…] cortices with diffusion restriction and T2 hyperintensity.

Treat empirically with IV acyclovir[…].

Angioinvasive infections — classically Aspergillus and Mucormycosis[…] — have high rates of ICH from invasion of perforating arteries.

Up to 6 months[…] of antimicrobials may be needed.

Tumefactive MS lesions have low cerebral blood volume[…] on MR perfusion (vs high in glioma).

Can be distinguished by incomplete rim[…] enhancement and CT hypodensity in the same location as the MRI lesion.

Area postrema[…] syndrome (nausea, vomiting, intractable hiccups[…]) is highly suggestive of NMOSD[…] — area is rich in AQP4 water channels.

Do NOT perform PLEX shortly after IVIG[…] — PLEX will remove the IVIG.

If concurrent with steroids, give steroids at the end[…] of the PLEX session to avoid clearance.

First-line treatment for GBS is IVIG 2 g/kg over 5 days[…] or 5 sessions of plasma exchange[…]. Repeat treatment after initial course doesn't help.

Axonal[…] variants predict prolonged ventilation and need for tracheostomy.

The "20/30/40 rule" guides intubation in neuromuscular respiratory failure: FVC <20 mL/kg, NIF less negative than -30 cmH2O, MEP <40 cmH2O[…], or a >30% reduction in any of these within 24 hours.

Anti-HMGCR[…] immune-mediated necrotizing myopathy shows MRI hyperintensity in adductor and hamstring[…] groups on T2 fat-sat. Biopsy shows fiber size variability, type-2 atrophy, and necrotic fibers. Only 2/3 have statin exposure.

Pituitary apoplexy: sudden headache + visual loss + bitemporal hemianopsia[…] + CN III palsy in a patient with a pituitary tumor → emergency replacement with glucocorticoid + mineralocorticoid[…] + surgery.

ICANS (immune effector cell-associated neurotoxicity syndrome): first-line anti-IL-6 (tocilizumab or siltuximab)[…] → high-dose corticosteroids if refractory → anakinra[…] (IL-1R antagonist) for steroid-refractory. For seizures: GABAergic agents + Keppra.

Radiation necrosis (most prevalent up to 3 years[…] after therapy) is treated with corticosteroids ± bevacizumab[…].

Distinguish from tumor recurrence on MR spectroscopy (recurrence shows choline peaks[…]).