Overview Flashcards
Which CN is typically very thin?`
CNIV - trochlear
Two components of the DCML?
Gracile
Cuneate
What type of information is conveyed in the DCML?
Sensory - fine touch, vibration, two point discrimination, proprioception
Gracile conveys information from where?
Lower limb
Cuneate conveys information from where?
Upper limb
CNI - name and function
Olfactory nerve
Scent
CNII - name and function
Optic nerve
Sight
CNIII - name and function
Oculomotor nerve
Movement of eye muscles
CNIV - name and function
Trochlear nerve
Movement of Superior oblique eye muscle
CNV - name and function
Trigeminal nerve
V1, V2, V3 - innervation of different regions of the skin
V3 - innervation of muscles of mastication
Lingual nerve - general sensation to the anterior 2/3 of the tongue
CNVI - name and function
Abducens
Movement of the lateral rectus eye muscle
CNVII - name and function
Facial nerve
Movement of muscles of facial expression
Chorda tympani - special sensory to the anterior 2/3 of the tongue
CNVIII - name and function
Vestibulocochlear
Cochlear nerve - hearing
Vestibular nerve - balance
CNIX - name and function (x3)
Glossopharyngeal nerve
All sensation to the posterior 1/3 of the tongue
Sensation from the pharynx
Parasympathetic to the parotid gland
CNX - name and function
Vagus nerve
Mainly parasympathetic actions
CNXI - name and function
Spinal accessory nerve
Innervation of the SCM and the trapezius muscles
CNXII - name and function
Hypoglossal nerve
Motor innervation of the tongue
The four muscles of mastication are?
Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
Five terminal branches of the facial nerve are?
Temporal Zygomatic Buccal Mandibular Cervical
Forehead wrinkling is absent in what type of damage?
LMN lesion
Forehead wrinkling is spared in what type of damage and why?
UMN lesion - dual innervation of the forehead
Three main nuclei of the basal ganglia are?
Caudate
Putamen
Globus pallidus
Lateral ventricle to the third ventricle is via?
Interventricular foramen
Third ventricle to the fourth ventricle is via?
Cerebral aqueduct
Corpus striatum consists of?
Caudate and putamen and globus pallidus
Accumbens located where?
Inferior to the caudate and anterior to the putamen
Two parts of globus pallidus are located where in relation to each other?
Globus pallidus interna - more inferiorly located
Globus pallidus externa - more superiorly located
Nucleus accumbens also known as?
Ventral striatum
Dorsal striatum consists of?
Caudate and putamen
Four functions of the basal ganglia
Regulate intensity of slow or stereotyped movements
Inhibit antagonist or unnecessary movement
Regulate attention and cognition
Motor program switch
Main neurone involved in the basal ganglia is?
Medium spiny neurone
Input to the MSN is?
Glutaminergic from the cortex
Output from the MSN is?
GABAergic
Two groups of GABAergic neurones in the basal ganglia express which receptors?
D1
D2
Dorsal striatum consists of?
Nucleus accumbens
Three actions of the D1 receptor
Increase cAMP
Increase sensitivity of striatal cells to glutamate
Project to the GPi directly via the direct pathway
D1/D2 - which is involved in the indirect/direct pathway?
Direct pathway - D1
Indirect pathway - D2
What is the action of dopamine at the D1 receptor?
Dopamine increases the action of the direct pathway - D1
What is the action of dopamine at the D2 receptor?
Dopamine decreases the action of the indirect pathway - D2
Function of the direct pathway is?
Activates motor program switch
Function of the indirect pathway is?
Blocks motor program switch
Overall action of dopamine at the basal ganglia
Dopamine increases action of direct pathway and decreases action of indirect pathway SO allows motor program change
Relation of dopamine to Parkinson’s?
PD - have reduced number of dopamine receptors and the person cannot facilitate movements
Death of cells where for PD?
Dopamine cells in the substantia nigra - input to the GPi and GPe
Level of cell death before PD presents is?
80% of SN dopamine cells dead before clinical signs of PD are seen
How can you recognise the substantia nigra?
Black region of the brain
Nigra - black
Four cardinal motor signs of PD are?
Tremor at rest
Rigidity
Bradykinesia
Loss of postural reflexes
First line treatment for PD is? x3
Levodopa
Dopamine agonist
MAO-B inhibitors
Second line treatment for PD? x2
In addition to first line:
COMT inhibitors
Amandadine/apomorphine
Last line treatment for PD?
Deep brain stimulation
Three sites for DBS in PD?
Subthalamic nucleus
Zona incerta
Globus pallidus interna
What is Huntington’s disease?
Extra, unwanted movements
Cause of Huntington’s disease is?
Loss of GABA-ergic neurones in the striatum
Inheritance of Huntington’s disease is?
Autosomal dominant
Anatomically, where is the direct pathway in relation to the indirect?
The indirect pathway surrounds the direct
Which neurotransmitter is released from the globus pallidus? (e and i?)
GABA
Which neurotransmitter is released from the STN?
Glutamate
Which neurotransmitter is released from the striatum?
GABA (Remember MSN)
Draw out the direct and indirect pathways !!
Draw out the direct and indirect pathways !!
What is the lentiform nucleus?
Putamen + globus pallidus
Arterial supply to the basal ganglia?
Lenticulostriate arteries
Lenticulostriate arteries originate from where?
Middle cerebral artery
When looking down on sliced brain, the head of the caudate nucleus can be seen through which structure?
Can be seen through the lateral ventricle
Triangular shaped ventricle of the brain is which ventricle?
Third ventricle
Grey matter of the cerebellum is called?
Folia
Running through the centre of the cerebellum is the?
Vermis
Direction that the vermis runs is?
Medio-lateral
Three lobes of the cerebellum are?
Anterior lobe
Posterior lobe
Floculonodular lobe
The lobes of the cerebellum are located on what aspects of the cerebellum?
Anterior and posterior lobes are located on the posterior lobe view of the cerebellum
Floculonodular lobe is located on the anterior view of the cerebellum
What separates the anterior and posterior lobes from each other?
Primary fissure
What is located on the inferior view of the cerebellum?
Cerebellar tonsils
And also the vermis - curves around
Relation of the flocculonodular lobe to the ventricles of the brain?
Forms the roof of the fourth ventricle
Blood supply to the cerebellum via which arteries? x3
Posterior inferior cerebellar artery - PICA
Superior cerebellar artery
Also branches of basillar artery
Most common site for clinical infarct in an artery leading to the cerebellum is?
Hairpin bend of PICA
Function of superior cerebellar peduncle?
Output from the cerebellum
Function of middle cerebellar peduncle? - specific
Contralateral input to the cerebellum from cerebral cortex and cranial nerves
Function of inferior cerebellar peduncle?
Input to cerebellum from spinal cord
Input to cerebellum at the inferior cerebellar peduncle is via which tracts? x2
Dorsal and ventral spinocerebellar tracts
Which cerebellar peduncle is the largest?
Middle
Two components of the spinocerebellar tract are?
Dorsal
Ventral
Spinocerebellar tracts are ipsilateral or contralateral?
Dorsal - ipsilateral
Ventral - contralateral and then recrosses
Dorsal spinocerebellar tract carries what information?
Proprioception
Ventral spinocerebellar tract carries what information?
Information about state of reflexes and interneurones in the spinal cord
Cerebellar signs present on what side of the body compared to the lesion?
Cerebellar signs are always on the same side as the lesion
Deep cerebellar nuclei are?
F - fastigial
G - globose
D - dentate
E - emboliform
Anterior lobe of cerebellum is associated with which nucleus?
Fastigial and interposed (globose and emboliform)
Posterior lobe of cerebellum connects to which nucleus?
Dentate
Posterior lobes of the cerebellum may also be referred to as?
Cerebellar hemispheres
Flocculo-nodular lobes of the cerebellum is associated with which nucleus?
Pontine vestibular nucleus
Vermis of the cerebellum is associated with which nucleus?
Fastigial
What is meant by the interposed nucleus?
Globose and emboliform
Three functional zones of the cerebellum are?
Vestibulocerebellum
Spinocerebellum
Cerebrocerebellum
Vestibulocerebellum is composed of?
Floculonodular lobe
Spinocerebellum is composed of?
Anterior lobe and vermis
Cerebrocerebellum is composed of?
Posterior lobe (cerebellar hemispheres)
Function of vestibulocerebellum? x3
Head and eye movement coordination to ensure stability of gaze
Balance of head - medial tract
Balance of body - lateral tract
Input to the vestibulocerebellum for it’s function is via the? x2
Extra occular eye muscles
Muscles of the neck
Output from the vestibulocerebellum is via the? x2
Medial longitudinal fasciculus
Medial vestibulospinal tract
Function of the spinocerebellum?
Control of locomotion and limb coordination
Output from the spinocerebellum? x2
Lateral vestibulospinal tract
Reticulospinal tract
Function of the cerebrocerebellum?
Coordination of movement initiated by the motor cortex e.g. speech, limbs, hand-eye coordnation
Cerebrocerebellum also known as?
Neocerebellum
Three major disorders caused by cerebellar damage are?
Floculonodular syndrome
Anterior lobe syndrome
Neocerebellar syndrome
Symptoms and signs of floculonodular syndrome? x7
Poor balance Disordered eye movements Nystagmus, ocular dysmetria Poor visual pursuit (tracking) Truncal ataxia - fall to one side of lesion Ataxic gait
Those with floculonodular syndrome perform badly on what test?
Romberg test
Most common cause of floculonodular syndrome is? this most often occurs in whom?
Medulloblastoma in the fourth ventricle - in young children
Five symptoms of anterior lobe syndrome?
Incoordination of the limbs Ataxia Hypotonia Dysdiadochokinesis Depressed/pendular reflexes
Common cause of anterior lobe syndrome?
Alcoholism - malnutrition and lack of B vitamins
Five symptoms of neocerebellar syndrome?
Loss of hand-eye coordination Dysmetria Dysdiadochokinesis Intention tremor Slurred speech
Common cause of neocerebellar syndrome?
PICA infarct
Five symptoms of cerebellar stroke?
Headache, vertigo, nausea, vomiting
Eye changes
Dysarthria
Five symptoms of cerebellar stroke?
Headache, vertigo, nausea, vomiting Eye changes Dysarthria and dysphagia Ataxia Arm weakness (one side) and incoordination
Cerebellar stroke will affect what art of the cerebellum?
Whole cerbellar cortex on one side - global signs
What is dysarthria?
Motor disorder of speech - weakened muscles of the face, mouth and respiratory system
What is ataxia?
Loss of balance and coordination whilst walking
What type of intoxication mimics features of cerebellar damage?
Alcohol intoxication
Why does alcohol intoxication mimic features of cerebellar damage?
Cerebellum has many GABA-ergic interneurones
These are especially sensitive to the effects of alcohol
What does an EEG record?
Changes in voltage as a result of ionic current flowing within neurones in the cerebral cortex of brain
EEG waves are affected by what?
State of arousal
EEG wave amplitude can vary to what degree?
10-150
Where are the three EEG leads placed?
Occipital lobe
Frontal lobe
Third is a ground electrode
Four types of EEG waves are?
Alpha
Beta
Theta
Delta
Alpha waves in EEG are present when?
In most awake adults
Beta waves in EEG are present when?
When subject is awake and alert - mental task
When eyes are open - alpha or beta EEG waves predominate?
Beta waves have an increased amplitude
When eyes are closed - alpha or beta EEG waves predominate?
Alpha waves have an increased amplitude
Function of anterior and posterior lobes of the cerebellum?
Movement of the limbs (anterior)
Movement of the trunk (posterior)
Function of the floculonodular lobe of the cerebellum?
Posture and balance
Cerebellum accounts for what percentage of total brain mass?
11%
Two non-motor functions of the cerebellum are?
Word association
Puzzle solving
What is the arbour vitae of the cerebellum?
Distinctive white matter pattern at the centre of the cerebellum
Sensory information to the cerebellum is from which tract?
Spinocerebellar
Motor information to the cerebellum is from which tract?
Corticocerebellar
Six symptoms associated with cerebellar injury and way to remember this?
DANISH Dysdiachokinesia Ataxia Nystagmus Intention tremor Slurred speech Hypotonia
What is the limbic system?
Group of cortical and subcortical nuclei
Where is the limbic system located?
Medial aspect of frontal, parietal and temporal lobes
Function of the limbic system is? x2
Rewarding and punishment in pleasure/pain
Learning and memory
The type of learning/memory involved with the limbic system is?
Motivational/emotional
Three cortical regions of the limbic system are?
Orbito-frontal cortex
Cingulate cortex
Parahippocampal cortex
Location of orbitofrontal cortex?
Frontal lobe - medial
Location of cingulate cortex?
Parietal lobe - medial
Location of parahippocampal cortex?
Temporal lobe - medial
Two components of the cingulate cortex are?
Anterior cingulate
Posterior cingulate
Most anterior part of the limbic system is?
Orbito-frontal cortex
Most posterior part of the limbic system is?
Posterior cingulate cortex
Most inferior part of the limbic system is?
Parahippocampal cortex
Blood supply to the limbic system via which arteries? x2
Anterior cerebral artery
Posterior cerebral artery
The middle cerberal artery MAY supply what parts of the limbic system? x2
Top of the temporal lobe and orbital cortex
Anterior cingulate cortex activated in which two scenarios?
Experience of pain
Depression
Two parts of the anterior cingulate cortex are?
Rostral
Caudal
Function of rostral anterior cingulate cortex?
Registers quality of pain - how bad from 1-10
Function of posterior cingulate cortex?
What actions to take to deal with the pain
What is a cingulotomy?
Procedure of cutting into the cingulate gyrus
Why is a cingulotomy performed?
To reduce the emotional distress of pain
Function of orbito-frontal cortex?
How to avoid pain - how to behave to an anticipated threat
Excessive activity in the orbito-frontal cortex has been linked to which condition?
OCD
Function of posterior cingulate cortex?
Visuo-spatial memory
Loss of function in visuo-spatial memory is associated with which condition?
Alzheimer’s
Function of parahippocampal gyrus?
Learning and memory
Four subcortical regions of the limbic system are?
Hippocampus
Amygdala
Accumbens nucleus
Septal nuclei
Hippoxcampus and amygdala are closely associated to which structure?
Inferior horn of the lateral ventricle
Septum pallucidum is?
Connection between the two fornices on either side
End point of the fornix is at the? x2
Mammillary body of the hypothalamus
Septal nuclei
Pathway of information transmission in the limbic system is?
Cingulate cortex - parahippocampal gyrus - hippocampus - fornix - mammillary bodies of hypothalamus - anterior thalamus - cingulate cortex
Pathway of information transmission in the limbic system is known as?
Papez’s circuit
What is retrograde amnesia?
Cannot access memories prior to the trauma
What is anterograde amnesia?
Cannot make new memories - failure to transfer new memories into long term memory
Cause of retrograde amnesia?
Damage to the cingulate gyrus
Cause of anterograde amnesia?
Damage to the hippocampus/loss of hippocampal function
Memory formation occurs where?
a
Memory storage occurs where?
a
Memory relay occurs where?
a
What is Korsakoff’s syndrome?
Encephalopathy - brain damage
Cause of Korsakoff’s syndrome?
B1 deficiency often in chronic alcoholics
B1 also known as?
Thiamine
Four symptoms of Korsakoff’s syndrome are?
Anterograde amnesia
Some degree of retrograde amnesia
Confabulation
Apathy
Two areas that are damaged in Korsakoff’s syndrome are?
Mammillary bodies
Projection of mammillary bodies to the anterior thalamus
What will a patient typically experience during temporal lobe epilepsy?
Remain conscious but experience powerful emotions e.g. intense joy/fear
Kluver-Bucy syndrome is due to damage to?
The amygdala
Five symptoms of Kluver-Bucy syndrome?
Psychic blindness Oral tendencies Hypermetamorphosiss Altered sexual behaviour Emotional changes
Main symptom/sign of Kluver-Bucy syndrome?
Loss of all sense of fear
Electrical stimulation of the amygdala in humans results in what?
Fear or anxiety
Amygdala is embedded in whcih cortex?
Entorhinal
Relation of amygdala to the sympathetic nervous system?
Amygdala - fear - can activate sympathetic nervous system fight or flight response
Effect of amygdala damage on emotion recognition?
Cannot recognise fearful expressions or different degrees of emotions
Where do the septal nuclei lie?
Basal of the septum pallucidum
Septal nuclei merge into which nucleus?
Basal nucles/nucleus of Meynert
Ventral striatum is composed of?
Septal nucleus
Accumbens nucleus
Nucleus of Meynert/basal nucleus
Nucleis accumbens is part of which dopaminergic pathway?
Mesolimbic dopamine pathway
Function of the ventral striatum?
Initiation and termination of behaviours/motor actions that trigger reward pathways
Blockage of dopamine receptors in the accumbens may be useful in the treatment of what?
Addictive behaviours
How can you differentiate between alpha and beta waves on an EEG?
Beta waves have a much greater frequency
When are alpha waves active?
Awake and resting individual
When are beta waves active?
Awake with mental activity
When are theta waves active?
Sleeping
When are delta waves active?
Deep sleep
Relation of the thalamus to the putamen on lateral aspect?
Thalamus is deeper to the putamen
Relation of thalamus to the third ventricle?
Thalamus is lateral to the third ventricle on either side
Percentage of blood supply to the bran is from which arteries?
80% - internal carotid arteries
20% - vertebral arteries
What is the blood supply to the anterior part of the brain?
Internal carotids
What is the blood supply to the posterior part of the brain?
Vertebral arteries
Vertebral arteries originate from where?
Subclavian arteries
Vertebral arteries enter the skull through which foramen?
Foramen magnum
Terminal branches of the internal carotid arteries/anterior circulation is? x2
Anterior cerebral
Middle cerebral
Terminal branches of the vertebral arteries/posterior circulation is? x1
Posterior cerebral artery
The classic circle of Willis is seen in what percentage of people?
34.5%
What is the biggest branch of the internal carotid artery?
MCA
Branches of the MCA that supply the basal ganglia are?
Lenticulostriate arteries
MCA supplies which region of the cortex?
Lateral portion of the brain (majority)
ACA supplies which region of the cortex?
Middle and anterior medial portion of the brain
PCA supplies which region of the cortex?
Posterior medial portion of the brain
MCA/ACA/PCA - supply to the caudate nucleus?
Anterior cerebral artery
MCA/ACA/PCA - supply to the putamen?
Middle cerebral artery
MCA/ACA/PCA - supply to the thalamus?
Posterior cerebral artery
MCA/ACA/PCA - supply to the globus pallidus?
Middle cerebral artery
MCA/ACA/PCA - supply to the internal capsule?
Posterior internal capsule - posterior cerebral artery
MCA/ACA/PCA - supply to the midbrain?
PCA
Blood supply to the pons?
Pontine arteries from the basillar artery
Blood supply to the medulla?
PICA
Cerebral veins/arteries - which ones pierce through the dura mater?
Veins
MCA/ACA/PCA - supply to the thalamus?
Posterior cerebral artery
Function of arachnoid granulations is? x2
Allow CSF to flow into the venous blood of sinuses
Prevents back flow of blood into the subarachnoid space
Majority of the cerebral blood flow will drain to which sinus?
Superior sagittal
Straight sinus is between which cerebral veins?
Inferior sagittal and confluence
All (most) dural sinuses eventually drain into which vein?
Internal jugular vein - 80%
Where will the remaining 20% of dural venous blood drain to?
Facial vein to the external jugular vein
Infarct of the temporal lobe can lead to damage to which two regions?
Broca’s area
Wernicke’s area
Presentation of MCA stroke?
Neglect syndrome - one side
Global aphasia
Define global aphasia?
Cannot produce words and have trouble understanding words
Why do MCA stroke patients have global aphasia?
Damage to both Broca’s and wernicke’s areas
Four symptoms of ACA stroke?
Contralateral sensorimotor loss below the waist
Urinary incontinence
Personality defects
Split-brain syndrome (damage to corpus callosum)
Three symptoms of PCA stroke?
Contralateral homonymous hemianopsia Reading and writing deficits Impaired memory (temporal lobe)
TIA resolves within what length of time?
24 hours
TIA is a warning sign of what?
Stroke or heart attack
Three types of extra-axial bleeds i.e. outside of the brain?
Epidural/extradural haematoma
Subdural haematoma
Subarachnoid haematoma
Epidural bleed looks like?
Concave lense
Epidural bleed arterial/venous?
Arterial
Epidural bleed fast or slow?
Fast
Epidural bleed between which two structures?
Dura and skull
Epidural bleed presentation?
Brief lucid period following trauma and then unconsciousness
Epidural bleed can cause compression of which CN?
CNIII - occulomotor
Epidural bleed may cause a loss of vision in which visual field?
Visual field opposite to lesion
Subdural bleed looks like?
Crescent shape
Cause of subdural bleed?
High speed acceleration and deceleration
Subdural bleed fast/slow?
SLOW - does not present for about two weeks
Subdural bleed arterial/venous?
Venous
Differnetiate between subdural and epidural bleeds other than shape of bleed?
Subdural can cross the suture lines
Subdural bleed between which two structures?
Dura mater and arachnoid mater
Subarachnoid haematoma presentation?
Severe headache
Vomiting
Confusion
Lowered level of consciousness
Common cause of subarachnoid haematoma?
Burst aneurysm
Subarachnoid haematoma fast or slow?
Fast
Three types of cerebral aneurysms are?
Saccular
Fusiform
Berry
What is Wallenberg syndrome?
Ischaemic stroke to PCIA
What is Wallenberg syndrome also known as?
Lateral medullary syndrome
Presentation of Wallenberg syndrome?
SUDDEN ONSET
Horner syndrome
Vertigo, nystagmus, nausea and vomiting
Patient has a stroke and presents with ipsilateral Horner’s syndrome - which artery is most likely to have been affected?
PICA
Five layers of the scalp and way to remember these?
SCALP Skin Connective tissue Aponeurosis Loose connective tissue Pericranium
What is a brain contusion?
Superficial bruising
Brain contusions are associated with which type of extra-axial bleed?
Subdural
Expressive aphasia is Broca’s or Wernicke’s aphasia?
Broca’s
Receptive aphasia is
Wernicke’s
Imaging of the brain - what will be used?
MRI
Comminutive types of fractures to the skull?
Depressed
Compound
Closed
Comminutive
What is diffuse axonal injury?
Term given to widespread damage to axons caused by acceleration of the head
PICA comes off of which artery?
Vertebral artery
Cranial nerves that innervate the brainstem are? x2
CNXI
CNXII
Central sulcus of the brain separates which two lobes?
Frontal
Parietal
Somatosensory region of the brain is located in which lobe?
Parietal
Motor movement region in the brain is located in which lobe?
Frontal
Hearing and memory region is located in which lobe of the brain?
Temporal
Vision region is located in which lobe of the brain?
Occipital
Lateral/sylvian fissure separates which two lobes of the brain?
Frontal and tempiral
Primary cortex area just anterior to the central sulcus is?
Primary motor cortex
Primary cortex area just posterior to the central sulcus is?
Primary sensory cortex
Which of the primary cortex areas are mostly medial rather than lateral?
Primary visual cortex
Function of Broca’s area?
Language expression
Function of Wernicke’s area?
Language comprehension
Function of DCML?
Discriminative touch
Function of corticospinal tract?
Motor
Function of spinocerebellar tract?
Proprioception
Function of spinothalamic tract?
Pain and temperature
DCML crosses over where?
Medulla
Corticosinal tract crosses over where?
Spinomedullar junction
Spinocerebellar tract crosses over where?
No functional crossover
Spinothalamic tract crosses over where?
Sinal cord
Major inhibitory neurotransmitter in the brain is?
GABA
Major excitatory neurotransmitter in the brain is?
Glutamate
Primary motor cortex is located where?
Immediately anterior to the central sulcus
Lesion to primary motor cortex presents how?
Paralysis/paresis of specific muscle group
Primary motor cortex is area number?
4
What is remapping/neuronal plasticity?
Motor homonculus/map adjusts slightly to compensate for damage to another region
Stroke of MCA affects what region of the brain?
Almost all of one side of the frontal lobe
One region MCA stroke does not affect in the body?
Does not affect lower limb (different blood supply)
Blood supply to the lower limb is?
Anterior cerebral artery
Blood supply to basal ganglia is?
Lenticulostriate arteries from MCA
What is apraxia?
Difficulty performing complex motor tasks e.g. tying shoelaces
Apraxia occurs as damage to what two regions?
Premotor cortex (6) Supplemntary motor cortex (8)
Stroke to only one side of the brain may not present that greatly - why?
Contralateral area may be able to compensate
Broca’s area regulates what muscles?
Muscles controlling speech - programming of words
Damage to Broca’s area results in?
Motor aphasia
What is motor aphasia?
Patient cannot verbalise complex sentences - tend to stick to one word sentences
Damage to frontal eye fields results in?
Oculomotor apraxia
What is oculomotor apraxia?
Difficulty moving eyes horizontally and in following an object
Presentation of oculomotor apraxia?
Patients will turn their head more to compensate for lack of eye movement
Common cause of oculomotor apraxia?
Bilateral lesions of frontal eye fields
Where is the somatosensory cortex?
Immediately posterior to the central sulcus
Function of somatosensory cortex? x2
Modulation of sensory input
Modulation of reflex e.g. suppression of nociceptive reflexes
Prefrontal cortex is located where?
Most anterior region of the cortex
Function of prefrontal cortex? x2
Planning (of movement)
Executive functions - problem solving, judgment
Symptoms of prefrontal cortex lesions? x3
Apathy
Personality changes
Lack of ability to plan/sequence actions or tasks
Location of orbitofrontal cortex?
Anterior and inferior
Inferior to the prefrontal cortex
Function of orbitofrontal cortex?
Involved with the limbic system
Two regions that project into the motor thalamus are?
Basal ganglia
Cerebellum
Motor thalamus projects to where?
Motor cortex
Motor thalamus is also known as?
VL thalamic nucleus
Why is corticobulbospinal tract susceptible to stroke?
Travels through the internal capsule - particularly prone
Red nucleus is located where?
Midbrain of brainstem
Corticobulbospinal tract is composed of which two tracts?
Corticobulbar tract
Corticospinal tract
Three terminations of the corticobulbar tract?
Pontine nuclei
Reticular formation
Red nucleus
Motor decussations occur where in the spinal cord?
In the upper spinal cord
Injury to the brain above the spinal cord - where is motor deficit?
Contralateral side
Injury to the spinal cord - where is motor deficit?
Same side
Damage to the corticospinal tract in teh spinal cord results in what?
Loss of control of hands and fingers
Red nucleus gives rise to which tract?
Rubrospinal tract
Rubrospinal tract descends to where?
Motor thalamus
Function of interneurones?
Modulate strength and activity of reflex pathways
Only upper motor neurones that act directly on lower motor neurones are? x4
Driving muscles of thumb, fingers, lips and tongue
Function of tectospinal tract/optic tectum?
Coordination of voluntary head and eye movements
Function of the medial vestibulospinal tract?
Mediates involuntary (reflex) coordination of the head and the neck
What is spasticity?
Abnormally increased muscle tone
Increased tendon reflexes
Spasticity is a result of UMN or LMN lesion?
UMN lesion
What is clonus?
Series of jerky contractions of the muscle following sudden stretching
What is hyperreflexia?
Abnormally brisk tendon reflexes
Position of the arms in decorticate posturing?
Flexed
Decorticate posturing occurs due to damage to what?
Corticospinal tract in the midbrain
Position of arms in decerebrate posturing?
Arms extended
Decerebrate posturing occurs due to damage to what?
Injury to brain at the level of the brainstem - corticospina/ruprospinal tracts
Decereberate/decorticate posturing - which is more dangerous?
Decerebrate
Clasp-knife reflex indicates what lesion?
Chronic cerebral motor lesion
Babinski indicates what damage?
Corticospinal damage
Presentation of damage to the spinal cord is known as?
Spinal shock
Damage to corticospinal tract presents as? x2
Paralysis/weakness of voluntary movement
Hyperactive tendon reflexes
Damage to reticulospinal tract presents as? x3
Loss of bladder/bowel control
Loss of temperature regulation
Loss of blood pressure regulation
Damage to vestibulospinal tract presents as? x1
Loss of ability to stand upright/balance properly
UMN lesion - increased or decreased muscle tone?
Increased
LMN lesion - increased or decreased muscle tone?
Decreased
Five motor symptoms of PD?
Rigidity Resting tremor Bradykinesia Gait freezing Problems wth balance
One of the earliest non-motor symptom of PD is?
Loss of sense of smell
Late non-motor symptom of idiopathic PD is?
Dementia
Three targets of DBS in PD?
Subthalamic nucleus
Thalamus/zona incerta
Globus pallidus interna
Three phases of DBS?
Electrode insertion
Pulse generator insertion
DBS adjustment
What scan of the brain should be undertaken prior to DBS?
MRI
What type of anaesthesia should be administered prior to DBS?
General anaesthesia
What is dystonia?
Movement disorder causing muscle spasms and contractions
Site of DBS for dystonia?
Globus pallidus interna
Site of DBS for pain?
Sensory thalamic nuclecus
PAG
Site of DBS for epilepsy?
Anterior thalamic nucleus
Site of DBS for deperession?
Subgenual cingulate gyrus
DBS funded for use in only what in teh UK?
Only funded for use in movement disorders in the UK
Site of DBS in tremor? x3
Thalamic nucleus
Zona incerta
Subthalamic area
Which region of the basal ganglia can DBS be carried out for treatment of PD?
Globus pallidus interna
What is meant by consciousness?
State of full awareness of the self and one’s relationship to the environment
What is meant by vegetative state?
Full arousal but no awareness - look like they are awake but not aware
What is meant by minimal consciousness state?
Full arousal and some degree of awareness
Stages of vegetative state? x4
Coma
Vegetative state
Persistent vegetative state
Permanent vegetative stage
Timeline for vegetative stage stages?
Coma - 2/3 weeks
Vegetative stage - 4 weeks
Persistent vegetative stage - 6 months
Permanent vegetative state
Define permanent vegetative state
Longer than twelve months following trauma and longer than six months following anoxia
Anatomical changes causing vegetative stage? x3
Widespread subcortical white matter cell death
Damage to the thalamus
Disconnection from fronto-parietal cortex
What is akinetic mutism?
People lack motivation to respond to anything - can visually track and can talk or move normally if htey have to but tend not do
Cause of akinetic mutism?
Injury to white matter cingulate gyrus - frontal lobe
What is meant by a coma?
Temporary state of unconsciousness
Three diagnostic criteria for vegetative state?
Cycles of eye opening adn closing
Complete lack of self or environment
Complete or partial preservation of hypothalamic adn brainstem autonomic functions
Two forms of imaging used for vegetative state?
Electrophysiology
MRI
Two forms of electrophysiology used for vegetative state?
EEG - electrical activity of the brain
ERP - even related potentials - listen to headphones and look for response
Three factors affecting recovery from vegetative state
Time spent in vegetative state
Age
Type of brain injury e.g. hypoxic has poor prognosis
Two medications used for treatment of vegetative state?
Amantadine
Zolpidem
DBS location for vegetative state?
Central thalamus
Dysdiachokinesis presents in what type of brain damage? x2
Damage to the anterior lobe and also to the posterior lobe of the cerebellum
Define dysmetria
Overshooting movements
Define dysarthria
Poor articulation of speech
