Neurosonography Part ONE Harry H Neurosonography Part ONE Harry H. Holdorf PhD, MPA, RDMS (Ab, OB/Gyn, BR), RVT, LRT

Introduction 7-10 MHz transducer Scans are performed through The anterior fontanelle; Coronal planes sagital planes The coronal suture or the squamous portion of the temporal bone; Axial plane , to identify extracerebral fluid Doppler studies of the “Circle of Willis” Posterior fontanelle; Evaluation of the posterior fossa

Embriology, Color page 169 Centeral nervous system develop from ectoderm; it folds back and forms the “neural tube” which makes the CNS: brain and spinal cord Surrounding mesoderm forms: Cranium, vertebral column, muscles After 3 weeks development- three regions: Fore brain (prosencephalon) Midbrain (Mesencephalon) Hindbrain (Rhombencephalon)

Embriology images

Embriology

Embriology images

Embriology

Forebrain( Prosencephalon) Forms: Telencephalon- forms Cerebrum Surrounds the Lateral ventricles Diencephalon Thalamus Hypothalamus Epithalamus Surrounds the 3rd ventricle

Midbrain Forms Mesencephalon which develops into: Cerebral peduncles Colliculi The Aqueduct of Sylvius is located at this level.

Hindbrain (Rhombencephalon) Forms: Metencephalon (Upper) Pons Cerebellum The Upper part of the 4thventricle is located at this level. Myelencephalon (Lower) Spinal cord Medulla Oblongata The Lower part of the 4th ventricle is located at this level.

Bones of cranium Color pages 24-25 One frontal bone- Form forehead Two parietal bones- Form top Two Temporal bones- Form sides One Ethmoid bone - between eyes One Sphenoid bone Anterior to temporal bone Wing-like shaped “sella tursica” holds pituitary gland-located: @ center of Sphenoid bone One occipital bone; large hole(Foramen Magnum) for passage of the spinal cord

Bones of cranium lateral view

Bones of cranium top view

Cranium bones interior view

Sutures, Page 24 of coloing book Bones are connected by sutures, which are fibrous movable joints. Allow for molding of the skull during birth.

Sutures cont. Sagital suture Coronal suture Lambdoidal suture Between parietal bones- Form ant. And pos. fontanels Closes from posterior to anterior Fuses when frontal fontanels closes Coronal suture Between frontal and parietal bones Perpendicular to sagital suture Lambdoidal suture Between parietal and occipital bones Courses from mastoid portion of temporal bone to posterior portion of sagital suture Squamosal suture Between temporal and parietal bones

Skull of new born

Skull sutures and fontanels in neonates

Skull sutures top view

Skull sutures lateral view

Skull sutures lateral view

Skull sutures posterior view

Fontanels: Anterior Fontanel Posterior Fontanel Lateral Fontanels Junction of sagital and coronal sutures called Bregma Closes between 5-18 months Posterior Fontanel Junction of sagital and lambdoidal sutures called Lambda Closes between 2-6 months Lateral Fontanels Sphenoidal/squamosal fontanels- Ant., closes @ 2-3 months. Mastoid fontanels-post., closes @ 12 months

Fontanels

Fontanels

Cranial Meninges: Page 81 There are three layers of meninges: Dura Mater- Outer layer Arachnoid- Middle layer Pia Mater- Innermost layer, highly vascular The cerebral meninges are continious with the spinal meninges The main function of meninges and CSF (cerebrospinal fluid) is to protect the brain and cord

Cranial Meninges:

Dura Mater Folds inward and divide the cranial cavity. These folds include: Falx cerebri- Between the cerebral hemispheres Falx cerebelli- Between the cerebellar hemispheres Tentorium cerebelli- Between cerebrum and cerebellum Diaphragma sellae- Forms a bridge over the Sella Turcica

Cranial Meninges cont. Dura Mater is separated from Arachnoid by the subdural space. Arachnoid is separated from Pia Mater by the subarachnoid space. Note- Subarachnoid space is where fluid is sampled for a spinal tap in the lumbar region.

Cranial Meninges cont. The convolutions of the surface of the brain are called Sulci and Gyri. The hills are gyri while the furrows are sulci. The pia mater and arachnoidnare in close contact with gyri. Pia mater follows the dip of sulci while arachnoid bridges over the top of gyri and make subarachnoid spaces.

Grey and White matter organization of the brain and cord: Found on The inner portion of the crebrum Found on The outer portion of the spinal cord Mostly axons Grey matter: Grey matter of cerebrum divides into: Grey matter of the cerebral cortex Grey matter of the basal ganglia Grey matter of the cerebellar cortex Grey matter of the inner portion of the spinal cord Mostly cell bodies

Regions of the brain (CNS) Cerebrum Diencephalon Cerebellum Brain stem

CNS

Cerebrum Largest portion of the CNS Has two hemispheres. There is a deep cleft between the cerebral hemispheres called Longitudinal Fissure or Interhemispheric Fissure.