Neuro / Neurosurgical Flashcards
Cerebral Perfusion Pressure Formula
MAP - ICP
Cerebral blood Flow = (Carotid Arterial Pressure - JVP) / Cerebral Vasc Resistance.
Physical Exam and Imaging Tests for Measuring / Evaluating ICP
Pupillary dilation
Motor Posturing
GCS < 8
CT: Compression of cisterns
Midline shift > 10 mm = High ICP
US: Optic nerve sheath diameter. NOT RECOMMENDED AT THIS TIME
Management Goals in Elevated ICP
1) Hemodynamic Stability:
- Normotension (140-180 sBP)
- Normoxia (PaO2 80-120 mmHg), ) >92%
- Normothermia (36-37.9)
Rx: Labetalol 5-20 mg IV, norepi 0.1-0.2
2) Positioning
- Head of bed at 30
- Loose C-spine collar
- Neck midline
3) Pain
- Analgesia
- Anti-emetic (no valsalva)
- Mitigate stimuli (quiet room, limited exam)
Rx: Fentanyl, Ketamine, Zofran
4) Intubate
- Apneic Oxygenation
- Head of Bed at 30 degrees
- Vasopressors ready (Phenyl bolus or Norepi)
- Pretreat: Topical lidocaine if time. Fentanyl 3-5 mcg/kg (give at least 3-5 minutes to work)
- Induction: Ketamine (1-2 mg/kg), Etomidate (0.3 mg/kg), Prop if pressure allows (1-2 mg/kg)
- Paralytic: Succs or Roc
- Gentle placement - minimize glottic stim
- Post-intubation sedation/analgesia: Fentanyl 25-50 mcg/hr or dilaudid infusion (0.2-0.4/hr
- Propofol 0.3 mg/kg/hr
Management of refractory ICP
Hypernatremia: Na < 155
- Foley
- Mannitol 1mg/kg over 20 mins
and NS 3% 250 cc over 5 minutes
Hyperventilation as a bridge to procedure / definitive mgmt
Spontaneous ICH management
Stop Expansion:
- Reverse anticoags
- BP control (target 140 mmHg, starting < 220)
- Rx: Labetalol, hydralazine, enalapril, smooth control is better. insert art line for monitoring
- Neurosurgical Intervention
Target MAP in isolated spinal cord injury without other hemorrhage / trauma
MAP > 90
Target PO2 in Head Injured Airway
> 95% . Avoid hypoxia.
Brief hypoxia can lead to significant deleterious effects.
Target pCO2 in the head injured patient
35-38 mmHg
ETCO2 = 35%
SAH Rule (headache peaking in < 1 hr, > 15 years, at neuro baseline, atraumatic)
Age > 40
Neck pain or stiffness
Limited neck flexion on exam
Thunderclap
Witnessed LOC
Onset during exertion
Differential for thunderclap headache
SAH
Dissection
Cerebral venous sinus thrombosis
Reversible cerebral vasoconstriction syndrome
?Paroxysmal Hemicrania
Elements of the FAST-ED Stroke Assessment
Face - Any asymmetry with show me your teeth (0-1)
Arms - Pronator Drift (0-2)
Speech - Expressive aphasia naming 3 objects
- Receptive aphasia, 1 or 2 step command
Time from onset (<4.5 or <24 if large vessel)
Eyes: Deviation (can test FOV to finger counting)
Denial / Neglect:
- Does this arm feel weak, who’s arm is this?
Initial stroke labs and management
Labs: CBC, INR/PTT, Creatinine, Glucose, liver enzymes and lipid profile
Management: Call stroke code. CT Non-con, with CT-A if infarct. BP reduction to < 185/110 if candidate for thrombolysis, <220 if not a candidate.
Meningitis microbiology
1) S. Pneumo (gram +ve diplococci)
2) Neisseria Meningitides (gram -ve diplococci)
3) Listeria (gram +ve bacilli)
4) H Flu
5) TB
6) Lyme, Ricketsia
Viral
1) Enterovirus
2) HSV
3) ++ other
Fungal
Other:
- SLE
- Vasculitis
- Drug Induced
- Carcinomatosis
- Sarcoidosis
LP Results for Bacterial Meningitis
> 500, >80% neuts, Protein elevated, Gluc <50% of serum
Seizure Type
Simple Partial
Complex Partial (LOC)
Generalized
2nd causes of seizure
Metabolics: Hypo Na, Ca, glucose
Drugs / Infection: Anticholinergic, antidepressants, Sympathomimetics, Toxic EtOH, Isoniazid, Shrooms
CNS: Meningitis, encephalitis
Lesions: Hemorrhage, tumors, stroke, vasculitis, hydrocephalus
Febrile Seizure
Trauma
Eclampsia
ABCD2
Age > 60 y
BP > 140/90
Unilateral Symptoms
Diabetes
Duration - <60 mins
tPA Exclusion
Age < 18
Rapidly improving
Bleeding on CT
History of ICH
Known AVM
Endocarditis
Bleeding diathesis (platelet < 100k, INR > 1.7, heparin in last 48 hours
Active internal bleeding
BP > 185/110
Head trauma in last 3 months / Nsx or stoke
Relative
Recent GI or GU bleed
Seizure at onset
Recent LP
Recent puncture at noncompressible site
Pericarditis
Pregnancy
Encephalitis mostly viral
Arboviruses
Mosquito and tick born
HSV
EBV / CMV
Rabies
Mgmt: 10 mg/kg IV Q8H
Headache types and treatments
Primary:
Migraine: Triptans (sumatriptan), NSAIDs, Dopamine agonists, DHE
Cluster: High flow O2 (works 70%), Sumatriptan or DHE, verapamil for prophylaxis
- Conjunctival injection, lacrimation, nasal congestion, rhinorrhea, facial swelling, miosis
Tension
Reversible:
- RCVS
- Coital migraine
- Post LP
Secondary Causes:
- Vascular
- Infectious
- Neoplasm
- ICP
- Eyes
- Drugs
- Toxic: Carbon monoxide
- Hypoxia, Hypoglycemia, hypercapnia, pre-eclampsia
GCA - Temporal Arteritis Criteria
3 of 5:
- Age > 50
- New onset localized headache
- Temporal artery tenderness / decreased pulse
ESR > 50
- + biopsy
Headache Red Flags
Systemic signs and symptoms
Neuro symptoms
Onset after age 40
Onset sudden
Pattern Change
Exertional
Worse lying flat
Morning symptoms / waking from sleep
Pregnancy
Carotid and Vertebral Dissection
Most common cause of stroke in < 45
Symptoms:
- Unilateral neck pain, headache around the eye / frontal area.
- Usually acute onset
- Ipsilateral Horner, contralateral stroke or TIA symptoms
Vert: occiput or posterior neck pain, signs of brainstem TIA or stroke
CONSIDER WITH NECK PAIN AND NEURO SYMPTOMS
CVST
Symptoms:
- Headache +/- neuro symptoms
- Focal syndrome
- Diffuse encephalopathy
- Caused by high ICP and local ischemia
1% of all strokes
Risk Factors:
Most common 20-50 yrs
Female x 3
Oral contraceptive - 6 fold increase, 30 fold when patient obese)
Pregnancy
APLS
Malignancy
Any hypercoag state - DM2, nephrotic syndrome, HIT,
HEENT infections
Instrumentation or surgery
Ataxia Types and Features
Motor: Ipsilateral findings. If Vermis involved, more central / trunkal ataxia
Sensory: Difficulty ambulating, weakness, falls.
- Worse with loss of vision / eyes closed
Testing: Rapid alternating movements (motor)
- Romberg Test (sensory)
Vertigo Types and Red Flags
Red Flags:
- Diplopia
- Dysarthria
- Dysmetria
- Dysphagia
Central vs Peripheral:
HINTS
Head Impulse: Central = NO corrective saccade
Nystagmus: Central - vertical, bidirectional
Test of skew: Cover / uncover
Acute Vestibular Syndrome:
- Spontaneous nystagmus
- Continuous vertigo, exacerbated by movement
Peripheral Vertigo Causes
BPPV
Meniere’s - Ear fullness and hearing loss
Labrynthitis - Recent URI or AOM. Tinnitis and hearing loss
Acute vestibular neuronitis
Ramsay Hunt - HSV 8th cranial nerve
Ototoxicity
CN VIII lesions
CN Palsies
III - Levator of eyelid and 4 eye muscles and pupil constriction (down and out eye)
- Causes: Congenital, aneurysm (PCOM), Ischemic (DM, HTN), trauma, migraine
*if pupil sparing, likely benign
IV - Trochlear nerve. Superior oblique muscle. 40% trauma, 30% idiopathic, 20% to vascular, 10% are tumor/aneurysm
VI - Abducens nerve. LR. Affected eye cannot abduct past midline.
Causes: Tumor, aneurysms, fracture, CVST
V: Trigeminal neuralgia
- Facial pain
- Tx: Carbamazepine and analgesia
VII Bell’s Palsy:
Most commonly due to HSV, can also be due to Lyme, HIV)
- Usually a viral prodrome
- Non-forehead sparing
- Can have loss of tase on anterior 2/3 of tongue
- Bell Phenomenon: Eye rolls back when closing eye
DDx: Lyme, Ramsay Hunt, Otitis Externa, Acoustic Neuroma
Tx: Steroid and antivirals vs Abx if Lyme suspected
Spinal epidural abscess RF
IV drug use
Endocarditis
Renal Failure
Diabetes
EtOH
Dental Abscess
Spinal Neoplasm most common met
Lung
Breast
Lymphoma
Neuromuscular Disorders:
- Presentation/features and treatment
1) Guillain-Barre Syndrome
- Acute demyelinating polyneuropathy
- Preceding viral illness.
- Campylobacter jejuni, URI
- Ascending symmetric parasthesias and motor weakness
- Miller Fisher Variant: Opthalmoplegia, ataxia and decreased reflexes
Dx: EMG, CSF (increased protein and lymphocytes)
Tx: IVIG, plasmapheresis
Diptheria:
- Toxin mediated multisystem illness
- Respiratory or skin
- Toxin release and peripheral neuropathy
DM2 Peripheral Neuropathy:
- Distal symmetric
- Can have CN 3,4,6
ALS:
- UMN disease with associated LMN disease
- Anterior horn cell neuronopathy
Tx: Riluzole, supportive therapy
Myesthenia Gravis:
- AI disease of the NM junction
- Antibodies against the ACh receptors
- Associated with thymoma
Sx: Fatiguable weakness. Improves with rest. Ocular muscle weakness. Improved with cold
- Myesthenic Crisis: Resp failure requiring mechanical ventilation. Triggers include infection and medications
Tx: Plasmapheresis, IVIG, Thymectomy
Lambert -Eaton:
- Anitbodies that reduce ACh at NMJ. Associated with cancers SCC lung
- Symptoms improve with repeated movement. (Primarily leg)
- Autonomic symptoms to dry mouth and impotence
Botulism:
- Toxin mediated
- Descending flaccid paralysis
- Diplopia, dysarthria and dysphagia early
Tx: Supportive and horse serum antitoxin
Tick Paralysis:
- Should find an attached feeding tick
Periodic Paralysis:
- Muscle ion channelopathy. Hyper and hypo K are most common
Multiple Sclerosis
CNS Demyelination
- Lesions separated by time and space
- Optic neuritis most common first presentation
- LE > UE: loss of strength, vibration/propriception, increased tone and reflexes
- Internuclear opthalmoplegia
- Uhthoff phenomenon: symptoms worse with increase temperature
- Lhermitte phenomenon: electrical shock with neck flexion
Parksinson’s Disease
4 main findings:
- tremor
- rigidity
- akinesia
- postural instability
