Pattern recognition in Neurology

Question 1

Patterns of weakness 
-2 major types?
-give 3 features of each
describe the different patterns of weakness in each of the following:
-UPM
-LMN
-muscle disease
-NMJ 
-functional weakness

Answer 1

-focal of generalised

-Focal
in distribution of peripheral nerve or spinal root
hemi-distribution
pyramidal distribution

Non-focal
generalised
predominantly proximal or distal
truly generalise includes bulbs motor function, otherwise quadri or tetraparesis

• inc tone, brisk reflexes, pyramidal/corticospinal pattern (extensors in arm, flexors in leg)
• wasting, fasciculation, decreased tone, dec/absent DTR
• wasting (proximal), decreased tone, dec/absent DTR
• fatiguable weakness, normal or dec tone, normal DTR
• no wasting, normal tone, normal reflexes, erratic power, non-anatomical loss

Question 2

UMN weakness
-why would an UMN pattern occur? (3)
-give the clinal signs that would result from the following lesions:
Hemispheric
Parasagittal frontal lobe 
Spinal cord

Answer 2

• stroke, SOL, spinal cord problems
• contralateral pyramidal weakness in face, arms, leg

Paraparesis

pyramidal weakness below level of lesion e.g. cervical: arms and legs
Thoracolumbar: legs

Question 3

LMN weakness

• causes? (2)
• peripheral neuropathy, give the 2 different distributions and their causes?

Answer 3

-e.g. motor neurone disease, spinal muscular atrophy

-symmetrical polyneuropathy
in DM, alcohol

Mononeuropathy
due to nerve compression or mono neuritis multiplex

Question 4

Patterns of sensory loss, describe the following:

• stocking
• Sensory level
• Haemianaesthesia
• Dissociated sensory

Answer 4

• implies length dependent neuropathy
• implies a spinal cord lesion
• suggests contralateral cerebral lesion
• loss with lost spinothalamic but preserved dorsal column suggests hemicord damage

Question 5

Extrapyramidal symptoms

what are they? (14)

Answer 5

bradykinesia
rigidity
resting tremor 
impaired gait & posture
Hypomimia 
Hypophonia 
reduced arm swing
stooped posture
small steps 
destination 
trunking en block 
impaired postural reflexes 
asymmetry in PD

Question 6

Frontal lobe

• normal functioning? (3)
• what does damage to these particular areas cause?
  1. Orbitofrontal cortex
  2. Dorsolateral prefrontal cortex
  3. Cingulate gyrus and dorsomedial frontal lobe
• Give some signs of general frontal lobe dysfunction (8)

Answer 6

-generates novel strategies
executive functioning
enables self criticism

• 1. disinhibition
     
     2. executing work responsibilities
     3. abulia (lack of will) or akinetic mutism

-personality dysfunction 
paraparesis 
paratonia 
seizures 
incontinence
visual field defects
expressive dysphasia Anosmia

Question 7

Temporal lobe

what signs occur with temporal lobe dysfunction? (7)

Answer 7

Memory dysfunction
Agnosia
Langauge disorders- receptive Dysphsia
visual field defects (congruous upper homonymous quadrantanopia)
Auditory dysfunction 
limbic dysfunction 
temporal lobe epilepsy

Question 8

Parietal lobe

-what signs occur with parietal lobe dysfunction?

Answer 8

-visual field defect
(congruous lower homonymous quadrantanopia)
sensory dysfunction
Gerstmann’s syndrome (Dysgraphia, left-right disorientation, finger agnosia, acalculia)
Dyspraxia
Inattention
Denial

Question 9

What signs would be expected if the patient had a stroke in the following syndromes?

• lacunar syndromes?
• Posterior circulation syndrome?
• total ant circulation syndromes?
• Partial ant circulation syndromes

Answer 9

-No visual field defect
No new higher cortical or brainstem dysfunction
Pure motor hemiparesis, or pure sensory deficit of one side of the body, or sensorimotor hemiparesis or ataxic hemiparesis
At least 2 of the 3 areas (face, arm, leg) should be involved

-any one of:
Cranial nerve palsy
Unilateral or bilateral motor or sensory deficit
Disorder of conjugate eye movements
Cerebellar dysfunction
Homonymous hemianopia
Cortical blindness

-Hemiplegia and homonymous hemianopia contralateral to the lesion, and
Either aphasia or visuospatial disturbances
+/- sensory deficit contralateral to the lesion

-One or more of unilateral motor or sensory deficit, aphasia or visuospatial neglect (with or without homonymous hemianopia)
Motor or sensory deficit may be less extensive than in lacunar syndromes