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displayed.e Dural Venous Sinuses and Ventricular System nmartin31@qub.ac.ukLearning Outcomes Describe the location of and Describe the pattern of venous Identify the structures passing identify the dural venous drainage within the dural through the cavernous sinuses sinuses venous sinuses Describe the ventricular system of the brain and identify the relevant anatomy; describe the flow of CSFWhat are the DVS? • Endothelial lined spaces between the periosteal and meningeal layers of the dura. • Form where dural septa separate e.g., along the free edge of the falx cerebri. • Drain blood from the brain, scalp, and face into the IJV.DVS Location Superior sagittal Upper margin falx cerebri Occipital Attached border of falx cerebelli Inferior sagittal Lower margin of the falx cerebri Straight Postero-inferior attachment of falx cerebri, along tentorium cerebelli Transverse Posterolateral attached margins of tentorium cerebelli Sigmoid Posterior cranial fossa at the posterior aspect of the petrous temporal bones Superior petrosal Anterolateral attached margin of tentorium cerebelli Inferior petrosal Within a groove between the petrous part of the temporal bone and the basilar part of the occipital bone Cavernous Either side of the sella turcica Intercavernous Anterior and posterior (plexuses) around infundibulum of the pituitary gland Sphenoparietal Along lesser wing of the sphenoid boneDVS Direction of Drainage Superior sagittal Inferiorly into onfluence of sinuses Occipital Superiorly into confluence of sinuses Inferior sagittal Into straight sinus Straight Posteriorly into confluence of sinuses Transverse Laterally into sigmoid sinuses Sigmoid Inferiorly into internal jugular veins Superior petrosal Posterior-laterally into transverse/sigmoid sinus Inferior petrosal Posteriorly into sigmoid sinus IJV junction Cavernous Posteriorly into petrosal sinuses Intercavernous Communication between cavernous sinuses Sphenoparietal Medially into cavernous sinusesTh e pict ure can 't be dis pla yed .O TOM CATThe picture The picture can't be displayed. displayed. DVS Thrombosis • Usually the transverse, cavernous, and superior sagittal sinuses affected • Women onOCP, pregnancy, steroids, infection, trauma, vaccine (AZ) The picture can't be displayed. • Headache, nausea, vomiting, o papilloedema (optic disc swelling 2 to ↑ICP , therefore bilateral) • Unstable? Local thrombolysis • Oral anticoagulation for 3-6 monthscan't beure displayed. The picture can't be displayed. Danger T riangle • Facial vein drains blood of danger triangle to IJV • Facial vein communicates withuperior ophthalmic veins, of which are drained The picture can't be displayed. by cavernous sinus • Infection from the face can enter the cavernous sinus and therefore brain via the facial vein. eh uret The picture can't be displayed. 'tn What are the ventricles? dis yed . • Produce and circulate CSF • Choroidal epithelial cells (modified ependymal cells) line the ventricles. • ~400-500mL/day of CSF is The picture can't be displayed. secreted to bathe the surfaces of the brain and spinal cord • CSF gives cushioning against trauma, creates buoyancy, removesmetabolises Th e pict ure can The picture can't be displayed. 't be dis pla yed . Th e pict ure can 't be dis pla The picture can't be displayed. yed . Th e pict ure can 't be dis pla yed The picture can't be displayed. . Th e pict ure can The picture can't be displayed. 't be dis pla yed . eh uret can be Flow of CSF pla .ed • Beginning in the lateral ventricles, some CSF flows due to pulsation of blood through two passageways called the interventricular foramina to drain into the third ventricle • From the third ventricle it flows down a long, narrow passageway called the th aqueduct of Sylvius into the fourth ventricle. The 3rd and 4 ventricles are posterior-inferiorly as connected by this aqueduct • From the fourth ventricle it passes through three small openings (foramina) into the subarachnoid space surrounding the brain and spinal cord. CSF can pass into the paired lateral apertures before exiting to SA space or travel into the single median aperture before reaching the SA space and can collect in cisterns eg. cisterna magna • Some CSF escapes into spinal column passing via the median aperture. The subarachnoid space is continuous around the spinal cord and posterior-superiorly over the cerebellum eh pict can The picture can't be displayed. 't Absorption of CSF dis pla .ed • Arachnoid granulations (clusters of arachnoid villi) • Granulations protrude through the meningeal layer of dura mater • Open into DVS • Absorption of CSF from arachnoid granulations into the DVS occurs when the CSF > DVS pressure: • Some absorption may occur directly in the veins of the subarachnoid space or through the lymphatic system. • Some CSF may even escape through the perineural lymph vessels of the spinal and cranial nerves. Once in the bloodstream, it is carried away and filtered by our kidneys and liver in the same way as are our other body fluids. Th e The picture can't be displayed. pict ure can 't be dis pla yed .The picture The picture can't be displayed. displayed. Hydrocephalus Expansion of the cerebral ventricles caused by anexcessive accumulation of CSF ± herniation of cerebral tissue (coning) • Communicating – CSF cannot get The picture can't be displayed. reabsorbed (absent arachnoid villi) • Non-communicating– flow of CSF is blocked Ventriculoperitoneal shuntQ) Nicholas is an 18-year-old male who has recently started university. He attends a party and has many alcoholic drinks and wakes the a) L1-2 next morning with a severe headache. He puts this down to being hungover, however, b) T12-L1 by the next day the headache is worse and c) T12-L2 he has a widespread non-blanching purpuric rash. He attends the emergency department d) L3/4 who suspect meningitis and would like to e) L4/5 perform a lumbar puncture to obtain a cerebrospinal fluid (CSF) sample. The doctor would like to take the sample from the cauda equina to avoid spinal cord injury, at which level does the spinal cord terminate?Q) Nicholas is an 18-year-old male who has recently started university. He attends a party and has many alcoholic drinks and wakes the a) L1-2 next morning with a severe headache. He puts this down to being hungover, however, b) T12-L1 by the next day the headache is worse and c) T12-L2 he has a widespread non-blanching purpuric rash. He attends the emergency department d) L3/4 who suspect meningitis and would like to e) L4/5 perform a lumbar puncture to obtain a cerebrospinal fluid (CSF) sample. The doctor would like to take the sample from the cauda equina to avoid spinal cord injury, at which level does the spinal cord terminate?Q) Which one of the following statements relating to the Cavernous Sinus is false? a) The pituitary gland lies medially b) The internal carotid artery passes through it c) The temporal lobe of the brain is a lateral relation d) Tlateral wallr branch of the trigeminal and optic nerve lie on the e) The ophthalmic veins drain into the anterior aspect of the sinusQ) Which one of the following statements relating to the Cavernous Sinus is false? a) The pituitary gland lies medially b) The internal carotid artery passes through it c) The temporal lobe of the brain is a lateral relation d) Tlateral wallr branch of the trigeminal and optic nerve lie on the e) The ophthalmic veins drain into the anterior aspect of the sinusQ) A 13-year-old boy presents with his mother to the emergency department. This past two mornings he has had a severe headache on waking. The pain becomes less severe when he gets out of bed. He is a) Third ventricle morning. There is no history of trauma. On b) Cisterna magna ophthalmoscopy, papilloedema is present c) Subdural space bilaterally. A CT head scan shows a mass d) Superior sagittal sinus invading the fourth ventricle. The mass is e) Extra-dural space reducing the diameter of the median median aperture (foramen of Magendie) ofThe the fourth ventricle allows cerebrospinal fluid (CSF) to flow from the fourth ventricle into which space?Q) A 13-year-old boy presents with his mother to the emergency department. This past two mornings he has had a severe headache on waking. The pain becomes less severe when he gets out of bed. He is a) Third ventricle morning. There is no history of trauma. On b) Cisterna magna ophthalmoscopy, papilloedema is present c) Subdural space bilaterally. A CT head scan shows a mass d) Superior sagittal sinus invading the fourth ventricle. The mass is e) Extra-dural space reducing the diameter of the median median aperture (foramen of Magendie) ofThe the fourth ventricle allows cerebrospinal fluid (CSF) to flow from the fourth ventricle into which space?Q) Which one of the following cranial venous sinuses is unpaired? a) Transverse b) Cavernous c) Superior sagittal d) Sigmoid e) Inferior petrosalQ) Which one of the following cranial venous sinuses is unpaired? a) Transverse b) Cavernous c) Superior sagittal d) Sigmoid e) Inferior petrosalQ) A 2 week neonate has been diagnosed with hydrocephalus secondary to congenital spina bifida. Where is the site of cerebrospinal fluid (CSF) production? a) Pia mater b) Cerebral aqueduct c) Choroid plexuses d) Arachnoid granulations e) Cribiform plateQ) A 2 week neonate has been diagnosed with hydrocephalus secondary to congenital spina bifida. Where is the site of cerebrospinal fluid (CSF) production? a) Pia mater b) Cerebral aqueduct c) Choroid plexuses d) Arachnoid granulations e) Cribiform plateQ) Which one of the following is not a feature of normal cerebrospinal fluid? a) It has a pressure of between 10 and 15 mmHg b) It usually contains a small amount of glucose c) It may normally contain up to 5 red blood cells per mm d) It may normally contain up to 3 white blood cells per mm e) None of the aboveQ) Which one of the following is not a feature of normal cerebrospinal fluid? a) It has a pressure of between 10 and 15 mmHg b) It usually contains a small amount of glucose c) It may normally contain up to 5 red blood cells per mm d) It may normally contain up to 3 white blood cells per mm e) None of the aboveQ) Which one of the follow HX are the most typical for normal pressure or communicating hydrocephalus? a) Elderly man presents with b) Overweight teenage girl gradual worsening dementia presents with a headache and and bradyphrenia associated blurred vision. On examination with a slow, shuffling gait. Heshe is noted to have has also recently suffered withpapilloedema urinary incontinenceQ) Which one of the follow HX are the most typical for normal pressure or communicating hydrocephalus? a) Elderly man presents with b) Overweight teenage girl gradual worsening dementia presents with a headache and and bradyphrenia associated blurred vision. On examination with a slow, shuffling gait. Heshe is noted to have has also recently suffered withpapilloedema urinary incontinenceQ) Which of the following neoplasms are most associated with hydrocephalus? a) Ependymoma b) Retinoblastoma c) Craniopharyngioma d) Mengioma e) VentriculomaQ) Which of the following neoplasms are most associated with hydrocephalus? a) Ependymoma b) Retinoblastoma c) Craniopharyngioma d) Mengioma e) Ventriculoma