Neuro Flashcards
What does a lesion in the cerebellum cause
A lesion in the cerebellum can cause scanning dysarthria presenting as jerky, loud speech with pauses between words and syllables. Other features that can occur include dysdiadochokinesia, nystagmus and an intention tremor.
What does a lesion in the superior temporal gyrus cause
A lesion in the superior temporal gyrus can cause Wernicke’s (receptive) aphasia leading to sentences that do not make sense with word substitution and neologisms. It can also cause comprehension to become impaired which is not seen in this patient.
What does a lesion in the substantia nigra cause
A lesion in the substantia nigra can cause Parkinson’s disease which can cause speech to become monotonous. Other features that can occur are bradykinesia, rigidity and a resting tremor which are not seen in this patient.
What does an articulate fasciculus cause
The arcuate fasciculus is an area that connects Wernicke’s and Broca’s area with a lesion causing poor speech repetition which is not seen in this patient.
What groove separates the left and right hemispheres of the brain
-the longitudinal fissure
What structure connects the left and right hemispheres
-the corpus callosum
Where is the lateral fissure located
- the lateral fissure also sometimes called the sylvian fissure
- between the temporal and parietal lobe
What is the significance of the opercula
- opercula means lips in latin
- it lies over the insurer cortex (also called insula) which is deep to the sylvian fissure
Which structure runs from the longitudinal fissure to the lateral fissure and why is it important
- the central sulcus
- it separates the frontal cortex from the parietal cortex
- just anterior to it is the motor cortex
- just posterior to it is the somatosensory cortex
What joins the two lobes of the cerebellum
-the vermis
Which structures form the brainstem
- midbrain
- pons
- medulla
Give a brief summary of how we get information from the optic nerve
- half of the information from one eye is taken to the thalamus and then to he occipital cortex in the same side of the brain
- half crosses over in decussating tracts at the optic chasm into the thalamus and then the occipital cortex at the other side of the brain
What is meningitis
-inflammation of the meninges
Give the 3 layers of the meninges
- Dura mater (endosteal/periosteal layer and the inner meningeal layer)
- arachnoid mater
- pia mata
Where are the venous sinuses found
-between the endosteal layer and the meningeal layer of dura mater
What is the falx cerebri
-where the dura meter goes in between the left and right hemisphere
What is the tentorium cerebelli
- a piece of dura mater between the cerebellum and the occipital pole
What is the falx cerebelli
- a piece of dura that sits between the two lobes of the cerebellum
What is lies in the subarachnoid cisterns
-cerebral spinal fluid
What would a bleed actually penetrating into brain tissue be called
-an intracerebral hemorrhage
What are the two roles of the dura mater
- stops the brain moving around in the skull
- forms the venous sinuses
Give the venous sinuses and where they are found
- superior sagittal sinus - found running along the superior surface of the falx cerebri
- inferior sagittal sinus - found along the inferior edge of the falx cerebri
- straight sinus -running along the middle of the tentorium cerebelli
- transverse sinus -runs between the edge of the tentorium cerebelli and the occipital bone
- sigmoid sinus - runs along the mastoid portion of the temporal bone and drains into the jugular vein
- cavernous sinus - lies lateral to the optic chasm
What is the role of the diaphragm sellae
-it is a ring of dura that forms the roof over the pituitary gland
Which structures are within the cavernous sinus and why is it a site of clinical significance
- cranial nerve 3,4,6 (oculamotor, trochlear and abducens nerve)
- branch 1 and 2 of cranial nerve 5 (opthalmic and maxillary branch of the trigeminal nerve)
- internal carotid artery
-can be a root of infection into the brain