Flashcards in Localising Lesions Deck (80):
1
what are movement disorder features arise from lesions in the corticospinal/ pyramidal tracts
pyramidal/ UMN features:
pyramidal weakness (corticospinal distribution: hemiparesis, quadriparesis, paraparesis, monoparesis, faciobrachial)
spascticity
2
what are the types of movement disorders that arise from lesion in the basal ganlgia
(extrapyramidal)
hyperkinetic
- dystonia
- tics
- myoclonus
- chorea
- tremor
hypokinetic (rigidity and bradykinesia)
- parkinsonism
- parkinson's disease
3
what movement disorders arise from the cerebellum
ataxia
4
what makes up the peripheral nervous system
spinal nerve
root
plexus
peripheral nerves
5
what are the features of focal weakness
in distribution of peripheral nerve or spinal root
hemi-distribution (one side of body)
pyramidal distribution
6
what is pyramidal distribution weakness
where the extensors are weaker in the arms and the flexors are weaker in the legs
7
what are the features of non focal weakness
generalised
predominantly proximal or distal
if truely generalised will include bulbar motor function
8
UMN weakness:
distribution
corticospinal
-hemiparesis
-quadriparesis
-paraparesis
-monoparesis
- faciobrachial
9
LMN weakness:
distribution
generalised
predominantly proximal, distal or focal
no preferential involvement of corticospinal innervated muscles
10
UMN weakness:
Sensory loss
central pattern
11
LMN weakness:
Sensory loss
-can be none
-glove
-stocking
-peripheral nerve or root distribution
12
UMN weakness:
-deep tendon reflexes
-superficial reflexes
-pathological reflexes
deep- increased (unless very acute= flaccid)
superficial- decreased
pathological- increased
13
LMN weakness:
-deep tendon reflexes
-superficial reflexes
-pathological reflexes
deep- normal/ decrease
superficial- normal
pathological- normal
14
what are the superficial reflexes
plantar
gag/ swallow
cremasteric
corneal
15
what are the pathological reflexes
babinski (upward plantar, fanning and hyperextension of the toes), hoffmans etc
16
UMN weakness:
sphincter function
sometimes impaired
17
LMN weakness:
sphincter function
usually normal (except in cauda equina)
18
UMN weakness:
muscle tone
increased
19
LMN weakness:
muscle tone
decreased/ normal
20
UMN weakness:
muscle bulk
sometimes hypertrophy
21
LMN weakness:
muscle bulk
wasting
22
UMN weakness:
other CNS signs?
possibly
23
LMN weakness:
other CNS signs?
no
24
increased tone, brisk reflexes, pyramidal/ corticospinal pattern of weakness (= weak extensors in the arm, weak flexors in the legs) = ?
upper motor neurone pattern
25
wasting, fasciculation, decreased tone, decreased or absent reflexes, flexor plantars = ?
lower motor neurone pattern
26
what are the features of muscle disease
wasting (usually proximal)
decreased tone
decreased/ absent tendon reflexes
27
what are the features of NMJ weakness
fatiguable weakness
normal/ decreased tone
normal reflexes
NO SENSORY SYMPTOMS
28
what are the features of functional weakness
no wasting
normal tone
normal reflexes
erratic power
non anatomical loss
29
what causes UMN weakness
acute stroke syndromes
space occupying lesions
spinal cord problems
30
what weakness results from a hemispheric lesion
contralateral pyramidal weakness in face, arm, leg
31
what results from a parasagittal frontal lobe lesion
paraparesis
32
what UMN weakness results from a spinal cord lesion
pyramidal weakness below the level of the lesion
if cervical spine- arms and legs
if thoracolumbar- legs
33
what part of spinal cord do lower motor neurones attach to
anterior horn
34
what can cause a lower motor neurone lesion in the anterior horn cells
motor neurone disease
spinal muscular atrophy
lead poisoning, poliomyelitis etc
35
what are the two patterns of lower motor lesions in peripheral nerves
symmetrical (often length dependant):
- polyneuropathy with weakness and sensory symptoms: can be complication of diabetes, alcohol, metabolic insults
mononeuropathy:
-result of nerve compression (carpal, ulnar tunnel, radial neuropathy) or
-mononeuritis multiplex (asymmetric polyneuropathy) (occurs in diabetes or vasculitis)
36
what are the features of a median nerve mononeuropathy
thumb abduction paresis
thenar atrophy
sensory loss - thumb, second, third fingers, lateral 1 half of fourth finger
e.g. carpal tunnel syndrome
37
what are the features of a ulnar nerve mononeuropathy
finger and thumb adduction paresis
sensory loss- fifth and medial one half of fourth finger
38
what are the features of a radial nerve mononeuropathy
wrist, thumb and finger extension (wrist drop)
brachioradialis DTR lost
sensory loss on dorsum of hand
e.g. saturday night palsy
39
what are the features of a femoral nerve mononeuropathy
knee extensor paresis
loss of quads DTR
sensory loss over anterior thigh and medial calf
40
what are the features of a sciatic nerve mononeuropathy
ankle dorsiflexions and plantarfelxion paresis (flail ankle)
loss of achilles DTR
sensory loss on buttock, lateral calf, most of foot
e.g. caused by herniated disc
41
what are the features of a fibular nerve mononeuropathy
ankle dorsiflexion and evertors paresis (foot drop)
sensory loss on dorsum of foot and lateral calf
e.g. foot drop
42
what do NMJ disorder occur in
acetylecholine receptor antibodies mediated myasthenia gravis:
-ocular/ generalised
inhibition of acetylcholinesterase by organophosphate poisoning
lambert-eaton paraneoplastic syndrome
-interference with presynaptic calcium channel function
43
what can cause muscle disorders
inflammatory
endocrine (e.g. hypothyroidism, cushings, electrolyte abnormalities)
metabolic disorders
durgs and toxins
infections
rhabdomyelisis
44
shoulder abduction:
name the
-muscle
-nerve
-nerve root
deltoid
axillary
C5
45
elbow extension:
name the
-muscle
-nerve
-nerve root
triceps
radial
C7
46
finger extension:
name the
-muscle
-nerve
-nerve root
extensor digitorum
posterior interossues (radial)
C7
47
index finger abduction:
name the
-muscle
-nerve
-nerve root
first dorsal interosseus
ulnar
T1
48
hip flexion
name the
-muscle
-nerve
-nerve root
iliopsoas
femoral
L1,2
49
knee flexion
name the
-muscle
-nerve
-nerve root
hamstrings
sciatic
S1
50
ankle dorsiflexion
name the
-muscle
-nerve
-nerve root
peroneals
common peroneal and sciatic
L4,5
51
great toe dorsiflexion
name the
-muscle
-nerve
-nerve root
extensor hallucis longus
common peroneal
L5
52
what roots innervate the ankle DTR
S1,2
53
what roots innervate the knee DTR
L3,4
54
what roots innervate the biceps DTR
C5,6
55
what roots innervate the triceps DTR
C7,8
56
what does stocking (and later glove) sensory loss suggest
length dependent neuropathy
57
what is length dependent neuropathy
a polyneuropathy= it is the longest nerve-fibers that are most at risk, while the shorter
nerve-fibers are less affected. In brief, polyneuropathy is a "length-dependent" neuropathy. Because the
longest nerve-fibers in the body are those that run from the lower back to the feet, in typical cases of
polyneuropathy the first part of the body to become weak or numb is the feet.
58
what does a sensory level loss suggest
spinal cord lesion
59
what does hemianaesthesia suggest
contralateral cerebral lesion
60
what does dissociated sensory loss suggest (loss of spinothalamic (temp and pain) but reserved dorsal column (vibration, light tough, proprioception)
hemi cord damage (anterior spinal artery syndrome, brown sequard, syringomyelia)
61
what are the cerebellar signs
gait is broad-based and unsteady
Intention tremor / ataxia is assessed in the arms by finger-nose test and in the legs by knee-heel testing. Tremor gets exaggerated the nearer the target
Dysdiadochokinesis: clumsy fast alternating movements
Nystagmus and dysarthria are additional features of cerebellar disorders
62
what are extrapyramidal symptoms/ parkisonism
Bradykinesia, Rigidity, resting tremor, impaired gait and posture
Hypomimia
Hypophonia
Reduced arm swing, stooped posture, small steps, festination, turning en bloc
Impaired postural reflexes
Asymmetry in PD, symmetry in drug induced or atypical PD
63
what is the role of the frontal lobe
generates novel strategies and has executive functions. It enables self-criticism and trying again
Orbitofrontal cortex: response to primitive stimuli (hunger, thirst, sexual function) damage causes disinhibition
Dorsolateral prefrontal cortex: response to external stimuli (executing work resposnibilities)
Cingulate gyrus and dorsomedial frontal lobe: motivation, damage causes abulia (lack of will) or even akinetic mutism
64
what does the prefrontal cortex connect to
other association cortices, basal ganglia, limbic system, thalamus and hippocampus
65
what symptoms can arise from damage to the frontal lobe
Personality dysfunction
Paraparesis
Paratonia
Grasp reflex
Frontal gait dysfunction (magnetic gait)
Cortical hand
Seizures
Incontinence
Visual field defects (anterior visual pathway incl optic chiasms are beneath frontal lobe)
Expressive dysphasia (Broca’s area is in the dominant frontal lobe)
Anosmia (olfactory pathway is beneath frontal lobes)
66
what symptoms can arise from temporal lobe disorders
Memory dysfunction especially episodic memory
Agnosia (visual and sensory modalities in particular)
Language disorders receptive dysphasia (Wernicke, dominant hemisphere)
Visual field defects (congruous upper homonymous quadrantanopia)
Auditory dysfunction (Heschel’s gyrus, as hearing is represented bilaterally, deafness is not a cerebral feature)
Limbic dysfunction
Temporal lobe epilepsy
67
what symptoms can arise from damage to the parietal lobe
Visual field defect (congruous lower homonymous quadrantanopia)
Sensory dysfunction (visual and sensory modalities in particular)
Gerstmann’s syndrome (disease of the dominant angular gyrus, part of the inferior parietal lobe): Dysgraphia, left-right disorientation, finger agnosia, acalculia
Dyspraxia
Inattention (non-dominant angular gyrus)
Denial
68
what is the treatment protocol for parkinsons
Symptomatic treatment with Levodopa replacement or dopamine agonist
Multidisciplinary team management including Speech and language, OT, PT, exercise
For selected patients deep brain stimulation (subthalamic nucleus, globus pallidus int)
69
how does levodopa work
crosses the blood brain barrier while dopamine does not. Levodopa is then converted to dopamine in the brain while peripheral break down is prevented by the addition of ‘inhibitors of aromatic amino acid decarboxylase (carbidopa). Thus a carbidopa/levodopa formulation is often prescribed.
70
name some dopamine agonists used in PD
pramipexole, ropinirole, and bromocriptine
71
what other drugs can be used in PD
MAO-B inhibitors such as selegiline and rasagiline can improve symptoms in patients with mild disease (as monotherapy) as well patients already on levodopa.
Anticholinergics such as trihexyphenidyl or diphenhydramine (Benadryl) aim to combat tremor, but usually cause severe side effects
Amantadine blocks NMDA receptors and has a mild attenuation of resting tremor and dystonia. May alleviate levodopa induced dyskinesias.
72
is PD usually symmetrical or asymmetrical
asymmetrical
73
what does failure to respond to even high doses of levodopa mean in PD
suggests it is not idiopathic PD
74
what can levodopa cause in PD
dyskinesias
75
what is primary lateral sclerosis
a presentation of MND
pure upper motor neurone syndrome
76
what imaging for stroke
MRI T1/T2 and FLAIR images to identify old lesions and lesions of non-vascular origin
Diffusion weighted images (DWI) to identify new ischemic lesions (hyperintensities)
T2 to identify bleeds and microbleeds
Perfusion-weighted images (PWI) may be useful to identifies brain areas at risk of ischemia
CT brain: hyperintenisities – bleed, subtle ischemic signs in the acute phase of stroke (may be normal, early signs: loss of limits of lentiform nucleus, poor grey white matter differentiation, loss of insular ribbon)
77
what are the features of a lacunar syndrome
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 (dysarthric clumsy hand syndrome or ipsilateral ataxia with crural hemiparesis)
At least 2 of the 3 areas (face, arm, leg) should be involved in its entity
78
what are the symptoms of a posterior circulation syndrome (stroke)
any one of:
Cranial nerve palsy
Unilateral or bilateral motor or sensory deficit
Disorder of conjugate eye movements
Cerebellar dysfunction
Homonymous hemianopia
Cortical blindness
79
what are the symptoms of a total anterior circulation syndrome (stroke)
Hemiplegia and homonymous hemianopia contralateral to the lesion, and
Either aphasia or visuospatial disturbances
+/- sensory deficit contralateral to the lesion
80