LearnNeurosurgery.com
  • Index
    • 3 Column Model
    • ACh: Acetylcholine
    • Acute MS
    • Ia (A-alpha) Muscle Spindles
    • Ib (A-alpha) Golgi Tendon
    • II (A-beta) - touch, vibration, pressure
    • Acid-Base
    • Actinomyces
    • ABC: Aneurysmal Bone Cyst
    • Acute Transverse Myelitis
    • Aldosterone
    • AA: Anaplastic Astrocytoma
    • Achondroplasia / Dysplastic Pedicle Syndrome
    • ACTH
    • Acute Phase Reactants
    • AD: Alzheimer's Disease
    • ADEM
    • ADH / Vasopressin
    • AEDs: Anti-Epileptic Drugs
    • AIDP / Guillain-Barre
    • Angiolipoma
    • Alcohol
    • Alexia without Agraphia
    • Alpha-2
    • AIP: Acute Intermittent Porphyria
    • ALS: Amyotrophic Lateral Sclerosis
    • Altitudinal Retinal Defect
    • Amaurosis Fugax
    • Amyloid Angiopathy
    • Anemia
    • Anencephaly
    • Anesthetics
    • Angiogram Anatomy
    • ANS: Autonomic Nervous System
    • ANS Dysautonomia
    • Arachnoiditis
    • ARDS: Acute Respiratory Distress Syndrome
    • ARF: Acute Renal Failure
    • Carotid Artery Dissection
    • Agenesis of Corpus Callosum
    • Aneurysms - By Type
    • Ankylosing spondylitis
    • Aqueductal Stenosis
    • Arachnoid Cyst
    • Ataxia-Telangectasia
    • ATRT: Atypical Teratoid Rhabdoid Tumor
    • AVM: Arteriovenous Malformation
    • Bacteria
    • Balo's Concentric Sclerosis
    • BA: Basilar Artery
    • Behcet
    • Bell's Palsy
    • Beriberi
    • Black Widow Spider
    • Blue Rubber Bleb
    • Bone Hemangioma
    • Botulism
    • Brain Herniation
    • Brainstem Glioma - Medulla
    • Buerger's Thromboangitis Obliterans
    • Burst Fracture
    • Caput Medusa
    • Cardiac Arrhythmias
    • Cardiac Tamponade
    • Carotidynia
    • C1 - Atlas
    • C1 - C2
    • C2 - Axis / Odontoid / Dens
    • C5-6: Erb's Palsy
    • C3-C7 - Subaxial Cervical Spine
    • CN XI: Spinal Accessory Nerve
    • CADASIL
    • Capillary Telangiectasia
    • Carbon Monoxide Poisoning
    • Cardiac & Renal Drugs
    • Cardiac Risk Index
    • Carotid Stenosis
    • CCF: Carotid Cavernous Fistula
    • Cavernous Malformation
    • C. Diff: Clostridium difficile
    • Cerebral Autoregulation
    • Central Neuroblastoma
    • Central Neurocytoma
    • Cephalohematoma
    • Cerebrovascular Disease
    • Cerebral Abscess
    • Cerebral Arteries - Embryology
    • Cerebral Cortex - Frontal Lobe
    • Cerebral Edema
    • Cerebral Palsy / Spasticity
    • Cervical Spine Trauma
    • Cervical Degenerative Disease
    • Cervical Plexus
    • Chance Fracture
    • Chemical Vasculitis
    • Chemotherapy Drugs
    • Chiari Malformation
    • Cholesterol Granuloma
    • Cholinergic Crisis
    • Chordoma / Chondrosarcoma / Chondroid Chordoma
    • Choroid Plexus Papilloma / Carcinoma
    • Chromosomal Abnormalities
    • CIDP: Chronic Inflammatory Demyelinating Polyneuropathy
    • Classic Avellis Syndrome
    • Cleidocranial Dysostosis
    • CNS Lymphoma
    • CN II: Optic Nerve
    • CN III: Oculomotor Nerve
    • CN IV: Trochlear Nerve
    • CN VI: Abducens Nerve
    • CN VII Pathology
    • CN IX: Pathology
    • CN X: Vagal Nerve
    • Colloid Cyst
    • Coma
    • Complete Basilar Syndrome
    • Compression Fracture
    • Concussion
    • Congestive Heart Failure
    • Congenital Muscular Dystrophy / Walker-Marburg
    • Corneal Ulcer
    • Corpus Callosum Disconnection Syndromes
    • Corticobasal Degeneration
    • CST: Corticospinal Tract
    • Craniopharyngioma
    • Craniosynostosis
    • CRPS: Complex Regional Pain Syndrome / Reflex Sympathetic Dystrophy
    • CSF Leak
    • CY-P450 Drugs
    • DAI: Diffuse Axonal Injury
    • Dandy Walker / Dandy Walker Variant / Mega Cisterna Magna / Posteriro Fossa Arachnoid Cyst
    • DAVF: Dural Arteriovenous Fistula
    • DCML: Dorsal Columns Medial Lemniscus
    • Dejerine - Roussy / Thalamic Pain
    • Delirium
    • Dementia
    • Dementia Pugilistica
    • Denervation Hypersensitivity
    • Dermal Sinus Tract
    • Dermoid Cyst
    • Developmental Ventricle Abnormalities
    • Devic's / Neuromyelitis Optica
    • DPL: Diagnostic Peritoneal Lavage
    • DIC: Diffuse Intravascular Coagulation
    • DIG: Desmoplastic Infantile Ganglioglioma
    • DIPG: Diffuse Infiltrative Pontine Glioma / Pontine Glioma / Brainstem Glioma
    • Diphtheria
    • DISH: Diffuse Idiopathic Skeletal Hyperostosis
    • DNET: Dysembryoplastic Neuroepithelial Tumor
    • Dopamine
    • DVST: Dural Venous Sinus Thrombosis
    • Duret Hemorrhage
    • Dystonia
    • ECA Stenosis
    • Eclampsia
    • Ectopic Neurohypophysis
    • EDH: Epidural Hematoma
    • EEG / Sleep
    • Electrolytes -Ca, P
    • Embolic Stroke
    • EMG: Electromyogram
    • Encephalopathy
    • Encephaloceles / Cephalocele
    • Empty Sella Syndrome
    • Enteric Nervous System
    • Enterogenous Cyst
    • Enuresis
    • Ependymoma / Ependymoblastoma
    • Epidural Abscess
    • Epidermoid Cyst
    • Epidural Lipomatosis
    • Esthesioneuroblastoma
    • Ethics
    • Ewing's Sarcoma
    • Fahr's Disease
    • Failed Back Syndrome
    • Familial Periodic Paralysis
    • Fat Embolism
    • Fibrous Dysplasia
    • Fibromuscular Dysplasia
    • Foix Syndrome
    • Folate / Methionine / Homocysteine / Vitamin B 12
    • Foramen Magnum Meningioma
    • Foster Kennedy Syndrome
    • Fracture - Dislocation
    • Freidrich's Ataxia
    • Frontal Sinus Fracture
    • FSH / LH
    • Fungus
    • GABA
    • Gait
    • Ganglioglioma / Gangliocytoma
    • Garcin's Hemibasal Syndrome
    • GBM: Glioblastoma Multiforme
    • Gemistocytic Astrocytoma
    • Germ Cell Tumors
    • Germinal Matrix Hemorrhage
    • Giant Arachnoid Granulations
    • Giant Cell Pituitary Granuloma
    • GI Bleed
    • Gliomatosis Cerebri
    • Gliosarcoma / Feigin Tumor
    • Glutamate
    • Glycine, Renshaw Cell
    • Glycogen Storage Diseases
    • Gradenigo's Syndrome
    • GH: Growth Hormone
    • Gunshot Wound
    • Hallervorden-Spatz
    • Headache
    • Head Injury
    • Hemangioblastoma / VHL: Von Hippel Lindau
    • Hemangiopericytoma
    • Heme Drugs
    • Hemiballismus
    • Hemifacial Spasm
    • Hirschsprung's
    • High Intracranial Pressure
    • Histology Stains
    • HMSN: Hereditary Motor Sensory Neuropathies / Onion Bulb / Hypertrophic / Peroneal muscular atrophy
    • HNP: Herniated Nucleus Propopus
    • Holoprosencephaly
    • Horizontal Gaze
    • HTN: Hypertension
    • Huntington's Disease
    • Hydrancephaly
    • Hydromyelia
    • Hyperostosis Frontalis
    • Hypothalamic Hamartoma
    • Hypothermia
    • Hypothyroid
    • ICA - Persistent Fetal Circulation
    • ICP Monitoring
    • Immunohistochemistry
    • Infectious Vasculitis
    • Intracranial HYPERtension / Pseudotumor Cerebri
    • Intracranial HYPOtension
    • IVH: Intraventricular Hemorrhage
    • Ion Channels
    • IPH: Intraparenchymal Hemorrhage
    • Irregular Central Breathing
    • Ischemic Pathology
    • Ischemic Stroke
    • Isolated 4th Ventricle
    • Jacod's Syndrome
    • JPA: Juvenile Pilocytic Astrocytoma
    • Jugular Foramen Syndromes: Vernet, Collet-Sicard, Villarett
    • Jump Facet
    • K: Potassium
    • Kawasaki
    • Kernicterus
    • Kippel-Trenaunay-Weber
    • Klippel-Fiel
    • Lacunar Stroke
    • Lambert Eaton
    • Landau-Kleffner
    • Langerhan's Histiocytosis X
    • Lateral Recess Syndrome
    • Leber Hereditary Optic Atrophy
    • Leprosy
    • Lesch-Nyhan Syndrome
    • Leukodystrophies
    • Lewy Body Dementia
    • Lhermitte-Duclos
    • Lipoma
    • Lipomyelomeningocele
    • Lissencephaly
    • Locked In
    • Low Grade Diffuse Astrocytoma / Fibrillary Astrocytoma
    • Lowe Syndrome (Oculo-Cerebro-Renal Syndrome)
    • Luckenschadel
    • Lumbar Degenerative Disease
    • Lupus / SLE
    • Lymphocytic Hypophysitis
    • Lysosomal Storage Diseases
    • Malignant Hyperthermia
    • Maple Syrup Urine Disease
    • Mannitol
    • Median Nerve: Carpal Tunnel Syndrome
    • Medulla
    • Medulloblastoma
    • Melatonin
    • MEN: Multiple Endocrine Neoplasia
    • Menke's Kinky Hair Disease
    • Meniere's Disease
    • Meningioma
    • Meningitis
    • Meningioangiomatosis
    • Metastasis
    • Methanol Poisoning
    • Microglia
    • Micturation Syncope
    • Mg: Magnesium
    • MG: Myasthesnia Gravis
    • MI: Myocardial Infarction
    • Mitochondrial Diseases
    • Mononeuritis Multiplex
    • Moya Moya
    • MRI - Study for Disease
    • MS: Multiple Sclerosis
    • MTS: Mesial Temporal Sclerosis
    • Mucopolysaccharidases
    • Multiple Myeloma / Plasmacytoma
    • Muscular Dystrophy
    • Musculocutaneous Nerve
    • Multi-Infarct Dementia
    • Myotonic Dystrophy / Myotonia
    • Myositis
    • Na: Hyponatremia
    • Na: Hypernatremia
    • NAHT: Non-Acciddental Head Trauma
    • Narcolepsy
    • NCS / EMG Examples
    • NCS: Nerve Conduction Studies
    • NE: Norepinephrine
    • Necrotizing Fascitis
    • Neuroepithelial Cyst
    • Neurofibroma / MPNST: Malignant Peripheral Nerve Sheath Tumor
    • Neuroleptic Malignant Syndrome
    • Neuropathy
    • NF1: Neurofibromatosis Type I
    • NF2: Neurofibromatosis Type 2
    • Nisseria Meningitis
    • Nocardia
    • Nodular Heterotopia
    • NPH: Normal Pressure Hydrocephalus
    • Nystagmus
    • O-C1
    • Occipital Neuralgia
    • Olfactory Groove Meningioma
    • Oligodendroglioma
    • Oligodendrocytes
    • Olivopontocerebellar Atrophy
    • Opioids
    • OPLL: Ossified Posterior Longitudinal Ligament
    • Optic Glioma
    • Orbit
    • Orbital Pseudotumor
    • Osteochondroma
    • Osteogenesis Imperfecta
    • Osteoid Osteoma
    • Osteoma
    • Osteomyelitis
    • Osteopetrosis
    • Osteosarcoma
    • Otalgia
    • Oxygen
    • OWR - HHT: Osler Weber Rendu / Hereditary Hemorrhagic Telangiectasia
    • Palatopharyngeal Paralysis of Avellis
    • Paget's Disease
    • Pancoast Tumor
    • Paraganglioma / Glomus Jugulare / Chemodectoma
    • Paramedian Diencephalic Syndrome
    • Paraneoplastic Syndromes
    • Paraneoplastic Limbic Encephalitis
    • Parasites
    • Parietal Foramina
    • Parietal Lesion
    • Parkinson's Disease
    • Parsonage-Turner
    • Pars Fracture
    • PCom Aneurysm
    • PE: Pulmonary Embolism
    • Pediatric Stroke
    • Peds Specific Vitals, Fluids, Blood Volume
    • Perineuroma
    • Peripheral Nerve
    • Periventricular Leukomalacia
    • Pick's Disease
    • Pineal Cell Tumors
    • Pineal Cyst
    • Pituitary Adenoma
    • Pituitary Apoplexy
    • Posterior Vertebral Body Scalloping
    • Pons
    • Pupillary Light Reflex
    • PNA: Pneumonia
    • PNET: Primitive Neuroectodermal Tumors
    • Poisons
    • Polyarteritis Nodosa
    • Polymicrogyri
    • Porencephaly
    • Postherpetic Neuralgia
    • PCA: Posterior Cerebral Artery
    • PRES: Posterior Reversible Encephalopathy Syndrome
    • Pressors
    • Primary Autonomic Insufficiency
    • Prions
    • Progressive Supranuclear Palsy
    • Prolactin
    • Protoplasmic Astrocytoma
    • Pseudolaminar Necrosis
    • Psych Drugs
    • PXA: Pleomorphic Xanthoastrocytoma
    • PTX: Pneumothorax
    • Pulmonary Edema
    • Radiation Necrosis
    • Raeder's
    • Rasmussen's Encephalitis
    • Rathke's Cleft Cyst
    • Respiratory Meds
    • Retinitis Pigmentosa
    • Retinoblastoma
    • Rexed Laminae
    • Rhabdomyolysis
    • Right Heart Failure
    • Rubrospinal Tract
    • Sacral Agenesis / Caudal Regression
    • Sacral Fractures
    • Sacral Meningocele
    • Sarcoidosis
    • Schizencephaly
    • Schwannoma
    • Schilder's
    • Scoliosis
    • Saethre-Chotzen
    • SAH: Subarachnoid Hemorrhage
    • SDH: Subdural Hematoma
    • SEGA: Subependymal Giant Cell Astrocytoma
    • Seizures
    • 5HT: Serotonin
    • Sheehan's Syndrome
    • Shock
    • Shunt Malfunction / Infection
    • Shy Drager
    • Sinus Pericranii
    • Skull Fracture
    • SMA: Supplementary Motor Area Syndrome
    • Spasticity
    • Speech
    • Spina Bifida / Neural Tube Defect
    • Spinal Cord Injuries
    • Spinal Cord Stroke
    • Spinal Epidural Abscess
    • Spinal Epidural Hematoma
    • Spinal Muscular Atrophy (SMA)
    • Spine Anatomy - Degenerative Disease
    • Spine Aneurysms
    • Spine Fractures
    • Spine Vasculature
    • Spinobulbar Muscular Atrophy / Kennedy's Disease
    • Spinoreticular
    • Spinal Tectal Tract
    • Split Cord Malformation / Diastematomyelia
    • Strep Pneumoniae
    • Striatonigral Degeneration
    • STT: Spinothalamic Tract
    • Sturge-Weber Syndrome
    • Subclavian Steal
    • Subdural Empyema
    • Subependymoma
    • Sural Nerve Biopsy
    • Stargardt's Disease
    • Stevens Johnson
    • Stiff Man Syndrome
    • Stimulants
    • Syncope
    • Synovial Cyst
    • Syphillis
    • Syrinx / Synringomyelia
    • Statistics
    • Takayasu's Arteritis
    • Taste: CN VII, IX, X
    • TectoSpinal Tract
    • Temporal Arteritis
    • Tetanus
    • Thoracic Outlet Syndrome
    • Thoracic Spondylosis
    • Thrombotic Stroke
    • Thyroid
    • TIA: Transient Ischemic Attack
    • Tethered Cord
    • TORCH
    • TIMI Score
    • Spinous Process Fracture / Transverse Process Fracture
    • TPN: Total Parenteral Nutrition
    • Traumatic IPH
    • Traumatic Neuroma
    • Trigeminal Neuralgia
    • Trigeminal Neuropathic Pain
    • TS: Tuberous Sclerosis
    • Tolosa-Hunt
    • Transfusion Reaction
    • Tremor
    • Ulnar Nerve
    • Ultrasound
    • Upper Extremity Exam / Brachial Plexus
    • Uremic neuropathy
    • Vagoglossopharyngeal Neuralgia
    • Vertebral Basilar Insufficiency
    • Vertical Gaze
    • VOGM: Vein of Galen Malformation
    • VOR: Vestibulo-Ocular-Reflex
    • Venous Air Embolism
    • Vestibulospinal Tract
    • Ventilator
    • Viruses
    • Eye / Retina
    • VWD: Von Willebrand's Disease
    • Wegener's Granulomatosis
    • Whipple's Disease
    • Wilson's Disease
    • Wormian Bones
    • Wound Healing
    • Wyburn - Mason
    • Zollinger-Ellison
  • Questions

Skull Base Anatomy


DEVELOPMENT
Skull base: endochondral ossification (cartilage --> bone)
Skull face: intramembranous ossification (bypasses cartilage stage)
Growth: brain doubles in size by 6 months, again at 2 yrs
Skull 35% of size at birth, 90% of size by 7 yo
Picture

SURFACE
Picture
Picture
Picture
  • Nasion: midline fronto-nasal suture
  • Glabella: most forward point on the midline supraorbial ridge
  • Pterion: junction of frontal, parietal, temporal, and greater wing of sphenoid
    • Located 2 fingerbreadths above zygomatic arch and a thumb’s breadth behind the frontal process of the zygomatic bone
  • Asterion: junction of lambdoid, occipitomastoid, and parietomastoid sutures
    • Lies on top of the lower half of the transverse/sigmoid junction
  • Lambda: junction of the lambdoid and sagittal sutures
  • Inion: marks the torcula
  • Opisthion:  posterior margin of the foramen magnum
  • Styloid process: 2nd brachial arch
    Muscles: stylohyoid (CN VII), stylopharyngeus (CN IX), styloglossus (CN XII)
    Ligaments: stylohyoid, stylomastoid

  • Slyvian Fissure: 
    75% from Nasion → Inion
    Frontozygomatic point = 2.5 cm up from orbital rim past zygomatic portion
    Sylvian fissure lies on lie connecting these two points, the pterion is 3 cm behind the frontozygomatic point along this line
  • Central Sulcus
    Upper rolandic point: 2 cm posterior to the 50% point of the midline nasion-inion line
    Lower rolandic point: junction of the line from the upper rolandic point to the mid zygomatic arch where it intersects with the sylvian fissure line OR 2.5 cm behind the pterion on this line
  • Motor Cortex: 4-5.4 cm behind the coronal suture
  • Angular Gyrus: above pinna (variable)
Picture

HOLES
Picture

Cribiform plate
Olfactory nerves
Anterior & Posterior Ethmoid arteries & nerves
Foster Kennedy

Optic Canal
CN II
Ophthalmic artery

SOF: Superior Orbital Fissure
Above:
CN 4, V1Frontal, V1Lacrimal
Sympathetic fibers from ICA
MMA (orbital branch)
SOV (superior ophthalmic vein)
Annulus of Zinn
SOF: CN 3s, CN 3i, V1NC (nasociliary), 6
Optic canal: CN 2, ophthalmic artery
Picture
Picture
Foix Syndrome

IOF: Inferior Orbital Fissure
V2 - zygomatic nerve, pterygopalatine branch
Infraorbital artery & vein
IOV: Inferior ophthalmic vein

Peterygopalatine Fossa
Maxillary artery
V2
Pterygopalatine gangliona
Vidian Nerve
Picture

Foramen Rotundum
V2

Infratemporal Fossa
Temporalis muscle
Pterygoid muscles (medial & lateral)
Maxillary artery
Pterygoid venous plexus
V3
Chorda Tympani
Otic ganglion
Inferior alveolar nerve
Lingual nerve
Buccal nerves
Picture

Foramen Ovale
V3
Lesser Petrosal Nerve
Otic ganglion
Accessory meningeal nerve
Emmissary vein

Foramen Spinosum
MMA & vein

Foramen Lacerum
Nothing - ICA traverses upper portion

Carotid Canal
ICA
Sympathetic plexus

IAC: Internal Acoustic Canal / IAM: Internal Acoustic Meatus
VII, VIII, labyrinthine vessels, +/- AICA

Stylomastoid foramen
CN VII
Stylomastoid artery

Jugular foramen
Pars nervosa: IX, Jacobsen's nerve (CN IX)
Pars venosum: X, Arnold's (X), XI, IJ vein, inferior petrosal sinus, posterior meningeal artery

Hypoglossal canal
XII, anterior meningeal artery

Foramen Magnum
XI (spinal), spinal cord
Vertebral artery, Anterior & Posterior spinal arteries

Dorello's Canal
VI

Mandibular foramen
V3 (inferior alveolar)
Picture

Mental Foramen
V3 (mental nerve)

Incisive Foramen
V2 (nasopalatine)
Vessels to hard palate

Greater Palatine Foramen
Greater palatine nerve
Vessels to hard palate

Lesser Palatine Foramen
Lesser Palatine Nerve
Vessels to soft palate

Foramen cecum
Emissary veins from SSS to frontal sinus, nose

Vidian Canal
Vidian nerve (Greater Superior Petrosal Nerve VII + Deep Petrosal Nerve X)

Greater Petrosal Foramen
Greater Petrosal Vein

Lesser Petrosal Foramen
Lesser Petrosal Vein





BONE PARTS
Stylomastoid
Muscle attachments: styloHYOID (CN VII), styloPHARYNGEAL (CN IX), styloGLOSSUS (CN XII)
Ligament attachments: styloHYOID, styloMANDIBULAR
Origin: second branchial arch