Neurology Flashcards
What does a sensory level suggest?
Location of injury is in spinal cord
What cell counts are significant on LP?
Lymphocyte >5
Polymorph >0
Will lesions in cranial nuclei in brainstem and anterior horn cell nuclei have UMN or LMN signs?
LMN, despite being within central nervous system
Pyramidal weakness
Weakness of
Upper limb extensors
Lower limb flexors
Frontal Lobe Signs
Primary motor cortex
Personality change
Primitive reflex (pout, moro, palmomental, glabellar tap)
Expressive dysphagia (dominant)
Anosmia
Optic nerve compression
Gait apraxia
Parietal Lobe
Primary sensory cortex
Gerstmann syndrome:
- Dominant, angular gyrus
- Acalculia, agraphia, L-R disorientation, finger agnosia (ALF)
Sensory, visual and spatial inattention (non dominant lesions)
Construction and dressing apraxia
Lower quadrantanopia
Temporal Lobe
Primary auditory cortex
Receptive aphasia (dominant)
Memory loss
Upper quadrantanopia
Foster Kennedy Syndrome
Tumour in frontal lobe
Altered vision in one eye
Papilloedema in opposite eye
Smell disturbance
Other frontal signs
Occipital Lobe
Homonymous Hemianopia
Anton’s Syndrome: cortical blindness with confabulation (bilateral lesions of occipital lobe)
Alexia without agraphia
What does the presence of quadrantanopia signify?
Cortical lesion
How to work out where the lesion is in quadrantanopia?
Flip everything
Up is down
Left is right
Broca Aphasia
Expressive, non fluent aphasia
Can comprehend, know what to say, but just can’t
Dominant frontal lobe
Wernicke’s Aphasia
Fluent, receptive aphasia
Not frustrated, can speak but incomprehensible
Dominant temporal lobe
Conduction Aphasia
Mix of Broca’s and Wernicke’s
Due to damage to the connection arcuate fasciculus)
Struggle with repetition, can comprehend some things,
Global Aphasia
Can’t comprehend, can’t express themselves
Left MCA stroke is classical cause
Transcortical aphasias
Can repeat things
So Transcortical motor: Broca’s but can repeat
Transcortical sensory: Wernicke’s but can repeat
Corticospinal Tract
Descending motor pathway
From primary motor cortex in frontal lobe → corona radiata → posterior limb and genu of internal capsule → pyramids → decussate in lower medulla
Blood supply from penetrating branches of MCA (M1)
Prone to damage from small vessel disease, hypertension.
Dense pure motor hemiparesis. No cortical signs. No aphasia, dysphasia, hemianopia/quadrantopia.
Thalamus
Largest nuclear mass of nervous system,
All sensory nerves come through here
PCA arterial supply
Pure sensory loss if stroke here
Pure Sensory Loss Stroke
PCA lesion affecting Thalamus
Pure dense motor stroke
M1 MCA affecting internal capsule if no additional cortical signs such as inattention, aphasia, etc.
Parts of Thalamus
Anterior: language, memory
Lateral: motor + sensory
Medial: arousal, memory
Posterior: visual
Think about where they’re pointing to. Can mimic other lesions
Spinothalamic Tract
Run contralateral in spinal cord
Decussate at level
Pain, temperature, crude touch
Peripheral nerve body is in dorsal root ganglion, synapse in dorsal horn
Another synapse in thalamus then to primary sensory cortex
Run generally lateral
Dorsal column
Run Ipsilateral in spinal cord
Proprioception, vibration, fine touch
Peripheral nerve penetrates into central nervous system up to lower medulla, running medially. Body still in dorsal root ganglion.
Decussates in lower medulla and synapses to 2nd order nerve here
Then again synapses in Thalamus
Rules of the Brainstem
Rule of 4s
- 4 Cranial nerves in the medulla, 4 in the pons and 4 above the pons
- 4 structures midline beginning with M
- 4 structures to side beginning with S
- The 4 motor nuclei are in the middle are those divide equally into 12 (except 1 and 2): 3, 4, 6, 12